cs-5198-v1

TOPICS: Electrostatics Particulates Fly ash Aa quality Pollutron control Env~ronment

Electrostatic Precipitator Guidelines Volume 1 : Design Specifications

EPRl CS-5198 Volume 1 Project 2243-1 Final Report June 1987

Prepared by Ebasco Sew~ces. Incorporated Norcross, Georg~a

R E P O R T S U M M A R Y SUBJECTS Particulate control 1 Air quality

TOPICS Electrostatics Particulates Fly ash

Air quality Pollution control Environment

AUDIENCE Environmental engineers / Generation operators

Electrostatic Precipitator Guidelines Volumes 1-3

In summarizing the latest information on electrostatic precipitator technologies, these three volumes make up a central utility reference source. Plant engineers and operators will find in it detailed guidelines for preparing precipitator design specifications, for planning and conducting operations and maintenance programs, and for troubleshooting problem precipitators.

BACKGROUND Increasingly stringent particulate emission regulations place great demands on the performance of electrostatic precipitators, the devices that control fly ash emissions at most coal-fired utility plants. Fortunately, a slow but steady improvement in electrostatic precipitator technology is making acceptable performance easier to achieve and maintain. This evolution has, however, created a need for a new examination of the developments that have taken place in recent years and has also created the need for a new and comprehensive source of information on precipitator technology.

OBJECTIVES To evaluate the trends and to assemble in one source the most reliable and useful information on electrostatic precipitator technology.

To recommend procedures for preparing design specifications, for planning operations and maintenance, and for troubleshooting.

APPROACH A team of engineers and scientists with extensive experience in precipitator procurement and operation conducted a comprehensive review of the litera- ture on the latest technical developments. Drawing on that review and on their own knowledge, they prepared a set of practical manuals for utility use.

RESULTS The report includes three companion manuals for design specifications, operations and maintenance, and troubleshooting. Although the manuals primarily address users having some knowledge of precipitator design and operation, they provide enough background material and precipitator theory to make them useful as training aids. The loose-leaf format will aHow updating.

Volume 1, Design Specifications, contains information helpful to utility engineers preparing or reviewing precipitator design specifications. Because long experience indicated that many precipitator problems resulted from a lack of attention to detail, this volume includes guidelines for the specification of

EPRl CS-5198s Vols. 1-3

virtually every component of a precipitator and of viltually every step in the specification and procurement process.

Volume 2, Operations and Maintenance, presents material useful to plant engineers and operators developing operation and maintenance programs for electrostatic precipitators. The manual-for use in conjunction with vendor-supplied manuals-provides the information needed to develop step-by-step procedures for precipitator startup, operation, and shutdown and for routine and periodic maintenance.

Volume 3, Troubleshooting, identifies approaches and details to help utility engineers and plant operators determine the causes of unsatis- factory precipitator performance. Because the root causes of performance problems can be difficult to determine, the manual recommends that troubleshooting be done by the most knowledgeable and experienced precipitator operators. Used with manufacturer-supphed manuals, this volume is a guide to step-by-step procedures for examining the operation of a precipitator when a problem is suspected.

EPRl PERSPECTIVE

- - - -

Today, more than 1000 precipitators are in use at electric utility plants- and pollution control regulations require that all of them operate effi- ciently and reliably. Because many precipitators were buift when cost was a principal consideration in the selection of pollution control equipment, many of these in use are difficult to operate and maintain. In response to this ~ndustrywide problem, EPRl has an ongoing program to develop ways of improving both performance and reliability in precipitators. That effort has advanced flue gas conditioning systems (project RP724-2) and promoted the adoption of controls to improve performance (project RP1835-8). The guidelines In these manuals address the reh- ability issue. Users of these manuals will find a useful supplement in the summary of precipitator technology in EPRt report CS-2809.

PROJECT RP2243-1 EPRl Project Manager: Ralph F. Altman Coal Combustion Systems Division Cantractors: Ebasco Services, Incorporated; Southern Electric Interna- tional; Southern Research Institute

For further information on EPRl research programs, call f PRl Technical Information Specialists (415) 855-2411.

Electrostatic Precipitator Guidelines Volume 1: Design Specifications

CS-5198, Volume 1 Research Project 2243-1

Final Report, June 1987

Prepared by

EBASCO SERVICES, INCORPORATED 145 Technology Park

Norcross, Georgia 30092

Principal Investigators C. A. Altin

G. J. Grieco

Prepared for

Electric Power Research Institute 3412 Hillview Avenue

Palo Alto, California 94304

EPRl Project Manager R. F. Altman

Air Quality Control Program Coal Combustion Systems Division

DISCLAIMER OF WARRANTIES AND LIMITATION OF LIABILITIES

THIS REPORT WAS PREPARED BY THE ORGANIZATION(S) NAMED BELOW AS AN ACCOUNT OF WORK SPONSORED OR COSPONSORED BY THE ELECTRIC POWER RESEARCH INSTITUTE, INC. (EPRI). NEITHER EPRI, ANY MEMBER OF EPRI, ANY COSPONSOR, THE ORGANIZATION(S) NAMED BELOW. NOR ANY PERSON ACTING ON BEHALF OF ANY OF THEM:

(A) MAKES ANY WARRANTY OR REPRESENTATION WHATSOEVER, EXPRESS OR IMPLIED, (I) WlTH RESPECT TO THE USE OF ANY INFORMATION, APPARATUS, METHOD. PROCESS, OR SIMILAR ITEM DISCLOSED IN THlS REPORT, 1NCLUOlNG MERCHANTABlLiTY AND FITNESS FOR A PARTICULAR PURPOSE, OR (11) THAT SUCH USE DOES NOT INFRINGE ON OR INTERFERE WlTH PRIVATELY OWNED RIGHTS, INCLUDING ANY PARTY'S INTELLECTUAL PROPERTY, DR (Itl) THAT T H E REPORT IS SUITABLE TO ANY PARTICULAR USER'S CIRCUMSTANCE; OR

13) ASS-MES RESPONS13i-ITY FOR ANY DAMAGES 0 2 O'HER L.AB LITY WhA-SOEbiR (INCLLDIXG AhY CONSEQJELT AL DAMAGES. EVE4 IF EPRI OR AAY E'RI REPgESENTAT VE rlAS BEEN ADVISE3 OF Tr'E '0% Bl i iTY OF SUCrl 3AMAGES) RESULTlhG FROM YOU3 SELECTIOP. OR 3% OFTIilS RE?O?T OR ANY MFORVAT'OI, A?PAXATUS, METhCD. DROCfSS. OR SIMILAR ITEM DISCLOSED IN THIS REPORT.

ORGANIZATION(S) THAT PREPARED THIS REPORT EBASCO SERVICES, INCORPORATED

ORDERING 1NFORMATION

R e q u e s t s for copies o f this report should be directed t o the EPRI Dis t r ibut ion Cen te r , 207 Coggins Drive, P.O. B o x 23205, Pleasant Hill, C A 94523, (510) 934-4212.

Electric Power Research Inst i tute a n d EPRI a re regjstered s e w i c e marks of the Electric P o w e r Research Institute, Inc. EPRI. P O W E R I N G P R O G R E S S i s a senoce mark of the Electric Power Research Institute, Inc. Copyright O 1987 Electr ic Power Research Institute, Inc. Al l rights resewed.

ABSTRACT

During the past few years, the electric utility industry has been faced with

ever more stringent, environmentally related regulations. In addition to

this regulatory pressure, political and public awareness has caused utilities

to continually reassess their efforts regarding environmental protection

equipment and procedures. As a result, electrostatic precipitators have

received particular attention because they represent the traditional and most

widely used piece of equipment for particulate controT in steam electric

generatins plants.

Currently, more than 1400 precipitators are in service i n the United States

electric utility industry. By and large, these precipitators have performed

in a satisfactory manner in terms of their original design conditions and the

regulatory climate. However, throughout the many years of operating

experience there have been persistent and sometimes serious problems. In

fact, significant efforts have been required by some electric utilities to

maintain compliance with environmental regulations. When considering today's

regulatory requirements of the Clean Air Act of 1970, its Amendments and

State statutes, very high particulate matter collection efficiencies are

required on a sustained basis. These laws provide for financial penaities

for noncompliance with emission regulations. Moreover, cease and desist

orders are available to the regulatory bodies for the more severe cases of

noncompliance. In addition to these regulatory requirements, electric utilities must cope with changing fuel characteristics, fluctuating

precipitator performance levels and inherent equipment reliability.

In an effort to improve precipitator performance and reliability, the

Electric Power Research Institute, precipitator manufacturers, governmental

organizations, private research laboratories and electric utilities are

sponsoring and/or conducting research to enhance precipitator technology.

These efforts have resulted in the development of a significant and

substantial body of new information regarding theory, design, engineering,

construction, operation and maintenance of precipitators. This body of

information is generally complex as it represents the diversity of approaches

and perspectives of the many supporting groups. In order to promote

appropriate application of this information to electric utility practices,

the Electric Power Research Institute has developed a series o f

guidelines, in manual form, dealing with t h e current status of electrostatic

precipitator technology. These guidelines are separated into three separate

topical areas, as the following manual out1 ines indicate:

Volume 1 - Design Specifications

. Introduction

. Overview of Principles of Precipitator Design

. Precipitator Size Selection

. Specification of Mechanical Features

. Specification o f Electrical/Control Features

. Specifications for Operation and Maintenance

Related Systems

. Specification Preparation, Inquiry, Proposal

Evaluation and Contract Administration

. Fuels Other Than Coal

. The Effects of Dry Scrubbers on Precipitators

Volume 2 - Operation and Maintenance

. Introduction

. Electrostatic Precipitation Process

. Precipitator Subsystems

. Operation

. Maintenance

. Equipment Re1 iability

Volume 3 - Troubleshooting and Upgrading

. Introduction

, Electrostatic Precipitation Process

. Electrical Condition Evaluation

. Mechanical Condition Evaluation

. Development of Operation Log

. Performance Measurement

. Performance Prediction

. Analysis of Troubleshooting Data

. Discussion of Specific Problems - Symptoms, Causes and Cures

. Performance Upgrading

It is the intent of these manuals to provide utility personnel with a basic

understanding of the design, engineering, operation, maintenance and

troubleshooting of electrostatic precipitators. Every attempt has been made

to include all important topics common to most utility precipitator

applications. It is, however, impossible to cover all situations that can

arise in a specific application and it will still be necessary for a utility

to supplement the information contained in these manuals with the experience

and expertise of its own technical staff. Nevertheless, the understanding

and application of the information in these manuals should lead to improved

precipitator performance levels through better equipment selection practices

and an awareness by plant personnel o f the importance of their role.

It i s planned that these manuals will be updated as the need arises

ACKNOWLEDGMENTS

T h i s manual r e p r e s e n t s t h e e f f o r t s of many i n d i v i d u a l s . The p r i n c i p a l a u t h o r s

w i s h t o acknowledge t h e c o n t r i b u t i o n s o f t h e f o l l o w i n g i n d i v i d u a l s : Warren Kinney

f o r h i s e d i t o r i a l e f f o r t s ; J e f f N icho lson f o r h i s g e n e r a l e d i t o r i a l e f f o r t s and

a u t h o r s h i p of S e c t i o n 2; Mike Nelson f o r a u t h o r s h i p of t h e economic e v a l u a t i o n

subsec t ion o f S e c t i o n 7; and J i m DuBard and Grady N i c h o l s f o r t h e i r work on

p r e c i p i t a t o r per formance e s t i m a t i o n techn iques i n c l u d e d i n S e c t i o n 3. Ebasco

Serv i ces , I n c o r p o r a t e d a l s o recogn izes t h e t i m e and e f f o r t c o n t r i b u t e d by

D r . Ralph A l tman of EPRI, t h e Techn ica l Review Committee ( s e l e c t e d i n d i v i d u a l s

r e p r e s e n t i n g a r c h i t e c t / e n g i n e e r s , ESP manufacturers , and e l e c t r i c u t i l i t i e s

reques ted by EPRI t o r e v i e w and comment on t h e manuals), and t h e s t a f f o f t h e

Eng ineer ing P u b l i c a t i o n s Sec t ion o f Southern Company S e r v i c e s , I n c .

CONTENTS

S e c t i o n

1 INTRODUCTION

Purpose

Scope

2 OVERVIEW OF PRINCIPLES OF PRECIPITATOR DESIGN

Phys ics and P r i n c i p l e s o f O p e r a t i o n

T h e o r e t i c a l S i m u l a t i o n 3 f ESPs

F a c t o r s A f f e c t i n g ESP Performance

Opera t ing F a c t o r s A f f e c t i n g ESP Performance

Design Fac to rs A f f e c t i n g ESP Performance

3 PRECIPITATOR SIZE SELECTION

I n t r o d u c t i o n

H i s t o r i c a l P e r s p e c t i v e

Contemporary S i z i n g P r a c t i c e s

Parameter S e l e c t i o n

Des ign Coal P r o p e r t i e s

F lue Gas Volume F low

P r e c i p i t a t o r Gas V e l o c i t y

I n l e t Mass Loading

I n l e t P a r t i c l e S i z e D i s t r i b u t i o n

Fly Ash R e s i s t i v i t y

E l e c t r i c a l O p e r a t i n g P o i n t s

P r e c i p i t a t o r S i z i n g Models

The Deutsch-Anderson Equa t ion

The Mat t s -Ohn fe ld t Equa t ion

The EPA/SRI Computer S i m u l a t i o n

Design Marg ins

F1 ue Gas Flow

Col i e c t i ng P l a t e Area

Section

Spare Casing Capacity

Flue Gas Opacity

Hot Side Versus Cold Side

Size Reduction With Gas Conditioning

4 SPECIFICATION OF MECHANICAL FEATURES Physical Design

Number Of Precipitators

Number Of Chambers

Number Of Gas Passages

Collecting Plate Spacing

Collecting Plate Height

Ductwork/Precipitator Gas Velocities And

Distribution

Mechanical Sectionalization (Number O f Fields)

Electrical Sectionalization

Aspect Ratio

Treatment Time

General Arrangement

Precipitator Arrangement

Ductwork Arrangement

Flue Gas Dampers

Structural Requirements

General

Seismic Considerations

Wind, Ice And Snow Loads

Common Division Walls

Ductwork

Hoppers - Dust And Ash Handling Equipment Loads Sl ide Bearings

Expansion Joints

Materials Of Construction And Thickness

Temperature Excursions

Section

Electrode Systems

Collecting Electrode Design

Discharge Electrode Design

Anti-Sway/Positioning Deuices

Hoppers and Accessories

Hopper Design

Hopper Heaters

Hopper Vibrators

Hopper Aerators

Hopper Pokeholes and Anvils

Hopper Level Indicators

Hopper Materi a1 s of Construction

Hopper Access

Hopper Enclosure

Ash Handling System and Precipitator Interface

Thermal Insulation System

Thermal Insulation

Lagging

Testing

Flow Modeling

Rapping Tests

Field Leakage Test

Field Velocity Distribution Test

Field Performance Tests

5 SPECIFICATION OF ELECTRICAL/CONTROL FEATURES

Design Philosophy

Electrical Power Systems

Central Versus Localized Control

Page

4-25

4-25 4-23

4-33

4-33

4-33

4-35

4-36

4-36

4-37

4-37

4-38

4-38

4-39

4-39

4-40

4-40

4-40

4-41

4-42

4-44

4-45

4-46

4-47

S e c t i o n

6 SPECIFICATION FOR OPERATIONS AND MAINTENANCE RELATED SYSTEMS

Key I n t e r l o c k System

S a f e t y Feature

Lock Components

System Design

A p p l i c a t i o n t o ESPs

R e l i a b i l i t y o f O p e r a t i o n

D e f e a t o f t h e System

C o n t r o l Room Equipment L o c a t i o n

A la rm and M o n i t o r i n g Fea tu res

I n t e r f a c e s w i t h O the r P l a n t Systems

E l e c t r i c a l and C o n t r o l Equipment C o n s i d e r a t i o n s

T r a n s f o r m e r - R e c t i f i e r S e t s

Hopper Hea te rs

C o n t r o l Cab ine ts

Power D i s t r i b u t i o n Equipment

I n s t r u m e n t a t i o n

P r e c i p j t a t o r C o n t r o l System Phi 1 osophy

Au tomat i c Vo l tage C o n t r o l

Rapper C o n t r o l

Hopper Heater C o n t r o l

V i b r a t o r C o n t r o l

I n t e g r a t i o n w i t h Ash H a n d l i n g

Power Management System/Superv isory C o n t r o l System

P r e c i p i t a t o r C o n t r o l System Hardware

Ana log

D i g i t a l

CRTs, Keyboards, P r i n t e r s

System A r c h i t e c t u r e

I n s t a l l a t i o n C o n s i d e r a t i o n s

T e s t i n g and I n s p e c t i o n

S h i p p i n g and S to rage

I n s t a l l a t i o n

System Documentat ion

Procurement Aspects

S e c t i o n %

Ground ing - Permanent and Temporary, L i g h t i n g 6-8

General G r i d 6-9

Des ign Methods 6-9

S p e c i a l C o n s i d e r a t i o n 6-11

S p e c i f i c a t i o n Requirements 6-13

E n c l o s u r e s 6-14

ESP Roof 6-14

ESP Hopper Areas 6-15

O t h e r Areas 6-16


H e a t i n g , V e n t i l a t i o n and A i r C o n d i t i o n i n g (HVAC) 6-17

ESP C o n t r o l Room 6-17

Sample P o r t s 6-17

P a r t i c u l a t e Sampl ing 6-17

O p a c i t y Me te rs 6-18

Temperature 6-18

Access Doors, P l a t f o r m i n g , S t a i r w a y s , I n t e r - F i e l d Walkways 6-18

Types o f F a c i l i t i e s 6-18

Approach 6-19


Monora i l s /Equ ipmen t H o i s t s 6-22

L i m i t e d System 6-22

E x t e n s i v e System 6-22

Access Problems 6-22

Vacuum C lean ing Systems 6-23

S i z i n g 6-23

Personne l Hoist 6-23

Water Washing C o n s i d e r a t i o n s 6-23

Types o f C lean ing 6-24

A c o u s t i c a l Treatment 6-24

A i r 6-24

Water 6-24

E l e c t r i c a l 6-25

We ld ing C i r c u i t s 6-25

Section --

Special Tools

Maintainability Review of Drawings

Lighting

The Normal Lighting System

Normal/Emergency Lighting System

Isolation Dampers

Maintenance Drawings and Check Sheets

7 SPECIFICATION PREPARATION, INQUIRY, PROPOSAL EVALUATION AND CONTRACT ADMINISTRATION

Introduction

Purchasing Process

Sequence of Activities

Performance Oriented Versus Design Specifications

Material Only Versus Deliver and Erect Contracts

Preparation of Technical Specifications

Organization

Scope of Supply

Data Requirements

Document Requirements

Performance Warranty

Qual i f i ed Suppliers Review and Comment o f

Draft Specifications

Supplier Qualification

Assembly o f Vendor Experience

Commercial Eva1 uation

Criteria for Vendor Selection

Preparation of Commercial Terms and Conditions

Organization

Treatment o f Exceptions and Negotiations

Proposal Review

Preparation of Exception/Negotiation Book

Clarification Meetings

Negotiation Meetings

Investment Eva1 uation

S e c t i o n

Per formance Warranty E v a l u a t i o n

T e c h n i c a l M e r i t E v a l u a t i o n s

Commercial E v a l u a t i o n

Terms and C o n d i t i o n s

Terms o f Payment

E s c a l a t i o n

C a n c e l l a t i o n Charges

L i m i t a t i o n o f L i a b i l i t y t o F i x Nonper forming

Equipment

L i q u i d a t e d Carnages

Qua1 i t y Assurance

i n s u r a n c e and Bonds

R e t e n t i o n

C o n t r a c t Award

C o n t r a c t A d m i n i s t r a t i o n

Economic Eva1 u a t i o n

Genera l

A l t e r n a t i v e Economic Comparison Methods

F i n a n c i a l Mathemat ics

I n v e s t m e n t s and Expenses

Revenue Requi rements

D i s c o u n t Rate f o r P r e s e n t Value A n a l y s i s

The E f f e c t o f I n f l a t i o n on t h e D i s c o u n t Rate

Occur rence o f Payments

P r e s e n t Va lue o f Revenue Requirements

C a p i t a l Charges

Annual O p e r a t i n g Cos ts

Heat Loss Energy Cos ts

O p e r a t i n g and Main tenance Labor

8 FUELS OTHER THAN COAL

I n t r o d u c t i o n

O i l - F i r e d B o i l e r s

C a l c u l a t i o n o f P rocess Parameters

P r e c i p i t a t o r S i z e S e l e c t i o n

S p e c i f i c a t i o n o f Mechanica l and E l e c t r i c a l

Fea tu res

Section

Refuse Derived Fuel (RDF)

Calculation of Process Parameters

Precipitator Size Selection

Specification of Mechanical and Electrical

Features

Coal -Water Slurry (CWS)


Coal -0i 1 Mixture (COM) Plant Description

Pilot Precipitator Description

Performance Results

Limestone Injection Multistaged Burners (LIMB)

Modified Boilers

9 THE EFFECTS OF DRY SCRUBBERS ON PRECIPITATORS

Lime Spray Dryer Process Process Parameters Precipitator Sizing

Design Considerations

Energy Management System

Rapping Systems

Insulation Design and Hopper Heater Design

APPENDIXES

4A Flow Model i ng

4% Rapping Tests

4C Field Velocity Distribution Tests

40 Performance Tests

7A Example Scope o f Supply Statement

70 Example o f Purchaser Provlded Technical Data

7C Example of Seller Provided Technical D a t a

70 Commercial Terms and Conditions

7E Example o f Seller Provided Microprocessor Based

Control System Data

REFERENCES

INDEX

x v i

ILLUSTRATIONS

Figure

2-1 Wire and Pipe Precipitator

2-2 Typical Wire and Plate Precipitator

2-3 Relationship Between Electric Field at Corona Wire Surface

and Corona Wire Radius

Corona Generation Process

Variation in Corona Start Voltage and Wire Size

Simple Precipitator

Typical Data for Effective Migration Velocity and Collection

Efficiency as a Function of Particle Diameter

Typical Precipitator Fractional Curves

Comparison of Deutsch-Anderson and Matts-Ohnfeldt

Efficiencies

Fly Ash Resistivity as a Function of Temperature

A Typical Electrostatic Precipitator Peak Voltage Versus

Dust Collection Efficiency Curve

Electrical Clearance

Gas Velocity In a Precipitator Passage

Components of Aspect Ratio

Normal Precipitator Current Voltage Curves

Plan of Precipitator Bus Sections

Geometrical Parameters in the Mechanical Design of One

Precipitator Section

Total Mass Loading of Fly Ash from 28 Coals Versus the Percent Ash i n the Ultimate Coal Analysis Average Particle Size Distribution of Fly Ashes from

17 Bituminous Coals and 15 Subbituminous Coals

Particle Size Distributions of Fly Ashes from Western

Subbituminous Coals

Precipitator Performance Data Correlated Using the

Matts-Ohnfeldt Eouation

x v i i

Figure

Measured Precipitator Collection Efficiencies Compared

with ESP MODEL Computations

ESP MODEL Simulations o f the Example Precipitator

Comparison of Measured and Computed Opacity of Flue Gas

from Eleven Utility Fly Ash Precipitators

Computed Opacity of the Flue Gas from the Example

Precipitator with an Optical Path Length of 24 ft.

ESP MODEL Simulations of the Example Precipitator

Components of Aspect Ratio

Basic Diffuser Configurations

Typical Arrangement of Power Supplies

Key Interlock System Iliustration

Guarantee Performance Curve Gas Flow Versus Emission

Correction Factor

Sample Sheet from Exception/Negotiation Book

Actual Capability Versus Generation in the United

States for 1982

Test Results Showing Effects o f Combu=tion Air Swirl

on Particulate Emissions From An Oi ?-Fired Boiler

Variation of Particul ate €mi ssions from Oi 1-Fi red

Boilers with O2 Content in Flue Gas

Uncontrolled Oil-Fired Boiler Emissions Versus

Boiler Operating Capacity

Controlled Electric Utility Residual Oil-Fired Boiler

Emissions Versus Boiler Operating Capacity

Carbon/Acid Relationship in Oil-Fired Boiler Particulate

Emissions

Effect on Fuel Oil Additive on Composition of Superheater

Oil Ash Deposit

Particulate Ratio (with and without Additive)

Uncontrolled Industrial Oil-Fired Boiler Participate

Emissions Versus Wt. Percent Ash in Fuel Oil

Controlled Particulate Emissions versus W t . Percent

Ash in Fuel Oil for Residual Oil Fired Base-Loaded Utility Boilers at or Above 70 MW Capacity

xvi i i

Figure

Controlled and Uncontrolled Particulate Emissions as

a Function of Fuel Sulfur Content (at or Above 70 MW Capaci tyf

Effect of Fuel Oil Carbon Residue on Particulate

Emissions from Industrial Oil -Fired Boilers

Sulfuric Acid Mist Loading Versus Flue Gas Temperature

for Oil Fired Boilers

Typical Particle Size Distributions of Oil Fired Boiler

Emissions

Typical Resistivity versus Gas Temperature Curve for a

No. 6 Fuel Oil-Fired Boiler

Typical Oil Ash Resistivity Measurements, for Very Low-

Sulfur Content Fuel Oil Ash

Maximum Particulate Emissions for 20% Stack Opacity

versus Particle Diameter for Three Oil-Fired Boiler

Emissions Components

Stack Opacity versus Particulate Loading for Inorganic

Ash,Carbon Soot and Carbon Residue Emissions Components

from Oil-Fired Boilers

Stack Opacity versus Particulate Loading for Sulfuric

Acid Mist Emissions from Oil-Fired Boilers

Design Collection Efficiency versus Specific Col7ecting

Data for Precipitators on Oil-Fired Boilers

Design and Tested Collection Efficiency versus Specific

ColTecting Area for Five Oil-Fired Boiler Precipitator

Installations

Uncontrolled Particulate Emissions versus RDF Heat

Input at Ames Boiler Unit 7

Particulate Size Distribution for 80 Percent Load at

Ames Boiler Unit

Particulate Size Distribution for 100 Percent Load at

Ames Boiler Unit 7

Pilot Precipitator Test Results

Boiler Oxygen Effect on Ash Loss on Ignition (LOI) SCA vs. Migration Velocity, K = 1.0

SCA vs. Migration velocity, K = 0.5

xix

Figure

8-29 Estimated Precipitator Size

7A-1 Bus Section and Transformer-Rectifier Arrangements for

any Single Electrical Field as Used with Precipitators

having Various Groups o f Cells and Numbers of Fields

7C-1 Electrostatic Precipitator Terminology

7C-2 Bus Section and Transformer-Rectifier Arrangements for

Any Single Electrical Field as Used with Precipitators

Having Various Groups of Cells and Numbers of Fields

TABLES

Coal and Ash Analyses

An Example S t o i c h i o m e t r i c Combustion C a l c u l a t i o n f o r a

Western Subbi tuminous Coal and P r e d i c t i o n o f F l y Ash

R e s i s t i v i t y

Combust ion C a l c u l a t i o n s - C o i l and O i l

L i n e a r Least-Square F i t t i n g Parameters

E l e c t r i c a l O p e r a t i n g P o i n t s f o r t h e Example Western

Subbi tuminous Coal

ESP MODEL I n p u t Data f o r t h e Example P r e c i p i t a t o r

Maximum H e i g h t o f C o l l e c t i n g P l a t e f o r N ine M a j o r

P r e c i p i t a t o r Manu fac tu re rs

O r g a n i z a t i o n o f M a t e r i a l Supply C o n t r a c t s

O r g a n i z a t i o n o f E r e c t i o n C o n t r a c t s

Economic Eva1 u a t i o n Data

P r e s e n t Va lue A n a l y s i s

Cumu la t i ve Annual Cash F low A n a l y s i s

Terms o f Payment Data

Terms o f Payment A n a l y s i s (Labor)

Terms o f Payment A n a l y s i s ( M a t e r i a l )

Terms o f Payment A n a l y s i s ( I n t e r e s t )

A s s o c i a t e d A u x i l i a r y and A n c i l l a r y M a t e r i a l , Equipment,

C o n s t r u c t i o n and E r e c t i o n Costs and Economic E f f e c t s

A u x i l i a r y Power Cost

Impac t on Cyc le o f E x t r a c t i o n Steam

O p e r a t i n g and Maintenance Labor Costs

ASTM Standard S p e c i f i c a t i o n s f o r Fue l Oi 1 s

T y p i c a l Ranges o f Analyses o f No. 2 and No. 6 Grade

Fue l O i l s

Combustion Data Summary f o r T y p i c a l No. 6 Fuel O i l

Comparison o f a Clean No. 6 Clean O i l ve rsus a D i r t y

No. 6 Fue l O i l

x x i

Seven Distillate Fuel Oil Additives Found to Sub-

stantially Reduce Particulate Emissions

Estimated Particulate Emissions for Three Different

Fuel Oils Fired in a Utility Boiler

U.S.E.P.A. Emissions Factors for Determination

of Uncontrolled Emissions from Oil Fired Power Plants

Particle Size Range of Oil-Fired Boiler Particulate

Emissions Components

Resultant Opacity Levels from Various Emissions

Components of Oil-Fired Boiler

Summary of Design and Test Data for Participators on

Oil-Fired Boilers

Design Data for Weighted-Wire Precipitators on Oil-Fired

Boi 1 ers

Summary of Electric Utility Experience with Co-Firing

RDF with Coal

Average Properties of Refuse Derived Fuel (RDF) as

Reported at Various Facilities

Average RDF Proximate and Ultimate Analyses as


Average RDF Composition and Size as Reported at

Various Facilities

Average RDF Ash Properties as Reported at Various

Facilities

Average Air, Feedwater, and Steam Characteristics for

Experimental Runs at Ames Boiler Unit

As Fired Coal and RDF Characteristics at Ames Facility

Analysis of Bottom Ash Before and After Installation of

Dump Grates at Ames Boiler Unit 7

Analysis o f FlykhBefore and After Installation of Dump

Gates at Ames Boiler Unit 7 Selected Emissions Before and After Installation of Dump

Gates at Ames Boiler Unit 7

Average ESP Efficiency for Coal and Coal/RDF Firing as


Review of Changes in Critical ESP Process Parameters

During RDF Co-Firing at Ames Boiler Unit 7

x x i i

Tab1 e

9-1 Riverside ESP Results

9-2 Comparison of Range of Operating Variables Dry Product

Collection vs. Fly Ash Collection Range

9-3 Case I Steam Generator Fuel Data

9-4 Case I FED Requirements

9-5 Case I Dry FGD Expected Performance

9-6 Case I1 Flyash Requirement

9-7 Case I1 Expected Flyash Performance

9-8 Case I1 FGD Requirement

9-9 Case I1 FGD Expected Performance

4A-1 Velocity Measurement Inside Modeled Precipitation Chamber:

Instrumentation and Test Procedures

x x i i i

Section 1

INTRODUCTION

PURPOSE

The purpose of this manual is to assist the utility engineer in the

preparation o f specifications for electrostatic precipitators. Further, the

manual is intended to provide a framework within which the utility engineer

can evaluate precipitator proposals. This manual provides basic engineering

design information to enable the utility engineer to continue to broaden his

or her knowledge regarding electrostatic precipitators.

SCOPE

This manual includes discussions of precipitator design principles; process

parameter calculations; size selection; mechanical and electrical/control

features; operation and maintenance related systems; specification

preparation, inquiry, proposal evaluation, and contract administration; fuels

other than coal; and the effects of dry scrubbers on precipitators.

The information in the

Section 2 contains a d

following sections may be summarized as follows:

i scussi on of precipitator theory and design

principles. It presents precipitator terminology and concepts of electric

field generation, particle charging, and fly ash collection. In addition, it

addresses factors which limit or affect performance under start-up and stable

unit-load operation.

Section 3 discusses various, currently used sizing techniques. Fuel quality

is discussed in terms establishing appropriate ranges of constituents and in

identifying the effect of fuel purchasing strategies. Methods are presented

for calculating fly ash generation rates, design collection efficiency, and

flue gas flow rates. The nature and magnitude of design margins are also

addressed.

A summary of sizing hi story is presented with specific comparative examples,

and the issue of hot- or cold-side precipitators is also addressed.

Section 4 addresses the mechanical features of precipitators. Physical

design aspects such as the number of precipitators, chambers,

transformer-rectifier sets along with treatment time and aspect ratio are

discussed, Structural requirements, collecting and discharge electrode

features, hoppers and accessories, thermal insulation, and access facilities

are also addressed. Moreover, laboratory and field performance testing

methods are discussed, and erection procedures and tolerances are reviewed.

Section 5 treats the electrical components of a precipitator system:

automatic voltage controllers (analog and digital), microprocessors, control

philosophies, and component design requirements. Codes, standards, quality

control, and drawing requirements are reviewed.

Section 6 presents those features which enhance operation and maintenance

activities such as key interlock and grounding procedures, access, and

enclosures. Water-washing considerations are also addressed.

Section 7 discusses the procurement cycle for electrostatic precipitators,

beginning with specification preparation and continuing through contract

award and administration. Concepts for evaluating bidder's qualifications

and proposals are presented as well as techniques for evaluating technical

and commercial proposals.

Section 8 addresses the concerns and effects on electrostatic precipitators

when fuels other than pulverized coal are used.

Section 9 discusses the effect of lime spray drying for sulfur dioxide

removal on precipitator performance.

2 OVERVIEW OF PRINCIPLES OF PRECIPITATOR DESIGN

Sect ion 2

OVERVIEW OF PRINCIPLES OF PRECIPITATOR DESIGN

The electrostatic precipitation process consists of three basic steps: (1)

particle charging, (2) particle collection, and (3) removal of the collected

fly ash. Particle charging is accomplished by the generation of a corona

which produces gaseous ions that attach themselves to the gas borne dust

particles. Figure 2-1 shows a basic wire and cylinder type of electrostatic

precipitator (ESP). The wire acts as the discharge or corona electrode, and

the cylinder acts as the coilection (grounded) electrode. Corona generation

requires that a highly non-uniform electric field be developed between the

corona electrode and the collection electrode, a condition that occurs when a

high voltage is applied across the two. The electric field near the discharge

electrode causes free electrons in the gas stream to be accelerated to a

velocity necessary to ionize gas molecules through collision. These new

electrons are accelerated i n the electric field near the wire and generate

more free electrons and positive ions in an avalanche mode. The electrons

then move away from the wire surface and attach to gas molecules to form

negative ions or produce more collisions. The negative ions, produced as a

result of the corona, migrate toward the collecting electrode and in the

process collide with and become attached to the particles suspended in the

flue gas stream. Ion attachment to flue gas particles results in a build-up

of electric charge on the particle; the magnitude of the charge depends on

the number of attached ions.

The charge on the particles in the presence of the electrical field produces

a force on the particle in the direction of the collecting electrode. The

magnitude of the force is dependent directly on the particle charge and the

electrical field strength. The particles are deposited on the collecting

electrode and are held there by a combination of mechanical, electrical, and

molecular forces.

Once collected, particles must be periodically removed from the collecting

electrodes. Removal may be accomplished by periodic rapping or vibrating in

ELECTRODE

DUST ON PREClPlTATOR

COLLECTED DUST

Figure 2-1. Wire and Pipe Precipitator (1)

the case of solid material. A sufficiently thick layer of dust should be

allowed to accumulate so that it falls into the collecting hopper or bin i n

coherent masses to reduce the degree of reentrainment of particles into the

gas stream.

Particle charging and particle collection steps have been studied in detail,

and several mathematical formulae, and procedures have been developed to

quantify them. Removal of the collected particulate is less mathematically

quantifiable, a1 though empirical relationships have been developed through

experience and are useful in describing the precipitation process.

Physical arrangements of precipitators differ, depending upon the

application. Wire and cylinder precipitators are used in some cases;

however, for the majority of commercial applications, including the electric

utility industry, plate type collection electrodes are used.as shown in

Figure 2-2.

Most precipitators are of the single stage type. That is, the charging and

collecting steps occur in the same general region. Some precipitators have

an independent charging section followed by a section for particle

collection. Such precipitators are referred to as two-stage units.

The performance, or collection efficiency, of a precipitator i s defined as

the mass of particulate collected divided by the mass of particulate entering

the precipitator. Precipitator performance is primarily a function of

design, operating parameters, fly ash characteristics, and maintenance of the

precipitator and associated equipment.

PHYSICS AND PRINCIPLES OF OPERATION

The three basic steps in the electrostatic precipitation process interact

with each other i n a manner that makes mathematical simulation quite

complex. For example, as the particles in the flue gas stream are charged i n

the interelectrode space, a space charge is established which affects the

corona and electric field necessary for further particle charging and

collection. Also, particles, which are reentrained during rapping, must be

recharged and recollected if high collection efficiencies are to be achieved.

HIGH VOLTAGE SYSTEM ,

SUPPORT INSULATOR

PERFORATED- PLATES

I

BOTTOM END 3 FRAMES

i UPPER D.E. HAN FRAME ASSEMI

Figure 2 -2 . Typical Wire and Plate Precipitator

Courtesy of Research-Cottrell , Inc.

T h i s s e c t i o n i n c l u d e s a g e n e r a l d i s c u s s i o n o f c o r o n a g e n e r a t i o n , t h e e l e c t r i c

f i e l d , a n d p a r t i c l e c h a r g i n g . A l s o , t h e t h e o r e t i c a l s i m u l a t i o n o f

e l e c t r o s t a t i c p r e c i p i t a t o r s u s i n g t h e Deutsch-Anderson e q u a t i o n i s

a d d r e s s e d . L i m i t a t i o n s and d e f i c i e n c i e s o f t h i s e q u a t i o n a r e d e s c r i b e d .

F i n a l l y , a n e m p i r i c a l m o d i f i c a t i o n o f t h e Deutch-Anderson e q u a t i o n b y

M a t t s - O h n f e l d t i s d e s c r i b e d and e v a l u a t e d .

The p h y s i c s o f c o r o n a d i s c h a r g e have been i n v e s t i g a t e d e x t e n s i v e l y because o f

i t s i m p o r t a n c e i n h i g h - v o l t a g e t r a n s m i s s i o n , i n p l asmas , a s w e l l a s f o r i t s

u s e s i n e l e c t r o s t a t i c p r e c i p i t a t i o n . I n ESPs, c o r o n a g e n e r a t i o n o c c u r s i n a

r e g i o n o f h i g h e l e c t r i c a l s t r e s s p r o d u c e d by t h e a p p l i c a t i o n o f a h i g h

v o l t a g e a c r o s s an e l e c t r o d e sys tem w i t h a s h a r p , s m a l l , e f f e c t i v e r a d i u s o f

c u r v a t u r e ( d i s c h a r g e w i r e ) and a v e r y l a r g e e f f e c t i v e r a d i u s ( c o l l e c t i n g

p l a t e ) e l e c t r o d e . T h i s a r r a n g e m e n t p r o d u c e s a h i g h l y n o n - u n i f o r m e l e c t r i c

f i e l d . The f i e l d m a g n i t u d e i s h i g h n e a r t h e d i s c h a r g e o r c o r o n a e l e c t r o d e

a n d d e c r e a s e s r a p i d l y w i t h i n c r e a s i n g d i s t a n c e f r o m t h e w i r e s u r f a c e . F i g u r e

2-3 shows t h i s r e l a t i o n s h i p .

The c o r o n a p r o c e s s i n ESPs can b e b e t t e r u n d e r s t o o d by c o n s i d e r i n g e l e c t r i c a l

c o n d u c t i o n i n g a s e s . Gases f o u n d i n t h e f l u e g a s s t r e a m f r o m a u t i l i t y o r

i n d u s t r i a l b o i l e r a r e made up p r i m a r i l y o f t h e o x i d e s o f c a r b o n , s u l f u r ,

n i t r o g e n , and h y d r o g e n and t h e m o l e c u l a r gases o f n i t r o g e n a n d oxygen .

E x c e p t f o r s l i g h t p o l a r i z a t i o n , t h e s e gaseous m o l e c u l e s a r e n o t a f f e c t e d b y

t h e a p p l i c a t i o n o f a n e l e c t r i c f i e l d . However, when exposed t o r a p i d l y

a c c e l e r a t i n g f r e e e l e c t r o n s , some o f t h e gas m o l e c u l e s w i l l b e i o n i z e d b y

s t r i p p i n g an e l e c t r o n f r o m t h e m o l e c u l e , c r e a t i n g a f r e e e l e c t r o n and a

p o s i t i v e i o n . B o t h t h e e l e c t r o n and t h e p o s i t i v e i o n a r e a f f e c t e d by t h e

a p p l i e d e l e c t r i c f i e l d a n d m i g r a t e t o w a r d t h e c o l l e c t i n g and d i s c h a r g e

e l e c t r o d e , r e s p e c t i v e l y . The mov ing c h a r g e s c o n s t i t u t e a c u r r e n t , a l t h o u g h

i t s m a g n i t u d e i s s m a l l . However, a s s t a t e d e a r l i e r , t h e h i g h i n t e n s i t y

e l e c t r i c f i e l d n e a r t h e d i s c h a r g e e l e c t r o d e causes t h e f r e e e l e c t r o n s t o b e

r a p i d l y a c c e l e r a t e d t o h i g h v e l o c i t i e s . The e n e r g y a s s o c i a t e d w i t h t h e s e

h i g h v e l o c i t y e l e c t r o n s i s enough t o r e l e a s e a d d i t i o n a l e l e c t r o n s on i m p a c t

w i t h n e u t r a l gas m o l e c u l e s as shown i n F i g u r e 2 - 4 . T h i s p r o c e s s c o n t i n u e s so

t h a t a l a r g e number o f f r e e e l e c t r o n s and p o s i t i v e i o n s a r e p r o d u c e d i n an

a v a l a n c h e manner, The a v a l a n c h e p r o c e s s , as i t i s c a l l e d , i s d e p e n d e n t on t h e

i o n i z a t i o n p o t e n t i a l o f t h e gases p r e s e n t i n t h e f l u e g a s s t r e a m and t h e

\ COi3ONA CURRENT FLOWS IN THIS REGION

------ NO CORONA CURRENT FLOWS I N THlS REGION

0 I I I 0.0 0.2 0.4 0.6 0.8 1 .O

CORONA WIRE RADIUS. cm

Figure 2-3. Relationship Between Eleciri c Fie1 d a t Corona Wire Surface and Corona Wire Radius

SMALLRADIUS ELECTRODE AT HIGH NEGATIVE POTENTIAL

REGION OF ELECTRON AVALANCHE WHERE POSITIVE IONS AND ELECTRONS ARE PRODUCED

REGION OF IONiZATION WHERE ELECTRONS ATTACH TO NEUTRAL MOLECULES TO FORM NEGATlVE IONS

F i g u r e 2-4. Corona Generation Process

e l e c t r i c f i e l d s t r eng th near t he d ischarge e l e c t r o d e . Ion i za t ion p o t e n t i a l s

of t yp i ca l f l u e gas spec ies range from 10 t o 25 kV.

The e l e c t r i c f i e l d in t h e i n t e r e l e c t r o d e space of an ESP serves a t h r ee fo ld

purpose: f i r s t , a high e l e c t r i c f i e l d near t he discharge e l ec t rode causes

genera t ion of an e l e c t r i c a l corona; second, t he f i e l d i s t he d r iv ing force

t h a t causes i ons t o c o l l i d e with and a t t a c h t o p a r t i c l e s in t he f l u e gas; and

t h i r d , i t e s t a b l i s h e s t he force necessary f o r c o l l e c t i o n of t he charged

p a r t i c l e s .

The f i e l d requi red t o genera te an e l e c t r i c a l corona i s t h a t which wi l l

produce e l e c t r o n energ ies s u f f i c i e n t t o i on i ze t h e gas molecules present .

Semi-empirical ly, i t has been shown t h a t t h e onse t of corona i n a i r occurs

when t h e e l e c t r i c a l f i e l d s t r e n g t h , E c , i s def ined by Peek's formula:

where a = discharge e l ec t rode r ad ius i n meters

m = wire roughness f a c t o r

6 = r e l a t i v e a i r d e n s i t y = ( T P/TPo) 0

T = a i r temperature (OK)

To = 2 9 8 ' ~

P = a i r pressure (atm)

Po = I atm

Ec = corona s t a r t e l e c t r i c f i e l d (vol t s /meter )

For a c y l i n d r i c a l co l l ec t i on e l e c t r o d e , i n t eg ra t i on of t h i s i n i t i a t i n g f i e l d

equat ion from the discharge e l ec t rode sur face t o t he c o l l e c t i o n e l ec t rode

sur face y i e l d s t h e appl ied vol tage (Vc) requi red f o r corona generat ion:

where b = cy l ind r i ca l co l l e c t i on e l ec t rode rad ius (meters)

From e q u a t i o n (2-2), t h e a p p l i e d v o l t a g e r e q u i r e d f o r corona i n i t i a t i o n

i n c r e a s e s as t h e d i s c h a r g e e l e c t r o d e d iamete r i n c r e a s e s as shown i n F i g u r e

2-5. As t h e d i s c h a r g e - e l e c t r o d e d iamete r decreases, t h e e l e c t r i c f i e l d near

t h e d i s c h a r g e s u r f a c e i n c r e a s e s . However, w i t h v e r y smal l d iamete r w i r e s t h e

e l e c t r i c a l f i e l d s t r e n g t h f a l l s o f f r a p i d l y w i t h i n c r e a s i n g d i s t a n c e f r o m t h e

d i s c h a r g e s u r f a c e . W i t h l a r g e r d i a m e t e r w i r e s , t h e f i e l d s t r e n g t h n e a r t h e

d i s c h a r g e s u r f a c e i s l o w e r and f a l l s o f f l e s s r a p i d l y w i t h i n c r e a s i n g

d i s t a n c e f rom t h e d i s c h a r g e s u r f a c e .

Once t h e ava lanche p rocess has begun, t h e p a r t i c u l a t e m a t t e r i n t h e f l u e gas

s t ream must be charged so t h a t t h e e l e c t r i c f i e l d may i m p a r t a d r i v i n g f o r c e

on t h o s e p a r t i c l e s toward t h e c o l l e c t i o n e l e c t r o d e . Obv ious ly , t h i s f o r c e i s

dominant i n removing t h e p a r t i c u l a t e m a t t e r o r p a r t i c l e s f rom t h e gas and i s

dependent d i r e c t l y on t h e magni tude o f t h e charge on t h e p a r t i c l e and t h e

s t r e n g t h o f t h e e l e c t r i c f i e l d .

P a r t i c l e c h a r g i n g i s n o r m a l l y c o n s i d e r e d t o occu r i n t h e r e g i o n between t h e

co rona g l o w boundary and t h e c o l l e c t i o n e l e c t r o d e (see F i g u r e 2-4). There

a r e two b a s i c mechanisms r e s p o n s i b l e f o r p a r t i c l e c h a r g i n g : f i e l d and

d i f f u s i o n c h a r g i n g . Bo th mechanisms a r e a c t i v e i n t h e c h a r g i n g p r o c e s s , b u t

one t e n d s t o dominate depending on t h e s i z e range o f t h e p a r t i c l e s b e i n g

c o l l e c t e d . F i e l d c h a r g i n g dominates f o r p a r t i c l e s w i t h a r a d i u s g r e a t e r t h a n

a b o u t 0 . 5 p m . , w h i l e d i f f u s i o n c h a r g i n g i s t h e dominant mechanism f o r

p a r t i c l e s w i t h a r a d i u s o f l e s s than 0.2 urn. I n t h e i n t e r m e d i a t e range,

b o t h mechanisms c o n t r i b u t e t o t h e c h a r g i n g process.

F i e l d c h a r g i n g i s r e l a t e d t o t h e o r d e r e d mot ion o f i o n s under t h e i n f l u e n c e

o f an a p p l i e d e l e c t r i c f i e l d r e s u l t i n g i n t h e c o l l i s i o n o f t h e i o n s w i t h t h e

p a r t i c l e s i n t h e f l u e gas stream. D i f f u s i o n c h a r g i n g i s t h e r e s u l t o f

p a r t i c i e / i o n c o l l i s i o n s b r o u g h t abou t by random the rma l mo t ion o f t h e i o n s .

I n e i t h e r case, i f t h e p a r t i c l e s r e t a i n t h e i o n s a f t e r c o l l i s i o n , t h e

p a r t i c l e s become e l e c t r i c a l l y charged.

T h e o r e t i c a l S i m u l a t i o n o f ESPs

E a r l y r e s e a r c h e r s i n e l e c t r o s t a t i c p r e c i p i t a t i o n observed t h a t p a r t i c l e s

were c o l l e c t e d i n an e l e c t r o s t a t i c p r e c i p i t a t o r l o g a r i t h m i c a l l y a l o n g i t s

l e n g t h . There fo re , t h e e f f i c i e n c y o f an ESP can be w r i t t e n i n t h e form:

0.0 0.1 0.2 0.3 0.4 0.5

WIRE DIAMETER . in.

Figure 2-5. Variation i n Corona S t a r t Voltage and Wire S i z e - P i p e Diameter = 20 cm (1)

where L = length of t h e ESP

c = a cons tan t

A n equat ion such a s (2-3) was determined empi r i ca l l y by Anderson in 1919.

Deutsch derived a s imi l a r equat ion based on t h e o r e t i c a l cons idera t ions i n

1922.

The development of t he o r i g i n a l Deutsch equat ion was based on several

s impl i fy ing assumptions. These assumptions a r e l i s t e d below.

The p a r t i c l e s were considered f u l l y charged immediately upon en ter ing the ESP.

- P a r t i c l e d i s t r i b u t i o n in any c ros s s e c t i o n was uniform.

The migration v e l o c i t y (a) of t h e p a r t i c l e toward the c o l l e c t i o n e l ec t rode was not a f f e c t e d by t h e v e l o c i t y o f t he gas stream.

Dust p a r t i c l e s a r e s u f f i c i e n t l y separa ted so t h a t t h e i r mutual repulsion i s n e g l i g i b l e .

Erosion, reentrainment , uneven gas flow d i s t r i b u t i o n , back corona o r o the r d i s tu rb ing e f f e c t s a r e non-existent .

Charged p a r t i c l e s always move a t t h e i r e l e c t r i c a l terminal v e l o c i t y .

A11 p a r t i c l e s move wi th t he same v e l o c i t y (uniform p a r t i c l e s i z e and charge) .

Consider t he simple wire /cy l inder p r e c i p i t a t o r shown in Figure 2-6. A s i n g l e

charged p a r t i c l e moving in t he gas stream w i l l a c q u i r e a ve loc i ty , w , i n

t h e d i r e c t i o n toward the c o l l e c t i o n e l e c t r o d e . As t h e p a r t i c l e moves i n t o

t he boundary l a y e r , the overal

sum of w and t h e average veloc

Therefore, in a time i n t e r v a l ,

boundary l aye r ( 6 ) wi l l impact

6 = w A t

v e l o c i t y of t h e p a r t i c l e w i l l be the vec tor

t y o f t h e gas i n t h e boundary layer ( 6 ) .

~ t , a l l d u s t p a r t i c l e s present in t he

t h e c o l l e c t i o n e l e c t r o d e i f

During the time in t e rva l At, t h e gas stream w i l l have moved through t h e

p r e c i p i t a t o r a d i s t ance

GAS

Ac-CROSS SECTION OF PRECIPITATOR ZONE 6 -THIN

8'

LAYER \ --e

1

5 - PERIMETER OF PRECIPITATOR ELECTRODE

HIGH VOLTAGE

-WIRE WEIGHT

CORONA WIRE

Figure 2-6. Simple Precipitator (2)

where V = average gas v e l o c i t y .

The i n c r e m e n t a l e q u a t i o n f o r p a r t i c l e removal can be w r i t t e n as,

where AN = change i n t h e number o f p a r t i c l e s i n t h e f l u e gas s t ream

N = p a r t i c l e s r e m a i n i n g i n gas s t ream

S = c i rcumference o f t h e c y l i n d e r

Ac = c r o s s s e c t i o n a l a r e a o f c y l i n d e r

E q u a t i o n (2-6) i n d i c a t e s t h a t t h e r a t i o o f t h e p a r t i c l e s removed t o t h e

p a r t i c l e s r e m a i n i n g i n t h e gas s t ream a t t h a t t i m e i s equal t o t h e n e g a t i v e

o f t h e r a t i o o f t h e approx imate c r o s s s e c t i o n a l a rea o f t h e boundary l a y e r t o

t h a t o f t h e o v e r a l l p r e c i p i t a t o r c r o s s s e c t i o n . Tha t t h e a rea r a t i o i s

n e g a t i v e i n d i c a t e s t h a t p a r t i c l e s a r e b e i n g removed. S u b s t i t u t i n g e q u a t i o n s

(2-4) and (2-5) i n t o e q u a t i o n (2-6), r e s u l t s i n t h e f o l l o w i n g :

where AAco = inc rementa l c o l l e c t i o n a rea (SAL).

Pass ing t o t h e l i m i t w i t h e q u a t i o n (2-7)

where - vg

- A V = volume gas f l o w c

I n t e g r a t i n g (2-8) y i e l d s an e x p r e s s i o n f o r p a r t i c l e c o n c e n t r a t i o n a t t h e

p r e c i p i t a t o r o u t l e t .

- wAco N = No exp

"LI

where N = number o f p a r t i c l e s remaining in f l u e gas stream

No = p a r t i c u l a t e concent ra t ion a t ESP i n l e t .

As previous ly s t a t e d , p r e c i p i t a t o r e f f i c i e n c y i s the r a t i o o f t he p a r t i c l e s

removed t o t he i n l e t p a r t i c l e concent ra t ion .

A t h e o r e t i c a l equat ion f o r w can be derived from p a r t i c l e charging theory

and p a r t i c l e k i n e t i c s . The de r iva t ion of an equat ion de f in ing w depends on

both f i e l d charging and d i f f u s i o n charging. The s a t u r a t i o n charge acqui red by

a p a r t i c l e s u b j e c t t o f i e l d charging i s given by t h e equat ion

where q = charge (coulombs)

Ec = s t r eng th o f charging f i e l d (vol t / rneter)

p = 3 f o r a conducting p a r t i c l e and approximately 2 f o r a non-conducting p a r t i c l e and i s r e l a t e d t o t h e p a r t i c l e d i e l e c t r i c cons t an t .

a = p a r t i c l e r ad ius ( m )

P a r t i c l e s sub jec t t o f i e l d charging c l o s e l y approach t h e i r s a t u r a t i o n charge

i n a f r a c t i o n of a second o r in t he time requi red f o r t r a v e l through the f i r s t

few inches of a t yp i ca l p r e c i p i t a t o r .

P a r t i c l e s subjec t t o d i f fu s ion charging have been shown t o have a charging

r a t e due t o thermal motion a s fol lows:

2 @ = a e S N exp (-qe/akT) d t

2 = S r a N exp (e) In t eg ra t ing t h i s equat ion with respec t t o time r e s u l t s i n t h e fol lowing

expression f o r t h e charge, q , acquired in time t , by an f n i t i a l l y uncharged

p a r t i c l e :

where a = p a r t i c l e radius (m)

k = Boltzmann's cons tan t 0 T = absolu te gas temperature ( K)

e = t h e elementary e l e c t r o n i c charge ( c )

S = average ion ve loc i ty (rn/s) -3 N = ion concentrat ion (m )

t = t ime (8 )

Lowe and Lucas, using equat ions (2-:2) and (2-14), computed t h e charges t h a t

may be acquired by various p a r t i c l e s i z e s and charging t imes under t yp i ca l

p r e c i p i t a t o r cond i t i ons .

P a r t i c l e Number of elementaw charges acquired in t seconds, under 2

Radius Field charg ing - Diffus ion Charging 1.0 (Microns) t = 0 . 0 1 0.1 - - 0.01 -- 10 0 . 1 1.0 -

0 . 1 0 . 7 2 2 .4 2.5 3 7 11 15 1.0 7 2 200 244 250 70 110 150 190

10.0 7,200 20,000 24,000 25,000 1,100 1,500 1,900 2,300

E q u a t i o n (2-14) shows t h a t d i f f u s i o n c h a r g i n g c o n t i n u e s i n d e f i n i t e l y w i t h

t i m e . T h a t i s , t h e r e i s no p h y s i c a l l y r e a l i z a b l e maximum charge. From t h e

Lowe and Lucas t a b l e i t may be i n f e r r e d t h a t d i f f u s i o n c h a r g i n g o f a p a r t i c l e

c o n t i n u e s d u r i n g i t s e n t i r e t r a n s i t t h r o u g h a t y p i c a l p r e c i p i t a t o r . A l s o ,

f o r e x t r e m e l y f i n e p a r t i c l e s , t h e amount o f cha rge a c q u i r e d t h r o u g h f i e l d

c h a r g i n g i s n e g l i g i b l e as compared w i t h t h a t a c q u i r e d t h r o u g h d i f f u s i o n

c h a r g i n g .

Fo r p a r t i c l e s i n t h e i n t e r m e d i a t e s i z e range , f o r wh ich f i e l d and d i f f u s i o n

c h a r g i n g a r e s u b s t a n t i a l l y e q u i v a l e n t , t h e mathemat i ca l t r e a t m e n t i s much

more complex. The t i m e r a t e o f c h a r g i n g b y e i t h e r method i s r e l a t e d t o t h e

amount o f charge a l r e a d y on t h e p a r t i c l e , however a c q u i r e d . As an

a p p r o x i m a t i o n , Wh i te (1) suggests t h a t t h e a c t u a l p a r t i c l e s i z e shou ld be

i n c r e a s e d by abou t one mean-free p a t h o f t h e i o n , o r t y p i c a l l y by 0 . 1 vm.

I f t h e p a r t i c l e i s then assumed t o be charged t o i t s s a t u r a t i o n charge by

f i e l d c h a r g i n g f o r i t s e n t i r e r e s i d e n c e i n t h e p r e c i p i t a t o r , an e x p r e s s i o n

f o r t h e m i g r a t i o n v e l o c i t y , w , may b e d e r i v e d . The f o r c e , F1, a c t i n g

upon a p a r t i c l e c a r r y i n g a charge o f q i n a p r e c i p i t a t i n g f i e l d o f s t r e n g t h

E i s g i v e n by P

where E = s t r e n g t h o f p r e c i p i t a t i n g f i e l d , P

and is d i r e c t e d toward t h e c o l l e c t i n g e l e c t r o d e . I f q i s expressed by

e q u a t i o n (2-12) , t h e e q u a t i o n becomes

From S t o k e s ' law, t h e v i s c o u s d rag , F2, a c t i n g upon a s p h e r i c a l p a r t i c l e o f

r a d i u s a, moving t h r o u g h a f l u i d o f v i s c o s i t y p , w i t h a v e l o c i t y r e l a t i v e

t o t h e f l u i d o f w , i s

The e x t r e m e l y b r i e f p e r i o d o f p a r t i c l e a c c e l e r a t i o n can bs n e g l e c t e d . Than

f l can be equated t o F2 f o r s teady s t a t e c o n d i t i o n s , t h e e q u a t i o n

r e a r r a n g e d , and t h e f o l l o w i n g r e l a t i o n s h i p o b t a i n e d f o r

As s t a t e d e a r l i e r , p = 3 f o r a conduc t ing p a r t i c l e and can v a r y between 1 .5

and 2 .0 f o r non-conduc t ing p a r t i c l e s hav ing a d i e l e c t r i c c o n s t a n t o f

average va1 ue.

E q u a t i o n (2-18) i s u s e f u l because o f t h e r e l a t i o n s h i p s i t r e v e a l s . The

m i g r a t i o n v e l o c i t y f o r field c h a r q i n g l a r g e , c o n d u c t i n g p a r t i c l e s v a r i e s

d i r e c t l y w i t h p a r t i c l e d i a m e t e r , c h a r g i n g f i e l d s t r e n g t h , p r e c i p i t a t i n g

f i e l d s t r e n g t h , and i n v e r s e l y w i t h gas v i s c o s i t y . S ince, i n s i n g l e s tage

p r e c i p i t a t o r s , such as t h o s e used f o r f l y ash c o l l e c t i o n , b o t h t h e c h a r g i n g

and p r e c i p i t a t i n g f i e l d s a r e f u n c t i o n s o f t h e v o l t a g e a p p l i e d t o t h e

e m i t t i n g e l e c t r o d e s , t h e f o l l o w i n g a p p r o x i m a t i o n can be i n f e r r e d :

where E i s u s u a l l y t a k e n t o be t h e average e l e c t r i c f i e l d between t h e

d i s c h a r g e e l e c t r o d e and t h e c o l l e c t i n g e l e c t r o d e .

F l y ash i s composed o f w i d e l y v a r y i n g p a r t i c l e s i z e s t h a t have a range o f

r o u g h l y 0 . 0 1 t o 100 Vms. It would be expec ted t h a t t h e exper imen ta l v a l u e

o f w f o r a 100 urn p a r t i c l e would be a p p r o x i m a t e l y 1000 t i m e s t h a t f o r a

0 . 1 urn p a r t i c l e ( n e g l e c t i n g d i f f u s i o n c h a r g i n g ) . i n f a c t , i t i s n o t . Many

t e s t s have been r u n on p r e c i p i t a t o r s i n w h i c h e f f i c i e n c y as a f u n c t i o n o f

p a r t i c l e s i z e has been o b t a i n e d . The v a r i a t i o n i n w f rom those p a r t i c l e s

c o l l e c t e d w i t h maximum e f f i c i e n c y t o those c o l l e c t e d w i t h minimum e f f i c i e n c y

i s t y p i c a l l y a b o u t 2 o r 3 t o 1. (See F i g u r e 2-7.) T h i s l i m i t e d v a r i a t i o n i s

t h o u g h t t o be r e l a t e d t o n o n - i d e a l i t i e s i n t h e system.

Fu r the rmore , e q u a t i o n (2-19) i m p l i e s t h a t t h e v a l u e o f w would approach

z e r o as t h e p a r t i c l e s i z e decreases ( a g a i n n e g l e c t i n g d i f f u s i o n charg ing )

The minimum e f f i c i e n c y and t h e r e f o r e minimum w i s u s u a l l y found f o r some

0.1 1 .o PARTICLE DIAMETER, urn

Figure 2-7. Typical Data for Effective Migration Velocity and Collection Efficiency as a Function of Particle Diameter (2) -

particle size in the vicinity of 0.5 to 1 pm. (See Figure 2-8 for a

typical fractional efficiency curve from EPRI project 780-1, Figure 1-4.) For particles smaller than this size, the collection efficiency and w

actually increase (see Figure 2-8) because of diffusion charging.

Equation (2-19) also indicates that the migration velocity i s quite sensitive

to the applied voltage. Therefore, design objectives include maximizing

voltages with proper corona current for a maximum collection efficiency. The

above discussion implies several other basic concepts which are listed below.

As specific collection area (SCA) increases, collection performance generally increases.

An increase i n the physical size of the fly ash particles is beneficial to collection efficiency.

A decrease in gas viscosity generally results in an increased colTection efficiency. Viscosity decreases with decreasing temperature.

A minor increase i n the electric field strength can often substantially increase collection performance.

In an attempt to quantify

previously, the following

theoretical effect of fie

strongly w depends on the

the theoretical considera .ions di scussed

example is offered. The example is based on the

Id charging on large particles and shows how

electric field.

then, approximately,

10.0 90 + CASCADE

PARTICLE DENSITY 2.1 glee - s -

- 1 .o 99 5 s - z z

W - G U -

u

k I.L r W

I- z i l l 0 5 I- n 0

0.1 W

99.9 = 0 0

0.01 99.99 0.01 0.1 1.0 10

ACTUAL DIAMETER (cm)

Figure 2-8. Typical Precipitator Fractional Curves (L)

If the electric field can be increased to 4.0 kV/cm, then

The particle drift velocity to the collecting plate increased approximately

30 percent when the precipitator voltages were increased another 14.3

percent.

Consider the same example again, except with an average particle radius of

10 p m .

The purpose of the foregoing examples is to illustrate basic concepts.

Diffusion charging, process variables, particle characteristics, etc. tend to

make the analysis more difficult in reality.

Because of the previously mentioned problems with the theoretical value of

w, in practice the w value used in the Deutsch-Anderson equation has always

been obtained empirically by measuring the dust losses and gas quantity in a

precipitator of known size, and calculating the value of w . However, the

value of w so obtained is not in itself particularly useful because of the

spread in actual particle size distribution which violates the original

assumptions in the Deutsch-Anderson equation as well as other nonidealities.

The equation can be written in several ways, for example:

where w = drift velocity for a given particle size

Aco = collecting plate area

V = gas volume treated per unit time 9

L = total length of collecting electrode

R = distance between emitting and collecting electrodes

V = gas velocity

t = gas treatment time

Compatible units are to be used throughout so that the exponent is

dimensionless.

This equation can also be written as

-w SCA ~ f f ( n ) = 1-e (- ) (2-21)

508

2 when w is expressed in the customary units of cm/sec and SCA = ft /I000 acfm.

This form of the equation suggests that incremental portions of the

precipitator would have equal incremental efficiencies. For example,

doubling the size of a 90 percent precipitator would raise its efficiency

to 99 percent, while tripling its size would result in 99.9 percent

collection efficiency. For this condition to be true in fact would require

the precipitator to be non-discriminatory in its collection. That is, no

particle may be more difficult or easier to collect than any other. This

is known to be untrue since dust samples obtained from the outlet of a

precipitator usually differ in size distribution and chemical composi tion

from those entering, which shows that the precipitator is particle-size

sensitive.

Furthermore, adding increments of size to a precipitator (or decreasing the

gas volume handled) does not result in efficiencies that increase as

rapidly as the Deutsch-Anderson equation indicates because of the actual

particle size distribution of the particulate matter. The equation used in

this manner is useful anly for qualitative evaluation of ESP performances.

A modification to the Deutsch-Anderson equation, to account for these

nonideal effects, was devised by Sigvard Matts and Per-Olaf Ohnfeldt of

Svenska Flaktfabriken in 1964. They rewrote the Deutsch equation in the

following form:

E f f ( s ) = 1-exp (-wkA/Vg) k

where w k = an empr i ca l parameter w i t h u n i t s o f v e l o c i t y

k = a c o n s t a n t , u s u a l l y 0.4 t o 0.6, depending on t h e s tandard

d e v i a t i o n o f p a r t i c l e s i z e d i s t r i b u t i o n and o t h e r d u s t

p r o p e r t i e s a f f e c t i n g e f f i c i e n c y .

S i n c e b o t h w k and k a r e unknowns, two d i f f e r e n t s e t s o f e f f i c i e n c y

v e r s u s gas volume d a t a a r e needed t o s o l v e f o r b o t h unknowns f o r a s p e c i f i c

a p p l i c a t i o n . However, most users o f t h i s e q u a t i o n r e p o r t t h a t a v a l u e o f k

equa l t o 0 .5 u s u a l l y g i v e s s a t i s f a c t o r y r e s u l t s . F i g u r e 2-9 i l l u s t r a t e s

e f f i c i e n c y p r e d i c t i o n s f o r i nc reased p r e c i p i t a t o r s i z i n g u s i n g t h e

Deutsch-Anderson e q u a t i o n and t h e M a t t s - O h n f e l d t m o d i f i c a t i o n w i t h v a l u e s

o f 0.4, 0.5 and 0 . 6 f o r k. Note t h a t t h e M a t t s - O h n f e l d t e q u a t i o n i s

i d e n t i c a l t o t h e Deutsch e q u a t i o n when k = 1 . 0 .

No te t h a t t o p r e d i c t t h e e f f i c i e n c y due t o an i n c r e a s e i n r e l a t i v e s i z e ,

( i . e . , d e c r e a s i n g t h e gas volume handled by an e x i s t i n g p r e c i p i t a t o r ) ,

u s i n g l o w e r v a l u e s o f k y i e l d s more c o n s e r v a t i v e r e s u l t s . The r e v e r s e i s

t r u e when a t t e m p t i n g t o p r e d i c t t h e changes i n e f f i c i e n c y due t o a decrease

i n r e l a t i v e s i z e . I n t h i s case, more c o n s e r v a t i v e r e s u l t s w i i l be o b t a i n e d

by u s i n g a h i g h e r v a l u e of k . For example, compare t h e Deutsch p r e d i c t i o n

w i t h t h a t o f t h e M a t t s - O h n f e l d t , u s i n g a k o f 0.5; i f t h e r e l a t i v e s i z e o f

a 90 p e r c e n t ESP were doubled, Deutsch w o u l d p r e d i c t 99 p e r c e n t , w h i l e

M a t t s - O h n f e l d t wou ld p r e d i c t 96.2 p e r c e n t . However, i f t h e r e l a t i v e s i z e

o f a 99 p e r c e n t ESP were ha lved , Deutsch wou ld p r e d i c t 90 p e r c e n t , w h i l e

M a t t s - O h n f e l d t wou ld p r e d i c t 96.2 p e r c e n t . The M a t t s - O h n f e l d t

a p p r o x i m a t i o n g i v e s a more r e a l i s t i c a p p r o x i m a t i o n t o t h e a c t u a l b e h a v i o r

o f a g i v e n p r e c i p i t a t o r . ( I n p r e p a r i n g t h e f o r e g o i n g m a t e r i a l , s i g n i f i c a n t

use was made of Re fe rence 2 . )

FACTORS AFFECTING ESP PERFORMANCE

The f o l l o w i n g m a t e r i a l p r o v i d e s i n f o r m a t i o n concern ing f a c t o r s wh ich

a f f e c t o n l i n e p r e c i p i t a t o r performance. The i n f o r m a t i o n i s d i v i d e d i n t o

t w o a reas o f i n t e r e s t : o p e r a t i o n a l f a c t o r s and d e s i g n f a c t o r s .

O p e r a t i o n a l f a c t o r s c o n s i d e r e d i n t h i s s e c t i o n i n c l u d e f u e l

c h a r a c t e r i s t i c s , p r e c i p i t a t o r maintenance, t h e ash h a n d l i n g system,

e l e c t r i c a l c o n t r o l s and b o i l e r o p e r a t i o n s . The d i s c u s s i o n o f f u e l

Deutsch-Anderson, k = 1.0 A Matts-Ohnfeidt, k = 0.6

Matts-Ohnfeldt, k = 0.5 * Matts-Ohnfeldt, k = 0.4

I I I I

1 2 3 4 5

RELATIVE ESP SIZE (COLLECTION AREA/V9)

Figure 2-9. Cornparision o f Deutsch-Anderson and Matts-Ohnfeldt Efficiencies

2-24

c h a r a c t e r i s t i c s encompass c o a l q u a l i t y and v a r i a b i l i t y and genera l f l y ash

p r o p e r t i e s . The d i s c u s s i o n o f des ign f a c t o r s a f f e c t i n g p r e c i p i t a t o r

performance i n c l u d e e l e c t r o d e system des ign , s p e c i f i c c o l l e c t i o n a rea ,

d e s i g n gas v e l o c i t y , aspec t r a t i o and t h e number o f e l e c t r i c f i e l d s . Where

a p p r o p r i a t e , r e f e r e n c e s a r e made t o o t h e r s e c t i o n s o f t h i s manual f o r a

more d e t a i l e d d i s c u s s i o n .

O p e r a t i n g Fac to rs A f f e c t i n g ESP Performance

P r e c i p i t a t o r performance i s g r e a t l y a f f e c t e d by o p e r a t i n g v a r i a b l e s t o

w h i c h i t i s sub jec ted . These v a r i a b l e s i n c l u d e f u e l c h a r a c t e r i s t i c s , f l y

ash c h a r a c t e r i s t i c s , maintenance o f t h e p r e c i p i t a t o r and i t s a u x i l i a r y

equipment, and o t h e r p rocess f a c t o r s .

Coal C h a r a c t e r i s t i c s . C o n s i s t a n t coa l c h a r a c t e r i s t i c s a r e d i f f i c u l t t o

a c h i e v e o v e r t h e l i f e o f a power p l a n t . G e n e r a l l y , c o a l - f i r e d b o i l e r s

p roduce a wide spectrum o f i m p o r t a n t f l y a s h c o n s t i t u e n t s based on a change

o f c o a l s u p p l i e r s , coa l v a r i a t i o n s w i t h i n t h e same mine, and c o a l s t o r a g e

and b l e n d i n g procedures. T h i s f u e l v a r i a b i l i t y i s c r i t i c a l i n p r e c i p i t a t o r

a p p l i c a t i o n s and must be t h o r o u g h l y e v a l u a t e 1 t o m i n i m i z e i t s e f f e c t on

p r e c i p i t a t o r performance.

Coal V a r i a b i l i t y . S a t i s f a c t o r y p r e c i p i t a t o r per formance i s h e a v i l y

dependent on m a i n t a i n i n g a s teady supply o f f l u e gas w i t h u n i f o r m

c h a r a c t e r i s t i c s t o t h e p r e c i p i t a t o r . A l t h o u g h some f l e x i b i l i t y may be

d e s i g n e d i n t o a p r e c i p i t a t o r t o accommodate w ide ranges o f c o a l

c h a r a c t e r i s t i c s , c o a l v a r i a b i l i t y shou ld be l i m i t e d t o ensure s u c c e s s f u l

p r e c i p i t a t i o n . T h i s requ i remen t has become i n c r e a s i n g l y d i f f i c u l t i n

r e c e n t y e a r s s i n c e l a r g e u t i l i t y b o i l e r s r e q u i r e a s teady and dependable

s u p p l y o f f u e l f r o m s e v e r a l mines. One e f f e c t i v e approach i s t o base t h e

d e s i g n on t h e w o r s t case c o a l .

Coal Q u a l i t y . A n a l y s i s o f c o a l i s g i ven i n two fo rms : p r o x i m a t e and

u l t i m a t e . Prox imate a n a l y s i s i s a c h a r a c t e r i s t i c o f t h e t y p e -- b i t u m i n o u s , subbi turninous, o r l i g n i t e -- o f c o a l . U l t i m a t e a n a l y s i s

d e f i n e s t h e chemica l compos i t i on o f c o a l on an a s - r e c e i v e d b a s i s .

P r o x i m a t e a n a l y s i s i s g e n e r a l l y used f o r d e t e r m i n i n g q u a l i t y f o r

c o n t r a c t u a l purposes and i n c l u d e s measur ing s u r f a c e w a t e r c o n t e n t , ash

pe rcen tage , f i x e d carbon c o n t e n t , s u l f u r c o n t e n t and h e a t i n g va lue .

Vola t i l e ma t t e r i s a l s o r epo r t ed . Table 2-1 shows proximate and u l t imate

ana lyses of f o u r c o a l s chosen t o demonstrate t h e d i v e r s i t y among various

types of c o a l s .

The hea t c o n t e n t , based p r imar i l y on f i xed carbon, v o l a t i l e mat te r , ash and

s u l f u r f r a c t i o n s , w i l l b a s i c a l l y determine the q u a n t i t y of coal required t o

produce a given amount o f steam in a p a r t i c u l a r b o i l e r . In genera l , t he

higher t h e ash content , t h e lower heat content of t he c o a l . This f a c t

impacts p r e c i p i t a t i o n performance because t he need t o burn more coal with a

higher ash con ten t i nc reases t h e net concent ra t ion o f p a r t i c u l a t e mat te r

processed by t h e c o l l e c t i o n system.

Fly Ash C h a r a c t e r i s t i c s . The term " f l y ash" i s used t o descr ibe t h a t

port ion o f t h e s o l i d combustion waste t h a t i s en t r a ined in t h e f l u e gas and

c a r r i e d t o t h e p r e c i p i t a t o r . Fly ash c h a r a c t e r i s t i c s t h a t a f f e c t

p r e c i p i t a t o r performance inc lude chemical composition, e l e c t r i c a l

r e s i s t i v i t y , and p a r t i c l e s i z e d i s t r i b u t i o n . Fly ash concent ra t ion a1 so

a f f e c t s p r e c i p i t a t o r performance. These f a c t o r s a r e b r i e f l y discussed

be1 ow.

Concentrat ion. The concent ra t ion o f f l y ash leaving the b o i l e r can be

repor ted i n a va r i e ty of ways; t h e most useful f o r p r e c i p i t a t o r

performance ana lys i s i s in terms of mass per u n i t volume of f l u e gas ,

u sua l ly i n g r a in s per a c t u a l cubic f o o t (grains/ACF). However, s i nce

f l u e gas volume v a r i e s wi th temperature, p r e s su re , and excess a i r ,

comparison of f l y ash concen t r a t i ons under d i f f e r e n t opera t ing

cond i t i ons can be d i f f i c u l t using mass loadings p e r ac tua l cubic foot .

Hence, f l y ash concent ra t ion has a l s o been expressed in u n i t s of g ra in s

per s t anda rd cubic f o o t (qrains/SCF) and g r a i n s per s tandard dry cubic

f o o t ( g r a i ns/SDCF) . The United S t a t e s E n v i ronmental Pro tec t ion Agency

(U.S. EPA) has defined f l y ash concent ra t ion a s pounds per mi l l ion Btu 6 ( lbs / lO Btu) of hea t i n p u t t o t h e b o i l e r and may now be the

p r e f e r r e d manner f o r express ing such a concen t r a t i on .

Tab le 2-1

Coal and Ash Ana lyses (1)

N o r t h Eas te rn P rox ima te Analyses(%) Wyoming Dakota L i g n i t e Alabama High S u l f u r

Water 1 1 . 8 37 .1 V o l a t i l e m a t t e r 33.8 26.5 F i x e d Carbon 42.7 28.6 Ash 11.7 7 . 8 Su l f u r 0.56 0 .68

Water Carbon Hydrogen N i t r o g e n Sul f u r Ash Oxygen 12 .9

T o t a l 100.0

M i n e r a l Ana lyses o f Ash(%)

Fez 03 CaO MgO NazO K2 0 S i O2 T i 02 A 1 2 0 3 p205 SO 3 Undetermined &

E r r o r s

T o t a l 100.0

The ash content and heat ing value of a p a r t i c u l a r coal are gene ra l ly

s p e c i f i e d a s t h e average value obtained from a number of samples. Ash

v a r i a b i l i t y t a k e s two f a c t o r s i n t o cons idera t ion : 1) i t a l lows f o r

dev ia t i ons i n ash content from t h e mean f o r a given a n a l y s i s , and 2 ) i t

app l i e s a s t a t i s t i c a l f a c t o r t o t h e mean t o obtain t h e upper l i m i t of

t he ash con ten t a t t he 95 percent confidence l eve l . The second f a c t o r

can vary cons iderably with coal t ype , mining method and blending which

occurs dur ing mining, shipping, and s to rage . The E l e c t r i c Power

Research I n s t i t u t e (EPRI) r e p o r t s ash v a r i a b i l i t y f a c t o r s ranging from

1.25 t o 1.90.

Carbon con ten t of f l y ash i nc reases t h e ove ra l l p a r t i c u l a t e

concent ra t ion t o some exten t . Carbon content va r i e s with b o i l e r excess

a i r , burner p o s i t i o n , pu lve r i ze r s e t t i n g s , pu lve r i ze r maintenance, and

b o i l e r Toad. A typ ica l es t imate of f l y ash carbon con ten t i s around 5

percent f o r a pulverized-coal f i r e d b o i l e r .

Ash ca r ryove r i s t h a t port ion of t h e ash i n t h e coal t h a t appears a s

f l y ash r a t h e r than a s b o i l e r bottom ash . T r a d i t i o n a l l y , 80 percent

has been used with higher percentages represent ing more conserva t ive

approaches. Ash carryover v a r i e s wi th b o i l e r de s ign , opera t ing

cond i t i ons and ash fusion temperatures .

General ly, higher p r e c i p i t a t o r i n l e t d u s t loadings cause corona

suppression i n t he i n l e t f i e l d s (See Manual 2 , Sect ion 4 ) . Also,

higher i n l e t loadings requi re h igher ove ra l l removal e f f i c i e n c i e s t o

meet t h e same o u t l e t emissions s tandard .

Chemical Composition and Fly Ash R e s i s t i v i t y . The chemical composition

of t h e coal f i r e d i n a b o i l e r and the r e s i s t i v i t y of t h e r e s u l t i n g f l y

ash a r e d i r e c t l y r e l a t e d . Other f a c t o r s a f f ec t ing f l y a sh r e s i s t i v i t y

include the amount of excess combustion a i r , t h e moisture content o f

t he combustion a i r , and addi t iona l f l y ash condi t ion ing agent used

e i t h e r before o r a f t e r t h e coal i s burned. Fly ash r e s i s t i v i t y i s

gene ra l ly expressed i n u n i t s of ohm-centimeters (ohm-cm), which i s

numerical ly equiva len t t o the r e s i s t ance of a cube of f l y ash one

cent imeter on each s ide .

Fly ash c o n s i s t s mainly of g lassy spheres conta in ing t h e ash

c o n s t i t u e n t s of the coal with some unburned carbon a l s o p re sen t . The

su r f ace l a y e r s of t he p a r t i c l e s w i l l , depending upon f l u e gas

tempera ture , contain adsorbed gases and vapors , t he most important of

which a r e s u l f u r i c ac id and water vapor.

Fly ash r e s i s t i v i t y involves two independent conduction paths:

through the bulk of the material (volume conduction) and one a

su r f ace of each individual p a r t i c l e ( su r f ace conduction) . The

one

long t h e

bulk

chemistry of f l y ash determines i t s volume r e s i s t i v i t y . The previous ly

noted adsorbed gases and vapors s t rongly inf luence t h e su r f ace

r e s i s t i v i t y a s well a s adhesive, cohesive, and mater ia l handling

c h a r a c t e r i s t i c s .

The temperature of t he f l u e gas has a s t rong e f f e c t on t h e r e s i s t i v i t y

of f l y ash. When f l y ash r e s i s t i v i t y i s p l o t t e d a s a func t ion of f l u e

gas tempera ture , an inver ted "U" shaped curve t y p i c a l l y r e s u l t s ( s e e

Figure 2-10). The r e s i s t i v i t y curve has a maximum a t some temperature

in t h e 300 t o 400°F range. This curve can be expla ined in terms of

volume and su r f ace r e s i s t i v i t i e s .

A s f l u e gas temperature increases t h e adsorbed s u r f a c e contaminants

have l e s s inf luence on t h e sur face r e s i s t i v i t y . (At temperatures of up

t o approximately 200°F volume r e s i s t i v i t y shows very 1 i t t l e

i n f l u e n c e . ) As a r e s u l t , with sur face r e s i s t i v i t y dominating, a ne t

i nc rease in r e s i s t i v i t y up t o around 250 t o 30OoF i s observed. Between

approximately 200 and 350°F both sur face and volume conduction con t ro l

t he f l y ash r e s i s t i v i t y . Above t h i s range, volume conduction becomes

the dominant conduction mechanism, increas ing wi th i nc reas ing

tempera ture , r e s u l t i n g in a decreasing r e s i s t i v i t y .

TEMPERATURE

20I636

F igu re 2-10. Fly Ash R e s i s t i v i t y as a Func t ion o f Tenperature

Analyses of f o u r d i f f e r e n t types of coal a r e t abu la t ed in Table 2-1.

Analyses were performed by fol lowing ASTM procedures. I t i s important

t o note t h a t t h e s e a n a l y t i c techniques r e s u l t in a t abu la t i on of

m e t a l l i c ox ides f o r t he ash content . No at tempt i s made t o determine

the ac tua l chemical compounds t h a t may e x i s t i n t h e f l y ash. For

example, t h e repor ted SOj content may have a c t u a l l y e x i s t e d a s

calcium o r i ron s u l f a t e , and complex calcium-alumino-silicates may be

present .

Examination of Table 2-1 y i e l d s information about how a p r e c i p i t a t o r

would func t ion on each of t h e four c o a l s . The fol lowing statements a r e

q u a l i t a t i v e because t he p r e c i p i t a t o r cannot be q u a n t i t a t i v e l y s ized i f

only coal and ash chemistry a r e known. S iz ing a l s o r e q u i r e s a

knowledge of p a r t i c l e s i z e d i s t r i b u t i o n , f l u e gas volume and average

temperature, temperature d i s t r i b u t i o n , and the requi red c o l l e c t i o n

e f f i c i e n c y .

Wyoming Coal. The low-sulfur content of t h e coal would ind i ca t e

t h a t t h e su r f ace r e s i s t i v i t y w i l l be high. Furthermore, i t s low-sodium, high-calcium ash w i l l a l s o have a high volume

r e s i s t i v i t y . Thus, t he ash w i l l have a very high r e s i s t i v i t y a t

co ld-s ide temperature cond i t i ons and would d i s p l a y s i m i l a r

c h a r a c t e r i s t i c s a t hot-s ide opera t ing cond i t i ons .

North Dakota L ign i t e . The low- s u l f u r content would again r e s u l t

i n a high sur face r e s i s t i v i t y . However, t h e very high sodium

content of t he ash would tend t o make the volume r e s i s t i v i t y q u i t e

low, even a t co ld-s ide temperatures . Hence, a moderately s ized

co ld-s ide p r e c i p i t a t o r could be conf ident ly s e l e c t e d .

Alabama Coal. Both t h e s u l f u r content and t h e sodium content a r e

a t a leve l such t h a t cold-side r e s i s t i v i t y may be bo rde r l i ne . I f

a co ld-s ide p r e c i p i t a t o r i s s e l e c t e d , i t should be conserva t ive ly

s i zed because t he r e s i s t i v i t y may be high. Hot-side p r e c i p i t a t o r s

have been used on Alabama coal with some success , and t h i s might

a l s o be a good choice f o r t h i s app l i ca t i on .

Eas te rn H i g b S u l f u r Coa l . With a s u l f u r c o n t e n t i n excess o f 4%,

t h e s u r f a c e r e s i s t i v i t y w i l l be s u f f i c i e n t l y l ow a t v i r t u a l l y any

c o l d - s i d e tempera tu re . A c i d condensa t ion may be a prob lem a t l ow

gas temperatures, so adequate h e a t i n s u l a t i o n i s a n e c e s s i t y .

I n many h o t - s i d e i n s t a l l a t i o n s , p r e c i p i t a t o r per formance d e g r a d a t i o n

o c c u r s w i t h t ime . T h a t i s , a c l e a n h o t - s i d e p r e c i p i t a t o r w i l l p e r f o r m

as expec ted after s t a r t u p and show a t r e n d o f degrad ing per formance as

t h e u n i t i s opera ted . I n v e s t i g a t i o n i n t o t h e cause o f t h i s occu r rence

has r e v e a l e d t h a t t h e r e i s a r e g i o n o f sodium i o n d e p l e t i o n i n t h e d u s t

l a y e r immed ia te l y a d j a c e n t t o t h e c o l l e c t i o n e l e c t r o d e s ( < I mrn

t h i c k ) . T h i s sodium i o n d e p l e t e d l a y e r causes d r a s t i c i n c r e a s e s i n

t h a t l a y e r ' s r e s i s t i v i t y . I t i s b e l i e v e d t h a t t h e p o s i t i v e sodium i o n s

m i g r a t e f rom t h e p l a t e under t h e i n f l u e n c e o f t h e e l e c t r i c f i e l d .

Sodium d e p l e t i o n i s expec ted t o occu r w i t h sodium o x i d e i n ash l e v e l s

o f l e s s t h a n 0.5% and low c a l c i u m c o n c e n t r a t i o n s on t h e o r d e r o f 5.0%

c a l c i u m o x i d e , w h i l e f l y ash w i t h sodium o x i d e c o n c e n t r a t i o n s i n excess

o f 1 .0 p e r c e n t may e x h i b i t t h i s e f f e c t when c a l c i u m o x i d e

c o n c e n t r a t i o n s t y p i c a l l y g r e a t e r t h a n 15 t o 20 p e r c e n t .

P a r t i c l e S i z e D i s t r i b u t i o n . Most i n d i v i d u a l p a r t i c l e s o f f l y ash,

h a v i n g been formed by t h e s o l i d i f i c a t i o n o f l i q u i d ash i n gas

suspension, a r e s p h e r i c a l i n shape. A few o f t h e spheres may be

h o l l o w , some a r e i n c o m p l e t e o r broken, and some f l y ash p a r t i c l e s a r e

f l a k e s , aggTomerates o f s l a g , o r p i e c e s o f unburned o r p a r t i a l l y burned

f u e l .

When c o n s i d e r i n g t h e d i s t r i b u t i o n o f p a r t i c l e s i z e s i n a sample o f f l y

ash, i t i s common t o c o n s i d e r a l l p a r t i c l e s t o be s o l i d spheres. T h i s

assumpt ion p e r m i t s t h e use o f a n a l y t i c a l methods wh ich measure t h e

p a r t i c l e s i z e i n d i r e c t l y , by observ ing t h e b e h a v i o r o f t h e p a r t i c l e s

when s u b j e c t e d t o aerodynamic, g r a v i t a t i o n a l , and e l e c t r i c a l f o r c e s .

As previously noted, fly ash consists of a wide range of particle sizes

from about 150 urn to 0.01 pm in diameter. By weight, some 5 to 10

percent o f fly ash typically consists of fine particles, i.e., those

smaller than about 2 pin.

Electrostatic precipitators are particularly sensitive to fine

particles in several different ways:

Space Charge Effect (Corona Suppression) - All of the uncollected dust in a precipitator consists of suspended particles in the interelectrode space. These particles are electrically charged and carry some of the precipitator current from the emitting electrodes to the grounded plates. However, more than 99 percent of the current is carried by gaseous ions which have mobilities several hundred times greater than the drift mobilities of the dust particles.

The charged dust particles provide a space charge which tends to suppress the corona current. This effect is most pronounced for fine particles since the total charge carried by the dust per unit volume of gas is proportional to the surface area of the dust.

Efficiency - Theoretically, the log of penetration is inversely proportional to particle diameter. Although actual experience does not confirm this relationship, tests on precipitators do show a reduced collection efficiency for fine particles. Hence, the finer the dust entering a particular precipitator, the lower the efficiency.

Put another way, a larger precipitator is required to achieve the same overall mass efficiency on fly ash containing a larger proportion of fine particles.

Physical Properties - Because of their greater surface area, a mass of fine particles has greater adhesive and cohesive properties than do coarse particles. Thus, fine particles are generally less "free flowing" than ccarse particles. Since a precipitator is less efficient on fine particles, there is a size gradation in the collected material; coarse particles are more prevalent in the material collected i n the front of the precipitator, and fine particles tend to predominate in the material collected in the rear. Thus, the material caught in the rear-most hoppers of a precipitator, although smaller in quantity than that collected in the front, can have a greater tendency to bridge the hopper outlet 2nd cause ash handling problems.

Most of the fly ash particles larger than about 1 pm are formed by

the coalescence of the ash content of an individual coal particle into

a solidified sphere. Particles smaller than about 0.5 um are thought

to be formed by vaporization and subsequent condensation of those

volatile compounds found in the ash. Thus, the chemical composition of

fine particles may be expected to differ from that of the total ash,

having been enriched by the more volatile species. Since fine

particles are collected in the precipitator with lower efficiency than

that of coarse particles, it follows that the fly ash escaping a

precipitator will also show enrichment by the more volatile species in

the ash.

Maintenance. The best-designed ESP will not give satisfactory performance

if it and its related equipment are not operated and maintained properly.

ESP manufacturers supply instruction manuals with their equipment which

should be followed closely as each supplier's equipment is unique in some

respects. General operation and maintenance guidelines are discussed in Manual 11.

Electrical Contro7s. The control circuits of modern ESPs contain

sophisticated logic circuits designed to maintain the maximum possible

time-averaged voltage on each bus section. They have internaT sensors to

detect the onset of an arc, quench it by momentarily reducing voltage, and

restore power within milliseconds. Their design uses analog or digital

computer elements which are sensitive to ambient temperatures: hence, the

controls should be kept in a clean, air conditioned room. Routine

maintenance consists of cleaning them and checking their operation.

Failure of circuit elements can be detected by erratic operation, and

repair is usually made by replacing a complete circuit board.

Rappers. It is necessary to rap collecting plates and emitting electrodes

periodically to remove the accumulated fly ash. Most rigid frame ESPs use

tumbling hammers fastened to a rotating motor-driven shaft for this

purpose. Most manufacturers of weighted wire precipitators use a rapper

design in which a weight i s electromagnetically raised then dropped against

an anvil, or electric vibrators.

With either design, hammers and anvils may wear, or coils and control

timers may malfunction. If a portion of the rapping system ceases to operate, the electrical characteristics of the affected bus section(s) will

d e t e r i o r a t e , and t h e overa l l performance of t he ESP wil l decrease . Hence,

maintenance programs must include in spec t ions of t he rappers t o a s c e r t a i n

t h e condit ion of t he rapping system.

P r e c i p i t a t o r Clearances. As designed, a l l d i scharge e l e c t r o d e s in an ESP

should be exac t ly t h e same d i s t ance from t h e c o l l e c t i n g p l a t e s . This

enables maximum vo l t age t o be appl ied t o t he d ischarge e l ec t rodes and

maximum performance t o be achieved by t h e ESP. In r e a l i t y , f ab r i ca t i on and

cons t ruc t ion techniques n e c e s s i t a t e a compromise with t h e idea l condi t ion ;

p l a t e s and wire frames warp t o some e x t e n t i n s p i t e of t he b e s t e f f o r t s of

t h e bu i lde r s . Some to l e r ance i s s p e c i f i e d a s permissible by most

supp l i e r s . Since h i s t o r i c a l performance da t a has been obtained from

p r e c i p i t a t o r s having alignment t o l e r a n c e , i t should n o t be considered a

de f i c i ency .

However, opera t iona l f a c t o r s such a s ash pressure from o v e r f i l l e d hoppers

o r t r a n s i e n t ep isodes of high temperature may cause the e l e c t r i c a l

c learance t o decrease t o unacceptable va lues . This decreases t he vol tage

t h a t can be appl ied t o t he emi t t ing e l e c t r o d e s and the performance of t he

ESP.

Whenever an i n t e r n a l inspect ion of an ESP i s made, t he e l e c t r i c a l c learance

between high-voltage and grounded p a r t s should be checked t o v e r i f y t h a t i t

i s s t i l l within t h e s u p p l i e r ' s s p e c i f i e d t o l e r ance .

A s h Deposi ts . When an ESP, o r a por t ion of one, i s a t a temperature below

the dewpoint of t he f l u e gases , condensation of ac id and/or moisture occurs

i n t h a t region. Such events a r e most l i k e l y t o occur during opera t ion a t

low b o i l e r load o r when s t a r t i n g t h e b o i l e r a f t e r an outage. Condensate i s

co-prec ip i ta ted wi th and absorbed by t h e f l y a sh , c r e a t i n g a damp, cohesive

mass. Some f l y ashes a r e q u i t e pozzolanic ; upon dry ing , they remain

cemented toge ther and adhere t enac ious ly t o t he sur face on which they a r e

depos i ted . A succession of such i n c i d e n t s can cause ash d e p o s i t s of

considerable s i z e t o be formed in t h e ESP. When these appear on c o l l e c t i n g

p l a t e s o r emi t t ing e l e c t r o d e s , t h e s i z e of t he depos i t s reduces e l e c t r i c a l

c learance , r e s u l t i n g in a decrease i n t he maximum vol tages t h a t can be

supplied and a r e s u l t a n t decrease in performance.

Hard, c r u s t y , almost uniform depos i t s a r e of ten found on emi t t ing

e l e c t r o d e s following i n c i d e n t s of condensation. These depos i t s i nc rease

t h e e f f e c t i v e rad ius of t he emi t t ing e l ec t rode , r e s u l t i n g in a decrease of

corona cu r r en t .

Large cemented masses of f l y ash sometimes f a l l i n t o t h e hoppers. When

such masses a r e too l a r g e t o pass through t h e hopper o u t l e t , pluggage

occu r s , r e s u l t i n g in o v e r f i l l e d hoppers.

Therefore , opera t ion of t h e ESP a t temperatures below the ac id dewpoint i s

t o be avoided, o r a t l e a s t minimized. Maintenance inspec t ions should

i nc lude the removal of any ash depos i t s t h a t may be found.

Gas D i s t r i bu t ion Devices. In order t o obta in uniform gas ve loc i ty

throughout t h e t reatment zone of an ESP, custom designed vanes, b a f f l e s ,

and/or per fora ted p l a t e s a r e used a t t h e ESP gas i n l e t and l e s s f r equen t ly

a t t h e o u t l e t . These devices a r e usua l ly designed and se lec ted a s a r e s u l t

of a flow study conducted on a model of a p a r t i c u l a r duct system and ESP.

I f t h e modeling work i s properly done, the gas d i s t r i b u t i o n devices perform

t h e i r intended tunc t ion .

However, f l y ash depos i t s can form on the gas d i s t r i b u t i o n devices , as

desc r ibed above. Such depos i t s can cause ma ld i s t r i bu t ion of f l u e gas

wi th in t he ESP, lowering i t s performance. In severe ca se s , t h e ash

d e p o s i t s can cause s t r u c t u r a l f a i l u r e due t o t he increased weight of ash

bui 1 d u ~ .

Plugging of t h e gas d i s t r i b u t i o n devices can a l s o occur without

condensat ion i f t he dry f l y ash i s unusually adherent . I n such c a s e s , t h e

add i t i on of rappers or v i b r a t o r s w i l l o f t en so lve t h e problem.

Frequent opera t ion a t low gas v e l o c i t i e s w i l l cause d u s t t o s e t t l e t o t h e

bottom of an i n l e t duc t . This depos i t may not be swept away a t h igher

v e l o c i t i e s and r e s u l t s in an increas ing depth of depos i t w i t h time of

ope ra t ion . I f t h e depos i t covers a s i g n i f i c a n t por t ion of t he gas

d i s t r i b u t i o n b a f f l e s , mald is t r ibu t ion of f l u e gas i n t h e ESP wi l l fo l low.

F u r t h e r , r e e n t r a i n m e n t o f t h e f l y ash may t e m p o r a r i l y o v e r l o a d t h e

p r e c i p i t a t o r , r e d u c i n g c o l l e c t i o n e f f i c i e n c y . Redesign o f t h e i n l e t d u c t ,

p o s s i b l y i n c l u d i n g t h e a d d i t i o n o f a hopper bo t tom, may be r e q u i r e d .

Gas d i s t r i b u t i o n d e v i c e s may be des igned w i t h i nadequa te c lea rance f o r

expans ion due t o tempera tu re e x c u r s i o n s . I n such cases, expans ion r e s u l t s

i n b u c k l i n g and d i s t o r t i o n o f t h e d e v i c e s . Redesign and r e p a i r shou ld be

e f f e c t e d as soon as such an e v e n t i s d i s c o v e r e d .

B o i l e r . The q u a l i t y o f maintenance o f a b o i l e r and i t s accessor ies can

a l s o a f f e c t t h e per formance o f t h e ESP.

For example, b o i l e r t u b e l e a k s have t h e p o t e n t i a l t o cause t h e cement ing o f

f l y ash t o p l a t e s and d i s c h a r g e e l e c t r o d e s .

If one o r more b u r n e r s a r e d e f l e c t e d f rom t h e i r p r o p e r p o s i t i o n , t h e

f i r e - b a l l p o s i t i o n and tempera tu re d i s t r i b u t i o n i n t h e fu rnace w i l l be

a l t e r e d . T h i s has been known t o r e s u l t i n m a l d i s t r i b u t i o n o f t h e f l u e gas

e n t e r i n g a h o t - s i d e ESP. M a l d i s t r i b u t i o n o f t h e f i u e gas t o c o l d - s i d e

p r e c i p i t a t o r s can a l s o r e s u l t f rom p a r t i a l p l u g g i n g o f a i r h e a t e r s .

Coal M i l l s . Wear on c o a l m i l l s can change p a r t i c l e s i z e d i s t r i b u t i o n . It

can a l s o i n c r e a s e t h e carbon l o s s o f t h e b o i l e r , r e s u l t i n g i n carbon r i c h

f l y ash p a r t i c l e s . Such p a r t i c l e s , because o f t h e i r l ow r e s i s t i v i t y ,

r a p i d i y l o s e t h e i r e l e c t r i c a l charge when d e p o s i t e d on t h e c o l l e c t i n g

p l a t e s , become r e e n t r a i n e d i n t h e gas stream, and a r e l o s t i n

d i s p r o p o r t i o n a t e q u a n t i t i e s .

Ash H a n d l i n q System. O v e r f i l l e d hoppers a r e a m a j o r cause o f p r e c i p i t a t o r

prob lems. Hopper e v a c u a t i o n prob lems a r e m i n i m i z e d i n p l a n t s where t h e

hoppers a r e k e p t warm by adequate h e a t e r s , i n s u l a t i o n , and enc losu res , and

where t h e ash i s removed as c o n t i n u o u s l y as p o s s i b l e . F l u i d i z i n g hopper

ash w i t h d r y a i r , wh ich must be p rehea ted above t h e dewpoin t temperature ,

i s sometimes h e l ~ f u l .

Hopper level alarms a r e advantageous i n ensuring t h a t hoppers a r e not

allowed t o o v e r f i l l . Level sensors come in a va r i e ty of mechanical,

pneumatic, e l e c t r i c a l , and nuclear t yoes . Some, such a s capac i tance

probes, may g ive f a l s e alarms when out of adjustment o r when

h i g h - r e s i s t i v i t y ashes a r e involved. Non-contacting nuc lear type l eve l

i nd i ca to r s appear t o have fewer shortcomings than o t h e r dev ices , and a r e

being used more o f t en than o the r s a t t h e present t ime. They are more

expensive and r e q u i r e a l icensed technic ian f o r maintenance.

The e n t i r e ash removal system should be maintained in accord with i t s

manufacturer 's recommendations, and i t should not be allowed t o

d e t e r i o r a t e . Fly ash i s highly ab ra s ive ; worn p a r t s must be r epa i r ed o r

rep1 aced a s r equ i r ed .

Design Factors Affec t ing ESP Performance

Proper design i s c r i t i c a l t o acceptable long term performance of a

p r e c i p i t a t o r . Design cons idera t ions should include power supply, e l e c t r o d e

system des ign , s p e c i f i c co l l ec t i on a r e , . , gas ve loc i ty , aspec t r a t i o , number

of f i e l d s i n t h e d i r e c t i o n of gas flow and e l e c t r i c a l s e c t i o n a l i z a t i o n .

Power Supply. The power supply of an ESP c o n s i s t s of t h r e e main components:

H i g h v o l t a g e t r a n s f o r m e r

R e c t i f i e r

VoTtage c o n t r o l , metering and p ro t ec t ion c i r c u i t r y

The high vol tage t ransformer i s s p e c i f i c a l l y designed f a r use i n

p r e c i p i t a t o r s wi th the a b i l i t y t o withstand winding s t r e s s when severe

sparkover occurs i n t he p r e c i p i t a t o r . Genera l ly , t ransformer r a t i n g s range

from 15 t o 95 kVA with secondary vol tage l i m i t s of 45 t o 55 kV average and

secondary output c u r r e n t s of 250 t o 1500 milliamps (mA) D.C.

Most modern r e c t i f i e r s a r e of t he s i l i c o n type and a r e gene ra l ly contained

i n s i d e the t ransformer tank on newer i n s t a l l a t i o n s . The in t roduct ion of

t h e s i l i c o n c o n t r o l l e d r e c t i f i e r (SCR) o f f e r s g r e a t improvement i n power

input con t ro l and can minimize t he e f f e c t of e l e c t r i c a l d i s tu rbances in t h e

ESP by t h e speed of i t s response.

The power supply must be matched c o r r e c t l y t o the opera t ing requirements ,

o r several d i f f i c u l t i e s may a r i s e . The major d i f f i c u l t i e s a r e l i s t e d below.

The impedance of t he power supply may not be enough t o dampen e l e c t r i c a l breakdowns s u f f i c i e n t l y . This condi t ion i s l i k e l y i f the high vol tage t ransformer cu r r en t r a t i n g i s much l a r g e r than r equ i r ed .

If t h e power supply i s too small t o handle t h e physical s i z e of t h e p r e c i p i t a t o r , lower than des i r ab l e p r e c i p i t a t o r vo l tages may e x i s t because transformer cu r r en t l i m i t s would be exceeded.

I f t h e power supply i s too l a rge f o r a p a r t i c u l a r a p p l i c a t i o n , t he power usage as a percentage o f capac i ty i s smal l . This may cause poor power input cont ro l because t he c o n t r o l l e r may be unable t o d i s c r imina t e a control s ignal from l i n e noise .

Figure 2-11 shows the importance of maintaining a high secondary vol tage in

a p r e c i p i t a t o r . P r e c i p i t a t o r e f f i c i ency i s d i r e c t l y e f f e c t e d by t h e

secondary peak vo l t age .

Electrode System Design. Electrode system design has a d i r e c t e f f e c t on

the vol tage-cur ren t r e l a t i onsh ip i n s ide a p r e c i p i t a t o r . The two major

e f f e c t s a r e l i s t e d below:

The d ischarge e lec t rode diameter , o r sharpness of t he corona emi t t i ng po in t s o r edges, determines the corona s t a r t i n g vo l t age . Therefore , f o r a given vol tage , a small diameter wire o r pointed e l e c t r o d e wi l l y i e l d more c u r r e n t .

Co l l ec to r surface i r r e g u l a r i t i e s may produce sparkover a t a reduced vol tage .

Col lec t ion e l e c t r o d e spacing i s defined a s t he c e n t e r l i n e t o c e n t e r l i n e

d i s t ance between two adjacent c o l l e c t i n g e l ec t rodes , In modern ESPs,

c o l l e c t i o n e l ec t rode spacings genera l ly range from 9 t o 12 i n . f o r f l y ash

c o l \ e c t i o n . Weighted wire p r e c i p i t a t o r s usual ly have a 9 i n . spacing

whereas r i g i d frame and r i g i d e lec t rode p r e c i p i t a t o r s t y p i c a l l y use 10 t o

1 2 i n . spac ing . General ly, 12 i n . spacing i s required f o r p l a t e s t a l l e r

than 40 f t t o ensure t h a t acceptable alignment t o l e r ances may be

maintained.

- increases in Two (2) Kilowtts Steps. Typical Range 36 to 60 kV

PRECIPITATOR PEAK VOLTAGE (Kitovolts)

Figure 2-1 1 . A Typical E l e c t r o s t a t i c P r e c i p i t a t o r Peak Voltage Versus Dust Co l l ec t i on Ef f i c i ency Curve Shows How Ef f i c i ency Inc reases wi th Voltage ( 3 )

-

In p r e c i p i t a t o r design i t i s e s s e n t i a l t o maintain adequate e l e c t r i c a l

c learance between t h e high vol tage (d ischarge) e l ec t rode and the grounded

( c o l l e c t i o n ) e l e c t r o d e . A t sparkover vo l t age , a p r e c i p i t a t o r of good

design wi l l spark only between t h e d ischarge e l ec t rode and t h e co l l ec t i on

e l ec t rode . Sparking a t any o the r po in t i s a s ign of poor design o r

cons t ruc t ion inadequacy; sharp edges on c o l l e c t i o n p l a t e s or ou t of

t o l e r ance al ignment , f o r example. As a r e s u l t of t he spacing requirement,

r i g i d frame des igns gene ra l ly have a wider p l a t e spacing t o provide

adequate e l e c t r i c a l c learance between t h e discharge e l e c t r o d e frame and

s t i f f e n i n g elements on the c o l l e c t i o n p l a t e . S i m i l a r l y , r i g i d e lec t rode

des igns use wider p l a t e spacing t o al low f o r t he increased th ickness of t h e

d ischarge e l e c t r o d e .

A d i s t i n c t i o n betweeh physical c learance and e l e c t r i c a l c learance needs t o

be made. As shown in Figure 2-12, two smooth su r f aces i n c l o s e physical

proximity w i l l no t sparkover a t t h e same vol tage a s two pointed sur faces

phys ica l ly f u r t h e r a p a r t . Therefore , a smooth pipe frame may be phys ica l ly

c l o s e r t o t he c o l l e c t i o n e l ec t rode than t h e discharge e l e c t r o d e and s t i l l

possess adequate e l e c t r i c a l c l ea rance .

In designing a p r e c i p i t a t o r , t he manufacturer e s t a b l i s h e s f ab r i ca t i on and

cons t ruc t ion t o l e r a n c e s s ince i t i s impossible t o f a b r i c a t e o r cons t ruc t

t he co l l ec t i on o r d i scharge e l e c t r o d e system p e r f e c t l y plumb and s t r a i g h t .

Spec i f i c Col lec t ion Area. Spec i f i c c o l l e c t i o n area (SCA) i s defined a s t h e

t o t a l e f f e c t i v e c o l l e c t i o n p l a t e a r ea of a p r e c i p i t a t o r d iv ided by the

t o t a l gas volume being t r e a t e d . This parameter has found wide use

throughout t h e i ndus t ry and i s important because i t r e p r e s e n t s the

A /V r e l a t i o n s h i p found in t he Deutsch-Anderson equat ion . co 9

Design Gas Veloc i ty . P r e c i p i t a t o r gas v e l o c i t y i s a common design

parameter, but i t s t r u e value a s a design tool can be ques t ionable unless

t he gas flow d i s t r i b u t i o n a t t he p r e c i p i t a t o r i n l e t i s well understood.

Causes f o r gas d i s t r i b u t i o n e f f e c t s inc lude p l a t e b a f f l e s , and emit t ing

system elements ( s e e Figure 2-13). These e f f e c t s a r e unique t o each

p r e c i p i t a t o r des ign and a r e d i f f i c u l t t o descr ibe in d e t a i l . As a r e s u l t ,

NOTE THAT THE ARC FORMS BETWEEN THE TWO POINTS EVEN THOUGH THEY HAVE A GREATER PHYSICAL SEPARATION THAN THE TWO SMOOTH SPHERES.

Figure 2-12. Electrical Clearance ( 2 ) -

Figure 2-13. Gas Veloci ty i n a P r e c i p i t a t o r Passage ( 2 ) -

only an overall gas velocity can be calculated by dividing the total gas

volume entering the precipitator by the effective cross-sectional area of

the ESP. Effective cross-sectional area is obtained by multiplying the

height of the collecting plates by the number and width of the gas

passages. Mathematically,

Gas Velocity (fthec) = (2-22)

Total Gas Flow (ACFM) Plate Height (ft) x Width of Gas Passage (ft) x Number of Gas Passages x (60 sec/min)

In designing a precipitator both excessively high velocities and excessively

low velocities must be considered. High velocities in a precipitator may result in scouring collected dust f rom the collecting plate and excessive

reentrainment during rapping. High velocities also reduce SCA. Low gas

velocities such as occur during low-load operation can result in excessive

dust fallout in the ductwork leading to the precipitator, resulting in higher

than normal emissions during load increases and the possibility of structural

damage.

In general, there is a lack of agreement regarding the definition of excessively high gas velocities. Velocities in excess of 8 ft/sec have been

shown to contribute to excessive reentrainment. Design velocities of 6 to 8

ft/sec were considered normal up to about 1970, but 3 to 6 ft/sec is

considered reasonable to achieve modern efficiency goals. Less than 3 ft/sec

is considered too low and will cause the previously noted low velocity

problems to become noted. in addition, such low velocities will adversely

effect the economic design o f the precipitator.

Aspect Ratio. The aspect ratio (AR) of a precipitator i s defined as the

effective length (L) of the precipitator divided by the effective height (H) of the collecting plates. Figure 2-14 illustrates the concept of aspect

ratio. In the figure, the aspect ratio is mathematically described as

Figure 2-74. Components o f Aspect Rat io (2)

Notice that the walkways and other nonelectrified regions of the precipitator

are not included in the calculation. The quantity of dust dropout i n

non-electrified regions or dead spaces is unknown, and conservative design

practice does not include this space in calculating aspect ratio.

Historically ( I ) , - minimum aspect ratios ranged from 0.6 for 98 percent

collection efficiency to 1.5 for better than 99.6 percent collection

efficiency. TO meet today's New Source Performance Standards (NSPS), aspect

ratios of 1.5 to 2.0 are generally used.

It is generally believed that all other parameters being equal, a

precipitator having a high aspect ratio is more efficient than one with a

lower aspect ratio. The logic behind this reasoning is that the agglomerated

fly ash at the top of the col~ection plate tends to disperse and become

reentrained during rapping. The reentrained material must be reprecipitated

if it is to be collected before leaving the precipitator. The longer

effective length associated with a high aspect ratio helps achieve the

recollection of reentrained fly ash.

Using the aspect ratio to compare precipitators can present problems due to

the fact that all other design and operating parameters may not be equal.

For example, two precipitators with the same aspect ratios can have

drastically different SCAs. SCA will have an overriding affect on precipitator performance and cost.

Number of Fields in Direction of Gas Flow. Precipitator fields are

arrangements of bus sections in the direction of gas flow that are

independently energized by one or more power supplies situated laterally to

the gas flow direction (See Manual 11, IGCI Definitions). Each electrical

f i e l d o f an ESP i s an independent p r e c i p i t a t o r , i n e f f e c t , and i s preceded

and/or f o l l o w e d by a n o t h e r f i e l d . As a r e s u l t , each f i e l d encoun te rs f l u e

gas o f t h e same q u a n t i t y , compos i t i on , and approx imate temperature . The f l y

ash c o n c e n t r a t i o n i n t h e f l u e gas handled by each f i e l d i s reduced by t h e

amount o f f l y ash p r e c i p i t a t e d i n t h e p r e c e d i n g f i e l d The l e n g t h o f a g i v e n

f i e l d v a r i e s a c c o r d i n g t o each m a n u f a c t u r e r ' s des ign . G e n e r a l l y , f i e l d

l e n g t h ranges from t h r e e f e e t t o abou t f i f t e e n f e e t .

When d u s t c o n c e n t r a t i o n s a r e h i g h , as i n an i n l e t f i e l d , t h e space charge

e f f e c t reduces the corona c u r r e n t a v a i l a b l e a t a g i v e n v o l t a g e . The space

charge e f f e c t decreases i n subsequent f i e l d s due t o t h e charged p a r t i c l e s

b e i n g removed from t h e gas stream. As a r e s u l t , i n l e t f i e l d s g e n e r a l l y show

h i g h v o l t a g e s f o r a g i v e n c u r r e n t d e n s i t y ; d e c r e a s i n g v o l t a g e s and i n c r e a s i n g

c u r r e n t d e n s i t i e s o c c u r r i n g i n subsequent f i e l d s . F i g u r e 2-15 i l l u s t r a t e s

t h i s t r e n d .

S i n c e t h e e l e c t r i c a l c h a r a c t e r i s t i c s v a r y f rom t h e i n l e t t o t h e o u t l e t o f a

p r e c i p i t a t o r , i t i s d e s i r a b l e t o have a l a r g e number o f i n d i v i d u a l l y

e n e r g i z e d f i e l d s making up t h e e f f e c t i v e l e n g t h o f a p r e c i p i t a t o r . T h i s s o r t

o f d e s i g n enables o p t i m i z i n g e l e c t r i c a l c o n d i t i o n s f o r g i v e n p a r t i c u l a t e

c o n d i t i o n s a t any p o i n t i n t h e p r e c i p i t a t o r .

A n o t h e r reason f o r i n c o r p o r a t i n g more f i e l d s i n t h e des ign o f a p r e c i p i t a t o r

i s r e l i a b i l i t y . O b v i o u s l y , e l e c t r i c a l f a i l u r e o f one f i e l d i n a t h r e e f i e l d

p r e c i p i t a t o r would have a g r e a t e r e f f e c t on c o l l e c t i o n performance t h a n a one

f i e l d f a i l u r e i n a

r e s u l t f r o m severa l

and power supp ly f a

When e l e c t r i c a l f a i

o u r t e e n f i e l d p r e c i p i t a t o r . E l e c t r i c a l f a i l u r e can

m a l f u n c t i o n s i n c l u d i n g o v e r f i 71 hoppers, w i r e breakage,

l u r e . Such e l e c t r i c a l f a i l u r e i s n o t an uncommon even t .

u r e occurs , t h e f i e l d s tops p r e c i p i t a t i n g and c o l l e c t s

f l y ash o n l y by n a t u r a l s e t t l i n g and space charge c o l l e c t i o n . The f o l

t a b u l a t i o n i l l u s t r a t e s t h e t h e o r e t i c a l e f f e c t on e f f i c i e n c y o f v a r i o u s

numbers o f f i e l d s o u t o f s e r v i c e i n a p a r t i c u l a r c e l l i n t h e t h r e e f i e

f o u r t e e n f i e l d p r e c i p i t a t o r s .

1 owing

I d and

CLEAN PLATE AIR LOAD CURVE - ALL FIELDS

DIRTY PLATE AIR LOAD CURVE - ALL FIELDS f i ' SPARK

OPERATING CURVE, THIRD FIELD it- OPERATING CURVE, SECOND F1EL

I OPERATING CURVE, FIRST FIELD

0 5 10 15 20 25 30 35 40 45 50

V = ESP, VOLTAGE, kV

Figure 2-1 5. Normal Precipitator Current Voltage Curves (2)

Number o f F i e l d s Out o f S e r v i c e

0

1

2

3

4

5

6

7 8

9

10

11

12

13

14

C a l c u l a t e d C e l l E f f i c i e n c y (%)@I Three F i e l d ESP Four teen F i e l d ESP

" E f f i c i e n c y i s t h e o r e t i c a l l y 0 p e r c e n t , b u t g r a v i t a t i o n a l s e t t l i n g r e s u l t s

i n an e f f i c i e n c y o f abou t 50 p e r c e n t .

The c a l c u l a t i o n s used i n t h i s t a b u l a t i o n assume t h a t t h e des ign e f f i c i e n c y

i s 99.60 p e r c e n t and t h a t t h e M a t t s - O h n f e l d t e q u a t i o n a p p l i e s w i t h a k

v a l u e o f 0.5. A l s o t h e v a l u e s r e p r e s e n t t h e e f f i c i e n c y f o r one c e l l o f t h e

p r e c i p i t a t o r o n l y and t h e e f f e c t on o v e r a l l c o l l e c t i o n e f f i c i e n c y i s

dependent on t h e number o f c e l l s i n p a r a l l e l .

C u r r e n t d e s i g n p r a c t i c e s use f rom f o u r t o s i x f i e l d s f o r an ESP w i t h a

d e s i g n e f f i c i e n c y i n excess o f 99 p e r c e n t .

Electrical Sectionalization. A precipitator may also be electrically

divided in a direction perpendicular to that of gas flow. Divisions such

as these are referred to as cells. Consequently, the sma7lest portion of a

precipitator that can be independently energized is one field in one cell,

otherwise known as a bus section.

As in the case of fields, a greater number of bus sections i n a

precipitator offers some protection against drastic collection 'performance

degradation when a given section experiences electrical failure. Figure

2-16 shows typical field arrangements. The three field precipitator has

four cells, yielding twelve independent bus sections with twelve power

supplies. The fourteen field precipitator has two cells, yielding 28 bus

sections. However, in this case each power supply powers two bus sections

in the same field. Arrangements such as those shown in Figure 2-16 are

chosen in part to produce an economical power supply selection.

To illustrate the positive aspects of an increased number of power

supplies, consider the effect on each precipitator in Figure 2-16 when one

power supply experiences electrical failure. The three-field precipitator

has one-fourth of its width reduced to two fields while the remaining three

cells operate at the design efficiency of 99.6 percent. The overall

precipitator efficiency, from page 2-47, under these conditions is:

The fourteen field precipitator becomes a thirteen field precipitator,

resulting in an overall efficiency of 99.51 percent (see page 2-48).

Another very important reason for designing a precipitator with more

sectionalization across its width is the temperature gradients which may

exist i n the flue gas. Flue gas temperature gradients are often caused by

rotary air heaters and may persist in the precipitator. Since fly ash

resistivity is a function of temperature, this gradient can cause

significant variations in electrical characteristics across the

precipitator width. Also, poor gas distribution of fly ash stratification

may cause variations in dust loading across the precipitator, resulting in

non-uniform electrical characteristics.

3 FIELD PRECIPITATOR

14 FIELD PRECtPI'FATOR

Figure 2-16. P lan o f Precipitator Bus 'ections ( 2 )

3 PRECIPITATOR SIZE SELECTION

S e c t i o n 3

PRECIPITATOR S I Z E SELECTION

INTRODUCTION

There i s one c r i t i c a l aspec t o f p r e c i p i t a t o r d e s i g n wh ich has c r e a t e d and

w i l l c o n t i n u e t o c r e a t e t h e g r e a t e s t o p p o r t u n i t y f o r d i f f e r e n c e s o f o p i n i o n

among p r e c i p i t a t o r e x p e r t s - p r e c i p i t a t o r s i z e s e l e c t i o n . T h i s s e c t i o n

p r e s e n t s v a r i o u s s i z e s e l e c t i o n p r a c t i c e s and d e s c r i b e s c r i t i c a l parameters

wh ich a f f e c t s i z e s e l e c t i o n . A summary o f e a r l i e r d a t a bases and s i z e

s e l e c t i o n p r a c t i c e s was p u b l i s h e d i n 1977 (24). -

H i s t o r i c a l P e r s p e c t i v e

P i o n e e r i n g w o r k i n t h e f i e l d o f e l e c t r o s t a t i c p r e c i p i t a t i o n was conducted by

D r . F r e d r i c k C o t t r e l l i n t h e U n i t e d S t a t e s and S i r O l i v e r Lodge i n England

d u r i n g t h e l a t e 1800s and e a r l y 1900s. I n i t i a l a p p l i c a t i o n o f p r e c i p i t a t o r s

were i n t h e i n d u s t r i a l s e c t o r d u r i n g t h e f i r s t q u a r t e r o f t h e 2 0 t h c e n t u r y .

The f i r s t f u l l - s i z e u t i l i t y a p p l i c a t i o n o f a p r e c i p i t a t o r t o a p u l v e r i z e d

c o a l - f i r e d steam g e n e r a t o r o c c u r r e d i n 1923 a t a u n i t ope ra ted by t h e D e t r o i t

Ed i son Company.

Between t h a t f i r s t u t i l i t y i n s t a l l a t i o n and today , s i g n i f i c a n t s t r i d e s have

been made i n hardware des ign c o n s i s t e n t w i t h an unders tand ing o f t h e

fundamenta l processes i n v o l v e d . These equipment improvements have been

f o s t e r e d by t h e d i f f e r i n g p e r s p e c t i v e s deve loped by numerous s u p p l i e r s . T h i s

tended t o produce d i f f e r e n t i n s i g h t s i n t o t h e p r e c i p i t a t i o n process and s i z i n g

p r a c t i c e s .

S ince s u p p l i e r s sponsor t h e i r own r e s e a r c h work, t h e work was and i s

c o n s i d e r e d p r o p r i e t a r y and t h e r e f o r e n o t p u b l i c l y a v a i l a b l e . T h j s

n o n - p u b l i c i z e d work r e s u l t e d i n a un ique d a t a base f o r each s u p p l i e r . Even

today , w i t h a l l o f t h e r e s e a r c h p r o j e c t s , funded b y t h e government and p r i v a t e

i n s t i t u t i o n s , t h e s u p p l i e r s ' d a t a bases s t i l l p r o v i d e t h e b a s i s upon wh ich

s u p p l i e r s b a s e t h e i r guarantees. A l l o f t h i s makes i t v e r y d i f f i c u l t f o r a

u t i l i t y t o i n d e p e n d e n t l y e s t a b l i s h p r e c i s e p r e c i p i t a t o r s i z i n g techn iques .

Contemporary Sizing Practices

Although a utility does not have direct access to suppliers' data bases for

size selection, there are sizing models, to be discussed later, which are

available to a utility. Of course, any model is only as good as its data

input and data base. Recognizing the limited precipitator sizing resources

available to the utility, a practical approach must be taken in order to

develop a minimum precipitator size with which the utility will be confident.

Considering the penalties associated with a failure to comply with applicable

regulations, it is absolutely essential that the utility be confident in its

selected precipitator size. This confidence can be generated either by

development of a utility's own sizing procedures, selecting only qualified

suppliers to bid on the project, by extended performance warranties, or by

increased levels o f financial liability on the part of the suppliers. Over

the years, these techniques have been employed either singly or in discrete

combinations. The utility should consider using all of these techniques to

increase the probability of successful precipitator operation.

sizing procedure is to employ all of the following techniques t

consensus size:

Empirical models based on units firing the same or simi

Mathematical simulation models

Test burns in full or pilot size units

Size selections developed by qualified manufacturers.

A prudent

o develop a

lar coal

These techniques will result in distinct sizing factors for each case studied. It is still the responsibility of the utility to identify the

performance level required for a particular coal and ultimately to select the

size which i s believed to attain the objective. This responsibility leads to

a consensus size approach with a guiding rule that the minimum size to be

considered would never be less than the largest size submitted by the

qualified supplier. This largest size, i f significantly different from those

of other suppliers, must be thoroughly examined by a utility to ensure its

a p p l i c a b i l i t y t o t h e p r o j e c t . O f c o u r s e , t h e s i z e s e l e c t i o n process occurs

p r i o r t o a " r e q u e s t f o r p roposa ls . " Once t h e u t i l i t y e s t a b l i s h e s a minimum

p r e c i p i t a t o r s i z e and t h e n a p p l i e s d e s i g n marg ins , as d i s c u s s e d below, t h e

minimum d e s i g n s i z e i s then e s t a b l i s h e d . T h i s minimum d e s i g n s i z e i s then s e t

f o r t h i n t h e d e s i g n s p e c i f i c a t i o n s w i t h i n s t r u c t i o n s t o t h e b i d d e r s t h a t any

o f f e r i n g wh ich does n o t e x a c t l y con fo rm t o t h i s minimum w i l l be t h o r o u g h l y

rev iewed .

PARAMETER SELECTION

Coa l , f l u e gas, and f l y ash parameters a r e c r i t i c a l i n p u t d a t a t o any f l y ash

p r e c i p i t a t o r s i z i n g procedure. Severa l s i z i n g p rocedures a r e used i n t h e

p r e c i p i t a t o r i n d u s t r y . Two p rocedures a r e d e s c r i b e d be low w i t h examples, and

a comb ina t ion o f procedures i s s t r o n g l y recommended. No p rocedure w i l l g i v e

r e l i a b l e answers w i t h o u t r e l i a b l e d a t a on v a r i o u s c o a l s t h a t may be f i r e d and

r e l i a b l e d a t a on t h e f l u e gas and f l y ash t h a t t h o s e c o a l s p roduce . The

f o l l o w i n g subsec t ions d i s c u s s pa ramete r s e l e c t i o n f o r :

t h e f l u e gas e n t e r i n g t h e p r e c i p i t a t o r (volume f l o w , v e l o c

tempera tu re , w a t e r and s u l f u r t r i o x i d e c o n c e n t r a t i o n ) and

i t y , and

t h e f l y ash e n t e r i n g t h e p r e c i p i t a t o r ( t o t a l i n l e t mass load ing ,

p a r t i c l e s i z e d i s t r i b u t i o n , b u l k e l e c t r i c a l r e s i s t i v i t y . )

Des iqn Coal P r o p e r t i e s

The s t a r t i n g p o i n t i n f l y ash p r e c i p i t a t o r s i z e s e l e c t i o n i s a s p e c i f i c a t i o n

o f t h e v a r i o u s c o a l s t h a t may be f i r e d ove r t h e l i f e t i m e o f t h e p r e c i p i t a t o r .

I n a d d i t i o n t o t h e coa l h e a t i n g v a l u e ( B t u / l b ) , necessary c o a l d a t a a r e

o b t a i n e d i n a s tandard u l t i m a t e a n a l y s i s ( C , Hz, N2, S, H 0, O2 and 2 ash, by w e i g h t pe rcen t ) . I f f a m i l i a r c o a l s a r e t o be f i r e d a t a new

i n s t a l l a t i o n , these d a t a may be r e a d i l y a v a i l a b l e . I f a new c o a l f i e l d i s t o

b e mined, e x t e n s i v e t e s t b o r i n g s must be pe r fo rmed t o o b t a i n c o a l samples f o r

l a b o r a t o r y t e s t s . A d e t a i l e d map o f t h e v a r i a t i o n i n c o a l p r o p e r t i e s over t h e

new coa l f i e l d w i l l be developed. Fo r r e p r e s e n t a t i v e c o a l samples, f l y ash

p r o p e r t i e s t h a t a r e c r i t i c a l t o p r e c i p i t a t o r per formance m u s t b e determined.

The p r o p e r t i e s i n c l u d e t h e b u l k e l e c t r i c a l r e s i s t i v i t y o f a c o l l e c t e d f l y ash

l a y e r and t h e d f s t r i b u t i o n o f p a r t i c u l a t e mass among t h e f i n e p a r t i c l e s i z e s .

These d a t a and t h e i r e f f e c t s on p r e c i p i t a t o r per formance a r e d i scussed i n

d e t a i l below.

Rel i ab l e p a r t i c l e s i z e d i s t r i b u t i o n s f o r p r e c i p i t a t o r s i z ing can be obtained

only by in s i t u measurements during a t e s t burn o f t he coal i n a b o i l e r

s i m i l a r t o t h e p ro j ec t ed i n s t a l l a t i o n . I f a p i l o t - s c a l e t e s t burn i s used,

p a r t i c l e s i z e da t a from the p i l o t - s c a l e furnace must have been previous ly

c a l i b r a t e d aga ins t d a t a from a f u l l - s c a l e b o i l e r . In s i t u measurements of t he

c o l l e c t e d f l y ash r e s i s t i v i t y should be performed during a p i l o t - s c a l e o r

f u l l - s c a l e t e s t burn. These measurements shou7d be compared with r e s u l t s from

l a b o r a t o r y t e s t s from simulated f l u e gas environment and with numerical

e s t i m a t e s based on t h e mineral a n a l y s i s of t h e f l y ash and t h e c o n s t i t u e n t

a n a l y s i s of the f l u e gas. A numerical c o r r e l a t i o n of labora tory t e s t da t a i s

avai 1 a b l e f o r e s t ima t ing t h e f l y ash e l e c t r i c a l r e s i s t i v i t y from core-bore

sample d a t a ( I 3 ) . However, coal ash ( r a t h e r than f l y ash) samples do not y i e l d

meaningful labora tory measurements of r e s i s t i v i t y .

A t y p i c a l r e s u l t of pre l iminary coal and ash ana lyses i s a map showing such

wide v a r i a t i o n s i n c r i t i c a l p rope r t i e s a s t o cause wide v a r i a t i o n s i n

p r e c i p i t a t o r s i z e s e l e c t i o n . I f t h e des igner focuses on the worst-case

coa? /ash combinations, t h e . r e s u l t w i l l be a p r e c i p i t a t o r which i s oversized

and uneconomical) f o r a l l but a small por t ion o f t h e pro jec ted opera t ing

expe r i ence . Therefore , a numerical p r o b a b i l i t y of use must be assigned t o

va r ious c o a l s , o r t o var ious p a r t s of a new coal f i e l d . Then a r e s t r i c t e d

worst-case coal /ash combi nat ion w i ? 1 be s e l e c t e d a t some boundary of

cumulat ive p r o b a b i l i t y o f use t h a t i s below 99.99 percent . The adverse e f f e c t

on p r e c i p i t a t o r performance of coal/ash combinations t h a t l i e beyond t h i s

boundary e n t e r s i n t o t h e s e l e c t i o n of s a f e t y margins in a p r e c i p i t a t o r s i z ing

p r o c e d u r e ( g f .

The numerical example of a 0 .6 percent s u l f u r , western subbituminous coal i s

used throughout t h i s s ec t ion t o i l l u s t r a t e t he coal and ash parameters t h a t

a r e c r i t i c a l t o p r e c i p i t a t o r s i z i n g . Two d i f f e r e n t numerical procedures a r e

used t o s i z e a p r e c i p i t a t o r t o c o l l e c t f l y ash from f i r i n g t h a t coal i n a

500 MW e l e c t r i c gene ra t ing p l a n t . The as-received u l t imate a n a l y s i s f o r t he

example coal i s given i n Table 3-1.

Table 3-1

An Example S to i ch iome t r i c Combustion Ca l cu la t i on f o r a Western Subbituminous Coal and P r e d i c t i o n o f Flyash R e s i s t i v i t y

R e s i s t i v i t y p r e d i c t i o n based on work done by Dr. Roy B icke lhaupt o f Southern Research I n s t i t u t e . The Research was sponsored by the P a r t i c u l a t e Technology Branch, I n d u s t r i a l Environmental Research Laboratory of t h e Environmental P ro tec t i on Agency, Dr . L. E. Sparks, P r o j e c t O f f i c e r .

Hz0 Ash

As Received U l t i m a t e Coal

Ana l ys i s

Western Subbituminous Coal

Moles Per 100 Lb.

Required f o r Combustion Moles/100 Lb Fuel a t 100% To ta l A i r

Fuel 02 - Dry A i r

Required f o r Combustion Moles/ l00 Lb Fuel a t 30% Excess A i r

02 - Dry A i r

O2 and A i r x 130/100 T o t a l 7.067 33.635 Excess A i r 7.762 Excess 0 1.631

Products o f Combustion To ta l

Moles/100 % By Val % By Vol Lb Fuel Wet Basis Dry Basis

c02 4.854 13.337 14.663 H20 3.290 9.041 0.000 SO, 0.019 0 .052 0.057 li 2 26 -601 73.089 80.353 0 2 1.631 4.481 4.927 Sum Wet 36.395 Sum Dry 33.105

H 20 9.0% so 2 570 PPM so s 2.3 PPM

Table 3-1 (Con t inued)

C o r r e c t e d Ash Ash

A n a l y s i s A n a l y s i s

Sum o f L i t h i u m and Sodium Atomic C o n c e n t r a t i o n s Sum o f Magnesium and Calc ium Atomic C o n c e n t r a t i o n s I r o n A tomic C o n c e n t r a t i o n Po tass ium Atomic C o n c e n t r a t i o n

SO3 E f f e c t C a l c u l a t e d For Western Ash

Temp 100/T(OK) &

A t o m i c C o n c e n t r a t i o n

A s t o i c h i o m e t r i c combust ion c a l c u l a t i o n , assuming 30 p e r c e n t excess a i r ,

p r e d i c t s t h a t t h i s c o a l w i l l produce 9.0 p e r c e n t by volume w a t e r vapor i n t h e

f l u e gas and 570 ppm SO2, as shown i n Tab le 3-1. Combustion excess a i r

l e v e l s n o r m a l l y range f rom 20 t o 35 p e r c e n t .

F l u e Gas Volume Flow

The volume o f f l u e gas f rom any b o i l e r must be de te rm ined t o a c c u r a t e l y s i z e

t h e p r e c i p i t a t o r . G e n e r a l l y t h e s i z e o f t h e b o i l e r i s d e t e r m i n e d f rom h e a t

ba lances and knowing t h e amount o f e l e c t r i c a l power t o b e genera ted . Once t h e

b o i l e r s i z e has been determined, t h e f l u e gas volume can be d e t e r m i n e d by

combusion a n a l y s i s f o r the f u e l s wh ich w i l l b e burned.

The combust ion a n a l y s i s method uses t h e u l t i m a t e a n a l y s i s o f t h e f u e l t o

de te rm ine t h e p r o d u c t s o f combust ion. Each pound o f carbon, hydrogen, and

s u l f u r i s m u l t i p l i e d by a p p r o p r i a t e f a c t o r s t o a r r i v e a t t h e pounds o f oxygen

r e q u i r e d f o r combust ion. A t y p i c a l combust ion c a l c u l a t i o n shee t i s g i v e n as

T a b l e 3-2. Combustion a i r m o i s t u r e i s sometimes assumed t o be .013 l b s of

w a t e r p e r l b o f d r y a i r o r 60 p e r c e n t r e l a t i v e h u m i d i t y . Excess a i r f o r t h e

complete combust ion o f t h e f u e l must be added t o t h e combust ion a i r r e q u i r e d .

F l u e gas volume u n i t s can be expressed i n A c t u a l Cubic F e e t (ACF), o r Standard

Cubic Fee t (SCF). B o i T e r and a i r q u a l i t y c o n t r o l equipment d e s i g n n o r m a l l y

c o n s i d e r s ACF. A c t u a l c u b i c f e e t volume i s t h e gas volume a t t h e a c t u a l

t empera tu re and p r e s s u r e o f t h e gas. S tandard c u b i c f e e t volume i s r e f e r r i n g

t o a s tandard c o n d i t i o n f o r tempera tu re and p ressure . S t a n d a r d p r e s s u r e and

tempera tu re i s g e n e r a l l y 14.7 p s i a and 60°F. However, s t a n d a r d tempera tu re

may be 80°F, 68OF, o r 32OF and shou ld a lways be d e f i n e d when u s i n g t h e SCF

n o t a t i o n .

The p e r f e c t gas law shou ld be used t o c o r r e c t gas volumes. F o r example:

Where: PA = A c t u a l p ressure i n PSIA

TA = A c t u a l t empera tu re i n OF

SCF = Standard c u b i c f e e t volume (14.7 p s i a and 60°F)

Gas volume i s a l s o a f f e c t e d by a i r leakage i n t o t h e b o i l e r and a i r h e a t e r .

Some b o i l e r m a n u f a c t u r e r s use 10 p e r c e n t gas i n - l e a k a g e f o r a i r h e a t e r leakage

r a t e . T h i s a d d i t i o n a l gas volume must be p rocessed by t h e p r e c i p i t a t o r and

shou ld be n o t e d by t h e b o i l e r manu fac tu re r p r i o r t o d e s i g n i n g t h e p r e c i p i t a t o r .

P r e c i p i t a t o r Gas V e l o c i t y

Given a v a l u e o f volume gas f l o w , t h e average gas v e l o c i t y e n t e r i n g t h e

p r e c i p i t a t o r i s de te rm ined b y t h e f a c e a rea o f t h e p r e c i p i t a t o r . Lower d e s i g n

va lues o f gas v e l o c i t y r e q u i r e g r e a t e r p r e c i p i t a t o r f a c e area and p o s s i b l y

aggrava te prob lems w i t h g r a v i t a t i o n a 7 s e t t l i n g o f f l y ash i n t h e i n l e t

nozz les . H i g h e r d e s i g n v a l u e s o f gas v e l o c i t y r e q u i r e g r e a t e r p r e c i p i t a t o r

l e n g t h ( f o r t h e same gas t r e a t m e n t t i m e ) and p o s s i b l y l e a d t o prob lems o f

r e e n t r a i n i n g c o l l e c t e d f l y ash. R e e n t r a i n i n g c o l l e c t e d f l y ash may become a

s e r i o u s l i m i t a t i o n on p r e c i p i t a t o r per formance i f t h e f l y ash r e s i s t i v i t y

f a l l s be low a b o u t 2x10' ohm-cm; t h e corona c u r r e n t i s n o t u n i f o r m l y

d i s t r i b u t e d o v e r t h e c o l l e c t i n g p l a t e a rea or t h e f l y ash has a h i g h carbon

c o n t e n t . O p e r a t i n g e x p e r i e n c e has shown t h a t optimum va lues o f f l u e gas

v e l o c i t y i n a p r e c i p i t a t o r a r e u s u a l l y i n t h e range o f 3 f t / s t o 5 f t / s . Fo r

l o w - r e s i s t i v i t y f l y ash, a d e s i g n e r shou ld work a t t h e l o w e r end o f t h i s

v e l o c i t y range.

E q u a l l y as i m p o r t a n t a s t h e average v a l u e o f gas v e l o c i t y i s a u n i f o r m

d i s t r i b u t i o n o f gas v e l o c i t y o v e r t h e f a c e o f a p r e c i p i t a t o r . Lower average

v e l o c i t y can o f f s e t v e l o c i t y m a l d i s t r i b u t i o n . The degrad ing e f f e c t on

p r e c i p i t a t o r pe r fo rmance o f r e g i o n s of h i g h gas v e l o c i t y i s n o t compensated by

o t h e r r e g i o n s o f l o w gas v e l o c i t y . T h i s i s due t o t h e f a c t t h a t t h e

r e e n t r a i n m e n t o f f l y ash caused by t h e h i g h v e l o c i t y gas i s n o t compensated

f o r by t h e a reas o f l o w gas v e l o c i t i e s . W i t h a non-un i form gas v e l o c i t y

d i s t r i b u t i o n , a reas o f h i g h gas v e l o c i t y can cause excess ive r e e n t r a i n m e n t o f

f l y a s h . The h i g h e r c o l l e c t i o n e f f i c i e n c y t h a t occu rs i n t h e co r respond ing

a reas o f l ower gas v e l o c i t y does n o t compensate f u l l y f o r t h e e x c e s s i v e

r e e n t r a i n m e n t . T h i s f a c t can r e s u l t i n a degraded o v e r a l l p r e c i p i t a t o r

per formance. Common causes o f poor gas v e l o c i t y d i s t r i b u t i o n i n o l d e r

p r e c i p i t a t o r s a r e p o o r gas f l o w d i s t r i b u t i o n due t o inadequate t u r n i n g vanes

i n t h e i n l e t and o u t l e t d u c t s , p lugged, warped o r eroded d i f f u s e r p l a t e s , o r

deep beds o f s e t t l e d f l y ash i n i n l e t nozz les .

The gas velocity distribution is quantified by a matrix of measurements of gas

velocity over the face of the precipitator--inside the box, under air load.

The normalized standard deviation of the distribution ( a ) is calculated 9

as the standard deviation of the matrix of measurements divided by the average

value. An IGCX standard sets an upper limit of 0.25 for a Proper 9'

design in modern precipitators achieves a value of about 0.15. Scale-model

air flow measurements are essential to the design of inlet and outlet ducts

and nozzles to the design of baffles inside the box. The importance of this

part of the precipitator design process cannot be overemphasized (L,?,?).

Geometrical relationships in the mechanical design of one electrical section

of a precipitator are shown in Figure 3-1.

Vol m e Flow = Velocity x Face Area ( 3 - 2 ) = Velocity x Plate Height x N x Plate Spacing (3-3)

A design value of average gas velocity determines the precipitator face area.

Given manufacturing design standards of plate height and plate spacing, the

only remaining variable for adjusting the design value o f average gas velocity

i s the number of parallel gas passages (N). The specific collection area

(SCA) of one electrical section is given by

Section SCA = Section Plate Area Volume Flow

- - 2N x Plate Height x Plate Length Volume Flow

The only remaining variable for adjusting the SCA of one electrical section i s

the total plate length, or the number of standard plate sections used

end-to-end along each gas passage.

For example, the design of a precipitator to collect fly ash from western

subbituminous coal with a total volume gas flow of 1,760 kacfm can be divided

into eight precipitator chambers. Each electrical chamber is designed to

N GAS PASSAGES

/ - GAS FLOW

b- PLATE SPACING

Figure 3-1. Geometrical Parameters in the Mechanical Design of One P r e c i p i t a t o r Section

1 PLATE

HEIGHT

1

handle 220 kacfm at an average gas velocity of 4 ft/s. Therefore, the face

area of each electrical field i s 916.67 ft2. The plates are 41.67 ft high,

and there are 22 parallel gas passages with 12-inch plate spacing per bus

section. The section length is chosen to be 12.0 ft. This gives a total

plate area of 22,000 ftz and an SCA of 100 ft2/kacfm for each electrical

chamber.

Inlet Mass Loading

The total mass loading of fly ash at the precipitator inlet can be obtained

from a stoichiometric combustion calculation, given assumptions about excess

air in combustion, percent fly ash carryover, and air in-leakage ahead of the

precipitator. Assuming 85 percent fly ashcarryover and no air in-leakage, the

combustion calculation i n Table 3-1 yields.

0.85 (0.117 lb,ash/lb,coal) (7000 qrain/lb)

0.331 lb mole,gas 359ft3- 273 + 20

( lb, coal ) (lb mole, PC ( 273 1

which equals 5.46 grain/dscf (20°C). In terms of Ib/MBtu, the combustion

calculation yields (4)

Calculations of this sort are not very reliable because of the

uncertainties in the severai assumptions. One alternative is a

empirical correlation of measured mass loading with the percent

coal. Figure 3-2 shows such a corr~lation of data from 28

large

purely

ash in the

pulverized-coal-fired utility boilers ( 5 ) . The calculated value 5.46 gr/dscf

lies above the upper margin of scatter i n the data in Figure 3-2. The data

include actual effects of air in-leakage.

For example design of a precipitator to collect fly ash from a western

sub-bituminous coal, an inlet mass loading of 10 lb/MBtu is assumed. The

value corresponds to 5.46 grain/dscf (20°C), or 3.5 grain/acf of wet flue gas

at 290°F (143T). To meet an outlet emission standard of 0.03 Ib/MBtu, a

precipitator collection efficiency of 99.7 percent is required.

PERCENT ASH IN COAL

F i g u r e 3-2. Tota l Mass Loading of Fly Ash from 28 Coals versus the Percent Ash i n the U l t imate Coal Analysis

PARTICLE DlAMETER,pm

Figure 3-3. Average P a r t i c l e S i z e D i s t r i b u t i o n o f F ly Ashes from 17 Bituminous C o a l s and 16 Subb i tuminous C o a l s

Inlet Particle Size Distribution

A utility fly ash precipitator typically has minimum collection efficiency

(maximum penetration) for particles of diameter somewhere in the range of

0.1 vm to 1.0 un. Therefore, a specification of particulate mass

concentration in the submicrometer particle size range is needed for a

reliable estimate of overall mass collection efficiency. Furthermore,

particle diameters around 0.55 pm lie in the middle of the wavelength range

of visible light. The light scattered by escaping submicrometer particles is

the major cause of plume opacity. The loss of particles larger than a few

micrometers is due almost entirely to the reentrainment of large-particle

agglomerates. Reentrainment loss is typically around 10 pm particle

diameter (maximum).

Particle size distribution measurement by centrifugal separation (BAHCO) is a

standard laboratory technique. The data are obtained in the form of

cumulative percentages of the total m a s s that are contained in particles o f

diameter less than a sequence of cutpoints, typically over the range of I pm to 30 urns. These data are easy to obtain and give a rough measure of

particulate characteristics. Because the lowest cutpoint is about 1 pm,

however, these measurements have limited value in any estimate of collection

efficiency of a fly ash precipitator. Cascade impactors are routinely used

far sampling fly ash particle size distribution in situ. This technique

requires highly ski Iled operators for both aerosol sampling and data reduction

@,I , ! ) . Under ideal conditions, impactor data can be extrapolated from the

lowest cutpoint (typically around 0.3 pm down to about 0.1 ~m). Thus, the

most reliable aerosol data for sizing a new precipitator are obtained by

cascade impactor sampling during a test burn of the design coal in a boiler

that is similar to the projected installation,

Cascade impactor data have been reported from field tests of the aerosol from

33 pulverized-coal-fired utility boilers (5). There are 17 bituminous coals

and 16 subbituminous coals in this data base. The average data are plotted on

log-probability graph paper in Figure 3-3, for the particle diameter range

1 urn to 10 pms. For both data sets, the average values of cumulative

percent mass lie almost exactly along a log-normal distribution--a straight

line on the log-probability graph paper. However, there are large variations

in t he da t a f o r f l y ash from western subbituminous c o a l s , a s ind ica ted by t h e

wide e r r o r ba r s . For f l y ash from bituminous c o a l s , t he d a t a in Figure 3-3

can be used a s a f i r s t es t imate of t h e i n l e t p a r t i c l e s i z e d i s t r i b u t i o n ,

ex t r apo la t i ng down t o 0.1 prn along the f i t t e d log-normal

s t r a i g h t l i n e . The log-normal parameters a r e M M D = 16.3 pm, and a = 3 .4 .

Several measured p a r t i c l e s i z e d i s t r i b u t i o n s (cascade impactor da t a ) f o r f l y

ash from western subbituminous coa l s a r e p lo t t ed on log -p robab i l i t y graph

paper in Figure 3-4 ( 9 ) . The curve marked "Wyoming" i s an average p a r t i c l e

s i z e d i s t r i b u t i o n t h a t was used in an economic ana lys i s of u t i l i t y f l y ash

p r e c i p i t a t o r s (2). Figure 3-4 shows t h a t most measured p a r t i c l e s i z e

d i s t r i b u t i o n s do not l i e along a log-normal s t r a i g h t l i n e . For a numerical

example of p r e c i p i t a t o r s i z i n g , however, t he s t r a i g h t l i n e marked with the

log-normal parameters MMD = 21 .1 pm, and a = 4 . 8 i s used in t h e

following s e c t i o n s . This s t r a i g h t l i n e i s the f i t t e d mean l i n e shown in

Figure 3-3 f o r f l y ash from 16 western subbituminous c o a l s ( 5 , l O ) .

Estimates of p r e c i p i t a t o r performance can be made using t h e average p a r t i c l e

s i z e d i s t r i b u t i o n shown in Figure 3-3 ( a s in t he numerical example being

ca r r i ed ou t ) o r , p r e f e rab ly , using a p a r t i c l e s i z e d i s t r i b u t i o n measured

during a t e s t burn of the design coal in a s imi l a r b o i l e r . I t should be

noted, however, t h a t p a r t i c l e s i z e d i s t r i b u t i o n s a r e t y p i c a l l y not used in b i d

s p e c i f i c a t i o n s and performance guarantees. A performance guarantee should not

be based on p a r t i c l e s i z e d i s t r i b u t i o n because i t i s very d i f f i c u l t e i t h e r t o

measure o r t o cont ro l p a r t i c l e s i z e d i s t r i b u t i o n .

Fly A s h R e s i s t i v i t y

The amount of useful e l e c t r i c a l power t h a t can be supplied t o a p r e c i p i t a t o r

i s l im i t ed f o r t he most p a r t by the e l e c t r i c a l r e s i s t i v i t y of t he f l y ash

l aye r on t h e c o l l e c t i n g p l a t e s . The corona cu r r en t from t h e high vol tage

d ischarge e l e c t r o d e s flows through co

ground. The product o f f l y ash r e s i s

cu r r en t d e n s i t y ( j , A/cmZ) gives the

within t h e c o l l e c t e d f l y ash ( E = p j ,

r e s i s t i v i t y o r

l l e c t e d f l y ash t o reach an e l e c t r i c a l

t i v i t y ( p , ohm-crn) and local p l a t e

loca l value of average e l e c t r i c f i e l d

volt/cm). In t he l i m i t of high

0.1 0.2 0.4 0.6 0.8 1.0 2, 4. 6. 8. 10.0 20. 40. 60. 80. 100.0

PARTICLE DlAMETER {MICROMETERS)

Figure 3-4. P a r t i c l e S ize D i s t r i b u t i o n s o f Fly Ashes f r o m Western Subbi tuminous C o a l s

h i g h c u r r e n t d e n s i t y , t h e e l e c t r i c f i e l d w i t h i n t h e c o l l e c t e d f l y ash becomes

h i g h enough t o i n i t i a t e e l e c t r i c a l breakdown, c a u s i n g s p a r k i n g and/or back

co rona .

W i t h f l y ash o f h i g h r e s i s t i v i t y ( 2 ~ 1 0 ' ~ ohm-cm, f o r example) e l e c t r i c a l

breakdown may b e g i n w i t h a c u r r e n t d e n s i t y as l o w as 2 nA/cm2, o r an average

e l e c t r i c f i e l d abou t 4 kV/cm w i t h i n t h e c o l l e c t e d f l y ash. The breakdown

e l e c t r i c f i e l d r a r e l y exceeds 10 t o 15 kV/cm. The breakdown p o i n t i s so low

i n v o l t a g e on a t y p i c a l secondary V- I c u r v e t h a t t h e i n t e r e l e c t r o d e e l e c t r i c

f i e l d i s i n s u f f i c i e n t t o cause a spark t o p ropaga te f r o m t h e f l y ash l a y e r t o

t h e d i s c h a r g e e l e c t r o d e . I n s t e a d , p o i n t s o f p o s i t i v e corona d i s c h a r g e (back

corona) f o r m i n t h e f l y ash l a y e r , growing i n number and i n t e n s i t y w i t h

i n c r e a s i n g secondary c u r r e n t . S t a b l e p o i n t s o f i n t e n s e back corona a c t i n t h e

same way as need le p o i n t s on t h e h i g h v o l t a g e d i s c h a r g e e l e c t r o d e . Back

co rona has a r e g e n e r a t i v e feedback e f f e c t on t h e h i g h v o l t a g e

corona d i s c h a r g e , caus ing a runaway V-1 c u r v e i n wh ich t h e c u r r e n t i s l i m i t e d

by t h e e x t e r n a l c i r c u i t o f t h e T-R s e t .

W i th f l y ash o f l o w r e s i s t i v i t y , t h e u s e f u l e l e c t r i c a l power s u p p l i e d t o t h e

p r e c i p i t a t o r i s l i m i t e d by s p a r k i n g . ( W i t h modern T-R s e t c o n t r o l l e r s and a

c o n s e r v a t i v e l y l a r g e p r e c i p i t a t o r , however, t h e e l e c t r i c a l power i n p u t may be

s e t w e l l be low spark l i m i t f o r reasons o f energy conserva t ion . ) A t t h e same

t i m e , c o l l e c t e d f l y ash p a r t i c l e s q u i c k l y l o s e t h e i r charge, and t h e

e l e c t r i c a l h o l d i n g f o r c e on t h e c o l l e c t e d f l y ash i s g r e a t l y d i m i n i s h e d . W i t h

d e c r e a s i n g f l y ash r e s i s t i v i t y , excess ive r e e n t r a i n m e n t becomes t h e l i m i t on

p r e c i p i t a t o r per formance. Opera t ing e x p e r i e n c e has shown t h a t t h e

p r e c i p i t a t o r per formance may be s e r i o u s l y l i m i t e d by t h e f l y ash r e s i s t i v i t y

i f t h e va :w f a l l s be low 2x109 ohm-cm.

The e l e c t r i c a l r e s i s t i v i t y o f f l y ash f r o m t h e d e s i g n c o a l may be de te rm ined

by measurements i n s i t u d u r i n g a t e s t bu rn (g), b y l a b o r a t o r y measurements

pe r fo rmed on f l y ash samples f rom a t e s t burn, o r f r o m e s t i m a t e s based on t h e

m i n e r a l ana lyses o f c o a l ash samples f r o m t e s t b o r i n g s (11,12,23) (see

Manual 111). A t f l u e gas temperatures be low 350°F, f l y ash r e s i s t i v i t y can be

s t r o n g l y a f f e c t e d by w a t e r vapor and s u l f u r t r i o x i d e vapor . T h e r e f o r e ,

l a b o r a t o r y measurements must be p e r f o r m e d i n a s i m u l a t e d f l u e gas

env i ronment . A c o m b i n a t i o n o f methods i s recommended. Comparing r e s u l t s from

d i f f e r e n t methods can be v e r y i m p o r t a n t i n r e v e a l i n g unexpected anomal ies i n

f l y ash r e s i s t i v i t y . I t shou ld be n o t e d t h a t l a b o r a t o r y measurements

per formed on c o a l ash samples do n o t g i v e a r e l i a b l e i n d i c a t i o n o f f l y ash

r e s i s t i v i t y .

A mathemat ica l model has been deve loped f r o m c o r r e l a t i o n s o f l a b o r a t o r y

r e s i s t i v i t y measurements w i t h gas c o n s t i t u e n t ana lyses and t h e m i n e r a l

ana lyses o f 35 d i f f e r e n t f l y ashes (13). - The computer l i s t i n g s o f t h i s model

a r e p u b l i s h e d i n an E P R I r e p o r t (23). The model shou ld b e used w i t h c a u t i o n

f o r f l y ashes whose c h a r a c t e r i s t i c s l i e o u t s i d e t h e range o f t h e d a t a base.

W i t h c o a l ash samples, a r e - i g n i t i o n a t 1050°C i s recommended b e f o r e o b t a i n i n g

t h e m i n e r a l a n a l y s i s . The e l e m e n t a l ash c o n s t i t u e n t s t h a t c o r r e l a t e s t r o n g l y

w i t h f l y ash r e s i s t i v i t y a r e Na, K, Fe, Ca, and Mg. The measured c o r r e l a t i o n

o f r e s i s t i v i t y w i t h SO3 vapor i s o b t a i n e d a f t e r s u f f i c i e n t exposure t i m e a t

a f i x e d t e m p e r a t u r e f o r t h e r e s i s t i v i t y v a l u e t o s t a b i l i z e . The e l a p s e d

exposure t i m e t o e q u i l i b r i u m i s t y p i c a l l y much g r e a t e r w i t h SO3 t h a n w i t h

H 2 0 Ashes o f h i g h a l k a l i n i t y can a d s o r b c o n s i d e r a b l e SO3 f r o m t h e gas

b e f o r e ash r e s i s t i v i t y b e g i n s t o be a f f e c t e d . There fo re , t h e p r e d i c t e d

c o r r e l a t i o n o f r e s i s t i v i t y w i t h SO i n f l u e gas i s based on t h e r e s i d u a l 3 l e v e l o f SO3 t h a t remains i n e q u i l i b r i u m w i t h t h e f l y ash.

Tab le 3 -1 shows a p r i n t o u t f r o m t h e mathemat i ca l model o f f l y ash r e s i s t i v i t y

(13). The i n p u t d a t a a r e t h e u l t i m a t e a n a l y s i s o f t h e example wes te rn

subbi tuminous c o a l and t h e m i n e r a l a n a l y s i s o f t h e f l y ash, o r r e - i g n i t e d coa l

ash. C o n c e n t r a t i o n s o f H20 and SO2 i n t h e f l u e gas a r e o b t a i n e d f rom a

s t o i c h i o m e t r i c combust ion c a l c u l a t i o n , assuming 30 p e r c e n t excess a i r . From a

sma l l base o f f i e l d t e s t d a t a , t h e mathemat i ca l model e s t i m a t e s a r a t i o o f

2 .3 ppm SO3 t o 570 ppm S O p F o r t h i s h i g h l y a l k a l i n e f l y ash, however, a

reasonab ly c o n s e r v a t i v e assumpt ion i s t h a t a smal l c o n c e n t r a t i o n o f SO3 w i l l

be c o m p l e t e l y absorbed by f l y ash p a r t i c l e s w i t h o u t r e d u c i n g t h e r e s i s t i v i t y

o f t h e c o l l e c t e d f l y ash l a y e r . Assuming t h a t no SO3 remains i n e q u i l i b r i u m

i n t h e f l u e gas, t h e mathernat ica? model p r e d i c t s a r e s i s t i v i t y , RHO(VS), o f

2 x 1012 ohm-cm a t f l u e gas tempera tu re 290°F. For f u r t h e r i n f o r m a t i o n

r e f e r t o (13).

E l e c t r i c a l Operating Poin ts

The design value of f l y ash r e s i s t i v i t y i s t he b a s i s f o r es t imat ing

e l e c t r i c a l opera t ing po in t s i n each e l e c t r i c a l s ec t ion of a p r e c i p i t a t o r .

E l e c t r i c a l opera t ing po in t s s t rong ly inf luence t h e s i z e of t he p r e c i p i t a t o r

t h a t i s requi red t o achieve t h e des ign -pa r t i cu l a t e c o l l e c t i o n e f f i c i ency .

Numerical values of e l e c t r i c a l opera t ing po in t s a r e required t o es t imate

c o l l e c t i o n e f f i c i e n c y , f l u e gas opac i ty , and e : e c t r i c a l power consumption, and

t o spec i fy T-R s e t r a t i n g s and e l e c t r i c a l s e c t i o n a l i z a t i o n . The values of

secondary vol tage and cu r r en t dens i ty t h a t a r e a c t u a l l y useful in t he

p r e c i p i t a t i o n process a r e requi red t o es t imate c o l l e c t i o n e f f i c i ency and f l u e

gas opac i ty . I f a p r e c i p i t a t o r i s allowed t o opera te in a mode of severe

sparking o r back corona, t he ac tua l e l e c t r i c a l consumption can be very much

g rea t e r than useful power consumption. Modern T-R s e t c o n t r o l l e r s a r e

designed t o optimize t h e e l e c t r i c a l power consumption.

Estimated useful secondary e l e c t r i c a l operat ing p o i n t s versus i n s i t u

measurements of f l y ash r e s i s t i v i t y have been repor ted from 17 f i e l d t e s t s of

13 co ld-s ide u t i l i t y f l y ash p r e c i p i t a t o r s (g,E). (Four of the

p r e c i p i t a t o r s were t e s t e d with and without f l u e gas condit ioning t o reduce f l y

ash r e s i s t i v i t y . ) Measured va lues of r e s i s t i v i t y ranged from 2 x 10 10

t o 7 x lo1* ohm-cm. Mathematical c o r r e l a t i o n s of t he se da t a a r e given in

Table 3-3. For each e l e c t r i c a l f i e l d , the f i r s t equat ion c o r r e l a t e s useful

cu r r en t d e n s i t y with f l y ash r e s i s t i v i t y . The equat ion gives t he f i t t e d

o rd ina t e i n t e r c e p t value of both an average s t r a i g h t l i n e c o r r e l a t i o n and the

90% confidence l i m i t s . The second equation c o r r e l a t e s the useful cur ren t

dens i ty wi th t h e average i n t e r e l e c t r o d e e l e c t r i c f i e l d , E = AV/AX. Multiplying E by the wire-p la te spacing (within t he da ta base range of 4 .5 t o

6 . 0 i nches , 11.43 t o 15.24 cm) g ives an es t imate of opera t ing vol tage . The

c o r r e l a t i o n s in Table 3-3 a r e based on a l im i t ed s e t of da ta from

small-to-medium s i z e p r e c i p i t a t o r s . Like t he p a r t i c l e s i z e d i s t r i b u t i o n da t a

in Figure 3-3, however, they can be used t o advantage in t he absence of an

app rop r i a t e p rop r i e t a ry da t a base .

Because h i g h - r e s i s t i v i t y f l y ash can be expected t o severely l i m i t useful

e l e c t r i c a l power consumption, t h e example e l e c t r i c a l opera t ing poin ts given in

Table 3-3

Linear Least-Squares Fitting Parameters (With 90 Percent Confidence Levels) for the Relationships Between Ash Resistivity, Current Density, and Effective Interelectrode Electric Field in Each Electrical Section

Section 1

2 - loglO(J, nA/cm ) - (6.455 + 0.370) - 0.5013 loglO(p, ohm-cm) 2 - loglO(J, nA/cm ) - -3.5394 + 8.3841 loglo(E, kV/cm)

Section 2

2 - loglO(J, nA/cm ) - (6.839 + 0.360) - 0.5214 loglO(p, ohm-cm)

Section 3

2 - logl0(J, nA/cm ) - (5.497 + 0.304) - 0.3905 1 o g l 0 ( p , ohm-cm)

2 - logI0(J, nA/cm ) - -3.1735 + 8.5755 loglO(E, kV/cm)

Section 4

2 - loglO(J, nA/cm ) - (5.718 + 0.327) - 0.4005 loglO(p, ohm-cm) ioglO(J, nA/cmL) = -2.3438 + 7.5195 loglO(E, kV/crn)

Sections 5 and 6

loglO(J, n~/crnl ) = (3.328 1 0.306) - 0.1736 loglO(p, ohm-cm) 2 - loglO(J, nA/cm ) - -3.1818 + 10.0909 loglO(E, kV/cm)

Table 3-4 are conservatively estimated. That is, the estimates of useful

current density are calculated from the lower 90 percent confidence limits of

the data correlations in Table 3-3.

PRECIPITATOR SIZING MODELS

This section describes the use of three conventional numerical tools for

precipitator sizing:

the Deutsch-Anderson equation,

the Mstts-Ohnfelat equation, and

the EPA/SRI computer simulation.

The discussion includes numerical examples of the use o f these tools to size a

precipitator for collecting fly ash from a western subbituminous coal.

The Deutsch-Anderson Equation

The most fami.liar mathematical equation of electrostatic precipitation is the

Deutsch-Anderson collection efficiency equation

(- w A/V) Penetration Fraction (p) = e

- w A/V

Percent Efficiency ( q ) = 100 (1 - e 1 (3-6)

A/V is the ratio of collecting plate area to the volume gas flow. Omega

( w ) is the electrical migration velocity of charged fly ash particles of a

particular size.

It has been common practice in the precipitator industry to describe the

overall collection efficiency of a precipitator by the Deutsch-Anderson

equation. An effective value of w can be calculated from measured values

Table 3-4

Electrical Operating Po in ts f o r t he Example Western Subbituminous Coal

For the design of a precipitator with 12- inch plate spacing to collect fly ash of resistivity 2 x loL2 ohm-cm from the example western subbituminous coal, the data correlations i n Table 3-2 predict the following electrical operating points.

Section Voltage Current Density Current Number kV nA/cm2 mA/ft2 m A

- ( w k A/V) 0.5

Percent Penetration (P) = 100 e

of A/V and collection efficiency. When used in this way, however, w loses

its physical meaning and becomes an empirical data correlator. This type of

data correlation is not recommended for precipitator sizing. On the other

hand, the recommended methods of precipitator sizing are based on extensions

of the Deutsch-Anderson equation. (See Chapter 2 for greater detail.)

The Matts-Ohnfeldt Equation

A more appropriate measure of the overall collection efficiency of a fly ash

precipitator (a measure that is approximately independent of the size of t he

precipitator) is the parameter wk. This parameter appears in the Matts-

Ohnfeidt collection efficiency equation, sometimes called the modified Deutsch

equation (15).

In contrast to the Deutsch-Anderson equation, the Matts-Ohnfeldt equation was not mathematically derived from first principles. Instead, it was deduced by

analogy with the mathematical form of the exact integral collection efficiency

equation for an ideal log-normal particle size distribution. Thus, the

principal advantage of the Matts-Ohnfeldt equation is that it approximately

accounts for the strong effect of a polydisperse particle size distribution on

the overall collection efficiency of a precipitator. The general form for

this equation is:

k

Efficiency (n) = 100 (1 - e - (uk A/V) 1, (3-7)

Both the parameter wk, which has the physical dimensions of velocity, and

the exponent k are purely empirical parameters, determined by fitting

experimental data. For precipitators collecting fly ash from pulverized coal-

fired boilers, the value of the exponent k typically ranges between 0 . 4 and

0.6 (a reasonable estimate is k = 0.5). Then a percent penetration is given by:

and t h e v a l u e o f parameter w k can be e x t r a c t e d f rom a measurement o f p e r c e n t p e n e t r a t i o n as

I f A / V i s g i v e n i n u n i t s o f f t2 /ac f rn , 'k has u n i t s o f f t / m i n

P r e c i p i t a t o r performance d a t a t o be c o r r e l a t e d u s i n g t h e M a t t s - O h n f e l d t

e q u a t i o n can be p l o t t e d on unconven t iona l g raph paper , d e r i v e d as f o l l o w s :

a ) Take t h e n a t u r a l l o g a r i t h m o f t h e M a t t s - O h n f e l d t e q u a t i o n t o g e t

k log, (10O/P) = (wk A/V) .

b ) Take t h e common l o g a r i t h m t o g e t

c) Use commercial semi- log graph paper and p l o t A/V a long t h e l o g s c a l e .

d) Map a s c a l e o f loglO(loge (100/P)) o n t o t h e l i n e a r sca le by hand

c a l c u l a t i o n . The doub le l o g a r i t h m can be expanded over any c o n v e n i e n t

l i n e a r s c a l e b y a n o r m a l i z a t i o n c o n s t a n t .

An exampTe o f t h i s graph paper i s shown i n F i g u r e 3-5. I t s advantage i s t h a t

the M a t t s - O h n f e l d t e q u a t i o n appears as a s t r a i g h t l i n e . The s lope o f t h e

s t r a i g h t i s j u s t t h e exponent k, as shown i n e q u a t i o n (3-11). Three s t r a i g h t

dashed l i n e s a r e p l o t t e d on F i g u r e 3-5 f o r k = 0.5 and t h r e e va lues o f w k :

0.8, 1.1, and 1.5 f t / s . The v a l u e s o f c o l l e c t i o n e f f i c i e n c y o f p r e c i p i t a t o r s o f

d i f f e r e n t s i zes , b u t c o l l e c t i n g t h e same f l y ash, shou ld l i e a long a g i v e n

s t r a i g h t l i n e acco rd ing t o t h e Mat t s -Ohn fe ld t e q u a t i o n .

- DES

#

0

IGI

F i g u r e 3-5. P r e c i p i t a t o r Performance Data C o r r e l a t e d Using the Mat ts -Ohn fe ld t Equat ion

Figure 3-5 shows measured performance da ta from t h r e e p r e c i p i t a t o r s ( P l a n t s 8,

9, and 13) c o l l e c t i n g f l y ash from western subbituminous coa l s (10). The

unlabeled da t a poin ts a r e hypothe t ica l d a t a p o i n t s , used only t o i l l u s t r a t e

t he s i z i n g procedure. Fly ash r e s i s t i v i t y values measured in s i t u a r e given

in t he fol lowing t a b l e :

Plant R e s i s t i v i t y , ohm-cm -

Figure 3-5 shows t h a t t he t r end in decreas ing f l y ash r e s i s t i v i t y ( i n c r e a s i n g

useful e l e c t r i c a l power consumption) corresponds t o a t r end in i nc reas ing

values of w Figure 3-4 shows t h a t t h i s t r end corresponds a l s o t o k ' decreas ing concent ra t ion of t h e i n l e t mass loading among submicron p a r t i c l e s .

None of t h e t h r e e measured p a r t i c l e s i z e d i s t r i b u t i o n s i s r e a l l y c l o s e t o t he

example log-normal d i s t r i b u t i o n (Figure 3-41, but t h a t of Plant 9 i s c l o s e s t .

P lan t 9 has a more favorable p a r t i c l e s i z e d i s t r i b u t i o n ( t h a t i s , smal le r

concent ra t ion of mass in submicron p a r t i c l e s ) i n a d d i t i o n t o a lower f l y ash

r e s i s t i v i t y than the design va lue of 2x?012 ohm-cm. P l a n t 8 has a much l e s s

favorable p a r t i c l e s i z e d i s t r i b u t i o n nd a s i g n i f i c a n t l y higher f l y ash

r e s i s t i v i t y . The value of wk f o r t h e new p r e c i p i t a t o r should l i e between

the values f o r PTants 8 and 9 , but c l o s e r t o t h e value f o r P lan t 9 . A

reasonably conserva t ive e s t ima te f o r 99.7 percent c o l l e c t i o n e f f i c i e n c y i s an

SCA of 550 f t2/kacfm, a s shown in Figure 3-5. This design value of SCA does

not inc lude t h e necessary margins f o r ope ra t ing cont ingencies . Design margins

a r e d i s cus sed l a t e r i n this c h a p t e r .

The EPA/SRI Computer Simulation

Another method of p r e c i p i t a t o r s i z i n g uses t h e computer program (ESP MODEL)

developed by Southern Research I n s t i t u t e under sponsorship of the U. S.

Environmental Pro tec t ion Agency (16). The computer program mathematically

computes t h e charging and c o l l e c t i o n of f l y ash p a r t i c l e s t h a t t r ave l through

a s i n g l e gas passage of a p r e c i p i t a t o r . Each e l e c t r i c a l sec t ion o f t h e gas

passage is subdivided into small computational length increments, within each

of which the electrical conditions (including both ionic and particulate space

charge density) are approximately uniform. The inlet particle size

distribution is subdivided into small bands, within each of which the particle

size is approximately uniform. The ideal collection efficiency for each

psrticle size in each computational length increment i s calculated using the

Deutsch-Anderson equation. The bulk of the time required to execute the ESP

MODEL is used i n computing the particle charge and the collecting electric

field that are needed to compute the Deutsch migration velocity ( w ) , for

each particle size in each computational length increment. The computation of

ccl1ec~:on efficyency under ideal precipitator operating condirions is

followed by approximate corrections for the degrading effects of non-ideal gas

flow and rapping reentrainment. Corrections for rapping reentrainment are

based on the results of field tests of utility fly ash precipitators supported

by the Electric Power Research Institute (E).

The complete documentation of the ESP MODEL is available from the National Technical Information Service (NTIS) in two companion volumes, as well as the

FORTRAN code on magnetic tape (16). The first volume describes the physical

theory used in the model and the mathematical structure of the model. Each

FORTRAN variable is identified, and the complete FORTRAN listing is given. - !he second volume is a user's nanual. The manual describes each computation

option that is available to the user and each numerical parameter that must be

specified by the user. The manual contains twelve worked examples, using the

ESP MODEL, with complete listings of input data and output data.

A summary of experience in using the ESP MODEL to simulate the performance of

cold-side utility fly ash precipitators has been reported by Southern Research

institute (s, 18). A direct comparison of measured and computed collection

effjciency of 18 precipitators is shown in Figure 3-6. The ESP MODEL input

data for inlet particle size distribution and electrical operating points were

obtained by measurements on site. The horizontal error bars indicate the

range of scatter in day-to-day measurements of collection efficiency on site.

Plants 8, 9, and 13 in Figure 3-6 are the same as those in Figures 3-4 and

3-5.

MEASURED PENETRATION, %

MEASURED COLLECTION, %

Figure 3-6 . Measured Precipitator Col I e c t i o n E f f i c i e n c i e s Compared w i t h ESP MODEL Computations Us ing Measured Input Data , f o r 5% Gas Sneakage i n Each B a f f l e d Section and a = 0.75

9

same as

r e e n t r a

The ESP

The p l a n t s w i t h measured c o l l e c t i o n e f f i c i e n c y l e s s than about 97 p e r c e n t a r e

o u t l i e r s f rom t h e p e r f e c t agreement l i n e i n F i g u r e 3-6, as i s P l a n t 9 .

P l a n t s 3 , 7, 9 , and 11 o p e r a t e i n severe back corona. Es t ima ted va lues o f

u s e f u l v o l t a g e and c u r r e n t d e n s i t y ( e s t i m a t e d f r o m t h e measured V - I cu rves )

were used i n t h e mathemat ica l model ing. However, t h e computed c o l l e c t i o n

e f f i c i e n c y remained h i g h e r t h a n t h e measured c o l l e c t i o n e f f i c i e n c y . P l a n t 4

i s t h e same as P l a n t 3 , and P l a n t 1 2 i s t h e same as P l a n t 11, b u t t h e y were

t e s t e d w i t h f l u e gas c o n d i t i o n i n g t o e l i m i n a t e t h e back corona problem.

P l a n t s 22 and 25 s u f f e r e d e x c e s s i v e r e e n t r a i n m e n t o f f l y ash. P l a n t 26 i s t h e

P l a n t 22, b u t i t was t e s t e d under low- load c o n d i t i o n s t o e l i m i n a t e t h e

inmen t problem.

MODEL i n p u t d a t a i n c l u d e a s p e c i f i c a t i o n o f t h e f r a c t i o n a l gas

sneakage ( S ) w i t h i n each b a f f l e d s e c t i o n and t h e n o r m a l i z e d s tandard d e v i a t i o n

(a ) o f t h e i n l e t gas v e l o c i t y d i s t r i b u t i o n . The computat ions i n 9

F i g u r e 3-6 were per formed u s i n g S = 0 .05 , and o = 0.15. F i g u r e 3-6 shows 9

t h a t t h e approx imate c o r r e c t i o n s i n t h e ESP MODEL f o r non- idea l gas f l o w g i v e

a r e l i a b l e s i m u l a t i o n o f p r e c i p i t a t o r per formance, u s i n g va lues S,o t h a t 9

a r e c o n s i s t e n t w i t h t y p i c a l gas f l o w i n modern p r e c i p i t a t o r s .

For t h e d e s i g n o f an example p r e c i p i t a t o r t o c o l l e c t f l y ash from a wes te rn

subb i tuminous c o a l , t h e ESP MODEL i n p u t d a t a a r e g i v e n i n Tab le 3-4. The ESP

MODEL was r u n on a main f rame computer f o r t h e sake o f speed, b u t a

m ic rocompute r v e r s i o n i s a v a i l a b l e (2). Tab le 3-4 shows t h e i n p u t d a t a i n

t h e a c t u a l f o r m a t o f computer p r i n t o u t . Parameter s e l e c t i o n f o r t h e example

p r e c i p i t a t o r was d i scussed e a r l i e r . The p r e c i p i t a t o r handles 220,000 acfrn o f

f l u e gas p e r s e c t i o n a t 290°F and an average gas v e l o c i t y o f 4 .0 f t / s . Each

e l e c t r i c a l s e c t i o n i s des igned w i t h 22,000 f t2 o f c o l l e c t i n g p l a t e a rea , o r

100 f t 2 / k a c f m . The i n l e t p a r t i c l e s i z e d i s t r i b u t i o n i s e s t i m a t e d as t h e

log -no rma l s t r a i g h t l i n e i n F i g u r e 3-4 w i t h parameters MMd = 2 1 . 1 urn, and

a = 4.8. The f l y ash r e s i s t i v i t y i s e s t i m a t e d i n Tab le 3-1 t o be 2 ~ 1 0 ' ~

o hm-cm.

Us ing t h e c o r r e l a t i o n s o f d a t a i n Tab le 3-3 f o r e l e c t r i c a l o p e r a t i n g p o i n t s ,

t h e e s t i m a t e d va lues o f secondary v o l t a g e and c u r r e n t d e n s i t y a r e g i v e n i n

Figure 3-7 shows t h a t the ESP MODEL p r e d i c t s a c o l l e c t i o n e f f i c i e n c y of about

99.74 percent f o r the SCA of 550 f t2/kacfm t h a t was es t imated in t he

preceding sec t ion using the Matts-Ohnfeldt equat ion . The two numerical models

f o r p r e c i p i t a t o r s i z ing y i e l d r e s u l t s i n c lo se agreement f o r t h i s example.

Table 3-5. The ESP MODEL cannot s imula te p r e c i p i t a t o r opera t ion i n a mode of

severe sparking o r back corona. The s p e c i f i e d va lues of secondary vol tage and

cu r r en t dens i ty a r e t h e values t h a t a r e a c t u a l l y useful in charging and

c o l l e c t i n g p a r t i c l e s .

Resul ts of t he ESP MODEL computations f o r t h e example p r e c i p i t a t o r a r e shown

in Figure 3-7 on semi-log graph paper. The curves of c o l l e c t i o n e f f i c i e n c y

versus SCA a r e approximately l i n e a r because of t h e exponential form of the

Deutsch-Anderson equat ion. For each of 5 , 6 , and 7 e l e c t r i c a l f i e l d s in t h e

d i r e c t i o n of gas flow, t he gas v e l o c i t y i s var ied approximately +I0 percent

around the design value of 4 f t / s in o r d e r t o genera te curve segments. The

curve segments a r e d i s j o i n t e d because of t h e reduced performance degradat ion

due t o gas sneakage when a ba f f l ed s e c t i o n i s added. The number of ba f f l ed

s ec t ions in t he d i r e c t i o n of gas flow i s t he same a s t h e number of e l e c t r i c a l

f i e l d s ,

The dashed curve segments in Figure 3-7 show t h e e f f e c t of changes in the.

i n l e t p a r t i c l e s i z e d i s t r i b u t i o n on t h e p r e c i p i t a t o r c o l l e c t i o n e f f i c i ency .

The dashed curve segments a re ca l cu l a t ed using the p a r t i c l e s i z e d i s t r i b u t i o n

labe led "Wyoming" in Figure 3-4, w i t h a l l o the r parameters t h e same. A t f i r s t

g lance , t h i s p a r t i c l e s i z e d i s t r i b u t i o n might appear l e s s favorable than t h e

log-normal s t r a i g h t l i n e i n Figure 3-4 because of h igher mass concentrat ion i n

t he small p a r t i c l e s i z e s . However, t he two curves c r o s s below 0 . 7 pm, in a

t yp i ca l region of minimum p r e c i p i t a t o r c o l l e c t i o n e f f i c i e n c y . I t turns out

t h a t the lower mass concentrat ion i n p a r t i c l e s i z e s above 0.7 pm diameter

r e s u l t s in a s l i g h t l y more favorable e s t i m a t e of c o l l e c t i o n e f f i c i ency f o r t he

Wyoming f l y a sh .

T h e e f f e c t s of s a f e ty margins on the des ign value o f SCA a r e discussed i n

d e t a i l l a t e r . Operating contingencies t h a t must be cons idered i n each s t e p of

t he process of parameter s e l ec t ion a r e d i s cus sed . The cumulative e f f e c t of

Table 3-5

ESP Model I n p u t D a t a for t he Example Precipitator

T I T L E : EXAEPLE P R E C I P I T A T O R

C a l c u l a t i o n Pa ramete r s

Type o f d a t a s e t (1 = comple te , 2-4 = s h o r t e n e d ) NDATA (1) 1 Model t y p e ( 0 = r e g u l a r , 1 = m e t r i c , MODL (0) 0

2 = i n t e r n a l d a t a , 3 = VI o n l y ) Reduced p r i n t i n g (0-3) NOPRI.17' (0) 0 Rigorous o r e s t i m a t e d f i e l d c a l c u l a t i o n ( 1 o r 2) NEST 1 Rigorous o r e s t i m a t e d cha rge c a l c u l a t i o n (0 o r 1) NCALC 0 V I c u r v e s known o r c a l c u l a t e d by E i L G 2 ( 1 o r 2 ) NVI (1) 1

Dimsnsion of X g r j d (15 m a x ) K X (IC) 11 Dioiension of Y g r i d ( 1 5 m a x ) N Y (10) 1 i Max number of i t e r a t i o n s t o convergence NITER -- 2 Number of i n t e g r a t i o n inc remen t s i n c h a r g e c a l c N N (5 ) 1 D Es t ima ted e f f i c i e n c y (%) ETA0 9 9 . 0

P a r t i c l e S i z e Data

Number o f s i z e band end p o i n t s (21 max) Type o f s i z e d a t a (1 = measured, 2 = c a l c ) S i z e d i s t r i b u t i o n mrnd S m n d a r d d e v i a t i o n

S i z e Eand E n d P o i n t s

(lm)

ENDPT

KENDPT NDIST 030 S I GMAP

Cumula t ive P e r c e n t Kass

P R C U

L l .

Table 3-5 (Continued)

Sect iona l Data

Number of ESP Sec t ions

Number o f Increments per Sect ion

Sec t ion No. 1

LSECT

Val t age Current P l a t e a rea Total wi re length Corona wire r a d i u s Number of w i r e s F i r e - t o - p l a t e spacing Wire-to-wire spacing Gas volume flow r a t e Gas v e l o c i t y Gas temperature Gas pressure Gas v i s c o s i t y

Sec t ion No. 2

V o l t age Current P l a t e a rea Total wire length Corona wire r ad ius Number of w i r e s Wire-to-plate spacing Wire-to-wire spacing Gas volume flow r a t e Gas v e l o c i t y Gas temperature Gas p re s su re Gas v i s c o s i t y

VOS TCS AS WLS AC S NWS BS SYS"2 VGS VGPSS TEMPS PS ViSs

VOS TCS AS WLS ACS NWS B S SYS*2 V6 S VGASS TEMPS P S VISS

NUMSEC 6

Incremental Length f f t )

LINCS

I L

f t i n .

i n . i n . acfm

atm kg/m/s

1 L

f t i n .

i n . i n . acfm f t / s W L atm kc/m/s

Tab le 3-5 (Continued)

P h y s i c a l P a r a m e t e r s - I n l e t mass l o a d i n g P a r t i c l e d e n s i t y D i e l e c t r i c r a t i o I o n m o b i l i t y R e s i s t i v i t y

DL DD EPS (100) US RHO

To ta l ESP l e n g t h P L Cold s i d e o r h o t s i d e (1 o r 2 ) NTEMP (1) Peak- to-average v o l t a g e r a t i o VRATIO ( 1 . 2 ) E l e c t r i c 2 1 breakdown s t r e n g t h EBD

Non-Ideal P a r a m e t e r s

Number of Non-Ideal Data S e t s NONID 2

eakage f r a c t i o n . O O Gas v e l . sigma .00 .05 .15

No. b a f f l e s 6 6

Rapoinq Data

0 Type o f r app ing c a l c u l a t i o n ( 0 , 5 - o l d e s t i m a t i o n , 1-3 = dynamic) ( 0 )

Kumber o f r zpp ing d a t a s e t s NRAPD (1) Source o f r a p p i n g t i - s t N E ~ F (1) F l r s t r app ing d u s t M M D ARSIGM 6 . 0 um F i r s t r zpp ing d u s t SIGMA A R D X 2 . 5 A d d i t i o n a l v a l u e s ARS i G M

O p a c i t y Data

Opac i ty p a t h l e n g t h (0 = no o p a c i t y c a l c u Number i n d i c e s of r e f r a c t i o n (0-10) Number wave leng ths f o r o p a c i t y c a l c (D-10 Number i n d i c e s o f r e f r a c t i o n f o r v a r i a b l e

i a t i o n ) PATHL 2 4 . 0 f t b:CO"" ( ( 0 )

, l=l) NWAVES (0) i ndex (0-10) NLAMDA ( 0 )

0 1

4

7 3 FIE

I

4

Figure 3-7. ESP MODEL Simulations o f the Example Precipitator Designed t o Collect Fly Ash from a Western Subbituminous Coal

u n c e r t a i n t i e s in s e l e c t i n g a margin f o r opera t ing contingencies r e s u l t s i n t h e

use of t h e following r u l e of thumb: A t l e a s t one e l e c t r i c a l f i e l d in t h e

d i r e c t i o n of gas flow i s usua l ly added t o t he design SCA of a p r e c i p i t a t o r .

The a d d i t i o n of a f i e l d t y p i c a l l y adds p l a t e a rea t h a t i s e q u i v a l ~ n t t o 100 - 150 f t2 /1000 acfm f o r a p r e c i p i t a t o r of medium s i z e . For t he example

p r e c i p i t a t o r , 99.70 percent co l l ec t i on e f f i c i e n c y i s est imated t o r equ i r e more

than f i v e s ec t ions i n t he d i r e c t i o n of gas flow. A reasonably conserva t ive

des ign , including s a f e t y margins, would spec i fy seven sec t ions with a t o t a l

SCA of 700 ft2/kacfm.

DESIGN MARGINS

The s e l e c t i o n of a p a r t i c u l a r p r e c i p i t a t o r s i z e f o r a p a r t i c u l a r s e t of

cond i t i ons has been d i scus sed . I t i s now important t o t u rn o n e ' s a t t e n t i o n t o

those circumstances which w i l l occur over t he s e rv i ce l i f e of the u n i t . The

occurrence of these circumstances i s d i f f i c u l t t o p red i c t p r ec i se ly . Hence,

t h e r e i s a need t o e s t a b l i s h prudent design margins o r s a f e t y f a c t o r s .

One of t h e most widely used design margins i s t o couple maximum ash content

and minimum coal hea t ing value in order t o e s t a b l i s h a maximum ash product ion

r a t e i n terms of pounds per mi l l ion Btu. This ash production r a t e inc ludes

both bottom ash and f l y a sh . The predic t ion of t he proport ional s p l i t between

bottom and f l y ash i s d i f f i c u l t t o accomplish s ince i t i s in t imate ly r e l a t e d

t o and a func t ion of steam genera tor design and ash p a r t i c l e s i z e

d i s t r i b u t i o n . Hence, in terms of e s t ab l i sh ing a p r e c i p i t a t o r design

e f f i c i e n c y , i t would be most conservat ive t o assume t h a t a l l of t h e ash wi l l

be f l y a s h . H i s t o r i c a l l y , approximately 70 t o 95 percent of the ash would

appear a s f l y ash on pulver ized coal u n i t s . These carryover percentage have

been used with success. However, t he u t i l i t y should look t o i t s own

exper ience t o s e l e c t an appropr ia te f a c t o r f o r a s p e c i f i c type of f u e l . The

fol lowing subsec t ions desc r ibe o ther design margins.

Flue Gas Flow

Techniques f o r determining f l u e gas flow were discussed e a r l i e r in t h i s

s e c t i o n . Now, the u t i l i t y must determine what degree of va r i a t i on may occur

during ac tua l ope ra t ions . Some approaches look a t gas flow under f u l l load

o p e r a t i o n when f i r i n g a steam g e n e r a t o r "per formance" c o a l ; t hen a marg in o f

10 t o 25 p e r c e n t i s a p p l i e d t o i t . O t h e r s e s t a b l i s h m u l t i p l e gas f l o w s , each

f o r an i n d i v i d u a l f u e l a n a l y s i s . Hence, some c o a l s may have s i g n i f i c a n t

marg ins w h i l e o t h e r s have p r a c t i c a l l y none when i t comes t o a c t u a l o p e r a t i o n .

It appears t h a t everyone has h i s own c r i t e r i a f o r e s t a b l i s h i n g a p r e c i p i t a t o r

des ign gas f l o w .

Development o f a p r e c i p i t a t o r des ign gas f l o w shou ld be p r u d e n t i n concept and

should account f o r d e t e r i o r a t i o n i n t h e i n t e g r i t y o f t h e f l u e gas system. The

f o l l o w i n g des ign c o n d i t i o n s a r e suggested f o r use i n t h e development o f a

p r e c i p i t a t o r des ign gas f l o w :

Parameter C r i t e r i a

Steam g e n e r a t o r h e a t i n p u t Va lves w ide open w i t h 5% overp ressure

Steam g e n e r a t o r excess a i r l e v e l A minimum o f 20%

A i r h e a t e r leakage r a t e

Coa

AP P

1 ana ly5

l i c a t i o n

A minimum o f t w i c e t h e maximum l e v e l guaranteed by t h e steam g e n e r a t o r supp l i e r

T h a t c o a l w h i c h produces t h e g r e a t e s t gas volume on a p e r m i l l i o n B t u b a s i s .

o f t hese c r i t e r i a w i l l y i e l d a maximum a n t i c i p a t e d gas f l o w . To

t h i s f l o w an induced d r a f t f a n marg in r a n g i n g between 15 t o 25 p e r c e n t i s t h e n

added i n o r d e r t o e s t a b l i s h a t e s t b l o c k c o n d i t i o n . T h i s t e s t b l o c k c o n d i t i o n

i s used a s t h e p r e c i p i t a t o r des ign gas f l o w . A11 o t h e r p r e c i p i t a t o r d e s i g n

marg ins a r e t h e n added t o t h e des ign gas f l o w .

C o l l e c t i n g P l a t e Area

I t has become common p r a c t i c e t o s p e c i f y t h e minimum p r e c i p i t a t o r s i z e w i t h a

c e r t a i n p o r t i o n o f t h e p r e c i p i t a t o r o u t o f s e r v i c e ; t h i s i s subsequent ly

c a r r i e d ove r i n t o t h e performance w a r r a n t y . Commonly used concepts f o r p l a t e

a reas o u t - o f - s e r v i c e range f rom o n e - h a l f o f a f i e l d o u t t o one whole f i e l d o u t

t o 10 p e r c e n t o f t h e bus s e c t i o n s o u t . T h i s i s done i n o r d e r t o p e r m i t a

u t i l i t y t o meet emiss ion s tandards under t h e w o r s t case d e s i g n c o n d i t i o n s

(maximum d u s t l o a d i n g , maximum gas f l o w , maximum f l y ash r e s i s t i v i t y ) and w i t h

o p e r a t i n g m a l f u n c t i o n s such as broken d i s c h a r g e e l e c t r o d e s , o v e r f i l l e d

hoppers, f a i l e d t r a n s f o r m e r - r e c t i f i e r s e t s . Each one o f t h e o u t - o f - s e r v i c e

concep ts a f f e c t s p r e c i p i t a t o r c o n f i g u r a t i o n , p l a n t a rea , and c o s t . I n

a d d i t i o n , these e f f e c t s and t h e i r r e l a t e d pe r fo rmance l e v e l s w i l l be s e n s i t i v e

t o t h e s i z e o f t h e u n i t s . I n essence, a p r u d e n t s a f e t y f a c t o r on a sma l l u n i t

may be i n a p p r o p r i a t e f o r a l a r g e r u n i t . Examine t h e case o f a f o u r - f i e l d u n i t

p r e c i p i t a t o r - - a spare f i e l d wou ld r e s u l t i n a 25 p e r c e n t l a r g e r p r e c i p i t a t o r .

I n terms o f a 200 t o 300 MW u n i t t h i s may r e s u l t i n reasonab le c o s t and p l a n t

a r e a requ i remen t e f f e c t s , whereas a p p l i e d t o a 750 MW u n i t i t may be

unacceptab le . I n a d d i t i o n , t h e r e may have t o be d i f f e r e n t marg ins a s s o c i a t e d

w i t h we igh ted w i r e and r i g i d d i s c h a r g e e l e c t r o d e d e s i g n s . G e n e r a l l y , i t would

be p r u d e n t t o s t a r t w i t h t h e 10 p e r c e n t o f t h e bus s e c t i o n s o u t o f s e r v i c e

concep t f o r a l l s i z e u n i t s . Then c o s t impac t s t u d i e s can be pe r fo rmed t o

o p t i m i z e t h e d e s i g n i n terms o f t r a d e o f f s between adverse e f f e c t s .

Spare Casing C a p a c i t y

Ano the r concept ' f o r d e a l i n g w i t h u n c e r t a i n c i r c u m s t a n c e s has been t h e use o f

spare f i e l d s o r , more a p p r o p r i a t e l y , spare c a s i n g c a p a c i t y . T h i s p r o v i d e s

a d d i t i o n a l space f o r add ing more c o l l e c t i n g p l a t e a r e a a t a f u t u r e d a t e

w i t h o u t t h e need t o m o d i f y duc twork and p r e c i p i t a t o r c a s i n g . The s impTest

approach t o t h e concept i s t o f i r s t l e a v e an empty space, w i t h no d i s c h a r g e o r

c o l l e c t i n g e l e c t r o d e s . Adding t h e i n t e r n a l s n e c e s s i t a t e s an extended outage

shou ld t h e d e c i s i o n be made a f t e r t h e u n i t i s i n o p e r a t i o n s i n c e t h e m a j o r

p o r t i o n o f t h e p r e c i p i t a t o r r o o f o r hoppers wou ld have t o be removed i n o r d e r

t o p l a c e t h e i n t e r n a l s .

FLUE GAS OPACITY

F l u e gas o p a c i t y i s v e r y s e n s i t i v e t o t h e p r e c i p i t a t o r o u t l e t p a r t i c l e s i z e

d i s t r i b u t i o n , p a r t i c u l a t e c o l o r and t h e t o t a l o u t l e t mass l o a d i n g . S c a t t e r i n g

v i s i b l e l i g h t i s v e r y s e n s i t i v e t o t h e c o n c e n t r a t i o n o f p a r t i c u l a t e mass i n

t h e submicron p a r t f c l e s i z e range (around 0.55 pm) where f l y ash p a r t i c l e

d i a m e t e r s a r e comparable t o t h e wavelengths o f v i s l b l e l i g h t . T h i s i s t h e

p a r t i c l e s i z e range where in a p r e c i p i t a t o r t y p i c a l l y has minimum c o l l e c t i o n

e f f i c i e n c y . There i s no s i m p l e c o r r e l a t i o n between t o t a l p a r t i c u l a t e mass

emiss ion and f l u e gas o p a c i t y . Given two f l y ash p r e c i p i t a t o r s h a v i n g

0.03 lb/MBtu mass emiss ion , one may produce a s i g n i f i c a n t l y g r e a t e r f l u e gas

o p a c i t y i f i t

treats fly ash with a much finer inlet particle size distribution. Opacity

also varys exponentially with the optical path length. That is, the opacity

of a visible plume rising from a stack depends on the stack diameter.

All calculations of flue gas opacity use the mathematical theory of light scattering developed by Gustav Mie in 1908 (ZJ,G). Various computer models differ in their methods of handling input data for particle size

distribution. Calculations which use an estimated log-normal particle size

distribution are known to be unreliable because precipitator outlet particle

size distribution is rarely well-approximated by a log-normal distribution.

Figure 3-8 shows a comparison of measured and computed opacities of the flue

gas from eleven utility fly ash precipitators (19). The particle size distributions were determined by cascade impactor measurements in the precipitator outlet ducts. The effect of fitted log-normal approximations to

those measured particle size distributions is also shown. The flue gas

opacity calculation illustrated by the open circles in Figure 3-8 is

incorporated in the EPA mathematical model o f electrostatic precipitation (ESP MODEL). The computed outlet particle size distribution and outlet mass

loading are used in the opacity calculation, together with a specified optical

path length (16).

For the example precipitator designed to collect fly ash from a western

subbituminous coal, an optical path length of 24 ft is assumed. For the

550 MW generating plant, there are eight identical precipitator chambers feeding a single stack. The total volume gas flow is 1,760 kacfm. A stack

gas velocity of 65 ft/s is achieved with a stack diameter of 24 f t . Values of

plume opacity computed by the ESP MODEL are shown in Figure 3-9. For a

99.7 percent co?lection efficiency (for 0.03 lb/MBtu), the design value of SCA is about 550 ft2/kacfm with no design margins. The corresponding plume

opacity is about 21 percent. After consideration of design margins, the SCA

is increased to 700 ftz/kacfm, and plume opacity declines to 6 percent.

HOT SIDE VERSUS COLD SIDE

During the 1960s, utilities became more aware of the need to reduce emissions

of sulfur dioxide. Because of a need to produce more electric power and the

availability of low-sulfur coal i n the eastern United States, the use of

LOG-NORMAL SIZE DlSTRlBUflON

MEASURED OPACITY, X

Figure 3-8. Comparison o f Measured and Computed Opacity of the Flue Gas from Eleven Utility Fly ash Precipitators

Figure 3-9. Computed Opacity of the Flue Gas from the Example Precipitator with an O p t i c a l Path Length o f 24 ft

low-sulfur coal became important, but i t r e s u l t e d in poor performance f o r

t r a d i t i o n a l cold-side p r e c i p i t a t o r s . Cold-side p r e c i p i t a t o r s , loca ted

downstream of t he a i r hea t e r s , whose f l u e gas tempera tures range betwehn 260

and 30D0F, encountered h i g h - r e s i s t i v i t y ash condi t ions . In an at tempt t o

overcome the h i g h - r e s i s t i v i t y cond i t i ons , some s u p p l i e r s found t h a t in t h e i r

i n i t i a l cha rac t e r i za t i ons of eas te rn low-sulfur c o a l s , f l y ash r e s i s t i v i t y

l e v e l s s i g n i f i c a n t l y and dramat ica l ly decreased with f l u e gas temperatures

exceeding 600°F.

This reduct ion in r e s i s t i v i t y i nd i ca t ed t h a t i t would then be poss ib l e t o

c o l l e c t the f l y ash i f a p r e c i p i t a t o r was l oca t ed upstream of t he a i r

hea t e r s . Since f l u e gas temperatures leaving t h e economizer would normally be

in t h e range of 550 t o 85OoF, t he term "hot -s ide p r e c i p i t a t o r " i s used.

I n i t i a l i n s t a l l a t i o n s of hot-side p r e c i p i t a t o r s were gene ra l ly on r e l a t i v e l y

small u n i t s f i r i n g ea s t e rn low-sulfur c o a l s . These p r e c i p i t a t o r s performed

very well with very l i t t l e va r i a t i on i n t h e e f f e c t i v e migra t ion ve loc i ty .

This , then, seemed t o be t he answer t o t h e v a r i a b i l i t y i n e f f e c t i v e migration

v e l o c i t y , hence performance, experienced by cold-side p r e c i p i t a t o r s . This

reduction in t he v a r i a b i l i t y of e f f e c t i v e migrat ion v e l o c i t i e s assoc ia ted with

hot-side p r e c i p i t a t o r s led t o expedient s i m p l i f i c a t i o n s i n s i z i n g hot-side

p r e c i p i t a t o r s with migration v e l o c i t i e s on t h e o rde r of 10 cm/sec. The

hot-side s i z i n g f a c t o r , when compared t o cold-side s i z i n g f a c t o r s , y i e lded

p r e c i p i t a t o r cas ings which of fered a perceived compet i t ive advantage t o

cold-side p r e c i p i t a t o r s . The t rend of applying hot-s ide p r e c i p i t a t o r s t o

low-sulfur c o a l s expanded i n t o t he western coal marketplace. As more

experience was gained with hot-side p r e c i p i t a t o r s on a g r e a t e r v a r i e t y c o a l s ,

t he popular notion of universal s i z i n g f a c t o r s began t o erode. In t he ea r ly -

t o mid-19701s, ho t -s ide migration v e l o c i t i e s dropped t o approximately 6 cm/sec

f o r western c o a l s . During t h i s t ime, some supp l i e r s maintained t h a t cold-side

p r e c i p i t a t o r s could be designed and opera ted on these same western coa l s ;

however, t he co ld-s ide p r e c i p i t a t o r s s t i l l tended t o be s l i g h t l y l a rge r and

more expensive than comparable hot -s ide u n i t s . As t he economic advantages of

hot-side p r e c i p i t a t o r s had diminished, both hot-and c o l 6 s i d e u n i t s were

appl ied t o l o w s u l f u r coal u n i t s dur ing t h e 1970 ' s .

During the 1977 American Power Conference, Mr. A . B. Walker presented a paper entitled "Operating Experience With Hot Precipitators on Western tow-Sul fur

Coals". This paper described poor performance problems associated with

hot-side precipitators on western low-sulfur coals. The poor performance

problems were influenced by discharge electrode buildups, fly ash chemistry

and back ionization. The most effective solution to the problems seemed to be

to condition the fly ash with sodium based compounds. Research began as more

and more poorly performing hot-side precipitators were reported. It was found

that at elevated temperatures, the resistivity of western coal f l y ashes was

sensitive to chemical composition and the effects of time, leading to

significant variations in precipitator performance.

In addition to the performance problems experienced by some hot-side

precipitator insta?lations, several of the larger precipitators have also

exhibited signs of structural distress. Structural distress can be revealed

by:

Deformation of structural members

- Bowed beams

- Cracked columns

- Bent columns

Cracked or torn end connections of structural members

Torn platework welds

Cracked platework

Up1 ifted support col umvc

Non-functional or destroyed sliding bearings

The cause o f . such d i s t r e s s

of c r i t i c a l design assumpt

design assumptions inc lude

can be a t t r i b u t a b l e t o s i t u a t i o n s where the b a s i s

ions were not f u l l y analyzed o r apprec ia ted . These

Temperature s t r a t i f i c a t i o n under s t a r t -up and low load condi t ions

D i f f e r e n t i a l response t imes t o hea t ing of s t r u c t u r a l members

Asymmetrical expansion of ca s ing

Ver t ica l expansion of cas ing and ductwork

Ef fec t ivenes s of thermal i n s u l a t i o n

Therma7 g rad i en t e f f e c t s of f l y a sh buildup in ductwork and on

s t r u c t u r a l members

Thermal c reep

Load t r a n s f e r e n c e within support ing s t r u c t u r e s

Rotat ional fo rces on support ing columns.

The degree of s t r u c t u r a l d i s t r e s s su f f e r ed by hot-s ide p r e c i p t a t o r s can vary

from minor t o major; i n one extreme case , t h e hot-s ide p r e c i p i t a t o r wi l l be

abandoned i n f avo r of an a l t e r n a t e cont ro l technology. However, in most

ca se s , s t r u c t u r a l d i s t r e s s wi l l be r e c t i f i e d by t he redesign and replacement

of c r i t i c a l s t r u c t u r a l members o r by conversion t o cold-side operat ion w i t h

t h e use of f l u e gas condit ioning agents (155).

In the f i n a l a n a l y s i s , hot-side p r e c i p i t a t o r s have a l l but passed from f u r t h e r

cons idera t ion due t o :

Significant variability in performance without the use of sodium conditioning on many western low sul fur coals

Higher-than-anticipated flue gas temperature drops coupled with

higher fuel costs

* Deterioration in the structural integrity of precipitator casings

and ductwork along with their associated supporting systems

Performance problems may occur with eastern low-sulfur coals

High performance levels of modern cold-side precipitators

It must be noted that some utilities have had excellent experience with

hot-side precipitators and may wish to use them on new units. Considering the

current state-of-the-art of predicting hot-side precipitator performance,

utilities must use prudent judgement in seTection. If a particular coal has

worked well in the past and the utility can plan on having that same fuel

consistently available over the service life of the new unit, the performance

risk is substantially lowered. This seems to be the only practical criterion

that can be used today in deciding whether or not to consider a hot-side

precipitator.

SIZE REDUCTION WITH GAS CONDITIONING

Flue gas conditioning with sulfur trioxide (SO3) is routinely and

successfully used on many cold-side utility fly ash precipitators to improve

the cotlection of high-resistivity fly ash. A t flue gas temperatures below

350°F, the electrical resistivity of the collected fly ash may be

substantially reduced by SO3 i n the flue gas. SO3 is a natural

conditioning agent in the flue gas produced by firing medium- to high-sulfur

eastern bituminous coals (2). The result is a substantial increase in the useful electrical power consumption of the precipitator. The connection

between fly ash resistivity and useful electrical power consumption was

discussed earlier. The theory, practice, and economics of flue gas

conditioning with SO3 are described in detail in an EPRI report entitled "A

Manual for the Use o f Flue Gas Conditioning for Reduction of Fly Ash

Resistivity" (3).

Two commercial processes f o r f l u e gas condi t ion ing genera te SO3 e x t e r n a l l y

and i n j e c t the ac id vapor i n to t he f l u e gas j u s t before p r e c i p i t a t o r . They

a r e t h e combustion of molten s u l f u r and t h e vapor iza t ion of l i q u i d SO2, both

followed by c a t a l y t i c oxidat ion of SO2 t o SO3. The ove ra l ? economic

eva lua t ion of t h e s e t w o processes by the revenue requirement method favors the

s u l f u r burner by a margin of 10 t o 5 0 percent depending on t h e requi red SO3

i n j e c t i o n r a t e . A number of l i q u i d SO systems, however, have been 2 i n s t a l l e d because t h e i r cap i t a l cos t i s lower by roughly 10 percent .

Furthermore, t he l i q u i d SO2 systems a re s impler t o opera te and maintain than

s u l f u r burners but about t h r ee times more c o s t ? y t o opera te .

The highly a l k a l i n e f l y ash from western subbituminous coa l s i s very

suscep t ib l e t o r e s i s t i v i t y moderation by SO condi t ion ing . The necessary 3

i n j e c t i o n r a t e of SO3 i s d i f f i c u l t t o p r e d i c t , however, because t h e f l y ash

can adsorb a s i g n i f i c a n t quant i ty of SO3 be fo re t h e r e s i s t i v i t y of t he

c o l l e c t e d f l y ash l a y e r begins t o be a f f e c t e d . The e f f e c t of SO3 on f l y ash

r e s i s t i v i t y i s p red ic ted on the bas i s of l abo ra to ry measurements i n which f l y

ash absorbed a s much SO3 a s poss ib le and a measurable equi l ibr ium

concent ra t ion of SO3 (13) remained in t he gas . I f s u f f i c i e n t SO3 i s

i n j e c t e d i n t o f l u e gas t o achieve a res idua l equi l ibr ium concent ra t ion of a

few ppm, the l abo ra to ry da ta show t h a t t h e r e s i s t i v i t y i s more s t rong

moderated f o r f l y ashes of high a l k a l i n i t y .

A t l e a s t a s important a s the i n j ec t ion r a t e of SO3 i s a uniform d i s t r

of SO (and f l u e gas temperature) over t h e f ace of t he p r e c i p i t a t o r . 3

Y

buti on

Seemingly small v a r i a t i o n s in f l u e gas temperature and SO concent ra t ion can 3 r e s u l t in order-of-magnitude v a r i a t i o n s in t h e r e s i s t i v i t y of f l y ash

c o l l e c t e d in d i f f e r e n t a r ea s of an e l e c t r i c a l f i e l d . The p r e c i p i t a t i o n

process in t he e n t i r e f i e l d energized by one T-R s e t w i l l be l imi t ed by t h a t

po r t i on of the f i e l d having the h ighes t r e s i s t i v i t y of t he c o l l e c t e d f l y ash

l a y e r . Therefore, t h e uniform mixing of i n j e c t e d SO and t h e a v a i l a b l e time 3 of r eac t ion with f l y ash a r e very important a spec t s of a design f o r f l u e gas

condi t ion ing .

Tab le 3 - 1 shows a p r e d i c t e d e f f e c t o f f l u e gas c o n d i t i o n i n g on t h e f l y ash

from t h e h y p o t h e t i c a l wes te rn subbi tuminous c o a l t h a t was used as an example.

Table 3-1 g i v e s an e s t i m a t e of 2.3 ppm SO3 i n t h e f l u e gas. However, i n t h e

example d e s i g n o f a p r e c i p i t a t o r t o c o l l e c t t h i s f l y ash, i t was assumed t h a t

t h i s sma l l amount o f SD3 wou ld be c o m p l e t e l y absorbed by t h e h i g h l y a l k a l i n e

f l y ash w i t h o u t a f f e c t i n g t h e f l y ash r e s i s t i v i t y . Now, as an example o f f l u e

gas c o n d i t i o n i n g , assume t h a t SO i s i n j e c t e d ( w i t h adequate r a t e , m i x i n g , 3 and r e s i d e n c e t i m e ) such t h a t a t t h e p r e c i p i t a t o r i n l e t t h e r e remains 2 .3 ppm

SO3 i n e q u i l i b r i u m w i t h t h e f l y ash. The p r e d i c t e d f l y ash r e s i s t i v i t y ,

RHD(VSh), a t 29D°F i s 7 . 6 ~ 1 0 ~ ' ohm-cm. T h i s i s a d r a m a t i c decrease f r o m t h e

p r e d i c t e d n a t u r a l r e s i s t i v i t y l e v e l o f 2.0x1012 ohm-cm. A d r a m a t i c i n c r e a s e

i n t h e u s e f u l e l e c t r i c a l power consumption o f t h e p r e c i p i t a t o r r e s u l t s .

New e s t i m a t e s o f u s e f u l secondary e l e c t r i c a l o p e r a t i n g p o i n t s can be o b t a i n e d

from t h e average d a t a c o r r e l a t i o n s i n Tab le 3-3.

S e c t i o n Vo l tage C u r r e n t D e n s i t y C u r r e n t Number kV nA/cm2 mA/f tZ m A

I n t h e i n l e t e i e c t r i c a l s e c t i o n , f o r example, t h e new e s t i m a t e o f t h e

e l e c t r i c a l o p e r a t i n g p o i n t cor responds t o 15 t i m e s as much u s e f u l e l e c t r i c a l

power consumpt ion as t h e e a r l i e r e s t i m a t e c o r r e s p o n d i n g t o a f l y ash

r e s i s t i v i t y o f 2 . 0 ~ 1 0 ' ~ ohm-cm.

The e f f e c t o f f l u e gas c o n d i t i o n i n g on p r e c i p i t a t o r c o l l e c t i o n e f f i c i e n c y ,

computed by t h e ESP MODEL, i s shown i n F i g u r e 3-10. Fo r 99.7 p e r c e n t

c o l l e c t i o n e f f i c i e n c y , t h e d e s i g n s i z e ( w i t h o u t s a f e t y marg ins ) drops from

about 550 f t 2 / k a c f m t o abou t 300 f t z / k a c f m . A reasonab le s a f e t y marg in i s

t o add one more s e c t i o n w i t h an a d d i t i o n a l 100 f t 2 / k a c f m i n t h e d i r e c t i o n o f

gas f l o w . A compar ison o f F i g u r e s 3-7 and 3-10 shows t h a t 400 i t2/ kacfm

w i t h f l u e gas c o n d i t i o n i n g p r o v i d e s t h e same marg in o f s a f e t y as

700 ft2/kacfm without flue gas conditioning. With 400 ft2/kacfm, the

calculated plume opacity i s 4 percent.

Flue gas conditioning with SO3 has been employed mostly in retrofit

applications to cold-side utility fly ash precipitators. Utilities have

viewed flue gas conditioning as a fall-back position; however, the above

example illustrates the advantage o f considering flue gas conditioning in t h e

original design of a precipitator to collect high-resistivity fly ash. A

large saving in the size and capital cost of the precipitator possible.

3 Fields 1 4 Fields 1 5 Fields 1

Figure 3-10. ESP MODEL Simulations o f the Example Precipitator Designed to Collect Fly ash from a Western Subbituminous Coa1,wit.h Flue Gas Conditioning.

4 SPECfFlCATiON OF MECHANICAL FEATURES

Section 4

SPECIFICATION OF MECHANICAL FEATURES

PHYSICAL DESIGN

Number of Precipitators

The number of independent precipitator casings for each steam generator

varies from one to four as an industry practice; most installations have two

precipitators for each steam generator. Although sometimes influenced by

available site space, the decision to specify multiple precipitators is

usually considered on the basis of boiler load regimen, precipitator

reliability, limitations in size or width o f a casing, degree of redundacy,

and a desire to perform on-line maintenance.

The added expense of installing multiple precipitators over what would be

considered normal ( i . e . two) can be significant. Additional foundations,

support columns, insulation, accessways and platforms for the additional

sidewalls, as well as increased sectionalization of roof and hopper

enclosures, the control system, and safety systems, can increase the

precipitator cost by approximately one to two percent. However, should

isolation dampers and crossover ducts also be required, a cost increase on the

order of five to eight percent over a more conventional arrangement may be

expected.

The added expense of additional precipitator casings may be justified under

the following circumstances:

Precipitators with tumbling hammer rappers should be designed so t h a t the collecting plate area serviced by each rapper drive motor does not exceed the redundant collecting plate area provided by the designer in the event of transformer-rectifier set failures. This philosophy of sectionalization protects the precipitator against an opacity excursion in the event of rapper drive failures. Multiple precipitator casings are often necessary when increasing the number of rapper drives because they are mounted on sidewalls.

If the steam generating unit is to be operated at partial load for extended periods, it may be economicalTy advantageous to provide multiple precipitator casings, isolation dampers and crossover ducts so that one or more precipitators may be taken off-line and deenergized, as necessary.

For d i f f i c u l t app l i ca t i ons such t h a t f r equen t water washing and/ o r weighted wire e l ec t rode breakage i s a n t i c i p a t e d , i t may be economically advantageous t o provide mu l t i p l e p r e c i p i t a t o r c a s i n g s , man-safe i s o l a t i o n dampers, and p r e c i p i t a t o r crossover d u c t s so t h a t one o r more p r e c i p i t a t o r s may undergo on-l ine maintenance.

I f add i t i ona l p r e c i p i t a t o r cas ings cannot be t e c h n i c a l l y o r economically

j u s t i f i e d , then one p r e c i p i t a t o r per steam genera tor should be s p e c i f i e d f o r

small u n i t s , say l e s s than 300 MW, and two casing f o r u n i t s g r e a t e r than 300

MW .

Number of Chambers

The d e s i r a b i l i t y of d iv id ing a p r e c i p i t a t o r casing i n t o two o r more gas - t i gh t

chambers shauld be a point of j o i n t agreement between p r e c i p i t a t o r

manufacturer and u t i l i t y . O r i g i n a l l y , gas- t igh t d i v i s i o n wal l s were used t o

cont ro l gas flow d i s t r i b u t i o n within t h e c o l l e c t i n g chamber and termed an

in t eg ra l p a r t of the s t r u c t u r a l system. In t he p a s t , some cons idera t ion was

given t o using t h i s d iv i s ion wall t o permit shu t t i ng down half the

p r e c i p i t a t o r cas ing f o r purposes of on-l ine maintenance and/or reduced u n i t

load cons ide ra t i ons . This use of gas - t i gh t d iv i s ion wa l l s engenders design

concern r e l a t i n g t o thermal g rad i en t s and d i s t o r t i o n s within the s t r u c t u r e

along with personnel s a f e ty . As such, p r e c i p i t a t o r des ign p rac t i ce s have

evolved toward an open, truss-work type o f s t r u c t u r e wi thout de t r iment t o gas

flow d i s t r i b u t i o n within t he p r e c i p i t a t o r casings. Current u t i l i t y p r a c t i c e

does not spec i fy the number of chambers and does not employ the concept of a

gas - t i gh t w a l l .

Number of Gas Passages

A gas passage i s formed by two ad j acen t c o l l e c t i n g e l e c t r o d e p l a t e s . The

t o t a l number of gas passages per steam generator i s a ca l cu l a t ed parameter

which i s dependent upon p r e c i p i t a t o r gas v e l o c i t y , c o l l e c t i n g p l a t e spacing

and he igh t . Col lec t ing p l a t e he ight , in t u r n , i s a ca l cu l a t ed parameter which

depends on i n s t a l l e d co l l ec t i ng p l a t e a r e a , p r e c i p i t a t o r aspec t r a t i o , and t h e

s p e c i f i e d maximum allowable he ight of t h e c o l l e c t i n g p l a t e s . A p r e c i p i t a t o r

s p e c i f i c a t i o n wi l l normally s e t l i m i t s on these parameters a s fol lows:

Minimum c o l l e c t i n g p l a t e a r ea

Minimum aspec t r a t i o

Maximum p r e c i p i t a t o r gas ve loc i ty

Maximum height of c o l l e c t i n g p l a t e

Minimum/maxirnum c o l l e c t i n g p l a t e s p a c i n g

Minimum number o f f i e l d s

G i v e n t h e above, i t i s meaning less t o l i m i t t h e number o f gas passages.

T y p i c a l l y , t h e r e i s o n l y a sma l l v a r i a t i o n i n t h i s pa ramete r f r o m one

m a n u f a c t u r e r ' s d e s i g n t o t h e n e x t . T h i s v a r i a t i o n a r i s e s because some

m a n u f a c t u r e r s may p r e f e r t o s e l e c t a d i f f e r e n t a s p e c t r a t i o o r a l o w e r gas

v e l o c i t y f rom t h e maximum l i m i t s s p e c i f i e d .

C o i l e c t i n g P l a t e Spac ing

C o l l e c t i n g e l e c t r o d e p l a t e spac ing i s t h e c e n t e r - t o - c e n t e r d i s t a n c e between

any two a d j a c e n t rows o f c o l l e c t i n g p l a t e s w h i c h fo rm a gas passage.

H i s t o r i c a l l y , a d i s t a n c e between 8 and 1 2 i n . has been used f o r f l y ash

p r e c i p i t a t o r s . P r e c i p i t a t o r s wh ich u t i l i z e w e i g h t e d w i r e s f o r e m i t t i n g

e l e c t r o d e s most o f t e n use a 9 i n . p l a t e spac ing , w h i l e m a n u f a c t u r e r s o f r i g i d

e m i t t i n g e l e c t r o d e s t y p i c a l l y use 10 t o 12 i n . s p a c i n g ; 12 i n . spac ing i s most

p r e v e l a n t t o d a y e s p e c i a l l y w i t h c o l l e c t i n g p l a t e h e i g h t s g r e a t e r t h a n 40 f t .

Some m a n u f a c t u r e r s and EPRI a r e i n v e s t i g a t i n g p l a t e spac ings i n excess o f

12 i n .

As t h e spac ing between c o l l e c t i n g p l a t e s i s i n c r e a s e d , co rona v o l t a g e must be

i n c r e a s e d . I n c r e a s e d corona v o l t a g e enhances p r e c i p i t a t o r pe r fo rmance ;

however, i t i s a l s o e s s e n t i a l t o m a i n t a i n adequate e l e c t r i c a l c l e a r a n c e

between h i g h v o l t a g e p a r t s and grounded p a r t s . When co rona v o l t a g e i s r a i s e d

t o t h e l e v e l t h a t spa rkove r occu rs , a good p r e c i p i t a t o r w i l l s p a r k between t h e

e m i t t i n g e l e c t r o d e and t h e c o l l e c t i n g e l e c t r o d e . S p a r k i n g a t any o t h e r

l o c a t i o n i n d i c a t e s e i t h e r poor d e s i g n o r a c o n s t r u c t i o n d e f i c i e n c y . When

r i g i d e m i t t i n g e l e c t r o d e s a re used, p l a t e s p a c i n g must be i n c r e a s e d t o

compensate f o r t h e p h y s i c a l t h i c k n e s s and t o l e r a n c e o f t h e e m i t t i n g e l e c t r o d e

assembly . I n s e l e c t i n g a s t a n d a r d p l a t e spac ing, each m a n u f a c t u r e r c o n s i d e r s

t h e f a b r i c a t i o n and c o n s t r u c t i o n t o l e r a n c e s o f i t ' s p a r t i c u l a r d e s i g n . N e a r l y

a l l m a n u f a c t u r e r s o f r i g i d e m i t t i n g e l e c t r o d e s have s t a n d a r d i z e d on a

c o l l e c t i n g p l a t e spac ing between 11-1/2 i n . and 12 i n .

C o l l e c t i n g P l a t e H e i g h t

A c o n s e r v a t i v e pu rchase r w i l l want t o s p e c i f y a maximum a l l o w a b l e c o l l e c t i n g

h e i g h t no h i g h e r and p r e f e r a b l y l o w e r t h a n t h e maximum c u r r e n t l y i n s e r v i c e .

A few p r e c i p i t a t o r s o p e r a t e w i t h c o l l e c t i n g p l a t e s h i g h e r t h a n 48 f t . A

number of precipitators in the United States are satisfactorily operating with

a 46 ft. nominal plate height, and many more with plate heights of 40 ft. and

below (34). It should be noted that weighted wire designs are limited to a

maximum plate height of 36 ft. due to wire dynamics.

The cost of a large precipitator will decrease as plate height is increased.

However, for a given size (i.e., collecting plate area) precipitator, as

collecting plate height increases, the aspect ratio decreases, and this has

the net effect of deteriorating precipitator performance. Hence,

specifications of maximum plate height and precipitator aspect ratio must

always be considered together.

When specifying a maximum allowable collecting plate height, the operating

experience of all qualified bidders must be taken into consideration.

Table 4-1 represents the experience of nine major precipitator manufacturers

in the United States.

Ductwork/Precipitator Gas Velocities and Distribution

Precipitator gas velocity is caiculated by dividing the actual gas volume

flow rate, at design temperature and pressure, by the effective cross-

sectional area of the precipitator (%). The effective plate height in feet

is multiplied by the gas passage width and the totai number of gas passages to

yield the effective cross-sectional area.

Excessive velocity in a precipitator will result i n scouring the collected

dust from collecting plates and excessive reentrainment of fly ash during

rapping periods.

Unlike most other precipitator design parameters, there is a widespread lack

of uniformity within the industry regarding optimum precipitator gas

velocity. In practice, it historically varies from 3 to 8 ft/s; and most

modern high- efficiency precipitators operate in the 3.5 to 6 ft/s range. The

lower end of the spectrum is usually reserved for precipitators designed for

99.7 percent collection efficiency and above; however, some designers prefer

to maintain a 5 to 6 . 5 ft/s precipitator gas velocity together with high

aspect ratios for high-efficiency applications. In any event, these are

technical disagreements and not economic as there are very small cost

differenti a1 s associated with

Table 4-1

Maximum Height of Collecting Plate for Nine Major Precipitator Manufacturers

Maximum Height

of Collecting

Plate i n

Operation (ft)

Number of

Precipitator

Manufacturers

1 - 9 Total

Maximum Height of Collecting Plate in Operation for Nine Major Precipitator Manufacturers in the United States as of 1984 (82).

t h e t r a d e o f f between p r e c i p i t a t o r gas v e l o c i t y and aspec t r a t i o ( w i t h o u t

c o n s i d e r i n g t h e ext remes) . F o r t h e aspec t r a t i o s l i s t e d on page 4-10, a

p r e c i p i t a t o r gas v e l o c i t y o f between 3.75 and 4.5 f t / s e c i s most a p p r o p r i a t e

Nonuni form gas f l o w w i t h i n t h e p r e c i p i t a t o r a d v e r s e l y a f f e c t s per formance by

p romot ing uneven t r e a t m e n t t i m e s , i n c r e a s e d c o l l e c t i n g p l a t e s c o u r i n g and

r a p p i n g r e e n t r a i n m e n t i n l o c a l i z e d r e g i o n s o f h i g h v e l o c i t y f l o w . Suppress ion

o f hopper sweepage f l o w s and p r e v e n t i o n o f sneakage o f u n t r e a t e d gas around

p r e c i p i t a t o r c o l l e c t i o n zones a r e a l s o c r i t i c a l des ign aspec ts o f a h i g h

e f f i c i e n c y p r e c i p i t a t o r . I t i s e s s e n t i a l t o conduct a geomet r i c a i r f l o w model

s tudy b e f o r e a p r e c i p i t a t o r i s b u i l t . The c o s t o f c o n d u c t i n g a model s t u d y

d u r i n g t h e d e s i g n s t a g e i s i n s i g n i f i c a n t compared t o t h e c o s t o f c o r r e c t i n g

problems a f t e r s t a r t u p . Hence, a geomet r i c a i r f l o w model s t u d y s h o u l d a lways

be s p e c i f i e d as a p a r t o f t h e p r e c i p i t a t o r s u p p l i e r ' s scope o f work .

Ductwork gas v e 7 o c i t i e s shou ld a lways be s e l e c t e d so as t o o p t i m i z e t h e

t r a d e o f f between t h e low-pressure l o s s and good p r e c i p i t a t o r f l o w d i s t r i b u t i o n

c h a r a c t e r i s t i c s t h a t a r e a s s o c i a t e d w i t h l ower d u c t v e l o c i t i e s ( 3 5 fps t o

45 fps) , smal l f l u e s i z e , and s u p e r i o r p a r t - l o a d ash t r a n s p o r t c h a r a c t e r i s t i c s

o f h i g h e r d u c t v e l o c i t i e s (65 f p s t o 75 f p s ) . C o n s i d e r i n g a base- loaded

p u l v e r i z e d - c o a l - f i r e d u n i t h a v i n g a d e d i c a t e d c o a l source o f moderate ash

c o n t e n t , optimum d u c t v e l o c i t y u s u a l l y ranges between 55 t o 60 f p s . C y c l i n g

u n i t s and u n i t s f i r i n g h i g h ash c o n t e n t c o a l o r w ide range ( v a r i a b l e ) c o a l

sources t y p i c a l l y r e q u i r e h i g h e r d u c t v e l o c i t i e s i n p r e c i p i t a t o r i n 7 e t d u c t

runs.

Mechanica l S e c t i o n a l i z a t i o n (Number o f F i e l d s )

A p r e c i p i t a t o r f i e l d i s a p h y s i c a l p o r t i o n o f a p r e c i p i t a t o r i n t h e d i r e c t i o n

o f gas f l o w t h a t i s e n e r g i z e d by one o r more power s u p p l i e s (37). Each

e l e c t r i c a l s e c t i o n w i t h i n a f i e l d i s , i n e f f e c t , an independent p r e c i p i t a t o r

preceded and/or f o l l o w e d by ano the r p r e c i p i t a t o r . As such, i t hand les f l u e

gas o f t h e same q u a n t i t y , compos i t i on , and tempera tu re as p r e c e d i n g and

f o l l o w i n g f i e l d s . The f l y ash q u a n t i t y handled b y each f i e l d , however, i s

p r o g r e s s i v e l y reduced f rom t h e f r o n t t o t h e r e a r o f t h e p r e c i p i t a t o r b y t h e

amount c o l l e c t e d i n t h e p r e c e d i n g f i e l d s .

The l e n g t h o f a f i e l d i s de te rm ined b y a m a n u f a c t u r e r ' s p a r t i c u l a r d e s i g n and

may range f rom 3 f e e t t o abou t 18 f e e t . The e l e c t r i c a l c h a r a c t e r i s t i c s o f

each field are affected by the concentration of fly ash within that field.

Where ash concentration is high, as is the case with inlet fields, the

presence of charged particles in the inter-electrode space acts as a charged

grid and reduces the corona emission at a given voltage. This effect

decreases for subsequent fields, as the concentration of fly ash particles is

reduced by collection and removal from the flue gas. As a result, inlet

fields typically support higher corona voltages but lower current densities

than precipitator outlet fields.

Thus, since electrical characteristics vary from front to rear in a

precipitator, it is desirable to have a large number of independently

energized fields make up the total length of a precipitator. In this way,

electrical conditions can be optimized for the particulate concentration

present in each field.

In practice, precipitators have from two to eight fields; however, most modern

precipitators are designed with a minimum of four fields. As a rule of thumb,

the following table applies (3).

Minimum Number O f F i e'ids

Precipitator Efficiency Range (%)

Electrical Sectional ization

Theory and practical experience confirm that precipitator performance is

enhanced by increasing the degree of electrical sectionalization, i.e., the

number of transformer-rectifier sets and bus sections. There are several

reasons:

More transformer-rectifier sets and bus sections mean that the electrical properties of the gadfly ash combination will be more uniform for a smaller electrode area than for a larger electrode area. Hence, the amount of useful power delivered to the gas will be at higher levels for smaller plate areas on a transformer-rectifier set basis.

Electrode alignment and spacing are typically more accurate for smaller bus sections (this tends to be a less significant factor for rigid-frame precipitators with wide collecting electrode spacing than for weighted-wire precipitators with nine-inch spaced collecting electrodes).

Smaller transformer-rectifier sets, when matched well with their load, are inherently more stable under sparking conditions, and the sparks which occur are less intense and hence less detrimental to precipitator performance.

Outages of one- or two-bus sections due to wire failures have a much smaller effect on precipitator performance when a relatively high number of transformer-rectifier sets are utilized.

A high degree of electrical sectionalization can compensate to some degree for the deleterious effects of high fly ash concentration, gas temperature gradients, and fly ash concentration gradients within the precipitator.

In practice, the degree of ~recipitator electrical sect?onalization varies

from about 0.4 to 4 bus secticns per 1W,000 arfm gas flow. Szsfd on doab'e

half-wave operation with t w o bus sections per transformer-rectifier set, the 2 size of an individual bus section varies from approximately 5,000 ft up to

2 about 20,000 ft of collecting electrode plate area. Modern rigid-frame 2 2 designs range from a minimum o f 10,000 ft up to 45,000 ft on an

individual transformer-rectif ier basis.

It is difficult to present design guidelines for dsterminin~ a necessary

degree of electrical sectionalization. One of the more widely published

criteria was set forth by R. Ramsdell in 1968; however, this re:ationship was

based on the performance of weighted-wire precipitators, which may have more

electrode misalignment and failure problems than present day rigid-frame type

precipitators. To date, authoritative design guidelines for rigid-frame

precipitator sectionalization have not been made public. The sectionalization

practices of al; qualified bidders should be considered when specify5ng a

minimum number of transformer-rectifier sets. Current practice is to limit 2 collection electrode surface area to approximately 25,000 ft per

transformer-rectifier.

Aspect Ratio

The aspect ratio of an electrostatic precipitator is defined as its effective

height. As shown in Fig. 4-1, the aspect ratio ( A R ) is:

Figure 4-1. Components of Aspect Ratio

Note: Walkways and other unused spaces within the precipitator casing are not

included in this calculation.

Aspect ratio is an important parameter for high efficiency precipitation, as

it defines the time allotted for particles to fall into the hoppers ( 3 9 ) .

Particulate matter can be collected, rapped off, and re-collected several

times within a precipitator chamber prior to falling into a hopper. A

properly selected aspect ratio allows sufficient time for the particles to

fall into a hopper; whereas excessive reentrainment will occur if the aspect

ratio is too low.

In practice, aspect ratio varies from 0.5 to 2.0. As a rule of thumb, the

following table applies:

Aspect Ratio Precipitator

Efficiency Range (%)

Less than 98.0 98.0 to 99.0 99.1 to 99.4 99.5 to 99.7

99.8+

Treatment Time

Treatment time refers to the length of time a particle spends in the presence

of collecting electrodes, at design velocity, should it be allowed to traverse

the entire length of the precipitator in a horizontal path. Also, the

treatment length of the precipitator, upon which treatment time is based, is

the sum L1 + t2 + L3 as shown in Fig. 4-1.

A minimum treatment time may be calculated and specified; however,

specification of a minimum installed collecting plate area, a maximum

precipitator gas velocity, and a minimum aspect ratio will in fact determine a

minimum treatment time for a precipitator.

GENERAL ARRANGEMENT

A preliminary general arrangement drawing provided to the bidders along with

specifications, indicates the arrangement of the precipitation equipment,

d u c t w o r k , and f l u e gas dampers as needed t o meet a l l system o p e r a t i n g

r e q u i r e m e n t s . O p e r a t i n g requ i rements must be e s t a b l i s h e d e a r l y i n t h e p r o j e c t

i n c o n j u n c t i o n w i t h t h e o p e r a t i n g , u p s e t , and s a f e t y requ i remen ts o f t h e

b o i l e r , a i r h e a t e r s , d r a f t fans, and i f a p p l i c a b l e , t h e f l u e gas

d e s u l f u r i z a t i o n system. OnTy a f t e r a l l requ i remen ts have been f i rmly

e s t a b l i s h e d can a p r e l i m i n a r y genera l arrangement be deve loped.

P r e c i p i t a t o r Arrangement

M u l t i p l e p r e c i p i t a t o r cas ings may be a r ranged e i t h e r s i d e by s i d e o r

p iggyback (one p r e c i p i t a t o r above t h e o t h e r ) . The p iggyback arrangement

s h o u l d be used o n l y when severe space r e s t r i c t i o n s p r e v e n t use o f t h e

s ide -by -s ide arrangement, f o r t h e f o l l o w i n g reasons:

The p iggyback arrangement r e q u i r e s c o n s i d e r a b l y more s t r u c t u r a l suppor t s t e e l , and l a r g e r , more e x t e n s i v e f o u n d a t i o n requ i remen ts and access p r o v i s i o n s .

The s ide -by -s ide arrangement i s more conduc ive t o a t t a i n i n g u n i f o r m p r e c i p i t a t o r f l o w f i e l d s . Some p iggyback p r e c i p i t a t o r s have problems w i t h gas f l o w d i s t r i b u t i o n , v a r y i n g p a r t i c l e s i z e d i s t r i b u t i o n , and gas tempera tu re s t r a t i f i c a t i o n .

Rou t ine o p e r a t i n g and maintenance t a s k s can become more t i m e consuming w i t h t h e p iggyback arrangement because o f p r e c i p i t a t o r r o o f i n a c c e s s i b i l i t y , a l t h o u g h i n s t a l l a t i o n o f an adequate number o f e l e v a t o r s and s t a i r t o w e r s w i l l h e l p a l l e v i a t e t h i s prob lem.

Ma jo r o v e r h a u l s o f a p r e c i p i t a t o r ' s i n t e r n a f s become s i g n i f i c a n t l y more c o s t l y and t i m e consuming, e s p e c i a l l y f o r a l o w e r p r e c i p i t a t o r , wh ich has l i m i t e d overhead c l e a r a n c e .

* Water wash ing a c t i v i t i e s become much more d i f f i c u l t f o r t h e p iggyback arrangement, e s p e c i a l l y i n terms o f wet f l y ash d i s p o s a l .

It i s adv isab le when t h e p iggyback arrangement cannot be a v o i d e d t h a t s p e c i a l

a t t e n t i o n be p a i d t o duc twork l a y o u t , p r e c i p i t a t o r access p r o v i s i o n s , and t h e

geomet r i c a i r f l o w model s tudy program.

The most d i f f i c u l t f l o w - c o n t r o l prob lem i n a p r e c i p i t a t o r sys tem i s an even

expans ion o f f l u e gas w i t h i n t h e p r e c i p i t a t o r i n l e t d i f f u s e r s i n c e t h e

d i f f u s e r c r o s s - s e c t i o n a l area expands r a p i d l y t o abou t t e n t i m e s t h e d i f f u s e r

i n l e t area i n a v e r y s h o r t d i s t a n c e (40). The t h r e e b a s i c d i f f u s e r

c o n f i g u r a t i o n s a r e shown i n F i g . 4-2. It i s e a s i e s t t o o b t a i n u n i f o r m

v e l o c i t y p r o f i l e s w i t h a t r u n c a t e d py ramid n o z z l e . T runca ted py ramid n o z z l e s

s h o u l d always be g i v e n f i r s t c o n s i d e r a t i o n ; however, i f space r e s t r i c t i o n s

Distribution Plates

WEDGE

Figure 4-2. Basic Diffuser Configurations ( 5 9 ) -

TRUNCATED PYRAMID NOZZLE

EXPANSION TURN PLENUM

p r e v e n t t h e i r use, an expans ion plenum o r wedge d i f f u s e r may be s u b s t i t u t e d .

I n g e n e r a l , pyramid n o z z l e s r e q u i r e d i s t r i b u t i o n p l a t e s and sometimes i n l e t

s p l i t t e r vanes. Plenum and wedge d i f f u s e r s a lways r e q u i r e b o t h vane

assemb l ies and d i s t r i b u t i o n p l a t e s . Ladder vanes i n t h e plenum and s p l i t t e r

vanes i n t h e wedge a r e used t o t u r n t h e gas, and d i s t r i b u t i o n p l a t e s complete

t h e sp read ing and smoothing o f t h e gas f l o w . S p e c i a l a t t e n t i o n shou ld be

g i v e n t o t h e e x e c u t i o n o f t h e geomet r i c a i r f l o w model s tudy program when u s i n g

e i t h e r plenum o r wedge d i f f u s e r s . Many wedge d i f f u s e r s have gas f l o w

m a l d i s t r i b u t i o n and e x c e s s i v e ash d r o p o u t prob lems. Some p o o r l y - d e s i g n e d

py ramid n o z z l e and plenum d i f f u s e r s a l s o s u f f e r f rom excess ive f l y ash d r o p o u t

prob lems.

Ductwork Arrangement

T r a n s p o r t ductwork shou ld be des igned w i t h t h e f o l l o w i n g o b j e c t i v e s i n mind:

S i m p l i c i t y and symmetry o f d u c t geometry

Cost e f f e c t i v e n e s s o f s t r u c t u r a l s u p p o r t arrangement

Low system p r e s s u r e l o s s

Proper gas d i s t r i b u t i o n , e s p e c i a l l y a t t h e i n l e t t o t h e p r e c i p i t a t o r ' s d i f f u s e r s e c t i o n

Adequate c r o s s o v e r and i s o l a t i o n c a p a b i l i t y as d i c t a t e d by system o p e r a t i n g requ i remen ts

Adequate p r o v i s i o n s f o r accommodating u n i t l o a d r e g i m e n t and upse t c o n d i t i o n s .

Once an a p p r o p r i a t e duc twork t r a n s p o r t gas v e l o c i t y has been s e i e c t e d , as

d i scussed l a t e r , t h e arrangement o f d u c t r u n s u s u a l l y becomes a s imp le m a t t e r

o f c o n n e c t i n g p o i n t s A and B i n t h e most d i r e c t and symmetr ica l manner

p o s s i b l e . S i m p l i c i t y , l o w system p r e s s u r e l o s s , and p roper gas d i s t r i b u t i o n

t y p i c a l l y go hand i n hand.

A w e l l - a r r a n g e d d u c t system, hav ing l o w p r e s s u r e l o s s , can sometimes be

redes igned f o r s l i g h t l y l ower p r e s s u r e l o s s and i n c r e a s e d gas u n i f o r m i t y by:

P l a c i n g a r a d i u s on t h e i n s i d e c o r n e r o f each d u c t bend

Rep lac ing each 90' bend w i t h two 45O bends ( i f space p e r m i t s )

Ex tend ing t h e l e n g t h o f d u c t expans ion s e c t i o n s ( i f space p e r m i t s ) .

O p e r a t i n g c o s t b e n e f i t s o f t h e above p r a c t i c e s , however, r a r e l y overcome t h e

i n c r e a s e d c o s t of d u c t f a b r i c a t i o n .

Perhaps the only area i n t h e transport ductwork system where gas flow

uniformity is the primary design consideration is at the duct section located

immediately upstream of the precipitator inlet diffuser. A maldistributed

flow field i n this region wi17 make it difficult if not impossible for the

diffuser to deliver a uniformly distributed flow field at the entrance of the

precipitation chamber. Ideally, the duct section upstream of the diffuser

should be a three-hydraulic-diameter long straight duct run, preceded by a

well-vaned bend (or transition) section. As a minimum, this duct section can

be one-hydraulic-diameter long; however, it is good practice to radius the

inner corner of an upstream bend whenever this duct run is less than

two-hydraulic-diameters long.

The arrangement of precipitator outlet ductwork is less critical to

precipitator flow uniformity. A single distribution plate at the exit of the

precipitation chamber can overcome any back-pressure gradient caused by outlet

ductwork; however, outlet ductwork must be capable of delivering an even flow

split and uniform flow fields to the ID fans. This is usually accomplished by:

Use of a symmetrical outlet duct arrangement

Long, straight duct runs immediately upstream of the ID fans

A crossover duct, for flow split equalization between two or more parallel ID fans, situated between the precipitators and ID fans.

When the capability to isolate individual precipitator casings is desired, an

inlet crossover duct allows for any combination of operating air heaters and

precipitators. A damper is sometimes installed in this inlet crossover duct

to prevent excessive ash dropout in dead-flow zones during the one flow train

operati ng mode.

Flue Gas Dampers

Flue gas dampers can serve one of three functions in a precipitator system:

Isolation of a precipitator during unit part-load operation

Gas flow biasing between operating precipitators

Prevention of excessive ash dropout in a precipitator inlet crossover duct.

Each function requires a slightly different type o f damper.

P r e c i p i t a t o r i s o l a t i o n i s u s u a l l y ach ieved w i t h g u i l l o t i n e o r double

l o u v e r - t y p e dampers . I s o l a t i o n dampers a r e s i t u a t e d a t bo th t h e i n l e t and

o u t l e t o f a p r e c i p i t a t o r . When t h e s e dainpers a r e p r o p e r l y d e s i g ~ e d w i t h an

a i r s e a l f o r z e r o - l e a k a g e , personnel may s a f e l y e n t e r t h e o u t - o f - s e r v i c e

p r e c i p i t a t o r d u r i n g p a r t - l o a d o p e r a t i o n s .

Gas f l o w b i a s i n g dampers a r e n o r r a l l y of t h e s i n g l e - l o u v e r t y p e , which i s n o t

a g a s - t i g h t d a a p e r . Sometimes one l o u v e r of a doub le - louver i s o l a t i o n damper

can a l s o f u n c t i o n a s a g a s f low b i a s i n g damper. Flow b i a s i n g danper s a r e

u s u a l l y p o s i t i o n e d i n t h e p r e c i p i t a t o r o u t l e t d u c t , where f low r n a l a i s t r i b u t i o n . . - - m . downs;ream of t h e ~ a r ~ i c l l y c l o s e d c a n p c r K; ! l n z t C T ~ C Z ; r e c i p i t z t o r r.cw

. ? . . - - y FIcw b i a s : ~ : dzn;[;srs c n be ti5.d t c :

Compensate f o r an unsymmetrica? d u c t c o n f i g u r a t i o n , which i f l e f t u n c o r r e c t e d would o v e r l o a d one p r e c i p i t a t o r w i t h more than i t s a l l o t t e d g a s f low.

e a l a n c e t h e d i s t r i b u t i o n o f gas f low t o each p r e c i p i t a t o r , a s i s u s u a l l y r e q u i r e d d u r i n g m u l t i p l e p r e c i p i t a t o r o p e r a t i o n w i t h an o f f - l i n e ID f a n .

Change t h e d i s t r i b u t i o n of gas f low t o each p r e c i p i t a t o r from i t s d e s i g n d i s t r i b u t i o n ( i . e . , equal p e r c e n t a g e ) t o c o v p e n s ~ t e f o r cut o f s e r v i c e bus s e c t i o n s o r ma: f u n c t i o n i n g rapp ing components.

R e s t r i c t t o low g a s f low r a t e s t h e f low t o an o u t - o f - s e r v i c e p r e c i p i t a t o r f o r t h e purpose of pu rg ing and warm up of t h e p r e c i p i t a t o r d u r i n g i t s s t a r t u p .

For p r e v e n t i o n o f e x c e s s i v e a s h d ropou t i n an i n l e t c r o s s o v e r d u c t , a

s i n g l e - l o u v e r damper i s u s u a l l y s u f f i c i e n t . During normal c n i t o p e r a t i o n ,

thTs damper i s i n i t s f u l l y open p o s i t i o n . During s i n g l e p r e c i p i t a t o r

o p e r a t i o n , t h e damper i s c l o s e d .

STRUCTURAL REQUIREMENTS

General

With regard t o equipment longevity and r e l i a b i l i t y , t h e s t r u c t u r a l design

parameters of a p r e c i p i t a t o r a r e a s important a s t h e performance

requirements . General ly, s t r u c t u r a l d e t a i l s a r e not valued a s highly a s t h e

performance requirements during proposal eva lua t ions . Design pressures and

temperatures , cons t ruc t ion ma te r i a l s , and casing th i cknesses a r e usual ly t h e

only items considered during a proposal review. Other i tems t h a t should be

i nves t iga t ed a r e t he manufacturer 's design phi losophy, s tandard f a b r i c a t i o n

and e r ec t ion to l e r ances , and an inspec t ion and qua l i t y - con t ro l program.

Due t o var ious fo rces imposed on t h e s t r u c t u r e , e l e c t r o s t a t i c p r e c i p i t a t o r s

may be complicated t o analyze. An experienced s t r u c t u r a l engineer should be

employed t o review manufacturers ' p roposa ls before s e l e c t i n g a supp l i e r .

Seismic Considerat ions

S t ruc tu ra l s t e e l framework and suppor ts should be

withstand t h e seismic forces determined from Amer

I n s t i t u t e , ANSI, Standard A58.1 f o r t h e r i s k zone

p l an t s i t e . S t ruc tu ra l s t ee l t h a t must be design

designed t o s a f e l y

ican National Standards

developed f o r a s p e c i f i c

ed f o r se i smic fo rces

comprises main g i r d e r s and a s soc i a t ed hor izonta l bracing , a l l s t r u c t u r a l

support s t e e l (columns, bracing, p l a t fo rms , platform suppor ts , s t a i r s , e t c . ) ,

buckstay co rne r t i e s , l a t e r a l t i e s t o s t r u c t u r a l s t e e l top g r i d s t e e l , and gas

duc t s .

Live loads a r e not considered in c a l c u l a t i n g l a t e r a l se i smic fo rces . Also,

windloads a r e not usua l ly considered a s ac t i ng s imultaneously with seismic

f o r c e s . Equipment supports should be designed t o withstand spec i f i ed

( s i t e - s p e c i f i c ) seismic a c c e l e r a t i o n s ; t h i s fo rce i s considered t o a c t on t h e

base of equipment support . Supports should be designed t o prevent

displacement o f t he equipment, assuming t h a t f r i c t i o n does n o t e x i s t , and t o

maintain t h e primary s t r e s s e s induced by the se i smic loads wi th in t he e l a s t i c

l i m i t s of t h e support mater ia l . The e f f e c t of se i smic condi t ions when

s e l e c t i n g anchor b o l t ma te r i a l , b o l t d iameter , and number of b o l t s should a l s o

be considered.

Seismic loads a r e ca lcu la ted based on t h e p r e c i p i t a t o r load p lus 25 percent of

t h e l i v e load ac t ing on the s t r u c t u r e . One area of cont roversy i s t he

c l a s s i f i c a t i o n o f s t o r e d f l y ash and whether i t s h o u l d be c o n s i d e r e d as a

s o l i d o r f l u i d d u r i n g a se i sm ic even t . I f t h e l o a d i n g i s n o t s p e c i f i e d ,

m a n u f a c t u r e r s w i l l d e s i g n t h e s t r u c t u r e and equipment i n accordance w i t h t h e i r

own s tandards .

E x p e r i e n c e has shown t h a t p r e c i p i t a t o r w i n d l o a d s a r e u s u a l l y p redominan t o v e r

s e i s m i c l o a d s on a s t r u c t u r e ' s d e s i g n . However, se i sm ic c o n d i t i o n s must

a lways govern f o u n d a t i o n des ign .

Wind, I c e and Snow t o a d s

A p r e c i p i t a t o r and f o u n d a t f o n a re des igned t o w i t h s t a n d w i n d l o a d s as

s p e c i f i e d i n t h e U n i f o r m B u i l d i n g Code (UBC) and/or any s t a t e o r l o c a l code

w h i c h may a p p l y . I c e and snow loads shou ld be s p e c i f i e d as r e q u i r e d by l o c a l

c l i m a t e c o n d i t i o n s .

Common D i v i s i o n W a l l s

Common d i v i s i o n w a l l s a r e p l a c e d between i n t e r n a l p r e c i p i t a t o r s u p p o r t columns

t o c o n t a i n t h e f l u e gas w i t h i n t h e c o l l e c t i n g p l a t e chambers. D i v i s i o n w a l l s

reduce t h e q u a n t i t y o f gas bypass ing t h e c o l l e c t i n g f i e l d and e x i t i n g t h e

p r e c i p i t a t o r u n t r e a t e d . The w a l l s a r e n e i t h e r gas t i g h t n o r i n s u l a t e d .

D i v i s i o n w a l l s have been i n s t a l l e d t h a t a r e gas t i g h t . T h i s a l l o w s one

s e c t i o n o f a p r e c i p i t a t o r t o be removed f rom s e r v i c e f o r main tenance w h i l e

a n o t h e r s e c t i o n c o n t i n u e s t o ope ra te . There a r e m a j o r prob lems a s s o c i a t e d

w i t h g a s - t i g h t w a l l s such as d e s i g n i n g f o r p r e s s u r e and t h e r m a l g r a d i e n t s and

pe rsonne l s a f e t y . W i t h one s e c t i o n o f a p r e c i p i t a t o r o u t o f s e r v i c e , a

d i v i s i o n w a l l must w i t h s t a n d t h e p r e s s u r e d i f f e r e n t i a l between t h e two

chambers, and i t must a l s o be capab le o f a c c e p t i n g t h e t h e r m a l g r a d i e n t s

between t h e two chambers. On seve ra l i n s t a l l a t i o n s , d i v i s i o n w a l l s have

e x p e r i e n c e d weldment and s t r e s s f a i l u r e s due t o t h e extreme t e m p e r a t u r e

d i f f e r e n t i a l be tween a h o t and a c o l d chamber.

The g a s - t i g h t w a l l c o n c e p t c r e a t e s some s p e c i a l problems f o r pe rsonne l w o r k i n g

i n t h e c o l d chamber o f an o p e r a t i n g p r e c i p i t a t o r ; and t h e r e f o r e , a l l s a f e t y

p r e c a u t i o n s must be observed. A l l e l e c t r i c a l f i e l d s i n t h e chamber must be

deenerg i zed . The chamber t o be e n t e r e d must be shutdown w e l l i n advance o f

pe rsonne l e n t r y so t h a t i t i s a l l o w e d t o c o o l t o an a c c e p t a b l e tempera tu re .

The chamber i s t h e n p u r g e d w i t h o u t s i d e a i r b y use o f t empora ry v e n t i l a t i n g

f a n s .

A more p r a c t i c a l a l t e r n a t e t o u s i n g g a s - t i g h t w a l l s i s d i v i d i n g a l a r g e

p r e c i p i t a t o r i n t o m u l t i p l e p r e c i p i t a t o r cas ings . T h i s concept has s e v e r a l

advantages r e l a t i v e t o g a s - t i g h t w a l l s . I t reduces s a f e t y prob lems and

e l i m i n a t e s t h e des ign prob lems o f o p e r a t i n g one chamber w h i l e s e r v i c i n g t h e

o t h e r . I n a d d i t i o n , s m a l l e r p r e c i p i t a t o r c a s i n g s a r e e a s i e r t o e r e c t , and i t

i s e a s i e r t o m a i n t a i n d imens iona l t o l e r a n c e s d u r i n g t h e i r c o n s t r u c t i o n . The

m u l t i p l e p r e c i p i t a t o r c a s i n g ar rangement , however, r e q u i r e s more space t h a n a

s i n g l e u n i t , and t h e r e i s a d d i t i o n a l c o s t i n v o l v e d f o r e x t r a w a l l s ,

i n s u l a t i o n , access p l a t f o r m s , and s t a i r w a y s . However, t h e a d d i t i o n a l c o s t i s

smal l when compared t o d e s i g n and o p e r a t i o n a l prob lems a s s c c i a t e d w i t h

m a i n t a i n i n g a g a s - t i g h t d i v i s i o n w a l l .

Ductwork

Ductwork i s s u b j e c t e d t o and must be d e s i g n e d f o r :

Wind and se ismic l o a d s

I n t e r n a l gas p r e s s u r e ( o r vacuum)

F l y ash accumu la t ion

I n s u l a t i o n a n d l a g g i n g

Snow and i c e l o a d s .

A d d i t i o n a l l y , duc twork i s s u b j e c t e d t o t h e e l e v a t e d tempera tu re o f t h e f l u e

gas; t h e r e f o r e , i t s des ign must p r o v i d e f o r o v e r a l l expans ion. Duc twork

shou ld be des igned t o p r o v i d e smooth, s t a b l e f l o w c o n d i t i o n s wh ich a r e u n i f o r m

w i t h i n t h e requ i remen ts o f t h e p rocess .

Ductwork r o o f i n g shou ld have a d r a i n a g e system t o p r e v e n t wa te r f r o m cascad ing

t o t h e ground. It shou ld c o n s i s t o f s h e e t m e t a l g u t t e r s and c a s t i n g s o i l p i p e

downspouts p i p e d t o w i t h i n 12 i n . o f t h e f i n i s h e d ground l e v e l f o r c o n n e c t i o n

t o an underground d ra inage system.

Ductwork f rom t h e c o n n e c t i o n t o t h e a i r h e a t e r s h o u l d r i s e e i t h e r v e r t i c a l l y

o r a t a minimum a n g l e o f 45 degrees t o i t s t r a n s i t i o n w i t h t h e h o r i z o n t a l

duc twork l e a d i n g t o t h e p r e c i p i t a t o r i n l e t n o z z l e s . A d rop -ou t hopper s h o u l d

be p r o v i d e d f rom t r a n s i t i o n duc twork .

Dus t Loads. Des ign ing d u c t w o r k f o r f l y ash d u s t l o a d s should be c o n s e r v a t i v e .

The d i s p e r s i o n o f ash i n t h e f l u e gas and i t s b e h a v i o r as gas f l ~ o w s t h r o u g h

t he ductwork cannot be p red i c t ed . The ductwork should be designed f o r ash

loadings up t o 20 pe rcen t of t he c ross-sec t iona l a rea . Care should be taken

t o minimize the number of p ro j ec t ions , l edges , e t c . , in t he ductwork t h a t can

cause ash bui ldups.

In te rna l vs. External Bracing. A f l u e gas d u c t r equ i r e s support bracing t o

withstand the gas pressure o r vacuum, p u l s a t i o n s , and duct v ib ra t i ons . There

a r e two methods of bracing the ductwork: i n t e r n a l l y o r e x t e r n a l l y . I n t e rna l

bracing i s the l e a s t c o s t ? y way of support ing a duc t ; however, i t has several

disadvantages. Bracing causes high p re s su re drops within a duc t and i s

subjec ted t o temperature g rad i en t s which can cause a member t o buckle. The

bracing i s a l s o sub jec t t o erosion due t o f l y ash impingement on exposed

su r f aces . In te rna l bracing can c r e a t e gas flow d i s tu rbances , a s wel l .

External bracing has a higher i n i t i a l c a p i t a l c o s t , and i t can c r e a t e problems

when ductwork, i n s u l a t i o n , and lagging a r e i n s t a l l e d . S t andof f s , however, may

be secured t o ou t s ide s t i f f e n e r s t hus providing even sur faces on which t o

i n s t a l l prefab panels .

Maintenance c o s t s should be reviewed in cons idera t ion of t he type of bracing

t o use. In te rna l bracing r equ i r e s an annual inspec t ion and poss ib le r e p a i r

and/or minor replacement due t o i t s opera t ing environment. Inspect ion of

ex terna l bracing i s l im i t ed due t o t he presence o f i n su l a t i on and lagging

panels . On balance, t h e indus t ry t r end i s toward the use of ex t e rna l bracing.

Hoppers - Dust and Ash Handling Equipment Loads

P r e c i p i t a t o r hoppers a r e temporary s to rage b i n s used t o s t o r e co l l ec t ed f l y

a sh . General ly, mu l t i p l e rows of pyramid-shaped hoppers a re mounted d i r e c t l y

of f p r e c i p i t a t o r support s t e e l . Each hopper should have a minimum s to rage

capac i ty o f 12 hours a t f u l l load opera t ion based on a spec i f i ed maximum i n l e t

dus t loading. Capacity should be c a l c u l a t e d on the b a s i s t h a t t he ash level

i s 1 2 inches below t h e lowest pro t rus ion of t h e discharge e l ec t rode assembly.

Antisneakage b a f f l e s on the leading and t r a i l i n g hopper edges should be

provided t o prevent un t rea ted gas from bypassing the c o l l e c t i n g su r f ace

through t h e hoppers. Where two mechanical f i e l d s a r e spanned by t he same

hopper in the direction o f gas flow, antisneakage baffles should be provided

between the fields to prevent sneak-by and rapping reentrainment.

3 Hopper design should be based on a fly ash density of 100 lb/ft for 3 structural purposes and 50 lb/ft for capacity determination purposes. This

range in fly ash densities provides for a conservative design. The hopper

design load should allow for four mounted electromagnetic vibrators or rappers

on two sides.

Consideration must be given to the load imposed by ash handling equipment

mounted on each hopper outlet. Ash handling systems for fly ash removal are

generally pneumatic conveying systems with piping and control valves. Each

hopper should be designed to accommodate horizontal expansion loads and a

plugged pipe condition from the ash handling system.

Mechanical systems such as drag chains, screw conveyors, etc., have been used

for ash removal. This type of equipment requires close tolerances on multiple

hopper connections. Field-adjustable hopper flange connections should be

specified to simp1 ify equipment erection. When mechanical removal systems are

employed, each hopper should be designed to accept the equipment load plus the

material load based on a plugged condition. Expected ash loading can be found

from the expression:

where:

La = ash load (tons)

3 Vm = Carrying volume of equipment (ft )

D = Density of ash (lb/ft 3,

Sl ide Bearings

Flue gas temperatures result in a thermally induced expansion of the

precipitator casing and movement of the casing on its supporting structure.

These movements must be accommodated at the connection points between the

structural steel and precipitator column base. Generally, a fixed point is

established at or near the geometric center of the precipitator. With the

exception of the fixed middle column, all other support points are allowed to

grow outward

l o n g i t u d i n a l l y and t r a n s v e r s e l y , The c e n t e r column i s t h e o n l y column f i x e d

i n b o t h d i r e c t i o n s ; t h e o t h e r columns have gu ide b a r d t o a l l o w f o r d i r e c t e d

expans ion i n o r d e r t o keep t h e c a s i n g as square as p o s s i b l e .

To p r o v i d e f r e e expans ion and reduce f r i c t i o n a l r e s i s t a n c e , s l i d e b e a r i n g s

( g e n e r a l l y made o f t e f l o n ) a r e p o s i t i o n e d between t h e s t r u c t u r a l s t e e l and

p r e c i p i t a t o r column base. These b e a r i n g s a r e s e l e c t e d based on a l l o w a b l e

b e a r i n g p r e s s u r e s and d imens iona l d e t a i l s i n t h e c o l d and h o t o p e r a t i n g

p o s i t i o n s . A lso, c o n s i d e r a t i o n must be g i v e n t o speed o f movement and t o

t e m p e r a t u r e requ i remen ts o f t h e bear

The manner i n wh ich t h e b e a r i n g s a r e

o p e r a t i o n . S l i d i n g sur faces must be

ngs d u r i n g o p e r a t i o n

i n s t a l l e d i s c r i t i c a l t o t h e i r

p a r a l l e l , must m a i n t a i n a t i g h t

h o r i z o n t a l t o l e r a n c e , and v e r t i c a l ad jus tmen t p r o v i s i o n s , such as j a c k i n g

screws, shou ld be s p e c i f i e d t o a l l o w f i n e l e v e l i n g a f t e r t h e s t e e l i s

e r e c t e d . A f t e r f i n a l l e v e l i n g i s accompl ished, s t a i n l e s s s t e e l sh im packs

need n o t be used t o h o l d t h e v e r t i c a l a d j u s t m e n t i n p o s i t i o n i f a d j u s t a b l e

h e i g h t b e a r i n g s a r e used.

Shear b a r s and s tops s h o u l d be added a t t h e s u p p o r t s t r u c t u r e p r e c i p i t a t o r

column base c o n n e c t i o n t o c o n t r o l t h e o v e r a l l movement o f a p r e c i p i t a t o r .

These b a r s a l s o c o n t r o l t h e l a t e r a l shear a t t h e connec t ion p o i n t f r o m se ism ic

and /o r w i n d loads t h a t c o u l d be g r e a t e r t h a n t h e f r i c t i o n a l l o a d s . These b a r s

a r e p l a c e d a f t e r a p r e c i p i t a t o r ' s f i n a l a l i g n m e n t has been checked by a

q u a l i f i e d i n s p e c t o r .

D u r i n g b o i l e r s t a r t - u p and l o a d changes, t h e tempera tu re i n a p r e c i p i t a t o r

w i l l v a r y , wh ich causes t h e s t r u c t u r e t o expand a t v a r y i n g r a t e s . D u r i n g l o w

l o a d s , t h e upper beams w i ' i l expand f a s t e r than lower beams due t o h e a t i n g b y

t h e f l u e gas f l o w , and t h i s causes t h e c a s i n g t o t a k e t h e f o r m o f an i n v e r t e d

t r a p e z o i d and induces a bend ing moment ( r o t a t i o n ) a t t h e s l i d e b e a r i n g .

Consequent ly , t h e p a r a l l e l i s m between s l i d i n g s u r f a c e s i s l o s t , w h i c h causes

s t r e s s l e v e l s t o b u i l d wh ich may damage t h e bear ing . S p h e r i c a l s l i d e b e a r i n g s

a r e commonly used t o overcome t h i s s i t u a t i o n , e s p e c i a l l y i n t h e d e s i g n o f

h o t - s i d e p r e c i p i t a t o r s and c y c l i c l o a d u n i t s .

Expansion Joints

The importance of precipitator and ductwork expansion joints cannot be

overstressed. Improper selection and application of joints can create

failures and affect system reliability. Expansion joints are placed in

ductwork to accommodate thermal movement due to temperature gradients. Any single joint may be subjected to compression, lateral offset, elongation,

torsional/angular deflection, or any combination of these movements.

Additionally, expansion joints must compensate for fabrication and erection

tolerances. An ideal expansion joint material would be noncorroding, elastic,

and heat resistant.

There are two types of expansion joints available for flue gas service:

metallic and non-metallic (fabric). Both have merit, but the non-metallic

joint has gained strong acceptance within the industry in the last several

years.

A non-metallic joint has operating and economic advantages over metallic

joints. A non-metallic joint can adjust to movement in all directions (axial,

lateral, angular, and torsional), while metal joints can move in only one

plane. Non-metallic joints are less expensive to install and will compensate

for erection errors and thereby reduce the total fnstalled cost of the

ductwork. They also resist corrosion and reduce noise more effectively than

metal joints.

Since they can absorb multiple movement, fewer non-metallic than metallic

joints are required i n ducting arrangements. Toggles (spool piece) and

supporting structures required for meta7 joint arrangements are not needed

when employing non-metallic joints, which reduces the overaTl cost o f the

ductwork arrangement.

Non-metallic joints require less space than metallic joints. In a high temperature application where a 6 in. expansion may be expected, a metallic

joint requires a 48 in. width. In contrast, a non-metallic joint requires but

an 18 in. width for the same application.

Due to the current trend toward use of non-metallic joints, the discussion

will focus on the types available and their applications.

The two a reas i n a f l u e gas system t h a t r equ i r e expansion j o i n t s a r e between

t h e steam genera tor and a i r p rehea ter (ho t s i d e ) and from t h e a i r p r ehea t e r t o

t h e chimney ( co ld s i d e ) . Hot-side ductwork t r a n s p o r t s f l u e gas in t h e 650 t o

900°F range, and the cold-side ductwork t r a n s p o r t s f l u e gas of up t o 350°F.

A hot-side app l i ca t i on wi l l r equ i r e t h e use of a composite-type, b e l t j o i n t .

This j o i n t i s a layered product t h a t c o n s i s t s of var ious p l i e s of m a t e r i a l s

l a i d one over another and usua l ly vulcanized , bonded, sewn, o r mechanically

fas tened toge the r in the clamp o r f l ange a r e a . This method of cons t ruc t ion

al lows each mater ia l l aye r t o func t ion independently of t he o the r s . B a f f l e s

a r e used t o p r o t e c t t he b e l t from f l y ash impingement and abras ion .

A cold-side app l i ca t i on uses an e las tomer ic molded-type f lange design j o i n t .

The molded j o i n t has a wire o r f a b r i c s t r eng th member. The wire member i s a

monel o r inconel reinforcement t h a t can wi ths tand temperatures up t o 1200°F

and r e s i s t cor ros ion . Fabric s t r eng th members have a tendency t o d e t e r i o r a t e

causincj embri t t l emen t of t h e e las tomer .

A g r e a t many f a c t o r s must be considered when spec i fy ing non-metallic expansion

j o i n t s . Engineers should spec i fy t he expected app l i ca t i on and design

c o n s t r a i n t s . Careful a t t e n t i o n must be paid t o t h e d e t a i l s of j o i n t

cons t ruc t ion and, where p o s s i b l e , t h e u t i l i t y should spec i fy the exac t j o i n t

which i s t o be provided. Such a s p e c i f i c a t i o n should ensure t h a t long-term

r e l i a b i l i t y and the u t i l i t y ' s p a s t experiences a r e considered.

Mater ia l s of Construct ion and Thicknesses

P r e c i p i t a t o r s a r e operated a t high tempera tures , high d i f f e r e n t i a l p r e s su re s ,

and i n a co r ros ive atmosphere, and the m a t e r i a l s used in p r e c i p i t a t o r

cons t ruc t ion m u s t be s e l ec t ed based on withstanding t h i s type of s e r v i c e .

The s e l e c t i o n of material v a r i e s with t he type of p r e c i p i t a t o r used ( i . e . , hot

o r co ld ) . A hot-side p r e c i p i t a t o r ope ra t e s i n a range from 600 t o 90U°F.

S t r u c t u r a l c reep i s a major concern a t t h i s temperature range al though

cor ros ion r a t e s a r e re ta rded due t o t h e high temperature. Thermal c reep must

be accounted f o r in t h e chamber des ign . I f d i f f e r e n t r a t e s of expansion a r e

no t absorbed by t h e des ign , misalignment of t h e c o l l e c t i n g p l a t e s w i l l occur.

The mater ia l s e l ec t ed fo r hot-side opera t ion should be reviewed

i n terms o f the rma l c r e e p and c r e e p r u p t u r e a t e l e v a t e d tempera tu res . A t h i g h

tempera tu res , A-36 s t e e l p l a t e has a r e d u c t i o n i n a l l o w a b l e d e s i g n s t r e s s

l e v e l s and w i l l r e q u i r e a d d i t i o n a l s t i f f e n e r s and, perhaps, t h i c k e r p l a t e w o r k

wh ich means i n c r e a s e d c o s t s . H i g h tempera tu re a p p l i c a t i o n s t e n d t o use s t e e l

p l a t e m a t e r i a l l i k e A-242 (Cor ten ) w i

Co ld -s ide p r e c i p i t a t o r s o p e r a t e below

creep. The m a j o r concern f o r m a t e r i a

t h e c o r r o s i v e atmosphere c r e a t e d when

h A-36 s t i f f e n e r s .

35C°F and a r e n o t s u b j e c t e d t o the rma l

s e l e c t i o n i n a c o l d - s i d e a p p l i c a t i o n i s

t h e gas tempera tu re d r o p s be low t h e a c i d

dewpoin t . T h i s t e m p e r a t u r e w i l l change based on t h e amount o f s u l f u r

c o n t a i n e d i n t h e f u e l . M i x i n g w i t h oxygen a t e l e v a t e d temperatures, s u l f u r i s

o x i d i z e d t o s u l f u r d i o x i d e (SOp) w h i c h i s f u r t h e r o x i d i z e d t o s u l f u r

t r i o x i d e (SO3). SO3 h y d r a t e s w i t h w a t e r t o produce s u l f u r i c a c i d

(H2S04) w h i c h i s v e r y c o r r o s i v e t o s t e e l . Areas where a c i d a t t a c k s t h e s t e e l

a r e h e a t s i n k s such as hoppers, u n i n s u l a t e d s t e e l , e t c .

G e n e r a l l y , c o l d - s i d e p r e c i p i t a t o r s a r e c o n s t r u c t e d f rom A-36 p l a t e s t e e l . The

s t e e l s h o u l d be s p e c i f i e d as a minimum o f 1 /4- inch t h i c k , wh ich a l l o w s

1/16 i n . f o r c o r r o s i o n . Design c a l c u l a t i o n s f o r t h e s t r u c t u r e shou ld be based

on 3/16- in . t h i c k p l a t e w o r k . F l y -ash hoppers shou ld b e s p e c i f i e d as 3 /8- in .

t h i c k p l a t e wh ich i n c l u d e s a c o r r o s i o n a l l owance o f 3/16 i n .

Temperature E x c u r s i o n s

E l e c t r o s t a t i c p r e c i p i t a t o r s shou ld be des igned so as t o w i t h s t a n d expec ted

tempera tu re e x c u r s i o n s . One example o f a tempera tu re e x c u r s i o n i s a f a i l u r e

o f t h e a i r p r e h e a t e r r o t o r d r i v e , w h i c h w i l l cause f l u e gas tempera tu res t o

r i s e because no h e a t i s b e i n g t r a n s f e r r e d i n t o t h e p r i m a r y a i r system.

P a s t e x p e r i e n c e has r e v e a l e d t h a t a c o l d - s i d e p r e c i p i t a t o r may exper ience a

tempera tu re swing f rom 35C°F normal t o 650-750°F due t o an a i r p r e h e a t e r

f a i l u r e . A t e l e v a t e d tempera tu res , t h e expans ion movement o f t h e p r e c i p i t a t o r

can cause members t o bow, c o l l e c t i n g p l a t e s t o become m i s a l i g n e d , and

e l e c t r o d e w i r e s t o become e longa ted . A l s o , i f expans ion movement i s n o t

accounted f o r i n t h e s l i d e b e a r i n g c o n n e c t i o n , t h e p r e c i p i t a t o r may move and

d r o p f r o m i t s s u p p o r t s t r u c t u r e . To m i n i m i z e a i r p r e h e a t e r stoppage, severa l

u t i l i t i e s s p e c i f y an a l t e r n a t e r o t o r d r i v e such as an a i r mo to r t o reduce t h e

chance o f a tempera tu re excu rs ion .

Boiler manufacturers should be consulted to determine maximum flue gas

temperatures that may be experienced. Also, the time required to trip the

boiler and cool the unit should be estimated. This information should be

stated in design parameters for temperature excursions in precipitator

specifications. Precipitator suppliers should be requested to explain in

detail in their proposals thosespecific design measures to be implemented if the precipitator design is to withstand high temperature excursions. Care

must be taken not to make a cold side ESP into a hot side ESP.

Differential Pressure Loads

The design of a precipitator structure must take into account differential

pressure swings. Pressures will vary during an upset condition because of

increased flue gas fiow. Possible upset conditions can be caused by fan

failure, leakage, damper movement, etc.

A precipitator casing design should be specified as a minimum to handle

130 in. H20 for precipitator systems and up to 1 50 in. H20 for - precipitator-wet scrubber system pressure swings as required by NFPA Codes. Flue gas systems should be reviewed relative pressure changes within teh

preciptator due to opening and closing dampers.

ELECTRODE SYSTEMS

Collecting Electrode Design

In parallel-plate precipitators, collection-electrode plates are suspended

from the top of the precipitator and hang parallel to and in proper alignment

with the discharge electrodes. Collection-plate design must ensure that

(33,34): The contour of a plate be free of points or sharp edges that may cause sparking and a reduction in operating voltage.

- A plate has sufficient rigidity in order to maintain proper tolerance. Distorted or misaligned electrodes lead to reduced operating voltages and loss of efficiency.

Rapping accelerations are properly transmitted to all parts of a collection plate for effective removal of collected dust.

A plate's attachments are strong enough to support it and its collected dust load and durable enough to withstand continuous rapping impacts without fatigue failure.

Collecting electrode plates are usually made of light gage (16 to 20 gage)

metal sheets with structural stiffeners which are either roll-formed in the

4-25

shee t o r spot-welded t o i t . The p l a t e assembly i s fas tened t o t h e p r e c i p i t a t o r

s t r u c t u r e a t i t s top end. In most des igns , a p l a t e ' s s t r u c t u r a l s t i f f e n e r s

a r e contoured t o improve gas flow and provide a qu ie scen t zone i n t h e

c o l l e c t i n g space near t h e p l a t e su r f ace wh i l e imposing n e g l i g i b l e i n t e r f e r e n c e

t o t h e i n t e r e l e c t r o d e e l e c t r i c f i e l d (35).

The advantages and disadvantages of var ious p r o p r i e t a r y co l l ec t i on -e l ec t rode

p l a t e des igns a r e a t o p i c of deba te wi th in t h e i ndus t ry . There i s present ly

no consensus on an optimum p l a t e con f igu ra t ion o r on an optimum method f o r

p l a t e suspension. Consequently, i t ' i s meaningless t o impose c r i t e r i a on these

a s p e c t s of c o l l e c t i n g p l a t e des ign . However, t he fol lowing s p e c i f i c a t i o n s maif

be s t a t e d :

Mater ia l s of cons t ruc t ion

Rapper des ign/co l?ec t ion p l a t e a c c e l e r a t i o n response.

Ma te r i a l s of Construct ion. I n p r a c t i c e , c o l l e c t i o n p l a t e mater ia l th ickness

ranges from 16 t o 20 gauge; t h e majori ty o f i n s t a l l a t i o n s have 18 gauge

c o l l e c t i o n p l a t e s . Col lec t ion p l a t e s a r e t y p i c a l l y f a b r i c a t e d from mild s t e e l

tha t conform t o e i t h e r ASTM A-366 o r SAE 1010 o r 1008 Standards. They a r e

r a r e l y subjec ted t o opera t ing condi t ions conducive t o mater ia l cor ros ion

because of t h e i r l oca t ion i n t h e c e n t e r of t h e hot gas s tream. However,

severa l exceptional condi t ions should be considered. They include:

Use of a high s u l f u r fue l

O i l f i r i n g - Frequent b o i l e r s t a r t -ups and shutdowns

Frequent water washing

Frequent low load opera t ion a t a c i d dewpoint cond i t i ons .

In t h e s e i n s t ances , p ro tec t ion aga ins t premature c o l l e c t i o n p l a t e f a i l u r e due

t o cor ros ion a t t a c k should be considered. Use of a l t e r n a t e m a t e r i a l s f o r

co l l ec t i on -p l a t e f ab r i ca t i on i s , f o r t h e most p a r t , imprac t ica l a l though a few

manufacturers have u t i l i z e d ASTM A-242 (Corten) s t e e l i n t h e pas t . However, a

u t i l i t y must be aware and caut ioned t h a t t h e r e a r e no c la ims of enhanced

cor ros ion r e s i s t ance by material supp l i e r s f o r Corten-type mater ia l in a

p r e c i p i t a t o r environment. Specifying 16-gauge mild s t e e l mater ia l f o r t he se

d i f f i c u l t app l i ca t i ons may be t h e most c o s t - e f f e c t i v e method of providing

cor ros ion p ro t ec t ion . However, t h i c k e r than normal c o l l e c t i o n p l a t e s w i l l

affect rapping responsiveness on an individual supplier basis. Therefore,

this approach must be addressed with caution.

Rapper Design/Collecting Plate Acceleration. Perhaps the widest variation in

design among precipitator manufacturers occurs in the method of electrode

rapping and the energy imparted to electrodes.

There are several different types of collecting plate rappers in operation,

but most fall into one of two categories: tumbling hammer (mechanical)

rappers or falling slug (electromagnetic) rappers. Traditional rigid

electrode design precipitators normally use tumbling hammers that are fastened

to a motor-driven shaft, and impart a rapping blow to the leading or trailing

edge of the collecting plates. Nearly all manufacturers of weighted-wire

precipitators use a rapper design in which a slug weight is either

electromagnetically raised and gravity dropped or electromagnetically impelled

toward the anvil and spring-returned. These rappers provide impact forces to

the top of the collection-electrode plates. A few precipitator manufacturers

employ cam-lifted, gravity-impact slugs which also strike the top o f the

collection plates.

The rapping intensity of mechanical rappers is usually greater than that of

electromagnetic rappers, but the intensity depends upon the specific design

approach of a supplier. Electromagnetic rappers, however, are

intensity-adjustable and have the ability to produce multiple impacts within

seconds. Further, electromagnetic rappers offer greater flexibility in

selection of sequencing, even to individual rappers with modern control

packages. Since rapper design and philosophy are unique to each supplier, it

becomes impractical for a utility to specify rapper type. Therefore, it

becomes imperative that the utiTity exercise great care in selecting qualified

suppliers. It should be noted that there are many successful precipitator

installations of each type of rapper operating on a broad variety of coals.

Rapping systems must be highly reliable, adjustable (if practical), and

capable of maintaining uniform rapping effectiveness over long periods of time

without constant operator attention. To ensure these design goals are met, it

has been found necessary to specify:

A minimum acceptable rapping acceleration normal to the collecting electrode surface anywhere on that surface.

A rapping acceleration test procedure, in order to demonstrate the acceptable rapping acceleration.

An accelerated life test procedure, a condensed time evaluation of the expected life o f the rappers, rapper anvils, electrodes, and electrode supports.

When a utility specifies a minimum rapping acceleration for the collecting

electrodes, it must be understood that each supplier has produced a specific

and unique relationship among the plate shape, size, thickness and stiffners,

cleaning effectiveness and rapping impact forces. The question i s how does

the rapper/plate assembly respond and can it be kept in a clean condition

during actual operation. In examining plate structures of various suppiiers,

plates will exhibit widely varying degrees of flexibility. Some plates may be

considered as floppy and others extremely stiff, and there are variations

between the two extremes. Accordingly, the material vibration frequency will

vary from less than 3,000 Hz to greater than 20,000 Hz. Cleaning

effectiveness will be dependent upon the degree of useful energy imparted to the collected layer of fly ash. It must be recognized that most current

suppliers have demonstrated the ability to maintain plate cleanliness and high

collection efficiencies while collecting with high resistivity fly ashes. Ten

to fifteen years ago, the practice of specifying minimum normal-to-plate

rapping accelerations was developed because many of the suppliers had

difficulty dealing with high resistivity fly ash(z). At that time, a minimum

acceleration of 509 was used as a guideline although it was recognized

that some suppliers produced a 200g acceleration. It should be noted that

rapping accelerations normal to the collecting plate may not be the most

efficient vibrations in the rapping process. However, as previously stated,

minimum normal accelerations have traditionally been used in specifications.

Research is ongoing to determine the most effective plate motions in the

rapping process.

In terms of current experience and practices, a utility must exercise care in

establishing minimum acceleration levels in order not to preclude a qualified

supplier from bidding or requiring a supplier to offer a non-proven design.

With this i n mind, the bidder qualification process should address in depth

the features, successes, and failures of each supplier's rapping system.

Should a utility desire to specify a minimum acceleration parameter, it is

suggested that the starting point be a minimum of 50g, normal to the plate in

a frequency range between 2000 and 3000 Hertz. Suppliers may then provide

specific acceleration data and clarify their position in the proposal s.

Afterward, the bid evaluation process can and should modify acceleration

requirements on an individual supplier basis.

Discharge El ectrode Design

The heart of an electrostatic precipitator is the discharge electrode

system. It must produce a strong, uniform corona while maintaining the

correct distance and alignment with respect to the collecting electrodes to

prevent imbalances in the electric field and to avoid unnecessary arcing

discharges (36).

Discharge electrode configuration varies from manufacturer to manufacturer,

but all fall into one of four categories:

Weighted-wire electrodes; wires (typically 0.1 in diameter, but they can be up to 0.25 in diameter) are hung individually with a tensioning weight at the bottom.

Rigid frame electrodes; electrode elements (various shapes, typically 0.125 in. to 0.25 in. thick) are mounted within a frame fabricated from pipe or tube.

Rigid mast electrodes; the electrode elements are supported by a single vertical member, or mast, having several horizontal spars to facijitate mounting of individual electrode elements.

Rigid electrodes; each discharge electrode spans the full height of the collection plate, and is a substantial member usually fabricated from 2 inch diameter tube or roli-Formed sections of 16 gauge to 20 gauge steel.

In terms of today's application of terminology, any discharge electrode system

which is not a weighted-wire design is referred to as a rigid type electrode

design.

Most precipitator specifications written i n the last ten years do not permit

use of weighted-wire electrodes. Although there are many weighted-wire

precipitator installations which operate reliably, the collection of more

highly-resistive fly ashes and the perception of significant discharge

electrode breakage rates has lead to an increased use of rigid-type

electrodes. In EPRI Report 413-1 entitled "Corona Electrode Failure Study," weighted-wire units surveyed experience wire failure rates ranging from

essentially zero to 7.17 failures per month. One unit experienced 33.27

failures per month averaged over a 30 month period. Rigid-type discharge

electrode failures were not statistically significant over the testing

per iod . Depending upon t h e s p e c i f i c r i g i d type e l e c t r o d e des

f a i l u r e s can be a n t i c i ~ a t e d ,

S imi l a r t o c o l l e c t i n g e l e c t r o d e s , var ious p rop r i e t a ry designs

d ischarge e l ec t rodes have ind iv idua l mer i t s and disadvantages

gn, few i f any

f o r r i g id - type

and t h e r e i s no

industry-wide consensus on an optimum conf igu ra t ion . Consequently, i t i s b e s t

t o r e l y on t h e p r e c i p i t a t o r manufacturer 's e x p e r t i s e . Nonetheless, t h e

following c r i t e r i a should be evaluated in t he b idder q u a l i f i c a t i o n phase and

spec i f i ed where appropr ia te :

Material type and th ickness

Suspension system ( i . e . number of po in t s ) and support i n s u l a t o r mater ia l

I n su l a to r a i r purge/heaters

Rapper d e s i g d d i s c h a r g e e l ec t rode a c c e l e r a t i o n response

Anti-sway/positioning devices .

Material Type and Thickness. Unlike c o l l e c t i n g e l e c t r o d e s , t h e r e i s g r e a t e r

f l e x i b i l i t y in the s p e c i f i c a t i o n of material type and th ickness f o r

f a b r i c a t i o n of discharge e l e c t r o d e s . However, cau t ion must be exe rc i sed so

t h a t a s p e c i f i c p r e c i p i t a t o r manufacturer 's proposal i s not needless ly made

non-competitive because of overzealous s p e c i f i c a t i o n requirements . The

d ischarge e l ec t rode elements used i n r i g i d frame and r i g i d mast type

e l e c t r o d e s can usua l ly be f ab r i ca t ed t o any mater ia l t h i cknes s , whi le

roll-formed r i g i d e l ec t rodes may be l imi t ed t o a maximum th i ckness of 16

gauge. Use of high a l l o y ma te r i a l s may n o t always be c o s t - e f f e c t i v e ,

e s p e c i a l l y f o r the l a r g e r discharge e l ec t rode assembl ies which r e q u i r e more

mater ia l and shop welding. I t i s good p rac t i ce t o review the f a b r i c a t i o n

c a p a b i l i t i e s of a17 t he q u a l i f i e d b idders p r i o r t o spec i fy ing d i scha rge

e l ec t rode ma te r i a l p r o p e r t i e s .

Suspension System and Support I n s u l a t o r Mater ia l . A group of d i s cha rge

e l e c t r o d e s , when t i e d t oge the r by top frame and bottom frame assemblies and

hung a s a u n i t , i s known a s a bus s ec t ion . A bus s e c t i o n ' s suspension system

r e q u i r e s t h a t : - The bus sec t ion be e l e c t r i c a l l y i s o l a t e d from t h e p r e c i p i t a t o r ca s ing by means of porcelain o r alumina i n s u l a t o r s .

D i s c h a r g e e l e c t r o d e s b e a l i g n e d w i t h c o l l e c t i n g e l e c t r o d e s t o w i th in c lo se t o l e r a n c e s .

The e l e c t r o d e assembl ies be a l l o w e d t o t h e r m a l l y expand and c o n t r a c t d u r i n g p r e c i p i t a t o r s t a r t u p and shutdown.

Rapping a c c e l e r a t i o n s be t r a n s m i t t e d t o t h e d i s c h a r g e e l e c t r o d e s i n an e f f e c t i v e manner.

The suspension' system be s t r o n g enough t o s u p p o r t t h e w e i g h t o f t h e e l e c t r o d e assembly and c o l l e c t e d d u s t l o a d , and a l s o be r e s i s t a n t t o f a t i g u e f a i l u r e d u r i n g r a p p i n g .

The c o n f i g u r a t i o n o f a bus s e c t i o n suspension system v a r i e s f rom manu fac tu re r

t o m a n u f a c t u r e r , and t h e r e i s c u r r e n t l y no i n d u s t r y - w i d e concensus an optimum

c o n f i g u r a t i o n . None the less , two i m p o r t a n t aspec ts o f t h e suspens ion system

wh ich shou ld be s p e c i f i e d a r e t h e number o f s u p p o r t p o i n t s and t h e t y p e o f

i n s u l a t o r m a t e r i a l .

The number o f suppor t p o i n t s may v a r y f rom two t o f o u r . The more suppor t

p o i n t s u t i l i z e d , t h e g r e a t e r t h e s t a b i l i t y , and t h e b e t t e r the per formance and

r e l i a b i l i t y o f a bus s e c t i o n . Unless l i m i t e d by t h e sma l l p h y s i c a l s i z e o f a

bus s e c t i o n , a f o u r - p o i n t suspension shou ld be s p e c i f i e d .

Bus s e c t i o n suppor t i n s u l a t o r s may be f a b r i c a t e d from e i t h e r p o r c e l a i n o r

f u s e d a lumina . The fused a lumina m a t e r i a l i s t y p i c a l l y 85 p e r c e n t aluminum

o x i d e , wh ich i s a genera l -purpose a lumina c e r a m i c . A l t h o u g h more expens ive,

a l u m i n a r a t h e r than p o r c e l a i n i s u s u a l l y s p e c i f i e d because i t p r o v i d e s :

H i g h e r compress ive s t r e n g t h (280,000 p s i ve rsus p o r c e l a i n ' s 67,300 p s i , measured a t 68OF (20°C)).

S u p e r i o r e l e c t r i c a l p r o p e r t i e s ( 5 x 1 0 ~ ' ohm-cm volume

r e s i s t i v i t y ve rsus p o r c e l a i n ' s 10' ohm-cm, measured a t 39Z°F (20O0C)).

S u p e r i o r a b r a s i o n and chemical r e s i s t a n c e .

I n h o t - s i d e p r e c i p i t a t o r s , a lumina i s t h e o n l y p r a c t i c a l s u p p o r t i n s u l a t o r

m a t e r i a l because i t has a compressive s t r e n g t h exceeding 175,000 p s i a t

e l e v a t e d o p e r a t i n g tempera tu res . I n c o l d - s i d e p r e c i p i t a t o r s , t h e added

expense o f a lumina i s u s u a l l y a sound i n v e s t m e n t because i n t h e p a s t , suppor t

i n s u l a t o r breakage has been a common p r e c i p i t a t o r maintenance p rob lem.

I n s u l a t o r A i r Purqe/Heaters. Suppor t i n s u l a t o r s a r e t y p i c a l l y c o n t a i n e d i n

i n d i v i d u a l o r grouped i n s u l a t o r compartments; a l t e r n a t i v e l y , a l l t h e suppor t

i n s u l a t o r s may be housed i n a l a r g e t o p hous ing o r penthouse. I n many cases,

t h e p r e c i p i t a t o r m a n u f a c t u r e r r e q u i r e s t h e i n s u l a t o r s t o be a i r purged and

perhaps heated a t c e r t a i n t imes during the opera t ion o f t he p r e c i p i t a t o r .

This i s done t o maintain t he i n s u l a t o r s i n a c l e a n , d ry condit ion in o rde r t o

reduce t h e p o s s i b i l i t y of e l e c t r i c a l t r ack ing ac ros s t h e fouled su r f ace of an

i n s u l a t o r .

For p r e c i p i t a t o r s opera t ing with negat ive f l u e gas p r e s s u r e , t he requirement

f o r and des ign of t he i n s u l a t o r a i r purge/heater system should be thoroughly

i nves t iga t ed by a u t i l i t y . Most manufacturers w i l l i nc lude both i n s u l a t o r

purge a i r blowers and h e a t e r s i n t h e i r des ign; however, a few manufacturers

wil l d e l e t e t h e hea t e r s o r both the hea t e r s and blowers. A review of

manufacturers1 opera t ing experience a s well a s t h a t of a u t i l i t y i s usual Iy

necessary t o confirm t h e a c c e p t a b i l i t y of des igns .

For p r e c i p i t a t o r s opera t ing wi th p o s i t i v e f l u e gas p r e s s u r e , support i n s u l a t o r

a i r purge with f i l t e r e d , heated a i r should always be s p e c i f i e d . Typical

design va lues range form 25 t o 100 cfm of a i r per i n s u l a t o r , and from loOD t o

2000 wat t s of e l e c t r i c a l hea t ing per i n s u l a t o r .

Rapper Design/Discharge Elec t rode Accelerat ion Response. Accumulations of

dus t on d ischarge e l e c t r o d e s can cause corona suppress ion and prevent

appropr ia te p a r t i c l e charging i n t h e gas stream. Although not a s common a s

c o l l e c t i o n e l ec t rode f o u l i n g , minimum s tandards f o r d i scharge e:ectrode

rapping shouid never the less be s p e c i f i e d t o ensure r e l i a b l e p r e c i p i t a t o r

opera t ion .

Tumbling hammer and f a l l i n g s lug rappers a r e normally used t o clean d ischarge

e l ec t rodes . In t he p a s t , e l e c t r i c v i b r a t o r s have been used with some success

t o clean weighted-wire e l e c t r o d e s . I t appears t h a t f o r weighted-wire

a p p l i c a t i o n s , f l y ash p r o p e r t i e s w i l l d i c t a t e whether a v i b r a t o r o r an impact

rapper i s most app rop r i a t e . Modern, r igid-type e l e c t r o d e p r e c i p i t a t o r s use

e i t h e r mechanical o r e l e c t r o m a ~ n e t i c impact type rapping systems.

Although t h e r e i s no consensus of opinion, 35 t o 509 rapping acce l e r a t i on over

the e n t i r e su r f ace of t h e d i s cha rge e l ec t rode assembly has been suggested a s

t he level needed when dea l ing w i t h h ighly r e s i s t i v e f l y ash. Again, a u t i l i t y

must be caut ioned t h a t each s u p p l i e r has i t s own rapping acce l e r a t i on

s tandard , and i f t h e s u p p l i e r can show t h a t i t can keep e l ec t rodes c lean when

f i r i n g coal s i m i l a r t o t h a t of t he s p e c i f i c p r o j e c t , t h e need f o r t h e u t i l i t y

t o s p e c i f y a minimum a c c e l e r a t i o n i s reduced. A p r e c i p i t a t o r manu fac tu re r ,

however, shou ld be r e q u i r e d t o p r o v i d e a c c e l e r a t i o n t e s t r e s u l t s .

An t i -Sway /Pos i t i on ing Devices

Some we igh ted -w i re p r e c i p i t a t o r s (because o f t h e f l e x i b i l i t y o f t h e e l e c t r o d e

assembl ies and perhaps a l s o due t o t h e i n s t a b i l i t y o f 2 - p o i n t suspension

systems) r e q u i r e a n t i - s w a y / p o s i t i o n i n g d e v i c e s a t t h e b o t t o m o f each bus

s e c t i o n . Ant i -sway i n s u l a t o r s may a l s o be used on r i g i d t y p e e l e c t r o d e

p r e c i p i t a t o r s , e s p e c i a l l y when e x c e s s i v e l y na r row bus s e c t i o n a r e r e q u i r e d b y

e i t h e r p h y s i c a l arrangement o r s p e c i f i c a t i o n requ i remen ts . These d e v i c e s

a t t a c h each bus s e c t i o n t o t h e p r e c i p i t a t o r c a s i n g and a r e u s u a l l y f a b r i c a t e d

o f a lumina because of t h e need f o r e l e c t r i c a l i n s u l a t i o n . Thermal expans ion

of t h e bus s e c t i o n and exposure t o t h e h o t , d i r t y f l u e gas has caused many o f

t h e s e d e v i c e s t o f a i l p rematu re l y . A u t i l i t y s h o u l d c a r e f u l l y examine t h e

need f o r ant i -sway i n s u l a t o r s r e l a t i v e t o each o f t h e q u a l i f i e d b i d d e r ' s

d e s i g n and o p e r a t i n g exper ience .

HOPPERS AND ACCESSORIES

Hopper Des ign

Hopper geometry i s a f u n c t i o n of t h e t y p e o f ash removal system s e l e c t e d f o r

hopper evacua t ion . A pyramid-shaped hopper c o n v e r g i n g t o a s i n g l e d i s c h a r g e

p o i n t i s used when pneumat ic - type convey ing systems o r s l u i c i n g systems a r e

s e l e c t e d f o r hopper evacua t ion . A p y r a m i d hopper c o n v e r g i n g t o a t r o u g h

d i s c h a r g e i s used when a screw conveyor i s s e l e c t e d f o r hopper evacua t ion . A

f l a t b o t t o m box i s used when s t i c k y ash has a s t r o n g tendency t o adhere t o

s l o p i n g su r faces ; t h e ash i s evacuated by l a r g e d r a g - f l i g h t conveyors t h a t

cover t h e e n t i r e b o t t o m o f t h e box.

The pyramid-shaped hopper, converg ing t o a s i n g l e r o u n d o r square d i s c h a r g e

p o i n t o f a p p r o x i m a t e l y one square f o o t i n area, i s t h e most f r e q u e n t l y used

hopper geometry i n t h e e l e c t r i c u t i l i t y i n d u s t r y . A c r i t i c a l aspec t o f

pyramid-hopper d e s i g n i s t h e h o p p e r ' s v a l l e y a n g l e . V a l l e y ang le i s d e f i n e d

as t h e a n g l e formed by a co rne r o f t h e hopper and t h e h o r i z o n t a l p l a n e . I n

p r a c t i c e , hopper v a l l e y ang le ranges from 50 t o 70'. Most f l y ash a p p l i c a t i o n s

r e q u i r e a 55' v a l l e y ang le ; however, a s t i c k y ash may r e q u i r e v a l l e y a n g l e s

between 60 and 70° f o r p r e v e n t i o n o f ash b r i d g i n g d u r i n g hopper evacua t ion .

L a r g e r v a l l e y ang les c o n s t i t u t e an economic p e n a l t y because t h e y r e q u i r e

b i g g e r , deeper hoppers which i n t u r n make t h e p r e c i p i t a t o r suppor t s t r u c t u r e

t a l l e r .

Use of smal le r va l l ey angles ( 5 5 t o 6O0) f o r d i f f i c u l t app l i ca t i ons has been

considered when coupled with use of a t h i n , s t a i n l e s s s t ee l l i n e r f o r t h e

hopper. The use of s t a i n l e s s s t e e l l i n e r s f o r making ash flow e a s i e r i s not a

u n i v e r s a l l y accepted p r a c t i c e and should be approached w i t h c au t ion .

S t a i n l e s s s t e e l l i n e r s and use of t h i c k e r hopper mater ia l a r e concepts used i n

an at tempt t o deal with hopper cor ros ion .

A n ash hopper d ischarge nozzle (normally 1 2 inches in diameter) should be

designed t o ensure a free-f lowing d ischarge from the hopper. I t should be a s

l a r g e a s p r a c t i c a l with i t s i n t e r n a l su r f ace f r e e of a l l p ro j ec t ions . Square

co rne r s should be rep laced with well-rounded f i l l e t s .

There a r e p re sen t ly no industry-wide accepted s tandard p r a c t i c e s f o r s e l e c t i o n

of number of t he hoppers or f o r hopper con f igu ra t ions . The fol lowing

gu ide l ine i s suggested, however, when spec i fy ing pyramid-shaped hoppers f o r

high e f f i c i e n c y p r e c i p i t a t o r s : From an ope ra t ing and maintenance s t andpo in t ,

e s p e c i a l l y w i t h regard t o ash removal system f a i l u r e s and bus s ec t ions

sho r t i ng o u t , i t i s d e s i r a b l e t o have one hopper per t r ans fo rmer - r ec t i f i e r s e t .

I f a d i v i d e r p l a t e i s i n s t a l l e d in t h e hoppers a s an ant isneakage b a f f l e , t he

bottom edge of t h e p l a t e should te rmina te a s f a r a s poss ib le above t h e

d ischarge nozzle so t h a t i t w i l l not impair t h e f r e e flow of t h e f l y ash.

When the p l a t e ex tends too f a r i n t o a hopper, i t may cause bridging between

t h e b a f f l e and one o r both s ides of the hopper. Stopping the b a f f l e a minimum

of 2 f e e t c l e a r of t h e s loping hopper wall should avoid t h i s problem and

e f f e c t i v e l y prevent gas bypassing.

Hopper capac i ty i s def ined a s t h e t o t a l volumetr ic capac i ty of t h e hopper(s)

measured from a hor izonta l plane 12 i n . below the lowest pro t rus ion of t h e

d ischarge e l e c t r o d e assembly down t o t he hopper o u t l e t f lange . A p r e c i p i t a t o r

should have a minimum s to rage capac i ty o f 12 hours a t f u l l load opera t ion

based on maximum i n l e t d u s t loading. Such capac i ty provides reasonable time

f o r minor maintenance of ash handling systems. As t he bulk of t h e ash i s

c o l l e c t e d in t h e f i r s t f i e l d of t h e p r e c i p i t a t o r ( t y p i c a l l y 80 t o 95 percent

by weight ) , minimum s to rage c r i t e r i o n sometimes r equ i r e s en larg ing the

c a p a c i t y of t he upstream-most row of hoppers. In a d d i t i o n , should t h e f i r s t

f i e l d be ou t of s e r v i c e , t he major i ty of t he d u s t load wi l l be t r a n s f e r r e d t o

hoppers of t he next downstream f i e l d ; hence, the second f i e l d hoppers should

a l s o be s ized t o provide adequate s to rage capac i ty during an upset condit ion.

In p r a c t i c e , r e g a r d l e s s of hopper pos i t i on r e l a t i v e t o gas , hoppers a r e

usua l ly l im i t ed t o one s p e c i f i c s i z e by the supp l i e r a s a funct ion of overa l l

des ign , i n t e r c h a n g a b i l i t y , and having a l l d i scharge f l anges a t t he same

e l eva t ion f o r ea se in designing the ash handling system.

Hopper Heaters

A hopper hea t ing system i s necessary t o e l imina t e condensation on the hopper

w a l l s , thereby keeping the co l l ec t ed ash dry and free-f lowing. Such ex terna l

hea t ing i s p a r t i c u l a r l y useful during s t a r t -up and low-load opera t ion .

Hopper hea t ing systems usual ly c o n s i s t of 480V modularized low wa t t densi ty

hea t ing elements a t tached t o the o u t s i d e of t he hopper p l a t e s . A hopper

hea t ing d e n s i t y of between 20 and 25 w a t t s / f t 2 i s uniformly d i s t r i b u t e d over

t h e lower 33 t o 75 percent of t he hopper sur face a r e a . The hopper heating

system should be designed t o maintain a minimum s t e e l temperature of between

250 and 30D°F i n s i d e t he hopper a t a l l b o i l e r l oads . A t yp i ca l spec i f i ca t i on

f o r a low- t o medium-sulfur coal a p p l i c a t i o n may r equ i r e 20 w a t t s / f t 2

d i s t r i b u t e d over t h e lower 60 percent of t h e hopper sur face with a minimum

hopper su r f ace temperature of 270°F maintained a t a l l t imes.

Heating elements a r e grouped toge ther t o form zones on each hopper. Each zone

i s c o n t r o l l e d by means of two thermosta t s . There should be a minimum of two

zones, but p r e fe rab ly more, f o r each hopper. With t he system opera t ing , an

i nd i ca t ed temperature below the s e t po in t value on e i t h e r of the sensors wil l

energ ize t he h e a t e r zone; the hea ter zone shuts of f au tomat ica l ly when both

sensors reach t h e s e t po in t temperature. More expensive control systems

a c t i v a t e each hopper hea ter i n d i v i d u a l l y , and soph i s t i ca t ed , modulating hea ter

c o n t r o l s have a l s o been employed and i n t e g r a t e d i n t o a n ove ra l l power

management system f o r a p r e c i p i t a t o r .

A hopper heat ing system must be i n s e r v i c e a t a l l t imes except during extended

outages when maintenance o r inspec t ions a r e t o be performed on a p r e c i p i t a t o r .

Af te r an extended outage , hea ters a r e u sua l ly energized a t l e a s t e i g h t hours

before s t a r t -up .

Hopper Vibra tors

Many u t i l i t i e s requi re t h a t each ash hopper be provided with an e l e c t r i c or a i r d r iven v i b r a t o r , usual ly of t he type with an i n t e r n a l v i b r a t i n g p l a t e

mechanism, t o a s s i s t evacuation of t h e hopper. Vibra tors he lp i n prevent

br idging and so-cal led ra t -holes when t h e i r opera t ion i s proper ly c o n t r o l l e d

(43). When automatic opera t ion i s d e s i r e d , v i b r a t o r s should be ope ra t ed by

ash evacuat ion con t ro l s t o ensure t h a t hoppers v i b r a t e only when t h e ash

removal valve has a c t u a l l y opened (44). However, i f damp o r s t i c k y ash i s

p r e s e n t , v i b r a t o r s should be operated only a f t e r t he hopper has been

evacuated.

p u l l i n g s

V ib ra to r s

which wil

I f used during evacuat ion , v i b r a t o r s may aggravate a b o r d e r l i n e

t ua t ion by f u r t h e r compacting s t i cky ash (5).

should be capable of being manually operated on an ind iv idua l b a s i s

g r e a t l y a s s i s t maintenance personnel when manual evacuat ion o r

t e s t i n g and maintenance s i t u a t i o n s a r e encountered (43).

Should i t be decided, a f t e r a review o f t he ash p r o p e r t i e s and hopper des ign ,

t h a t v i b r a t o r s a r e not required or a r e perhaps not d e s i r a b l e f o r t h e

a p p l i c a t i o n a t hand, a s a minimum, the s p e c i f i c a t i o n should r eques t t h a t

v i b r a t o r mounting provis ions be included in t he hopper des ign . This w i l l

f a c i l i t a t e t h e r e t r o f i t of v i b r a t o r s a t a f u t u r e d a t e should t h e i r use be

warranted.

Hopper Aera tors

Hopper a e r a t o r s a r e ash f l u i d i z i n g devices which can help hopper evacuat ion ,

provided t h a t they a r e well-maintained, continuously monitored, and suppl ied

with dry a i r preheated above t h e moisture dewpoint. I f t he se requirements a r e

not met, hopper a e r a t o r s can aggravate evacuation problem: by caus ing t h e ash

t o cake and by providing add i t i ona l sur face a rea f o r accumulation and

br idging (46). A n a e r a t o r i s a porous membrane ( u s u a l l y a f l u i d i z i n g s tone )

which a l lows pressur ized a i r f l ow through i t t o be uniformly d i s t r i b u t e d t o the

ash above. By f l u i d i z i n g the ash above i t , t h e a e r a t o r e s t a b l i s h e s an

e f f e c t i v e discharge diameter l a r g e enough t h a t r a t hol ing and ash b r idg ing

cannot occur .

Aera tors a r e usua l ly operated when the hopper i s being evacuated. Unlike

v i b r a t o r s , t h e i r continuous use w i l l n o t compact t h e ash ; however, on ly t he

most severe opera t ing condi t ions (high ash content and a s t i c k y ash) j u s t i f y

t h e continuous use of hopper a e r a t o r s .

Aera tors should not be considered when t h e r e i s high p o t e n t i a l f o r f i r e and/or

explosion within t he p r e c i p i t a t o r .

Hopper Pokeholes and Anvils

Each hopper should be provided with two capped pokeholes, and two pounding

a n v i l s near t h e hopper o u t l e t t o permit manual c leaning of blockages a t t he

hopper d ischarge .

Hopper Level Ind i ca to r s

Level i n d i c a t o r s a r e provided in each hopper t o a l e r t opera t ing personnel t o

i n e f f e c t i v e ash removal o r t o abnormal opera t ing cond i t i ons . O v e r f i l l i n g a

hopper can cause e l ec t rodes t o break, bus s e c t i o n s t o s h o r t o u t , and damage t o

e l ec t rode support systems.

The loca t ion of leve l i nd i ca to r s i s s e l e c t e d so t h a t t h e hopper ash leve l wi l l

remain below t h e i nd i ca to r when the ash removal system i s ope ra t ing normally.

I f they a r e placed too high, they may be i nacces s ib l e f o r p e r i o d i c t e s t i n g ,

inspec t ion and maintenance, and/or be subjec ted t o high temperatures which can

cause f a i l u r e o r decreased accuracy. I t i s most he lpfu l t o p l a n t operat ing

personnel when leve l d e t e c t o r placement i s - c o o r d i n a t e d with t h e hopper access

platform system during the e a r l y s t ages of des ign .

In the p a s t , many e l e c t r o s t a t i c p r e c i p i t a t o r u se r s experienced un re l i ab l e ash

l eve l i nd i ca t ions and sporadic f a l s e alarms which caused o p e r a t o r s t o mi s t ru s t

a larms, and leve l i n d i c a t o r systems f e l l i n t o d i suse . Noncontacting

nuclear-type leve l i nd i ca to r s have solved some of t he shortcomings of t h e

previous ly used electromechanical types and a r e now being s p e c i f i e d and used

more f requent ly (43).

Each hopper should have a t l e a s t one nuclear-type level i n d i c a t o r mounted

d i r e c t l y t o i t . I nd i ca to r s should be designed f o r continuous opera t ion a t an

ambient temperature of 200°F. When a s i n g l e leve l i n d i c a t o r i s used, i t

should be so loca ted a s t o provide a one- t o four-hour warning p r i o r t o

reaching a hopper overflow level which would s h o r t ou t an e l e c t r i c a l bus

s ec t ion . When two l e v e l s of de t ec to r s a r e used on l a r g e c a p a c i t y hoppers, t he

f i r s t l e v e ? alarm may provide 8 hours of warning time t o permit one f u l l

maintenance s h i f t f o r c l e a r i n g . The second alarm l eve l would be s e t a t t h e

one hour l eve l so t h a t t he t r a n s f o r m e r - r e c t i f i e r s e t can be de-energized.

Normally, t h i s per iod of time w i l l permit t he p l a n t s t a f f t o e i t h e r c l e a r t he

hopper o r de-energize t h e t r a n s f o r m e r - r e c t i f i e r s e t . In addi t ion , i n d i c a t o r s

should be so l oca t ed t h a t f l y ash re-entrainment w i l l not occur p r i o r t o

maintenance. A remote source a c t u a t o r mechanism should be provided ad jacent

t o the hopper acces s door t o lock-out t he nuc lear source heads in t he "on" o r

"o f f " p o s i t i o n . A nuclear source head should a l s o be spring-loaded t o r e tu rn

t o i t s "o f f " pos i t i on should t h e remote a c t u a t o r cab l e f a i l .

Hopper M a t e r i a l s of Construct ion

Corrosion of hopper s idewa l l s can be a problem when f i r i n g medium- t o

h igh-su l fur c o a l , e s p e c i a l l y during b o i l e r cyc l ing and low-load opera t ion .

The dead gas region loca ted toward the t op of t h e hopper i s most suscep t ib l e

t o premature co r ros ion . There a r e several ways t o provide cor ros ion

p ro t ec t ion i n t h i s a r ea :

Provide add i t i ona l thermal i n su l a t i on on t h e hopper s idewal l s .

Provide add i t i ona l hopper heat ing elements t o maintain higher temperatures .

Design t h e hopper s idewa l l s with an a d d i t i o n a ? 1/8 i n . t h i cknes s f o r co r ros ion allowance; hence, i f t he p r e c i p i t a t o r casing i s f a b r i c a t e d from 1/4 i n . s t e e l , hopper s idewa l l s would be 3/8 i n . t h i c k .

Occas iona l ly , u t i l i t i e s have used ASTM A-242 ( t o r t e n ) s t e e l f o r add i t i ona l cor ros ion r e s i s t a n c e ; however, t h e s t e e l manufacturer makes no claims of add i t i ona l cor ros ion r e s i s t a n c e in a p r e c i p i t a t o r environment. Therefore , t h i s concept may not provide t h e measure of p ro t ec t ion a n t i c i p a t e d and must be approached with caut ion .

The proper use of hopper hea t e r s p r i o r t o p r e c i p i t a t o r s t a r t u p s w i l l a l s o

a s s i s t i n t h e prevention of hopper s idewall co r ros ion .

Hopper Access

For acces s dur ing maintenance, a t l e a s t one ex t e rna l a i r t i g h t ,

key-inter locked acces s door must be provided f o r each ash hopper. Two doors

f o r each hopper a l low access t o both s i d e s of t he hopper must be provided i f

t h e hopper i s d iv ided by an ant isneakage b a f f l e .

Hinge pins on hopper access doors should be vertical. Chain safety stops

should also be provided to prevent the door from fully opening upon its

initial unlatching. This arrangement somewhat reduces the risks to

maintenance personnel in the event that hot ash has filled the hopper and

could potentially spill out in large quantity.

The ash hoppers should have an expanded-surface maintenance deck situated

directly below them and permanent ladders and maintenance platforms for access

to all hopper appurtenances, doors, vibrators, aerators, pokeholes, pounding

anvils, and level indicators. On smaller precipitator installations,

consideration may be given to using a portable elevated work platform for

access to hopper appurtenances. This concept, however, tends to discourage

frequent, routine maintenance checks or walkdowns due to the inconvenience of

moving the platform. Therefore, this concept i s not recommended for use on

any unit.

Hopper Enclosure

Weather enclosures for the ash hopper areas are suggested to reduce heat loss

from the hoppers due to high winds and low temperatures and for protection of

hopper accessories and ash handling equipment. Enclosures also allow

inspection and maintenance of equipment under protected conditions (46). A

hopper enclosure should be ventilated by side wall fans, but it does not

require heating and air conditioning.

Ash Handling System and Precipitator Interface

All equipment located below the hopper outlet flange, including expansion joints and emergency cut-off slide gates, is normally supplied by the ash

handling system manufacturer.

Occasionally, small diameter vents are required in hopper sidewalls to

facilitate the venting of hopper valves. Hopper level indicators, aerators,

and vibrators should have spare input/output contacts for use in the ash

handling controls system.

It is imperative that ash be removed from the hoppers as continuously as

possible so that the ash may remain hot and loose (9). This practice also

reduces the potential for hopper ash re-entrainment.

THERMAL INSULATION SYSTEM

Thermal I n s u l a t i o n

Thermal i n s u l a t i o n i s r equ i red t o keep a l l i n t e r n a l meta l surfaces t h a t a re

i n con tac t w i t h t he f l u e gas s a f e l y above the a c i d dew p o i n t temperature and

f o r personnel p r o t e c t i o n when ex te rna l o r i n t e r n a l sur faces a re p resent i n

work areas.

I n s u l a t i o n should be minera l wool b l ocks , b a t t s , o r b l anke ts o f app rop r i a te

th ickness. The temperatures o f sur faces loca ted outdoors and access ib l e t o

con tac t by personnel should n o t exceed 140°F under expected outdoor ambient

cond i t i ons . I n conf ined areas, sur faces should n o t exceed 140°F when exposed

t o t he maximum ambient temperature. A l l i n s u l a t i n g m a t e r i a l s should conform

t o t he l a t e s t ASTM standards. Asbestos o r asbestos bea r i ng m a t e r i a l s a re n o t

acceptable. (See page 4-17)

Any i n s u l a t i o n which may be walked upon should be p ro tec ted by road mesh,

r a i s e d walkways, o r some o t h e r s u i t a b l e p r o t e c t i o n .

In cases where l agg ing i s n o t app l i ed d i r e c t l y over t h e i n s u l a t i o n , a

suppor t ing w i r e mesh shou7d be i n s t a l l e d aga ins t t h e c o l d face of t h e

i n s u l a t i o n and he ld by a second speed c l i p . Suppor t ing mesh can be e i t h e r

aluminum bea r i ng metal l a t h o r expanded diamond mesh l a t h . A l l seams o f mesh

should be t i e d w i t h hog-r ing c l i p s .

Access doo rs should be p rov ided w i t h i n s u l a t e d covers and/or a second door t o

prevent l o c a l i z e d coo l ing , condensation, o r cor ros ion a t t h e door. Support

s t ee l should n o t be enclosed i n i n s u l a t i o n .

Laqgi nq

Unless con ta ined w i t h i n a weather enclosure, thermal i n s u l a t i o n should be

p ro tec ted by weatherproof lagg ing . The o u t e r lagg ing shoujd have a

weatherproof f i n i s h . A l l outdoor l a g g i n g should be capable o f w i t hs tand ing

wind load, a p p l i c a b l e l i v e loads, and snow load, and should be sloped f o r

proper d ra inage.

P r e c i p i t a t o r t e s t i n g i s usual ly conducted f o r one o r more of t he fol lowing

reasons

To determine whether an equipment s u p p l i e r ' s performance guarantees have been s a t i s f i e d .

To determine whether t he p r e c i p i t a t o r i s in compliance wi th t h e emissions l i m i t a t i o n s of app l i cab l e a i r p o l l u t i o n codes.

To determine .whether t he design of a s p e c i f i c component i s in conformance with the p r e c i p i t a t o r s p e c i f i c a t i o n .

To determine whether t he p r e c i p i t a t o r has been properly f a b r i c a t e d and i n s t a l l e d in accordance with t h e p r e c i p i t a t o r s p e c i f i c a t i o n .

During t h e execution of a s ing l e p r e c i p i t a t o r c o n t r a c t , hundreds of individual

t e s t s may be performed. They range from r o u t i n e shop t e s t s of m a t e r i a l s ,

welds, and e l e c t r i c a l components, t o e l abo ra t e f i e l d t e s t programs f o r

measuring p r e c i p i t a t o r performance. The l a t t e r may inc lude over t en

s imultaneously performed t e s t i n g and sampling procedures, c a r r i e d ou t under

c o n t r o l l e d genera t ing condi t ions . The t e s t program might extend f o r severa l

weeks.

All t e s t i n g deemed necessary by a u t i l i t y must be c l e a r l y s p e l l e d ou t in t he

p r e c i p i t a t o r s p e c i f i c a t i o n . I t i s suggested t h a t t h e fol lowing t e s t r e l a t e d

information be included:

Tes t procedures

Responsible t e s t i n g par ty and u t i l i t y i n t e r f a c e procedure

Required t e s t r e s u l t s f o r compliance with s p e c i f i c a t i o n s

Procedures f o r repor t ing t e s t r e s u l t s t o t he purchaser

Test ing t ime tab l e , including t e s t p r e r e q u i s i t e s and purchaser wi tness n o t i f i c a t i o n ( i f necessary)

Consequences of a t e s t f a i l u r e .

Spec i f i ca t i on of a t e s t procedure may be, in i t s s imples t format , a r e f e r ence

t o a s tandard t e s t procedure. Standard t e s t procedures a r e published by t h e

Environmental Pro tec t ion Agency ( E P A ) , the American Socie ty of Mechanical

Engineers (ASME), t h e American Society f o r Tes t ing and Mate r i a l s (ASTM), t h e

I n d u s t r i a l Gas Cleaning I n s t i t u t e (IGCI) and o t h e r o rgan iza t ions . O n t h e

o the r hand, i f t he t e s t i s wholly non-standard, t h e complete procedure must be

l i s t e d in t h e p r e c i p i t a t o r s p e c i f i c a t i o n . I f the d e s i r e d t e s t procedure i s a

va r i a t i on of a s tandard t e s t procedure, a l l necessary modi f ica t ions t o t he

s tandard procedure should be desc r ibed . I f t he des i r ed t e s t procedure i s a

s tandard t e s t procedure which inco rpo ra t e s c e r t a i n opt iona l s t e p s , t he

p r e c i p i t a t o r s p e c i f i c a t i o n must d e s c r i b e which opt ions a r e app l i cab l e . In any

event , each t e s t s p e c i f i e d must be t r a c e a b l e t o an unambiguous, wr i t t en

procedure.

Performance c r i t e r i a , i .e . t he t e s t r e s u l t s required f o r compliance, should be

included i n t h e p r e c i p i t a t o r s p e c i f i c a t i o n i f these a r e not a l ready spec i f i ed

i n referenced standard t e s t procedures.

The consequences of a f a i l e d test should be c l e a r l y s p e l l e d ou t . Test

f a i l u r e s u sua l ly r e s u l t i n commercial p e n a l t i e s and/or an extended t imetable

f o r t h e purpose of implementing c o r r e c t i v e measures and r e t e s t i n g . The

t imetable , permiss ib le c o r r e c t i v e measures, and r e s p o n s i b i l i t y f o r r e t e s t i n g

expenses should be s t a t e d i n a p r e c i p i t a t o r s p e c i f i c a t i o n .

Tes t s which a r e e s s e n t i a l t o t h e success of a p r e c i p i t a t o r i n s t a l l a t i o n a re :

Flowmodeling

Rapping t e s t s : a cce l e r a t ed l i f e t e s t and rapping acce l e r a t i on t e s t

F i e ld leakage t e s t

. Fie ld ve loc i ty d i s t r i b u t i o n t e s t

F i e ld performance t e s t s : p r e s su re drop, i n l e t and o u t l e t p a r t i c u l a t e concen t r a t i ons , s t a c k v i s i b l e emissions, power consumption and f l u e gas temperature drop.

Nearly a l l of t h e s e t e s t s have e i t h e r non-standard t e s t procedures o r a r e

modi f ica t ions of s tandard t e s t procedures; hence, t h e i r proper s p e c i f i c a t i o n

i s c r i t i c a l . There have been many i n s t a n c e s in the r e c e n t p a s t such t h a t

incomplete s p e c i f i c a t i o n of t he se tests has downgraded o r negated t h e i r value

from both a design v e r i f i c a t i o n s t andpo in t and a con t r ac tua l s tandpoin t .

flow Modeling

Geometric model t e s t s of f l u i d flow systems a r e f r equen t ly undertaken a s an

a i d t o des igners . Geometric a i r flow models, usua l ly 1/16th t o 1/8th sca l e

p l e x i g l a s s models, have been used t o a s s i s t i n t h e d e s i g n o f e l e c t r o s t a t i c

p r e c i p i t a t o r systems s i n c e 1947.

The p r i m a r y o b j e c t i v e o f p r e c i p i t a t o r f l o w mode l ing i s t o o b t a i n t h e maximum

p o s s i b l e c o l l e c t i o n e f f i c i e n c y f r o m a p r e c i p i t a t o r b y p r o p e r l y c o n t r o l l i n g gas

f l o w f i e l d s w i t h i n t h e p r e c i p i t a t i o n chamber. Gas s t ream c h a r a c t e r i s t i c s t h a t

can be e v a l u a t e d i n a geomet r i c a i r f l o w model a r e :

Gas f l o w ( i . e . , v e l o c i t y ) u n i f o r m i t y between c o l l e c t i o n e l e c t r o d e p l a t e s w i t h i n t h e p r e c i p i t a t o r chamber.

Hopper f l y ash r e e n t r a i n m e n t p o t e n t i a l .

Gas tempera tu re d i s t r i b u t i o n (by use o f s p e c i a l procedures) .

Secondary o b j e c t i v e s o f p r e c i p i t a t o r f l o w mode l ing a r e t o p r e d i c t p r e s s u r e

l o s s e s t h r o u g h t h e modeled system and t o p r e v e n t a r e a s o f p o t e n t i a l d u s t

d ropou t on h o r i z o n t a l f l u e s u r f a c e s w i t h i n t h e modeled system.

I t i s now w i d e l y r e c o g n i z e d t h a t a model s tudy i s e s s e n t i a l b e f o r e t h e

p r e c i p i t a t o r i s b u i l t . The c o s t o f c o n d u c t i n g a model s t u d y d u r i n g t h e d e s i g n

stage i s i n s i g n i f i c a n t when compared t o t h e expense o f f i n d i n g and c o r r e c t i n g

problems i n t h e f i e l d . I t has been demonst ra ted t h a t c o r r e c t i n g an e x i s t i n g

i n s t a l l a t i o n can c o s t r o u g h l y t e n t o f i f t e e n t i m e s t h e c o s t o f p e r f o r m i n g a

d e s i g n s tage model s t u d y (2). There a r e two o t h e r f a c t o r s t h a t i n f l u e n c e t h e

d e c i s i o n t o conduc t a d e s i g n s tage model s tudy:

Gas f l o w u n i f o r m i t y becomes p a r t i c u l a r l y i m p o r t a n t f o r p r e c i p i t a t o r o p e r a t i n g e f f i c i e n c i e s i n excess o f 99 p e r c e n t . Because o f t h e tendency f o r t h e f i n e r p a r t i c l e s t o more c l o s e l y f o l l o w t h e gas f l o w s t r e a m l i n e s , t h e r e i s an i n c r e a s e d need f o r a l m o s t t o t a l suppress ion o f gas bypass ing and hopper sweepage.

System p r e s s u r e d rop can be m in im ized b y u s i n g t h e model t o l o c a t e a r e a s o f maximum dynamic l o s s e s . Today, t h i s has become a more i m p o r t a n t aspec t o f mode l ing because p r e s s u r e l o s s i s w o r t h i n excess o f $:00,000 p e r 0.10 i n WC o v e r t h e l i f e o f t h e i n s t a l l a t i o n .

U n f o r t u n a t e l y , t e c h n i q u e s used i n model s t u d i e s conduc ted p r i o r t o t h e

m i d - s e v e n t i e s may have been d e f i c i e n t i n some a s p e c t ; as a r e s u l t , t h e

p r e d i c t i v e v a l u e o f t h e s e p a s t s t u d i e s s u f f e r e d g r e a t l y . S i n c e t h e

m id -seven t ies , g r e a t e r c a r e has been used t o ensure t h a t dynamic s i m i l i t u d e

e x i s t s between t h e geomet r i c model and t h e f u l l - s c a l e system. T h i s concern

has been due i n p a r t t o t h e now w i d e spread p r a c t i c e o f c o n d u c t i n g a c c u r a t e

f i e l d ve loc i ty surveys of fu l l - s ca l e i n s t a l l a t i o n s in order t o v e r i f y t he

f i nd ings of model s t u d i e s .

Appendix I con ta in s a desc r ip t i on of model theory , flow c r i t e r i a s e l e c t i o n ,

and t e s t methods.

Rapping Tes t s

Electrode rapping i s an important s t e p i n t h e e l e c t r o s t a t i c p r e c i p i t a t i o n

process, and rappers must func t ion i n a highly e f f e c t i v e , p r e d i c t a b l e , and

r e l i a b l e manner. A u t i l i t y can p r o t e c t i t s e l f from d e f i c i e n c i e s i n t h i s a r ea

by requi r ing app rop r i a t e rapper t e s t i n g i n t h e p r e c i p i t a t o r s p e c i f i c a t i o n .

Many f a c t o r s i n f luence the e f f e c t i v e n e s s and r e l i a b i l i t y of e l e c t r o d e

rapping. The design of discharge e l ec t rode frames and rappers along wi th

co l l ec t i on e l e c t r o d e p l a t e s and rappers v a r i e s s i g n i f i c a n t l y from s u p p l i e r t o

supp l i e r . As might be expected, c e r t a i n designs a r e i nhe ren t ly more e f f e c t i v e

and/or r e l i a b l e than o t h e r s . The c o l l e c t i o n of high r e s i s t i v i t y f l y ash i s a

procedure t h a t many cons ider t o r equ i r e high i n t e n s i t y rapping and rugged,

f a t i g u e - r e s i s t a n t e l e c t r o d e s . Some c o l l e c t i o n p l a t e s a r e subjec ted t o rapping

a c c e l e r a t i o n s of lOOg o r more, zero t o peak, measured normal t o t h e p l a t e .

Col lec t ion of moderate t o ?ow r e s i s t i v i t y f l y ash consequently r e q u i r e s a

lower i n t e n s i t y rapping force. Another f a c t o r t h a t i n f luences rapping i s t h e

increase i n e l e c t o d e s i z e over t h e p a s t ten yea r s . Where 36 f t p l a t e s used t o

be t he upper l i m i t , s u p p l i e r s now o f f e r 50 f t p l a t e s . These en larged

e l ec t rodes can pose problems with rapping i n t e n s i t y d i s t r i b u t i o n , c l ean ing

e f f e c t i v e n e s s , and p l a t e support f a t i g u e f a i l u r e s .

Two t e s t s enable an equipment supp l i e r t o demonstrate t h a t t h e i r proposed

rapping system i s adequate f o r i t s intended duty: rapping a c c e l e r a t i o n t e s t s

and acce l e r a t ed l i f e t e s t .

Unfortunately, t h e t e s t i n g requirements and procedures a s soc i a t ed with t h e s e

t e s t s have n o t been e s t ab l i shed on an indus t ry wide b a s i s . These t e s t s a r e

exc lus ive ly conducted by supp l i e r s i n t e s t towers conta in ing a l i m i t e d amount

of f u l l - s c a l e p r e c i p i t a t o r components, usua l ly c o l l e c t i n g e l e c t r o d e s ,

discharge e l e c t r o d e s , and rapping systems. S u p p l i e r ' s r e p o r t s on p r i o r

t e s t i n g of i d e n t i c a l assemblies , which ind i ca t e t h a t a11 of t he s p e c i f i c a t i o n

requirements have been met, i s usua l ly accepted by a u t i l i t y a s s a t i s f a c t o r y

f u l f i l l m e n t of t h e i n t e n t of t he p r e c i p i t a t o r s p e c i f i c a t i o n . Rarely h a s a

u t i l i t y had t h e opportuni ty t o witness a t e s t o r t o comment on t e s t i n g

procedures.

Appendix I1 con ta in s a desc r ip t i on of methods f o r rapping acce l e r a t i on and

acce l e r a t ed l i f e t e s t i n g .

F i e ld Leakage T e s t

Leak t e s t i n g p r e c i p i t a t o r s and assoc ia ted ductwork i s c a r r i e d o u t i n t he

f i e l d a s soon a s t h e p r e c i p i t a t o r casing and ductwork envelope a r e i n t a c t .

Leak t e s t i n g can be a lengthy and demanding process, and a reasonable amount

of planning and expense i s required t o ensure t imely , conclusive t e s t

r e s u l t s . Sometimes, spec i f ied leak t e s t i n g i s waived because a s i t u a t i o n i s

reviewed dur ing p r e c i p i t a t o r e rec t ion and i t i s determined t h a t p o t e n t i a l

b e n e f i t s a r e outweighed by cos t . Under normal circumstances, however, t h e

f i e l d leakage t e s t i s a cos t e f f e c t i v e method f o r avoiding long term problems,

c o s t l y f i e l d r e p a i r s , and po ten t i a l forced outages.

The procedure f o r f i e l d leak t e s t i n g has not been s tandard ized on an indus t ry

wide b a s i s . Although the re a r e numerous recognized t e s t procedures, t y p i c a l

concepts f o r a f i e l d leakage t e s t a r e a s fol lows (2):

A l eak t e s t sha l l be performed p r i o r t o app l i ca t i on of thermal i n s u l a t i o n , a f t e r s l ag has been removed from t h e welds, and before cons t ruc t ion scaf fo ld ing i s removed.

Temporary duct blanking p l a t e s , i f requi red , a r e usua l ly supplied by the u t i l i t y . Su i t ab l e pipe plugs o r blanking p l a t e s f o r t he p r e c i p i t a t o r bushing a i r supply system a r e u sua l ly provided by t h e p r e c i p i t a t o r supp l i e r .

The p r e c i p i t a t o r and ductwork a r e pressur ized t o a leakage t e s t p r e s s u r e , t y p i c a i l y about 10 i n . WC. Af te r t h e t e s t p ressure i s s t a b i l i z e d , a pressure decay r a t e i s measured. I f t he decay r a t e exceeds a spec i f ied c r i t e r i a , usua l ly 10 percent pressure drop wi th in 10 minutes, l eaks must be located and r epa i r ed u n t i l t he c r i t e r i a i s s a t i s f i e d .

There a r e severa l f i e l d techn iques wh ich can be used t o l o c a t e l e a k s . One i s

t o r e p r e s s u r i z e t h e p r e c i p i t a t o r and d u c t w o r k and s e t o f f smoke bombs i n s i d e

t h e d u c t w h i l e t h e equipment i s under c o n s t a n t v i s u a l o b s e r v a t i o n . The use o f

v i s u a l i n s p e c t i o n approaches, however, may n o t be p r a c t i c a l on l a r g e

i n s t a l l a t i o n s . Ano the r techn ique i s t o use a vacuum box. T h i s d e v i c e

s u b j e c t s a sma l l a rea ( u s u a l l y abou t one square f o o t ) t o a p a r t i a l vacuum.

Sometimes hundreds o f i n d i v i d u a l vacuum box t e s t s must be conduc ted b e f o r e a l l

l eaks a r e i d e n t i f i e d .

Another approach t o l e a k t e s t i n g i s t o d e t e r m i n e t h e tempera tu re l o s s

exper ienced by t h e f l u e gas as i t passes t h r o u g h t h e p r e c i p i t a t o r system.

Temperature l o s s would be e s t a b l i s h e d and guaranteed by t h e s u p p l i e r and s e t

f o r t h i n t h e c o n t r a c t ; t h i s concept t h e n d e f i n e s an a c c e p t a b l e l e v e l o f a i r

i n f i l t r a t i o n .

It may be w o r t h w h i l e f o r a u t i l i t y t o use a comb ina t ion o f methods t o p r o v i d e

t h e most c o s t - e f f e c t i v e and schedule-aware approach t o f i e l d l e a k t e s t i n g .

The per formance o f such t e s t s r e q u i r e c l o s e c o o p e r a t i o n among t h e p r e c i p i t a t o r

s u p p l i e r , t h e c o n t r a c t o r , and t h e u t i l i t y ; i t i s suggested t h a t t h e

p r e c i p i t a t o r s p e c i f i c a t i o n c l e a r l y s p e l l o u t each p a r t y ' s r e s p o n s i b i I i t i e s .

F i e l d V e l o c i t y D i s t r i b u t i o n T e s t

S ince t h e e a r l y 19701s, t h e m a j o r i t y o f t h e p r e c i p i t a t o r s u p p l i e r s have

i n c l u d e d f i e l d v e l o c i t y surveys o f t h e p r e c i p i t a t o r i n p r e - s t a r t u p

procedures. The r e s u l t s o f t hese f i e l d t e s t s have been used t o v e r i f y t h e

accuracy o f f l o w mode l ing and t o a s s i s t s t a r t u p eng ineers i n i d e n t i f y i n g

p o t e n t i a l prob lem a reas s h o u l d a p r e c i p i t a t o r per formance prob lem a r i s e .

The p r i m a r y goa l o f f i e l d v e l o c i t y d i s t r i b u t i o n t e s t i n g i s t o measure t h e

degree o f v e l o c i t y f l o w u n i f o r m i t y i n s i d e a p r e c i p i t a t i o n chamber. T h i s i s

usual ly done by guiding s u i t a b l e v e l o c i t y measuring devices u p and down the

p r e c i p i t a t o r ' s e l e c t r o d e s a t p re-se lec ted t e s t l oca t ions dur ing cold-flow fan

opera t ion . Veloci ty probe pos i t i on ing r i g s normally use d ischarge e l ec t rodes

o r c o l l e c t i n g p l a t e s t o cen t e r and a l i g n t h e flow sensing element. The

conf igura t ion of t h e s e pos i t i on ing r i g s w i l l be a funct ion of e l ec t rode

des ign , i . e . , weighted wire o r r i g i d e l e c t r o d e . Secondary goa ls of t h i s

t e s t i n g a r e t o measure the degree of uniformity of ductwork flow pa t t e rns and

t h e degree of p r e c i p i t a t o r hopper flow a c t i v i t y .

Appendix 4C con ta in s a desc r ip t i on of t h e methodology f o r f i e l d v e l o c i t y

d i s t r i b u t i o n t e s t i n g .

F ie ld Performance T e s t s

P r e c i p i t a t o r performance t e s t s a r e conducted f o r t h e purpose of proving t h a t

t he performance guarantee o r requirements of appl icable a i r po l lu t i on

r egu la t i ons a r e met. Performance t e s t i n g h i s t o r i c a l l y c e n t e r s on the

determinat ion of a p r e c i p i t a t o r ' s p a r t i c u l a t e emissions; however, t oday ' s

p r e c i p i t a t o r i n s t a l l a t i o n s a l s o r e q u i r e performance t e s t s f o r o t h e r reasons:

s tack v i sua l emissions

pressure drop across t he p r e c i p i t a t o r / f l u e gas system

system power consumption

f l u e gas temperature drop .

While p a r t i c u l a t e emissions and s t ack v i sua l emissions t e s t i n g have

s tandardized procedures, t he remainder of t he above t e s t s a r e not f u l l y

s tandardized on an industry-wide b a s i s . In view of the economic p e n a l t i e s

usua l ly a s soc i a t ed with t he f a i l u r e of a p r e c i p i t a t o r performance t e s t , i t i s

e s s e n t i a l t h a t t h e procedures be unambiguously spec i f i ed i n p r e c i p i t a t o r

s p e c i f i c a t i o n s .

Appendix 40 con ta in s a desc r ip t i on of t h e performance t e s t procedures f o r

s t a c k visual emiss ions , p ressure drop , power consumption and f l u e gas

temperature drop.

5 SPECIFICATION OF ELECTRICAL/CONTROL FEATURES

Section 5

SPECIFICATION OF ELECTRICAL/CONTROL FEATURES

This section presents information regarding the preparation and organization

of a technical specification for the instrumentation, controls and electrical

components associated with an electric utility electrostatic precipitator. It

is not the intent of this section to provide the actual wording to be used in

a prospective specification, but rather to be illustrative of technical

features and issues which should be addressed. Actual wording should be

developed by a utility's Instrumentation and Controls Engineering and

Electrical Engineering departments. With the involvement of utility engineers

in these design areas, a utility can be assured that its interests and

philosophy will be incorporated into the precipitator control system.

DESIGN PHILOSOPHY

When specifying the electrical portion of a total ESP system, a utility's

general philosophy should be considered. Particularly on new plant

applications, compatibility with other major electrical systems should be

considered. Benefits of compatibility of an ESP's electrical components with

other plant equipment will become apparent during construction, training of

plant personnel, operation, maintenance and maintaining a spare parts

inventory. A?so, consistency in control equipment and philosophy can make

possible a p1 ant-wide information system capable of retrieving data from each

individual subsystem to be compiled for plant performance evaluation,

maintenance and troubleshooting programs, and historical record keeping.

Electrical Power Systems

The scope of equipment and services which are specified to be provided by the

ESP supplier in the area of electrical power systems varies among different

utilities. Some utilities choose to allow the ESP supplier to design, procure, and install all electrical equipment associated with the

precipitator; others prefer to keep portions of this work in house i n varying

degrees. The purpose o f this section is not to recommend the specific scope

of supply for the ESP, but to enable a utility engineer to make intelligent decisions regarding the specification of this type of equipment. It is

assumed that a utility's engineers are experienced in specifying general

electrical power equipment, and that they will be aware of the codes and regulations that must be met for this equipment. The major emphasis of th

section, therefore, will be directed toward the specification of electrica

power equipment unique to an ESP.

The electrical power system for a utility's ESP installation typically

includes the following: - Powertransformers

- Power distribution centers

480 V power centers and associated transformers

480 V motor control centers

Transformer-recti fier sets and controls

Auxiliary electrical equipment and contro

120/208 V lighting and power panels and a

Grounding system

Lighting system

Cable, cable trays and conduit

Communication system

Interface terminal boxes.

Is

ssociated transformers

In precipitator specifications, a utility engineer must carefully define the

scope of electrical supply to be provided by an ESP supplier. The

specifications should clearly state what is included as well as what i s nat included in the ESP supplier's scope o f responsibility. Electrical interface

points between the supplier and the utility must also be clearly defined.

Electrical and control equipment design considerations will be discussed in

more detail later in this section; however, as a matter of design philosophy,

utility electrostatic precipitator specifications should require that

electrical systems be designed to be operational during plant startup, normal

operation, and shutdown. During all operating modes, an ESP electrical system

w i l l usua l ly r ece ive power from separa te sources i n the main p l a n t ' s

e l e c t r i c a l a u x i l i a r y system. For t h i s reason, t h e ESP e l e c t r i c a l system m u s t

be capable of expected p l an t opera t ing vol tages . Usually, e l e c t r i c a l

components and con t ro l systems should be operable and proper ly func t ioning f o r

t yp i ca l power supply v a r i a t i o n s wi th in t he fol lowing ranges:

AC Power - Range of (+) 10 percent , (-) 10 percent long du ra t ion and (-) 20 percent fo r a period not t o exceed 1 minute (6 .6 kV base)

DC Power - Range of (+ ) 12 percent and (-) 16 percent .

Central versus Local ized Control

The evolu t ion of e l e c t r o s t a t i c p r e c i p i t a t o r cont ro l systems over t he y e a r s

l ed t o t h e development of two design phi losophies which a r e i n use today. The

f i r s t , l oca l i zed c o n t r o l , has been t h e dominant philosophy throughout t h e

h i s t o r y of ESPs. Localized control of an ESP incorpora tes a s epa ra t e loca l

cont ro l device f o r each t ransfor rner - rec t i f ie r and each a u x i l i a r y system

rapping system, hopper hea t e r s , e t c . These c o n t r o i l e r s conta in a17 required

l o g i c t o perform t h e i r s p e c i f i c func t ions and can opera te completely

independent of o t h e r c o n t r o l l e r s . A f a i l u r e of any s ing l e c o n t r o l l e r w i l l

t ake out of s e r v i c e only t h a t p a r t of t he system f o r which i t i s respons ib le ;

t he remainder of an ESP system wi l l cont inue t o opera te normally.

Only in very r e c e n t t imes , due t o t h e advent of microprocessor technology, has

c e n t r a l i z e d cont ro l become acceptable t o t he u t i l i t y i ndus t ry . This cont ro l

scheme, which w i l l be discussed in f u r t h e r d e t a i l l a t e r , i nco rpo ra t e s a

supervisory c o n t r o l l e r t o overview t h e overa l l system opera t ion and coord ina te

between local c o n t r o l l e r s , when necessary, t o opt imize system e f f i c i e n c y .

From t h e c e n t r a l i z e d supervisory cont ro l console , which usua l ly c o n s i s t s of a

microcomputer, a keyboard, a C R T , and a p r i n t e r , t he e n t i r e ESP system can be

placed i n s e rv i ce , taken out of s e r v i c e , o r placed in automatic s t a r t u p o r

shutdown mode. A17 func t ions of t h e local c o n t r o l l e r s a r e normally a v a i l a b l e

a t t h e supervisory console. The supervisory c o n t r o l l e r a l s o provides f o r d a t a

acqu i s i t i on and s t o r a g e . J u s t a s with the l oca l i zed cont ro l phi losophy, t he

local c o n t r o l l e r s shoujd include in a cen t r a l i zed design con t ro l a l l t h e l o g i c

requi red t o perform t h e i r s p e c i f i c func t ions , and they wi l l ope ra t e

independently i n t h e event of a f a i l u r e of t he supervisory c o n t r o l l e r .

Control Room Equipment Location

The location of the control room should take into account the amount of dirt

and dust to which it may be exposed, thermal radiation, and operator

convenience (100). - It must be provided with an air conditioning and

ventilating system that will provide, clean positive air pressure. Positive

pressure air helps prevent dirt from entering the control room. Cabinets

within the control room are usually rated NEMA 1 (general purpose) or NEMA 12 (dusttight and driptight). They can be affected by large quantities of dirt

which may impede cooling capacity by preventing proper cabinet ventilation.

Generally, control ro8ms are not located on a ground floor due to problems

with dirt. A ground floor can become extremely dust laden when maintenance

workers are servicing the fly ash handling equipment.

Other locations for a control room may be i n the main plant building, on the

precipitator roof, or between precipitator casings. In each of these

locations, care must be given not to expose the control room to excessive

thermal radiation which may cause premature failure of control equipment. The

location of the control room on or near the precipitator offers the advantage

of operator convenience and minimizes cable runs since controlling equipment

is then located near the equipment being controlled.

The precipitator control roam should be designed with the intent that it will

not require a full time operator, since the automatic control systems

available today are capable of running the system during normal operation.

Operator assistance may be required during start-up, shutdown, or abnormal

conditions, depending upon the degree of sophistication of the control

system. Therefore, all the components required to operate the system locally,

including the first and second level controls, should be located in the

precipitator control room.

A typical physical configuration o f the control system is shown on Figure 5-1,

with the following major control components located in the Precipitator

Control Room: - Power distribution equipment

Transformer-recti fier set control cab? nets

Rapper control cabinets

Hopper heat ing cont ro l cab ine t s

Other auxi 1 i a ry equipment cont ro l cab ine t s

P r e c i p i t a t o r cont ro l room input /output (I/O) equipment

Supervisory system equipment.

Remote monitoring and cont ro l equipment should be provided f o r t he

p r e c i p i t a t o r in t he main b o i l e r cont ro l room o r o ther cont ro l room which i s

manned f u l l time t o allow p l a n t personnel t o be a l e r t e d t o abnormal

cond i t i ons . Remote devices a r e b e s t placed i n an a i r q u a l i t y control system

(AQCS) con t ro l room, from which f l u e gas emissions a r e monitored f o r

compliance repor t ing and from which the f l u e g a s desu l fu r i za t i on system i s

monitored and cont ro l led .

Alarm and Monitoring Features

The p r e c i p i t a t o r control system should be capable of monitoring and provid ing

a d i s p l a y o f each of the fol lowing v a r i a b l e s :

Transformer- rec t i f ie r s e t primary vol tage

T rans fo rmer - r ec t i f i e r s e t secondary vol tage

Transformer-recti f ier s e t primary c u r r e n t

Transformer-rect i f i e r s e t secondary c u r r e n t

Transformer- rec t i f ie r set sparking r a t e

P r e c i p i t a t o r o u t l e t opac i ty

Indiv idua l ash hopper leve l

Indiv idua l ash hopper hea t e r system

Indiv idual ash hopper temperature.

Rapper s t a t u s

P r e c i p i t a t o r o u t l e t ga s temperature

The f i r s t f i v e func t ions a i d i n checking performance and should be d i sp l ayed

on t h e l o c a l T/R s e t cont ro l cab ine t a s well a s on t h e supervisory con t ro l

console.

Where a p p l i c a b l e , t h e f o l l o w i n g m i s c e l l a n e o u s i n p u t s t o t h e s u p e r v i s o r y

c o n t r o l system can p r o v i d e t h e o p e r a t o r w i t h t h e o v e r a l l s t a t u s o f t h e

complete p r e c i p i t a t o r system:

S t a t u s o f 6.9 kV b r e a k e r s (open - c losed) - S t a t u s o f 480 V power c e n t e r b reakers (open - c l o s e d )

6 .9 kv/480 V t r a n s f o r m e r a la rms

HVAC system s t a t u s

F i r e p r o t e c t i o n and d e t e c t i o n system s t a t u s

G u i l l o t i n e damper p o s i t i o n and sea l a i r b l o w e r s t a t u s

C o n t r o l power s t a t u s ( b o t h 120 V AC and 125 V DC)

I n s u l a t o r compartment h e a t i n g and v e n t i l a t i o n system s t a t u s .

The P r e c i p i t a t o r C o n t r o l Board s h o u l d be p r o v i d e d w i t h an a n n u n c i a t o r f o r

a l a r m i n g abnormal c o n d i t i o n s a s s o c i a t e d w i t h t h e f o l l o w i n g equipment and/or

systems:

6 .9 kV - 480 kV t r a n s f o r m e r s and power d i s t r i b u t i o n system

I s o l a t i o n damper sea l a i r system

I n s u l a t o r compartment h e a t i n g and v e n t i l a t i o n system

C o n t r o l room and e l e c t r i c a l equipment room HVAC system

F i r e p r o t e c t i o n system - The f i r e p r o t e c t i o n and d e t e c t i o n system a l a r m s a s s o c i a t e d w i t h each p r e c i p i t a t o r must b e h a r d w i r e d t o i t s r e s p e c t i v e f i r e p r o t e c t i o n c o n t r o l board. These s i g n a l s shou ld a l s o be i n p u t e d t o t h e s u p e r v i s o r y c o n t r o l system d a t a bus t o be made a v a i l a b l e on t h e CRT i n t h e AQCS c o n t r o l room o r t h e main b o i l e r room.

The p r e c i p i t a t o r a l a r m system s h o u l d be des igned t o be independent o f t h e

m ic rop rocessor -based s u p e r v i s o r y c o n t r o l system and s h o u l d i n c l u d e c r i t i c a l

a la rms a s s o c i a t e d w i t h t h e s u p e r v i s o r y c o n t r o l system i n a d d i t i o n t o t h e

a fo rement ioned a larms. T h i s w i l l p r o v i d e t h e o p e r a t o r w i t h t h e knowledge he

needs o f t h e system s t a t u s i n t h e e v e n t o f a f a i l u r e o f t h e c o n t r o l system.

F i r s t o u t i n d i c a t i o n shou ld be p r o v i d e d f o r a l a r m g roups where a p p r o p r i a t e .

I n t e r f a c e s w i t h O t h e r P l a n t Systems

The ESP s u p p l i e r s h o u l d be r e s p o n s i b l e f o r t h e c o o r d i n a t i o n o f i n t e r f a c e

r e q u i r e m e n t s w i t h c o n t r o l s and systems f u r n i s h e d w i t h o t h e r

systems procured by a u t i l i t y . The ESP supp l i e r should cooperate with t he

u t i l i t y and o the r equipment and systems manufacturers t o obta in d e f i n i t i o n of

i n t e r f a c e s in s u f f i c i e n t d e t a i l t o reso lve any po in t s o r d i f f e r e n c e . ESP

s u p p l i e r s should i d e n t i f y a l l po in ts o f i n t e r f a c e t o the Purchaser p r i o r t o a

con t r ac t being awarded. Such i d e n t i f i c a t i o n minimizes the chances f o r l a t e r

misunderstandings concerning i n t e r f a c e requirements.

The e l e c t r i c a l cont ro l system may i n t e r f a c e with the following p l a n t systems

o r components:

Fuel management system

Opacity monitoring system

Sootblower system

Ash handting system

F i r e p ro t ec t ion system.

ELECTRICAL AND CONTROL EQUIPMENT CONSIDERATIONS

Transformer-Recti f i e r S e t s

Transformer- rec t i f ie r s e t s f o r modern ESPs normally c o n s i s t of a t ransformer ,

c u r r e n t l im i t i ng r e a c t o r , r e c t i f i e r s and switches a l l contained i n a f l u i d

f i l l e d tank which i s completely sea led and s u i t a b l y prepared f o r autdoor use.

The func t ion of t h e main t ransformer wi th in t he T/R s e t i s t o i nc rease low

vol tage t o t he high vol tage required by an ESP. The windings of t h e

t ransformer should be e l e c t r o s t a t i c a l l y sh ie lded t o p ro t ec t ive ly d i s t r i b u t e

any sudden vol tage surges t h a t occur during p r e c i p i t a t o r ope ra t ion . The

sh ie ld ing should a l s o prevent adverse capac i t i ve coupling between t h e primary

and secondary windings.

A cu r r en t l i m i t i n g r e a c t o r i s usua l ly included with each t r a n s f o r m e r - r e c t i f i e r

s e t t o provide p ro t ec t ion from excess ive cu r r en t l e v e l s due t o spark ing and

consequent sho r t c i r c u i t i n g in t he p r e c i p i t a t o r . In add i t i on t o providing

p ro t ec t ion f o r the T/R s e t and c o n t r o l s , t h e c u r r e n t l im i t i ng r e a c t o r a l s o

improves waveform and form f a c t o r . The cu r r en t l i m i t i n g r eac to r i s designed

so t h a t the sho r t c i r c u i t cu r r en t i s l imi t ed t o a va lue spec i f i ed by t he

p r e c i p i t a t o r des igne r , usua l ly a maximum of 1.8 t imes t he r a t e d c u r r e n t . The

cu r r en t l im i t i ng r e a c t o r i s connected i n s e r i e s with t he T/R s e t primary

and can be phys i ca l ly located e i t h e r within t h e T/R s e t tank o r ou ts ide t h e

tank in a s e p a r a t e enclosure.

The r e c t i f i e r i s connected ac ros s the t ransformer secondary and conver t s AC

input t o nega t ive p o l a r i t y DC ou tput f o r use by an ESP. S i l i c o n diode

r e c t i f i e r c e l l s a r e recommended and should be conserva t ive ly r a t ed f o r high

vol tage ope ra t ion . Sui tab le low-loss impedance should be included a s requi red

t o l i m i t capac i tance discharge cu r r en t t o values within t h e r e c t i f i e r c e l l

r a t i n g . S i l i c o n type r e c t i f i e r s should e i t h e r be s e l f - p r o t e c t i n g avalanche

r e c t i f i e r s o r should be p a r a l l e l e d with s u i t a b l e c a p a c i t o r s o r capac i to r and

r e s i s t o r networks t o suppress low frequency t r a n s i e n t s and t o d i s t r i b u t e t h e

e f f e c t s of s t eep vol tage wave forms on long r e c t i f i e r s t r i n g s t h a t may be

impressed on the c i r c u i t during switching o r sparking. P ro t ec t ion sbould be

a t l e a s t adequate t o permit each leg of t he r e c t i f i e r t o withstand a s tandard

1-1/2 by 49 microsecond impulse vol tage wave equal t o t h e peak inverse vol tage

r a t i n g of each r e c t i f i e r c e l l t imes t he number of c e l l s used in each l eg .

Avalanche-type r e c t i f i e r s may be used without surge suppression networks.

Avalanche c e l l s should be adequately r a t ed t o withstand expected momentary

power surges and t o operate in t h e avalanche region wi thout damage.

An e x t e r n a l , heavy-duty, non-fused disconnect/grounding switch should be

provided f o r t he purpose of d i sconnect ing the T/R s e t from t h e p r e c i p i t a t o r

and grounding t h e p r e c i p i t a t o r bus s ec t ion . A v i s i b l e a i r gap i s recommended

f o r s a f e ty of maintenance personnel . The v i s i b l e gap may be obtained by use

of an exposed b lade d isconnect . swi tch in conjunction wi th a viewing window in

t he enclosure.

Each t r ans fo rmer - r ec t i f i e r assembly should be mounted i n a heavy gauge welded

s t e e l tank designed f o r a minimum of 7 psig t e s t p r e s su re and f u l l vacuum.

The un i t should be adequately sea led t o prevent contamination of i n s u l a t i o n

and the coojing medium. Outdoor type cons t ruc t ion should be used. Access

should be provided t o a l l i n t e r n a l 5 through wa te r t i gh t covers f o r ease of

maintenance and r e p a i r . Each tank should be provided wi th a plugged bottom

o i l d ra in va1

Each T/R s e t

low voltage i

terminal s .

ve and a sampling valve f o r t h e i n s u l a t i n g l i q u i d .

should be equipped with a low vol tage junc t ion box t o house a l l

nput bushings a s well as metering feedback bushings and

A s u f f i c i e n t q u a n t i t y o f i n s u l a t i n g f l u i d s h o u l d be f u r n i s h e d t o f i l l t h e T/R

t a n k s t o t h e p roper l e v e l r e q u i r e d f o r o p e r a t i o n . The u t i l i t y s h o u l d s p e c i f y ,

a c c o r d i n g t o i t s p re fe rence , e i t h e r o x i d a t i o n r e s i s t a n t o i l o r s i l i c o n e

f 7 u i d . R-Temp f l u i d i s a l s o a v a i l a b l e f o r t h i s a p p l i c a t i o n .

The T/R s e t shou ld b e equ ipped w i t h t h e f o l l o w i n g a d d i t i o n a l i t ems :

H i g h v o l t a g e b u s h i n g s

L i q u i d l e v e l gauge

Temperature gauge

Pressure vacuum gauge

Vo l tage m u l t i p l i e r and su rge a r r e s t o r

Top f i l l h o l e w i t h p r e s s u r e r e 1 i e f v a l v e .

The T/R s e t shou ld be p r o v i d e d w i t h s u i t a b l e means f o r l i f t i n g by e i t h e r a

h o i s t o r a f o r k l i f t .

I n c l u d e d i n t h e des ign o f t h e ESP shou ld b e a c o l l e c t i o n pan under each T/R

s e t o r g roup o f T/R s e t s w h i c h c o n t a i n s a l l l i q u i d r e l e a s e d f rom t h e T/R t a n k

i n t h e e v e n t o f a r u p t u r e o r e x p l o s i o n . Each pan s h o u l d be equ ipped w i t h a

d r a i n s i z e d t o handle 0.3 gpm p e r square f o o t o f s u r f a c e a rea (3" minimum

d i arneter).

Hopper H e a t e r s

Each hopper should be equ ipped w i t h modu la r e l e c t r i c h e a t i n g e lemen ts

a t t a c h e d t o t h e o u t s i d e s u r f a c e between t h e hopper and t h e the rma l i n s u l a t i o n

t o p r e v e n t m o i s t u r e a c c u m u l a t i o n and consequent f l y ash s o l i d i f i c a t i o n . Use

o f rod, h a i r p i n , and/or M I c a b l e h e a t e r s shou ld b e p r o h i b i t e d s i n c e improper

l o c a t i o n c o u l d cause l o c a l h o t s p o t s w i t h i n t h e hopper. Sur faces on t o wh ich

h e a t i n g e lements a r e t o b e mounted s h o u l d be f r e e o f w e l d i n g s p l a t t e r and/or

beads and any o t h e r m a t e r i a l w h i c h wou ld p r e v e n t f u 7 l f a c e c o n t a c t between t h e

h e a t i n g e lemen t and t h e hopper sur face. Hopper h e a t i n g shou ld be u n i f o r m l y 2 d i s t r i b u t e d i n terms o f w a t t d f t o v e r t h e l o w e r 33 t o 75 p e r c e n t o f t h e

e n t i r e hopper su r face a r e a , zoned i n t o two l e v e l s , and shou ld m a i n t a i n t h e

h e a t i n g d e n s i t i e s and hopper tempera tu res deve loped i n S e c t i o n 4. In

a d d i t i o n , a h e a t e r shou ld be p r o v i d e d around t h e hopper t h r o a t and c o n t r o l l e d

by t h e zone l o c a t e d a d j a c e n t t o i t .

Control Cabinets

In gene ra l , t h e loca l cont ro l c a b i n e t s f o r cont ro l of t r ans fo rmer - r ec t i f i e r

s e t s , rappers , hopper hea t e r s , and o t h e r a u x i l i a r y may be t he ESP s u p p l i e r ' s

s tandard des ign , modified as necessary t o achieve the con t ro l func t ions

descr ibed in the s p e c i f i c a t i o n . A con t ro l system should be designed and

i n s t a l l e d so t h a t normal c o n t r o l s f o r t r a n s f o r m e r - r e c t i f i e r s e t s , rappers , and

hopper hea t e r s , and o t h e r a u x i l i a r y equipment w i l l func t ion independently i f

t h e microprocessor-based supervisory con t ro l system should f a i l .

The loca l control c a b i n e t s should be of NEMA 12 cons t ruc t ion i f loca ted i n a

c lean indoor environment o r NEMA 4 i f l oca t ed outdoors , and should inc lude t h e

necessary opera tor i n t e r f a c e devices l oca t ed so t h a t they may be operated

wi thout opening the cab ine t . I n d i c a t o r l i g h t s , cont ro l swi tches , meters and

i n d i c a t o r s t o permit loca l opera t ion of t h e system o r subsystem on an opera tor

a s s i s t e d bas i s must be located on the f a c e of t he cont ro l c a b i n e t s . The local

con t ro l cabine ts may be e i t h e r f r e e s t a n d i n g , se l f - suppor t ing enc losures , o r

wall mounted u n i t s . S p e c i f i c requirements f o r t he f a b r i c a t i o n and t e s t i n g of

t he local control cab ine t s a r e normally desc r ibed in an at tachment

spec i f i ca t i on which r e f l e c t s a u t i l i t y ' s s tandard p r a c t i c e s .

The supervisory con t ro l system, o r power management system, which genera l ly

c o n s i s t s of a microcamputer, keyboard, CRT, p r i n t e r , and i n t e r f a c e

input/output equipment, may a l s o be of t h e ESP s u p p l i e r ' s s tandard design,

modified a s necessary t o achieve the con t ro l func t ions desc r ibed i n a

u t i l i t y ' s s p e c i f i c a t i o n . This equipment should be of NEMA 1 cons t ruc t ion .

Enclosures f o r a l l equipment should comply with ANSI Standard C194 - Indus t r i a l Control Apparatus Enclosures.

Power D i s t r i bu t ion Equipment

A s u i t a b l e power d i s t r i b u t i o n system must be provided t o t r ansmi t power from

p l a n t s t a t i on se rv i ce t ransformers t o each ind iv idua l ESP cont ro l system. A t

l e a s t two 480V, 3 phase, 60 cycle power f e e d s and a t l e a s t two 120V, 60 cyc le

power feeds should be supplied t o t h e power d i s t r i b u t i o n c e n t e r f o r each

p r e c i p i t a t o r ca s ing . This power i s then d i s t r i b u t e d by t h e power d i s t r i b u t i o n

c e n t e r t o each of t he T/R s e t con t ro l cab ine t s , rapper cont ro l cab ine t s , o t h e r

a u x i l i a r y equipment control c a b i n e t s , and the supervisory cont ro l system.

The power d i s t r i b u t i o n system should be designed so t h a t f a i l u r e of any s i n g l e

power feed wi l l t r i g g e r an alarm and a redundant supply w i l l au tomat ica l ly

assume t h e load without an i n t e r r u p t i o n in s e rv i ce . System overcur ren t

p r o t e c t i o n should be designed so t h a t a s ing l e fu se f a i l u r e w i l l n o t cause an

e n t i r e system t o f a i l . Each power consuming device should have overcur ren t

p r o t e c t i o n .

The des ign engineer should cons ide r redundant f e a t u r e s when formulat ing t h e

The proce

system conf igu ra t ions f o r power feeds to :

Processors

I/O cards

F ie ld c o n t a c t s

Final cont ro l dev ices .

s s o r s and I/O ca rds should be de signed t o accept power feeds from

e i t h e r of two independent sou rces . The l o s s of one source should not e f f e c t

t h e con t ro l system opera t ion . The in t e r roga t ing vol tage t o t h e f i e l d c o n t a c t s

should be der ived from two independent sources such t h a t t h e l o s s of one

source should not cause a system misoperation. Where app l i cab l e , f i n a l

cont ro l devices should be d iv ided i n t o "A" t r a i n and "B" t r a i n components w i t h

power t o t h e t r a i n s der ived from independent sources. This w i l l a l low f o r

p a r t i a l opera t ion of t he system i f t h e power t o one t r a i n f a i l s .

Enclosures f o r t he power d i s t r i b u t i o n equipment should be of NEMA-1

cons t ruc t

descr ibed

p r a c t i c e s

Instrumen

on. All e l e c t r i c a l wi r ing , t e rmina l s , and terminal blocks should be

i n an attachment s p e c i f i c a t i o n which r e f l e c t s t h e u t i l i t y ' s s tandard

Each loca l T/R s e t cont ro l cab ine t should be equipped wi th ins t ruments t o

i n d i c a t e AAC input cu r r en t and vo l t age , DC output cu r r en t and vol tage , and

spark r a t e , i f app l i cab l e . T h i s information should have +2 percent accuracy,

inc luding vol tage d iv ide r e r r o r .

M e t e r s should comply w i t h ANSI S tandard C39.1, "Requirements f o r E l e c t r i c a l

Analog I n d i c a t i n g Equipment." D i g i t a l panel m e t e r s should have an L . E . D .

d i s p l a y w i t h a minimum h e i g h t of 0 . 4 i n . The m e t e r s should be o f an

i n d u s t r i a l g rade and have a minimum of 100 hr o p e r a t i o n wi th 100 p e r c e n t

t e s t i n g . Over-range i n d i c a t i o n and over load p r o t e c t i o n should be p rov ided .

F u l l s c a l e m e t e r s a r e p r e f e r r e d t o d i g i t a l m e t e r s . P r o v i s i o n s shou ld be

i n c l u d e d f o r measur ing ESP v o l t a g e and c u r r e n t waveforms wi th an

o s c i l l o s c o p e .

PRECIPITATOR CONTROL SYSTEM PHILOSOPHY

The i n t e n t of t h e f o l l o w i n g pa ragraphs i s t o s u g g e s t one workable ph i losophy

f o r t h e d e s i r e d o p e r a t i o n , o p e r a t o r i n t e r f a c e , and f u n c t i o n a l r e q u i r e m e n t s f o r

a modern ESP c o n t r o l sys tem. The f o l l o w i n g pa ragraphs should n o t be c o n s t r u e d

a s i d e n t i f i c a t i o n o f a u n i v e r s a l p r e c i p i t a t o r c o n t r o l system f o r a l l u t i l i t y

a p p l i c a t i o n s .

Automat ic Vol tage Cont ro l

The f u n c t i o n of a l o c a l au tomat ic v o l t a g e c o n t r o l (AVC) i s t o p r o v i d e maximum

u s e f u l power t o t h e p r e c i p i t a t o r w h i l e m a i n t a i n i n g t h e h i g h e s t e f f i c i e n c y

p o s s i b l e a t v a r i o u s l o a d s and changing f u e l c o n d i t i o n s . I t accompl i shes t h i s

g o a l by us ing feedback s i g n a l s t o de te rmine t h e most optimum e n e r g i z a t i o n f o r

e a c h i n d i v i d u a l t r a n s f o r m e r - r e c t i f i e r s e t . The AVC moni to r s pr imary v o l t a g e ,

p r imary c u r r e n t , s econdary v o l t a g e , secondary c u r r e n t , and s p a r k r a t e i n o r d e r

t o e v a l u a t e system c o n d i t i o n s and t a k e a p p r o p r i a t e a c t i o n . The c i r c u i t r y i n

t o d a y s m i c r o p r o c e s s o r c o n t r o l l e r s p r o v i d e s r a p i d a r c quenching, r a p i d power

r e c o v e r y a f t e r quench ing , reduced power rapping ( f o r some a p p l i c a t i o n s ) , and

s e l f d i a g n o s t i c s t o a i d i n system t r o u b l e s h o o t i n g .

Each l o c a l AVC shou ld be des igned t o p r o c e s s a l l p r e c i p i t a t o r s i g n a l s from an

e l e c t r i c a l s e c t i o n , p r o v i d e l o c a l d i s p l a y and a n n u n c i a t i o n c a p a b i l i t y , p r o v i d e

s w i t c h i n p u t s f o r o p e r a t i o n s and maintenance p e r s o n n e l , communicate wi th a

s u p e r v i s o r y c o n t r o l sys tem, and r e c e i v e and p r o c e s s commands from and

a u t o m a t i c a l l y p r o v i d e c o n t r o l s i g n a l s t o i t s a s s o c i a t e d T/R s e t .

An AVC shou ld be f u l l y a d j u s t a b l e t o p rov ide v a r i a b l e v o l t a g e r i s e t i m e s .

C o n t r o l s should respond t o spa rk ing w i t h i n one-half c y c l e and shou ld have t h e

c a p a b i l i t y of a d j u s t i n g t h e spa rk r a t e from 2 t o 100 s p a r k s p e r minute and

from 20 t o 100 p e r c e n t of r a t e d T/R u n i t o u t p u t .

An AVC should be designed f o r an a d j u s t a b l e c u r r e n t ' l i m i t . Without spark ing ,

a cont ro l should be ab le t o maintain maximum r a t e d DC average cu r r en t

independent of t he opera t ing vo l t age . Manual con t ro l should be provided f o r

t e s t i n g and troubleshooting. The output of analog s i g n a l s f o r primary and

secondary vol tage , primary and secondary c u r r e n t , and spark r a t e should be

provided by an AVC.

AVC u n i t s should have a minimum of 100 hours of ope ra t ion with 100 pe rcen t

t e s t i n g .

Rapper Control

The rapper control system normally c o n s i s t s of an ESP s u p p l i e r ' s rapper

cont ro l cabine t f o r mechanical o r e lec t romagnet ic rapping systems.

I f t he rapper system i s mechanical, t h e cont ro l system should perform t h e

following minimum funct ions:

Provide loca l cont ro l swi tches f o r rapper motor off/on and sequence programming.

Provide output of rapper s h a f t r o t a t i o n v e r i f i c a t i o n , sequence complete, and cont ro l swi tch pos i t i on s i g n a l s l o c a l l y and t o t h e ESP supervisory control system.

Provide input of rapper motor off /on s i g n a l s t o the rapper d r i v e motor from e i t h e r t h e l oca l o r superv isory c o n t r o l l e r .

Fa i lu re of the ESP supervisory con t ro l system should a l low continuous

opera t ion of the rapper d r ive motor when t h e loca l off /on switch i s i n t h e 11 on 11 p o s i t i o n .

I f a rapper system i s e lec t romagnet ic , t he cont ro l system should perform t h e

following minimum funct ions:

Provide control switches f o r on/off c o n t r o l , i n t e n s i t y , and sequential programming.

= Provide input of rapper on/off and rapper i n t e n s i t y s igna l s on an Individual rapper b a s i s from t h e loca l o r superv isory cont ro l system.

Provide output of rapper opera t ion v e r i f i c a t i o n s igna l on an individual rapper b a s i s l o c a l l y and t o t h e supervisory cont ro l system. Fa i lu re of t he superv isory cont ro l system should not de-energize the 1 ocal rapper cont ro l system.

I n o r d e r t o o p t i m i z e p r e c i p i t a t o r per formance, an ESP s u p e r v i s o r y c o n t r o l

system may c o n t a i n a r a p p e r o p t i m i z a t i o n c o n t r o l c i r c u i t wh ich has t h e

c a p a b i l i t y o f o v e r r i d i n g t h e l o c a l r a p p e r c o n t r o l system when necessary .

Hopper Hea te r C o n t r o l

A hopper h e a t e r c o n t r o l system may c o n s i s t o f an ESP s u p p l i e r ' s s t a n d a r d

c o n t r o l c a b i n e t f o r two l e v e l s o f h e a t e r s on each p r e c i p i t a t o r hopper w i t h t h e

f o l l o w i n g minimum c o n t r o l f u n c t i o n s :

P r o v i d e c o n t r o l s w i t c h e s f o r hopper h e a t e r o f f / o n f o r each hopper .

P r o v i d e o u t p u t o f c o n t r o c o n t r o l system.

I s w i t c h s t a t u s l o c a l l y t o t h e s u p e r v i s o r y

M o n i t o r t h e tempera tu re i n two l e v e l s o f each hopper and modula te t h e upper

and lower hopper h e a t e r s t o m a i n t a i n a s e t p o i n t u s i n g i n d i v i d u a l power

c o n t a c t o r s f o r t h e h e a t i n g e lements i n each l e v e l .

F a i l u r e o f t h e ESP s u p e r v i s o r y c o n t r o l system shou ld e n e r g i z e a l l hopper

h e a t e r s whose c o n t r o l s w i t c h i s i n t h e "on" p o s i t i o n a t t h e l o c a l c o n t r o l

c a b i n e t .

V i b r a t o r C o n t r o l

The v i b r a t o r c o n t r o l system may c o n s i s t o f an ESP s u p p l i e r ' s s tandard

v i b r a t o r c o n t r o l c a b i n e t wh ich should p r o v i d e c o n t r o l f u n c t i o n s as f o l l o w s :

Loca l j o g pushbu t tons f o r each v i b r a t o r wh ich would prompt t h e o p e r a t o r t o v i s u a l l y i n s p e c t and check t h e hopper b e f o r e e n e r g i z i n g a v i b r a t o r .

Au tomat i c i n t e r l o c k w i t h t h e ash h a n d l i n g system t o e n e r g i z e a v i b r a t o r f o r a p rede te rm ined t i m e when ash i s b e i n g conveyed f r o m an i n d i v i d u a l hopper .

Remote manual c o n t r o l s h o u l d n o t be p r o v i d e d due t o t h e f a c t t h a t t h e ash may

be e a s i l y compacted i f t h e v i b r a t o r i s e n e r g i z e d when ash i s n o t b e i n g

d i s c h a r g e d due t o a p luggage, t h e f l y ash b l o w e r s n o t r u n n i n g o r t h e b o t t o m

g a t e v a l v e n o t open.

In t eg ra t ion With Ash Handling

In gene ra l , i n t eg ra t i on with t h e f l y ash handling system would be through an

AQCS cont ro l room, i f app l i cab l e , which provides f o r cont ro l of the e n t i r e

back end of t h e p l an t . This inc ludes t h e f l u e gas desu l fu r i za t i on system,

p r e c i p i t a t o r , f l y ash handling system, wastewater t reatment and the f l u e gas

emissions compliance monitoring system. I n t e r f a c e s with the ash handling

system should e s s e n t i a l l y be t he hopper level alarms and the hopper v i b r a t o r

c o n t r o l s . Automatic v i b r a t o r cont ro l i s a s previously descr ibed .

Power Management System/Supervisory Control System

Modern con t ro l systems a r e not only capable of achieving very hfgh removal

e f f i c i e n c i e s in e ? e c t r o s t a t i c p r e c i p i t a t o r s , but through microprocessor

technology, they a r e a l so ab le t o reduce overa l l power consumption t o a

minimum depending upon process c o n d i t i o n s . P r e c i p i t a t o r s a r e usua l ly designed

f o r a worst ca se condit ion and a r e normally not opera t ing a t t h a t p o i n t . When

on ly a spark r a t e o r cu r r en t l i m i t i n g c o n t r o l l e r i s used, t he T/R s e t s w i l l be

consuming maximum power a l l t he t ime, r ega rd l e s s of process condi t ions . The

use of an opac i ty feedback loop in t h e cont ro l c i r c u i t a l lows input power t o

be reduced when favorable condi t ions e x i s t and s t i l l maintain the guaranteed

emission leve l a s determined by f l u e gas opaci ty monitors. Condit ions such a s

t h e b o i l e r running a t p a r t i a l load o r t h e fue? being burned having a low ash

content and/or a favorable r e s i s t i v i t y , do not r equ i r e the T/R s e t s t o ope ra t e

a t maximum load.

The reduct ion of power i s normally performed on a T/R by T/R b a s i s ; each T/R

s e t i s reduced slowly t o provide t he system time t o a d j u s t t o the new

cond i t i ons . The order in which t h e power t o the f i e l d s i s reduced wi l l have

an e f f e c t on the frequency of opac i ty sp ikes . I t has been t h e experience of

some manufacturers (98) t h a t by reducing power t o t he f i r s t f i e l d o r t o

consequent f i e l d s , t h e occurrence of opac i ty sp ikes due t o reentrainment of

f l y ash i s reduced. Conversely, i f t h e power t o t he l a s t f i e l d i s reduced,

t h e frequency of opac i ty sp ikes w i l l be increased due t o rapping reentrainment .

Some manufacturers have found t h a t t h e most e f f e c t i v e power d i s t r i b u t i o n i s

formed by reducing power t o a l l f i e l d s a t t he same time (3). Corona power

consumption i s g r e a t l y reduced with only a s l i g h t l o s s i n e f f i c i e n c y . The

cont ro l system should be s p e c i f i e d w i t h t he a b i l i t y in t he system software t o

make changes t o t h e s e q u e n t i a l o r d e r o f f i e l d power r e d u c t i o n as necessary t o

t u n e t h e system.

Power management i s o n l y one o f many c a p a b i l i t i e s made p o s s i b l e i n s p e c i f y i n g

a t o t a l ESP s u p e r v i s o r y c o n t r o l system. As d i s c u s s e d e a r l i e r , t h e s u p e r v i s o r y

c o n t r o l system u s u a l l y c o n s i s t s o f a microcomputer , keyboard, CRT, p r i n t e r ,

d a t a s t o r a g e d e v i c e s , and r e q u i r e d i n p u t / o u t p u t i n t e r f a c e hardware. A

t e l e p h o n e modem i s a l s o sometimes i n c l u d e d . The a d d i t i o n o f a s u p e r v i s o r y

c o n t r o l l e r t o t h e ESP c o n t r o l system can b r i n g t h e c o n f i g u r a t i o n o f l o c a l ESP

pa ramete rs and o p e r a t i o n a l d a t a t o a c e n t r a l l o c a t i o n . I n f o r m a t i o n c o n c e r n i n g

t h e e n t i r e ESP sys tem may be c o n c i s e l y d i s p l a y e d , and f u l l c o n t r o l o f a l l

l o c a l u n i t s may be a v a i l a b l e a t a c e n t r a l l o c a t i o n . The s u p e r v i s o r y

c o n t r o l l e r may be des igned t o r e c o g n i z e and d i s p l a y abnormal o p e r a t i o n ,

t h e r e b y e n a b l i n g c o r r e c t i v e o r r e m e d i a l a c t i o n t o be q u i c k l y implemented.

I n a d d i t i o n t o ESP power management, t h e f o l l o w i n g a r e t y p i c a l f e a t u r e s o f a

p r o p e r l y s p e c i f i e d s u p e r v i s o r y c o n t r o l system:

Improved T/R c o n t r o l and p r e c i p i t a t o r per formance

Improved system r e 1 i a b i 1 i t y

C o ~ v e n i e n t c e n t r a l i z e d c o n t r o l , m o n i t o r i n g and d a t a l o g g i n g

I n t e g r a t e d r a p p i n g sys tem c o n t r o l

= Hopper ash l e v e l m o n i t o r i n g

Hopper h e a t e r m o n i t o r i n g and c o n t r o l

System f a u l t d i a g n o s i s

Main tenance s c h e d u l i n g

Modem communicat ions.

When a s u p e r v i s o r y c o n t r o l system i s s p e c i f i e d , t h e t o t a l ESP c o n t r o l sys tem

s h o u l d be des igned t o be t o l e r a n t o f i n d i v i d u a l component f a i l u r e s . The re

s h o u l d b e no c r i t i c a l component i n t h e system. Upon f a i l u r e o f t h e

s u p e r v i s o r y c o n t r o l system, t h e l o c a l c o n t r o l u n i t s must a u t o m a t i c a l l y r e v e r t

t o l o c a l , i ndependen t o p e r a t i o n .

PRECIPITATOR CONTROL SYSTEM HARDWARE

She e v o l u t i o n o f p r e c i p i t a t o r c o n t r o l systems has seen e l e c t r o n i c t e c h n o l o g y

b r i n g low c o s t s , r e l i a b i l i t y , m i n i a t u r i z a t i o n and improved o p e r a t o r

i n t e r f a c e . The c o n t i n u i n g r a p i d g rowth o f computer t e c h n o l o g y and d i g i t a l

e l e c t r o n i c s w i l l assure t h e g r e a t e r use o f d i g i t a l c o n t r o l systems as

p r e c i p i t a t o r manu fac tu re rs ' s tandard equ ipment . More and more manu fac tu re rs

have changed f r o m analog systems, w h i c h moved t h e e l e c t r o n i c s p rocess c o n t r o l

e v o l u t i o n away f rom pneumatic p rocess c o n t r o l t o s t a t e o f t h e a r t d i g i t a l

c o n t r o l . However, some aspec ts o f p r o c e s s c o n t r o l , such as t h e i n i t i a l

measurement and c o n v e r s i o n o f a p rocess v a r i a b l e , w i l l p r o b a b l y a lways be

ana log i n n a t u r e . The two t y p e s o f e l e c t r o n i c c o n t r o l a r e d i s c u s s e d b r i e f l y

i n t h e f o l l o w i n g paragraphs.

Analog

Analog c o n t r o l systems a r e f a i r l y easy t o o p e r a t e and do n o t u s u a l l y r e q u i r e

o p e r a t o r s t o undergo s p e c i a l i z e d t r a i n i n g . A l l system components a r e h a r d

w i r e d , and a d e d i c a t e d p i e c e o f equ ipment p e r f o r m s each s p e c i f i c f u n c t i o n .

Because o f t h i s , ana log systems t e n d t o r e q u i r e a l o t o f space. A l s o , t h i s

hardware o r i e n t a t i o n makes any changes t o t h e system l o g i c more d i f f i c u l t t o

accommodate, u s u a l l y r e q u i r e s a r e q u i r i n g o f t h e c o n t r o l system.

Data g a t h e r i n g may be accompl ished f a i r l y e a s i l y w i t h an a n a l o g system,

a l t h o u g h l a r g e amounts o f d a t a r e t r i e v a l and s t o r a g e may become cumbersome

s i n c e each p i e c e o f d a t a must be hand led t h r o u g h a d e d i c a t e d p i e c e o f

hardware. M u l t i p l e x i n g , wh ich i s u s e f u l when h a n d l f n g l a r g e amounts o f

i n f o r m a t i o n , cannot be used w i t h an a n a l o g system.

Some o f t h e s e l i m i t a t i o n s have prompted t h e i n d u s t r y t o l o o k toward d i g i t a l

systems t o p r o v i d e users w i t h s t a t e o f t h e a r t p r e c i p i t z t o r c o n t r o l .

D i g i t a l

D i g i t a l c o n t r o l systems u s u a l l y r e q u i r e s p e c i a l t r a i n i n g f o r o p e r a t i o n s and

maintenance s i n c e t h e techno logy i s new and c o n s t a n t l y chang ing . T e c h n i c i a n s

must l e a r n about components which can p e r f o r m a v a r i e t y o f f u n c t i o n s wh ich

t y p i c a l l y were per formed by severa l components i n t h e p a s t . T h i s

c o n s o l i d a t i o n o f equipment saves space i n t h e c o n t r o l room and e l e c t r o n i c s

equipment room. C R T ' s can d i s p l a y t h e i n f o r m a t i o n o f many i n d i c a t o r s and a l s o

f u n c t i o n as a manual/auto s t a t i o n f o r o p e r a t o r i n t e r f a c e .

D i g i t a l systems a r e ex t reme ly f l e x i b l e and system l o g i c can be e a s i l y changed

by making s o f t w a r e m o d i f i c a t i o n s .

Data g a t h e r i n g w i t h a d i g i t a l system i s accompl ished e a s i l y w i t h l a r g e amounts

o f d a t a b e i n g m u l t i p l e x e d , t h u s s a v i n g on hardware c o s t s . I n t e r f a c e w i t h

p r i n t e r s , CRT's and computers s i m p l i f i e s t h e t a s k o f d a t a l o g g i n g and s t o r a g e .

The c o n t i n u e d development o f i n t e g r a t e d c i r c u i t m i c r o p r o c e s s o r s t o improve '

r e l i a b i l i t y and backup methods t o a v o i d process shutdowns due t o a

m ic rop rocessor f a i l u r e has g i ven d i g i t a l c o n t r o l systems c o n s i d e r a b l e f a v o r

among p r e c i p i t a t o r manu fac tu re rs .

CRTs, Keyboards, P r i n t e r s

The ESP s u p p l i e r shou ld p r o v i d e CRTs w i t h keyboards and p r i n t e r s f o r o p e r a t o r

i n t e r f a c e when an ESP s u p e r v i s o r y c o n t r o l system i s s p e c i f i e d . CRTs may

e i t h e r be s u i t a b l e f o r panel moun t ing o r may be desk t o p u n i t s depending on

system des ign .

Some manu fac tu re rs p r o v i d e CRTs w i t h t o u c h screens, i n a d d i t i o n t o keyboards,

f o r t h e p r i m a r y o p e r a t o r i n t e r f a c e . T h i s makes t h e i n t e r f a c e a l i t t l e e a s i e r

f o r t h e o p e r a t o r , e s p e c i a l l y i f t h e CRT i s panel mounted. The CRTs may t h e n

be p r o v i d e d w i t h a preprogrammed s e t o f s p e c i a l f u n c t i o n touch-screen

pushbut tons t o enab le t h e o p e r a t o r t o c a l l up s p e c i f i c g r a p h i c s and o t h e r

d e d i c a t e d d i s p l a y s by means o f a menu-se lec t i on t e c h n i q u e r a t h e r than by

i n p u t t i n g alpha-numeric codes t h r o u g h a keyboard.

Each CRT d i s p l a y u n i t shou ld have t h e f o l l o w i n g f e a t u r e s :

A minimum o f a 19 - inch d i a g o n a l d i s p l a y a rea and enough r e s o l u t i o n t o d i s p l a y 3840 c h a r a c t e r s i n an 80 c h a r a c t e r by 48 l i n e fo rmat .

A l a r g e c h a r a c t e r mode f o r use w i t h a la rms and g r a p h i c t i t l i n g . The screen s h o u l d have 80 c h a r a c t e r s by 24 l i n e s i n t h i s mode.

An i n t e r a c t i v e keyboard f o r d a t a e n t r y , h a v i n g a t y p e w r i t e r f o r m a t s e c t i o n f o r g e n e r a t i n g t h e 128 A S C I I c h a r a c t e r codes, a numeric keypad s e c t i o n f o r g e n e r a t i n g t h e t e n numera ls and common s p e c i a l symbols. An a d d i t i o n a l u t i l i t y p r e f e r e n c e may be t h e s p e c i a l f u n c t i o n t o u c h screen key s e c t i o n f o r s e l e c t i n g s tandard s o f t w a r e f u n c t i o n s and c o n t r o l l i n g t h e d i s p l a y .

An RS-232C p o r t capable o f communicat ing, u s i n g a seven b i t ASCI I c h a r a c t e r w i t h even p a r i t y i n an asynchronous f o r m a t u s i n s one s t a r t b i t and one s top b i t a t speeds up t o 9600 b i t s p e r second.

. Sufficient local memory to hold all the pixels of a graphic display without dependence on an external processor or memory.

The ESP supplier should also provide printers to perform alarm functions and

also for system logging and reporting. Each printer should have the following

features :

Operate at a minimum of 180 characters per second and have a line length of at least 132 characters.

Communicate through an RS232C port using seven bit ASCII characters with even parity in an asynchronous format using one start bit and one stop bie at speeds up to 1200 bits per second.

Printers should be capable o f handling forms with perforated edges and sho~ld not. rely on frictioa only t? ~ o s 2 t 5 e papcr.

System Architecture

The architecture of the control system hardware is affected by

functional design being either of centralized control or local

philosophy. These two control philosophies were discussed ear

section. System architecture should be consistent with a util

plant control philosophy.

the system

ized control

lier in this

ity's overall

INSTALLATION CONSIDERATIONS

Three main areas of consideration must be addressed before a control system

is satisfactoriiy insta7led and operating. They are testing and inspection,

shipping and storage, and final installation.

Testinq and Inspection

A control system should be completely assembled and operationally tested for

wiring accuracy, hzrdware quality, software fmction, and failure m3do for a

period of time sufficient to demonstrate proper operation. The manufacturer

must provide simulated realistic inputs for the system during these tests.

The manufacturer must provide a sufficient number of simulated, realistic

inputs and outputs to accomplish convenient demonstration of the system

operating in its enxirety. All inputs must be live and manually

controllable. All outputs must be live and visually observable.

A ESP supplier should notify a utility at least two weeks in advance of all

significant stages of fabrication and shop testing. A supplier should furnish

or make certified copies of all factory test results available to a utility.

A l l equipment and m a t e r i a l shou ld be s u b j e c t t o f i n a l i n s p e c t i o n and should

n o t b e sh ipped w i t h o u t a n o t i f i c t i o n o f r e l e a s e f rom t h e u t i l i t y .

S h i p p i n g and S to rage

The s u p p l i e r must p repare equipment f o r sh ipment t o p r o t e c t i t f r o m damage

d u r i n g sh ipment and subsequent s t o r a g e . The equipment must be adequa te l y

p r o t e c t e d f r o m t h e e f f e c t s o f weather, shock and v i b r a t i o n . A l l openings must

be adequa te l y p r o t e c t e d t o p r e v e n t c o r r o s i o n o r e n t r a n c e o f f o r e i g n m a t t e r

d u r i n g shipment and s to rage .

Equipment must be adequa te l y suppor ted f o r shipment. A l l l o o s e p a r t s must b e

c r a t e d o r boxed f o r shipment and a p p r o p r i a t e l y i d e n t i f i e d . The equipment, as

sh ipped, must be s u i t a b l e f o r movement b y r o l l i n g and s k i d d i n g and c o n v e n i e n t

h a n d l i n g w i t h a c rane .

The equipment s h o u l d be s t o r e d i n an env i ronment s i m i l a r t o t h e i n s t a l l e d

l o c a t i o n , i . e . , i n d o o r equipment must be s t o r e d indoors , and ou tdoor equipment

may be s t o r e d o u t d o o r s . Where r e q u i r e d t o p r o t e c t a g a i n s t condensat ion and

h u m i d i t y , a d e s i c c a n t must be p r o v i d e d and i t s presence, w i t h t h e need o f

p e r i o d i c removal and d r y - o u t , must b e so marked. When e l e c t r i c space h e a t e r s

a r e p r o v i d e d f o r t h a t purpose, t h e y s h o u l d be w i r e d t o t h e o u t s i d e o f t h e

equipment such t h a t e n e r g i z a t i o n i m m e d i a t e l y upon r e c e i p t i s p o s s i b l e w i t h o u t

d i sassemb ly o f c r a t e s . T h i s a l s o r e q u i r e s t h a t no c o m b u s t i b l e m a t e r t a l be

l e f t i n s i d e o f t h e equipment.

The ESP s u p p l i e r must p r o v i d e s t o r a g e and h a n d l i n g i n s t r u c t i o n s , i n c l u d i n g

d e s c r i p t i o n s o f p e r i o d i c i n s p e c t i o n and/or s t o r a g e maintenance t o assure t h a t

no d e t e r i o r a t i o n w i l l o c c u r d u r i n g s t o r a g e . One s e t o f t hese i n s t r u c t i o n s

s h o u l d be f a s t e n e d s e c u r e l y t o t h e o u t s i d e o f each s h i p p i n g u n i t .

A c o r r o s i o n - r e s i s t a n t nameplate w i t h c l e a r l y l e g i b l e l e t t e r i n g must be

pe rmanen t l y a t t a c h e d t o each assembled p i e c e o f equipment a t an e a s i l y v i s i b l e

p l a c e . The namepla te must p r o v i d e necessary i n f o r m a t i o n p e r t a i n i n g t o t h e

equipment, b u t as a minimum, t h e f o l l o w i n g must be i n c l u d e d : M a n u f a c t u r e r ' s

name, t y p e o f equipment, s e r i a l number, shop o r d e r number, p r o j e c t

i d e n t i f i c a t i o n number, and w e i g h t . Any s p e c i a l maintenance i n s t r u c t i o n s must

a l s o be shown a t t h i s o r o t h e r s u i t a b l e l o c a t i o n s .

I n s t a l l a t i o n

I n a f u r n i s h and e r e c t c o n t r a c t , t h e ESP s u p p l i e r must have comp le te system

r e s p o n s i b i l i t y th roughou t f o r s a t i s f a c t o r y o p e r a t i o n and pe r fo rmance o f t h e

e l e c t r i c a l components and c o n t r o l system, subsystems. The ESP s u p p l i e r must

be r e s p o n s i b l e f o r i n s t a l l a t i o n , checkout, and p r e l i m i n a r y system o p e r a t i o n t o

t h e p o i n t o f acceptance o f t h e system by t h e u t i l i t y .

I f t h e u t i l i t y i s r e s p o n s i b l e f o r i n s t a l l a t i o n , t h e s u p p l i e r must p r o v i d e t h e

s e r v i c e s o f two eng ineers , one f o r hardware and one f o r s o f t w a r e , on an

as-needed b a s i s , w h i l e t h e equipment i s b e i n g i n s t a l T e d , checked o u t , and p u t

i n t o t r i a l o p e r a t i o n . The u t i l i t y shou ld s p e c i f y , i n t h e c o n t r a c t , t h e t o t a l

amount of i n s t a l l a t i o n a s s i s t a n c e t i m e a t t h e j o b s i t e f o r each u n i t . These

e n g i n e e r s must be t h o r o u g h l y f a m i l i a r w i t h a l l aspec ts o f t h e s u p p l i e r ' s

equ ipment and must be capable

o u t , and o p e r a t i o n o f t h e equ i

SYSTEM DOCUMENTATION

An ESP s u p p l i e r must p r a v i d e a

o f d i r e c t i n g a l l phases o f i n s t a l l a t i o n , check

pment.

complete system documentat ion package f o r a

p r e c i p i t a t o r e l e c t r i c a l system. T h i s w i l l e n a b l e a u t i l i t y t o f u l l y

u n d e r s t a n d system o p e r a t i o n s and w i l l a i d i n t r o u b l e s h o o t i n g and system

maintenance. T h i s documentat ion package s h o u l d i n c l u d e t h e f o l l o w i n g :

Equipment I n t e r n a l W i r i n g Diagrams

C o n t r o l W i r i n g Diagrams

I n s t r u m e n t L o c a t i o n and Arrangement Drawings

I n s t r u m e n t I n s t a l l a t i o n and I n s t r u m e n t Suppor t D e t a i l s

L o g i c Diagrams

C o n t r o l System S o f t w a r e Documentat ion

C o n t r o l System C o n f i g u r a t i o n Drawings

I n s t r u m e n t Schematics

E x t e r n a l I n t e r c o n n e c t i o n Diagrams

I n s t r u m e n t Data Base I n f o r m a t i o n

These documents a re d i s c u s s e d i n d e t a i l i n S e c t i o n 7 o f t h i s manual.

6 SPECIFICATION FOR OPERATION AND MAINTENANCE RELATED SYSTEMS

S e c t i o n 6

SPECIFICATION FOR OPERATIONS AND MAINTENANCE RELATED SYSTEMS

KEY INTERLOCK SYSTEM

S a f e t y F e a t u r e

The p r i n c i p a l f u n c t i o n o f t h e ESP key i n t e r l o c k system i s t o p r o v i d e a

sequence o f e n e r g i z a t i o n o r deenergization/grounding o f t h e ESP e l e c t r i c a l

sys tem t o ensure s a f e access t o a reas wh ich c o n t a i n exposed conduc to rs o r

e l e c t r o d e s . The use o f a key i n t e r l o c k system i s a p r ime e l e c t r i c a l s a f e t y

f e a t u r e o f ESP des ign and, a l t h o u g h n o t s p e c i f i c a l l y r e q u i r e d b y e l e c t r i c a l o r

s a f e t y codes, has a l o n g h i s t o r y o f a p p l i c a t i o n and i s i n -near ly t o t a l use i n

t h e U.S. e l e c t r i c u t i l i t y i n d u s t r y .

Lock Components

The key i n t e r l o c k c o n s i s t s o f a number o f key opera ted mechanica l l o c k i n g

d e v i c e s a r r a n g e d i n an o v e r a l l l o g i c a l sequence o f o p e r a t i o n . The d e s i g n o f a

s i n g l e l o c k d e v i c e depends on t h e t y p e o f a p p l i c a t i o n , b u t i t u s u a l l y c o n s i s t s

o f t h e f o l l o w i n g elements:

A h o u s i n g b l o c k w i t h r e t r a c t a b l e b o l t and one o r more l o c k s

keys

a moun t ing b r a c k e t o r p l a t e

b o l t s o r screws t o a t t a c h t h e hous ing t o t h e mount

A c h a i n a t t a c h e d wea the r /dus t cap wh ich f i t s o v e r a l o c k and key

A namepla te w i t h number code

The d e v i c e i s s i m i l a r i n des ign and o p e r a t i o n t o a d e a d b o l t door l o c k . A key

i s i n s e r t e d i n t h e l o c k and t u r n e d t o ex tend t h e b o l t . The extended b o l t

p r o t r u d e s t h r o u g h a ma t ing h o l e i n a s w i t c h handle o r l e v e r and l o c k s i t i n

t h a t p o s i t i o n .

The b o l t does n o t move a s w i t c h , b u t i t a l l o w s o r p r e v e n t s pe rsonne l f rom

m a n u a l l y chang ing a s w i t c h p o s i t i o n . When mounted on an access door , t h e l o c k

b o l t extends through a mating l a t c h block mounted on the door frame and

thereby prevents the door from being opened. Although ' in te r locks can be

designed so t h a t t h e b o l t makes o r breaks con tac t on a r e l a y o r l i m i t switch,

ESP i n t e r l o c k s a r e usua l ly purely mechanical with no e l e c t r i c a l o r cont ro l

c i r c u i t i n t e r f a c e s .

An add i t i ona l fundamental design f ea tu re of key i n t e r l o c k s hold t he key

cap t ive i n one b o l t pos i t i on and f r e e s i t i n t h e o ther b o l t p o s i t i o n . The

i n t e r n a l lock func t ion i s s i m i l a r t o t h e type of padlock from which t h e key

can be removed only a f t e r t h e shackle has been c losed .

System Design

The use of key i n t e r l o c k s i n a complete system i s discussed f o r a

r e p r e s e n t a t i v e two-device system comprising a T/R cont ro l c a b i n e t power

primary (low vol tage) c i r c u i t breaker and a mul t i -pos i t ion r o t a r y switch on

t h e T/R s e t . One pos i t ion on the ro t a ry switch i s a ground f o r t h e T/R s e t

secondary (high vol tage) and t h e d ischarge e l ec t rode in t e rna l t o t h e ESP.

The c o r r e c t two-step sequence required f o r grounding o r r e - e s t ab l i sh ing power

i n t h e c i r c u i t a re :

For grounding:

1. open t h e primary ccircui t breaker

2. t u rn t h e T/R s e t switch t o the ground pos i t i on .

For re-energizat ion:

1. tu rn t h e T/R s e t switch from ground t o one of t h e ope ra t ing p o s i t i o n s

2 . c lose t h e primary breaker .

I f e i t h e r sequence i s not performed in c o r r e c t order t h e secondary i s grounded

while t h e primary breaker i s ciosed and t h e r e w i l l be a c u r r e n t surge t o

ground u n t i l t he automatic over-current p r o t e c t i v e devices open t h e c i r c u i t .

The app rop r i a t e key i n t e r l o c k scheme f o r t h i s opera t ion i s shown i n a flow of

keys o r l o g i c diagram ( see Fig. 6-1). A n a r b i t r a r y lock and key numbering

system was assigned f o r i l l u s t r a t i o n . The w r i t t e n check l i s t procedure f o r

opera t ion would be:

Key 3 I

I I

I I

1 T IR SET B I b

Key 2 I 1 1

Key Storage Cabinet

Figure 6-1. Key interlock System I l l u s t r a t i on

For grounding:

1. obta in key 1 from a key s to rage cab ine t and i n s e r t in lock A1

2. open c i r c u i t breaker CB-1 and lock in open posi t ion by extending b o l t . Key 1 i s now c a p t i v e and key 3 i s now f r e e

3 . remove key 2 from lock A2 and i n s e r t i n 1 ock B1

4 . move T/R switch t o ground p o s i t i o n and lock in t he pos i t ion by extending b o l t . Key 2 i s now c a p t i v e and key 3 i s f r e e .

For r eene rg i za t ion , r e v e r s e t h e above procedure.

In t h i s example, key 3 would be f u r t h e r used in add i t i ona l s teps i n t he

sequence such a s opening an access door i n t h e penthouse roof . The s t e p s i n

t h e key i n t e r l o c k approach t o t h e opera t ion a r e i d e n t i c a l t o those i n a

s t r i c t l y manual approach except t h a t t h e c a p t i v e key f e a t u r e of t he i n t e r l o c k

design prevents t he ope ra to r from performing any s t e p s out of sequence. The

system i s t hus i nhe ren t ly s a f e a s i t mechanically fo rces the c o r r e c t sequence

of s t e p s and does not r e l y on t h e d i s c r e t i o n of o p e r a t o r s .

Appl i c a t i o n t o ESPs

When used on an ESP, t h e key i n t e r l o c k system usua l ly inc ludes t h e following

devices i n t he locking log i c :

T/R cont ro l cab ine t c i r c u i t b reakers

T/R set func t ion and grounding swi tches

Penthouse o r enc losure doors

Doors o r hatchways through the hot roof i n t o t he ESP i n t e r i o r

ESP casing s i d e acces s doors

Hopper doors

Hopper level d e t e c t o r s , i f nuclear type

I n l e t / o u t l e t nozzle (plenum) doors , i f des ign permits access t o t h e i n t e r i o r of t h e ESP

Ductwork doors , bolt-on inspec t ion doors on bus d u c t s , duct damper i n t e r l o c k s ,

and manual grounding dev ices f o r e l ec t rodes a r e gene ra l ly not p a r t of the ESP

key i n t e r l o c k system. I n s u l a t o r a i r f a n s , i f they a l s o purge the penthouse,

are sometimes in t e r locked with t h e penthouse acces s doors .

S i n c e t h e number o f keys i n an o v e r a l l system i s l a r g e , and t h e r e i s n o t

a lways a one-to-one correspondence between s e q u e n t i a l d e v i c e s , a t y p i c a l

system c o n t a i n s key t r a n s f e r b l o c k s . T r a n s f e r b l o c k s a r e mu1 t i p l e key panel s

w i t h l o c k s wh ich have t h e c a p t i v e / f r e e f e a t u r e , b u t no b o l t s a r e extended.

F o r example, when a penthouse door has been opened (so t h a t t h e exposed bus

may be manua l l y grounded) a key i s r e l e a s e d . When a l l such penthouse door

keys have been i n s e r t e d i n t h e t r a n s f e r b l o c k , a l l o f t h e s i d e c a s i n g door

keys a r e re leased . The t r a n s f e r b l o c k , t h e r e f o r e , a l l o w s b o t h s e r i e s and

p a r a l l e l o p e r a t i o n s t o be combined i n an o v e r a l l scheme.

F o r n u c l e a r t y p e l e v e l d e t e c t o r s mounted on t h e s i d e o f t h e hopper o r

suspended i n t h e c r o t c h between two hoppers, t h e source must be s h i e l d e d

b e f o r e t h e hopper access door i s opened. T h i s d e t e c t o r mechanism i s

i n c o r p o r a t e d i n t h e o v e r a l l key i n t e r l o c k system and t h e d e t e c t o r keys must

a l s o be i n s e r t e d i n t h e a p p r o p r i a t e t r a n s f e r b l o c k b e f o r e any c a s i n g o r hopper

d o o r keys a r e r e l e a s e d .

Re1 i a b i l i t y o f O p e r a t i o n

Three p r i n c i p a l t y p e s o f f a i l u r e f o r key i n t e r l o c k components a r e :

Lock i n t e r n a l s have accumulated f l y ash due t o f a i l u r e t o r e p l a c e t h e d u s t cap. F o r c i n g t h e o p e r a t i o n can l e a d t o b e n t o r b roken keys.

Poor a l i g n m e n t o f b o l t and j a t c h on d o o r s causes b i n d i n g o f t h e b o l t . Aga in , f o r c e d o p e r a t i o n can cause broken keys.

Over- temperature o f t h e l o c k "annea ls " t h e i n t e r n a l sp r ings , and p i n s w i l l n o t go t o t h e c o r r e c t p o s i t i o n when t h e key p o s i t i o n i s c o r r e c t .

F o r t h e f i r s t prob lem, caps on a c a p t i v e c h a i n can be p r o v i d e d as p a r t o f t h e

d e s i g n , b u t p r o p e r use can o n l y be e n f o r c e d t h r o u g h an i n - p l a n t O&M t r a i n i n g

program and p r o p e r s u p e r v i s i o n o f p rocedures .

The m isa l i gnment of l o c k b o l t and l a t c h i s due t o t h e f a c t t h a t these a r e

c l o s e d imens iona l t o l e r a n c e i t e m s , y e t access doors and frames a re n o t and can

s h i f t due t o sagging o r h inge p i n wear. T h i s t y p e o f prob lem can be avo ided

b y u s i n g t h e b o l t t o l o c k one end o f a c h a i n r a t h e r than mate d i r e c t l y w i t h a

l a t c h h o l e on t h e o t h e r member. T h i s t y p e o f d e s i g n i s easy t o implement

s i n c e access doors commonly employ a s a f e t y c h a i n f e a t u r e t o p r e v e n t excess ive

s p i l l a g e o f h o t f l y ash i f i t has accumulated above door l e v e l . Over

tempera tu re o f t h e l o c k can occur f o r d o o r l o c k s wh ich a r e covered w i t h a

separate insulating door when there is a high temperature excursion in the

ESP. High temperature locks (bronze blocks with stainless steel springs) can

be specified for appropriate physical locations.

Maintenance of locks consists of syringe washing with mineral spirits, air

blowing to dry, and lubrication with graphite. A typical recommended

maintenance interval would be 6 months although it should be noted that , due to the captive key feature of the locks, all locks can be maintained only by

proceeding through the sequence of unlocking and key transfer. This will

generally limit the maintenance interval to one year - during the annual outage.

Defeat of the System

The safety intent of the key interlock system can be defeated (accidentally

or deliberately) by any of the following: - Design

- Incorrect logic diagram - supposedly correct operat in fact prevent exposure to a hazard

- Incorrect lock type - the captive/free feature reie the wrong position.

Initial Instal lation

ion does not

ases keys in

- Incorrect sequence - locks installed in the wrong location

- Incomplete installation - locks not installed on all required devices.

Operation

- Master key misuse - poor control of master keys which open many locks or extensive use of masters as replacements for lost keys

- Duplicate keys - keys found that were not destroyed after replacements have been entered into the system

- Incorrect replacement - locks installed in wrong location or not installed at all

- Lock removal - with tools or direct assault.

Those problems which could occur during design and installation can be

avoided, in principle, through proper design review and construction

supervision. Operational areas are more difficult. There are sufficient ways

to defeat the system that it will: work in practice only i f those who use it

want i t t o work. The success o f t h e system, t h e r e f o r e , depends p r i m a r i l y on a

u t i l i t y ' s success i n e s t a b l i s h i n g s a f e p r a c t i c e a t t i t u d e s r a t h e r t h a n i n more

e l a b o r a t e d e s i g n approaches t o p r e v e n t d e f e a t .

Procurement Aspects

An ESP s u p p l i e r des igns a l o g i c d iagram f o r t h e system, s e l e c t s l o c k t y p e s ,

d e s i g n s and f a b r i c a t e s mounts, p repares i n s t a l l a t i o n d raw ings , and p r o c u r e s

t h e l o c k components f rom a l o c k manu fac tu re r .

The l o c k manu fac tu re r p r o v i d e s l o c k s , keys, t r a n s f e r b l o c k s and c a b i n e t s i f

any o f t h e t r a n s f e r b l o c k s a r e t o be l o c a t e d i n an e n c l o s u r e . Th ree p r i n c i p a l

l o c k manu fac tu re rs i n t h e U.S. a r e :

Brown B o v a r i E l e c t r i c , I n c .

S u p e r i o r I n t e r l o c k

The Brown Bovar i equipment i s more commonly known b y i t s t rademark name o f

KIRK ( o r K i r k I n t e r l o c k s o r I - T - E K i r k ) . S u p e r i o r a l s o p r o v i d e s rep lacement

s e r v i c e f o r systems p r e v i o u s l y manufactured by Bendix A v i a t i o n under t h e t r a d e

names Robinson, CORY-Robinson, o r Bendix-CORY. These m a n u f a c t u r e r s can

p r o v i d e c a t a l o g s o f l o c k equjprnent and v a r i o u s g e n e r i c schemat i cs f o r

d i f f e r e n t a p p l i c a t i o n s .

B o t h t h e l o c k manu fac tu re r and t h e ESP s u p p ? i e r l s spare p a r t s d i v i s i o n

m a i n t a i n permanent reco rds , and spare p a r t s may be o r d e r e d f r o m e i t h e r .

Sometimes the ESP s u p p l i e r w i l l employ a l o c k t y p e c o d i n g system on d raw ings

w h i c h does n o t cor respond d i r e c t l y t o t h e l o c k m a n u f a c t u r e r ' s model number

d e s i g n a t i o n s . I n such a case, a convers ion t a b l e shou ld be o b t a i n e d t o ensure

t h a t t h e c o r r e c t l o c k t y p e i s f u r n i s h e d shou ld spares be o r d e r e d d i r e c t l y f rom

a l o c k s u p p l i e r .

L o c k i n g equipment and mounts a re u s u a l l y f i e l d i n s t a l l e d by t h e e r e c t o r u s i n g

t h e ESP s u p p l i e r ' s i n s t a l l a t i o n drawings. These d raw ings u s u a l l y c o n t a i n a

t a b u l a r fo rmat o f code numbers t o i d s t r u c t t h e e r e c t o r on t h e c o r r e c t ma tch ing

o f l o c k s t o doors and sw i t ches . U s u a l l y a l l l o c k i n g equipment i s f i e l d

i n s t a l l e d , and no l o c k s a r e forwarded t o T/R se t , l e v e l d e t e c t o r , o r access

door suppliers. However, sometimes access doors are shipped to fabricators

who install thermal insulation pans and locks/safety chairs prior to shipment

field.

Reviewing design drawings is the responsibility of the ESP supplier, the

purchasing utility and its engineer. A lock manufacturer may review logic

diagrams but does not necessarily have all of the drawings necessary for

determination of safe operation. The erector has access to master keys during

installation and does not necessarily have to establish correct operation of

the system. Confirmation of actual correct installation is performed by the

startup engineer assisted by the ESP supplier startup advisor. The minimum

information required to establish the startup procedure and confirmation of

correct operation is as follows:

logic (key "flown) diagrams

installation diagrams which relate to lock type and number code to the device code

arrangement drawings which relate T/R sets to exposed buses and penthouse safety mesh partitions.

GROUNDING - PERMANENT AND TEMPORARY, LIGHTNING

The purpose of the grounding system is to provide a low resistance electrical

connection to ground potential i n order to protect personnel and equipment and

to bleed the capacitance change to ground before entrance. General principles

and s p e c i f i c d e s i g n f e a t u r e s o f g round ing systems a r e c o n t a i n e d i n t h e

N a t i o n a l E l e c t r i c Code (NFPA-70, A r t i c l e 50) and t h e N a t i o n a l E l e c t r i c S a f e t y

Code. These codes d e s c r i b e systems, c i r c u i t s and equipment t o be grounded,

and a l s o t h e methods, l o c a t i o n s , t y p e s and s i z e s o f g round ing system

components.

General G r i d

Each p r i n c i p a l s t r u c t u r e o r b u i l d i n g w i t h i n t h e power p l a n t i s p r o v i d e d w i t h

a be low grade ground g r i d . A t y p i c a l des ign m i g h t be a ba re No. 2 AWG copper

conduc to r b u r i e d a t a d e p t h o f a t l e a s t 2 1/2 f t and s u r r o u n d i n g t h e p e r i p h e r y

o f t h e ESP S t r u c t u r e i n a l oop - t ype des ign . T h i s c o n d u c t o r i s p e r i o d i c a l l y

a t t a c h e d t o v e r t i c a l p i p e e l e c t r o d e s d r i v e n v e r t i c a l l y a t l e a s t 8 f e e t i n t o

t h e s o i l . A ground l o o p may c o n t a i n branch c o n d u c t o r s o r connec t ions from one

s i d e o f t h e l o o p t o t h e o t h e r .

Ground c o n d u c t o r s and e i e c t r o d e s t h e r e f o r e form an e f f e c t i v e underground

g round ing g r i d i n good c o n t a c t w i t h t h e s o i l . Connec t ion t o t h e g r i d i s by

s h o r t conduc to rs w h i c h a r e b r o u g h t up v e r t i c a l l y and a t t a c h e d t o g round ing

l u g s on t h e ESP equipment . C o n v e n t i o n a l l y , t h e ESP s u p p l i e r does n o t have

r e s p o n s i b i l i t y f o r underground work, t h e ground g r i d and a t tachment conduc to rs

t o ground l u g s l o c a t e d near g rade w h i c h a re u s u a l l y p r o v i d e d by t h e u t i l i t y .

Design Methods

A l l ESP e l e c t r i c a : equipment and components a r e grounded by a t l e a s t one, and

p o s s i b l y more, o f t h e f o l l o w i n g methods:

D i r e c t c o n n e c t i o n t o t h e underground g r i d

Connect ion t o a n o t h e r system o r component wh ich has been grounded t o t h e underground g r i d

- an above grade conduc to r g r i d

- t h e m e t a l raceway ( c a b l e t r a y and c o n d u c t o r ) networks

- s t r u c t u r a l s t e e l

- a n o t h e r e l e c t r i c a l component.

Some examples o f each method i n c l u d e t h e f o l l o w i n g :

D i r e c t c o n n e c t i o n s f r o m equipment t o t h e ground g r i d can be made f o r

s t r u c t u r a l s t e e l columns ex tend ing t o grade, some grade l e v e l c o n t r o

a1 1

1 cab i n e t s

o r power d i s t r i b u t i o n panels , and the ends of cable t r a y s o r condui t s which

o r i g i n a t e near grade. Depending on the ground g r id layout r e l a t i v e t o t h e

equipment, some ground connections may run e leva ted f o r s h o r t d i s t a n c e s before

attachment t o a ground g r i d lug.

For equipment not near grade l e v e l , where an individual ground f o r each

component i s not p r a c t i c a l , t he ESP s u p p l i e r t y p i c a l l y provides an above grade

dedicated ground g r i d . This g r id normally c o n s i s t s of a cab l e conductor

extending throughout t h e cable t ray /condui t network f o r most of i t s rou t ing .

A loop-type design with mul t ip le connect ions t o the ground g r i d i s employed t o ensure re1 i a b i l i t y . A second, s epa ra t e , above-grade g r i d i s usual l y provided

f o r low energy e l e c t r o n i c and instrument equipment which may be prone t o

i n t e r f e r ence from e l e c t r i c a l noise. This system i s a l s o connected d i r e c t l y t o

t he ground g r i d .

Cable t r a y s and condu i t s , which a r e t o be grounded, r equ i r e e l e c t r i c a l

con t inu i ty which i s achieved by proper f i t t i n g s and bonding jumpers a t

physical connect ions between sec t ions . Grounding i s accomplished by

connecting t h e t r a y s and conduit t o t h e above- o r below-grade ground g r i d a t

various l oca t ions and a l s o through hanger supports t o s t r u c t u r a l s t e e l . When

addi t iona l NFPA 70 requirements a r e met (such a s minimum c ros s - sec t iona l a r e a

of metal i n a t r a y ) , t r a y s and condui t s may a l s o funct ion a s equipment

grounds. For l a r g e equipment (e .g . r a t e d g r e a t e r than 100 K U A ) , two a l t e r n a t e

ground paths may be spec i f i ed f o r s a f e t y r e l i a b i l i t y : t he primary ground i s a

d i r e c t connection t o t he above- o r below-grade ground g r i d , and t h e secondary

ground i s t h e metal raceway system t h a t i s u l t imate ly connected t o t h e ground

g r i d . For small equipment, the metal raceway may serve a s t h e primary ground.

Connections t o s t r u c t u r a l steel may be u t i l i z e d as a secondary ground f o r

small equipment s ince a l l s t r u c t u r a l columns a r e a l so connected t o t he ground

g r i d a t grade l e v e l .

Grounding by connection t o o ther equipment i s common f o r cont ro l cab ine t

modules which a r e bol ted toge ther t o form a complete panel . Individual

cab ine t s a r e connected t o each o t h e r by in t e rna l bonding jumpers, and only t h e

f i r s t and l a s t c ab ine t i n the s e r i e s a r e connected t o t h e ground g r i d .

The d e s i g n a n d a p p l i c a t i o n o f t h e s e g r o u n d i n g methods i s c o n s i d e r e d t o be

c o n v e n t i o n a l powe r p l a n t t e c h n o l o g y . These methods a r e r o u t i n e l y u t i l i z e d f o r

ESP d e s i g n and , i n t h i s sense , e f f e c t i v e g r o u n d i n g o f t h e m a j o r i t y o f ESP

e q u i p m e n t js c o n s i d e r e d t o b e s t r a i g h t f o r w a r d . However , some g e n e r a l a r e a s

r e q u i r e s p e c i a l c o n s i d e r a t i o n .

S p e c i a l C o n s i d e r a t i o n

The ESP d i s c h a r g e e l e c t r o d e and c o l l e c t i n g p l a t e d e s i g n f u n c t i o n s a s a

c a p a c i t o r t h a t s t o r e s e l e c t r i c a l e n e r g y . As t h e e l e c t r o d e sys tem i s c h a r g e d

by c c n n e c t i o n t c a s o u r c s o f power , a d e f i n i t e v o l t a g e (15-25 KV) i s r e a c h e d

S s f o r e gas i o n i z a t i o n o c c u r s 2nd c u r r e n t f l o w s be tween t h e d i s c h a r g e e l e c t r c d e

and t h e p l a t e . L i k e w i s e , as t h e e l e c t r o d e s a r e d i s c o n n e c t e d f r o m t h e p o w e r

sou rce , v o l t a g e and s t o r e d e n e r g y d e c : i n e due t o c u r r e n t f l o w be tween t h e

e l e c t r o d e s u n t i l t h e c o r o n a s t a r t i n g v o l t a g e i s r e a c h e d . A t t h i s p o i n t , t h e

c h a r g e and v o l t a g e on t h e e l e c t r o d e s r e m a i n s c o n s t a n t because t h e

i n t e r e l e c t r o d e c u r r e n t f l o w has s t o p p e d ; t h e r e c t i f i e r components i n the

c i r c u i t a c t as c h e c k v a l v e s and p r e v e n t c h a r g e f r o m f l o w i n g b a c k i n t o t h e

power s o u r c e . A l t h o u g h t h e e l e c t r o d e c h a r g e may d e c l i n e o v e r t h e l o n g t e r m

dce t o t r a c k i n g a c r o s s i n s u l a t o r d u s t l a y - r s , t h e ESP h i g h v o l t a g e s e c o n d a r y

nus t be c o n s i d e r e d t o be a c h a r g e d s y s t e m u n t i l p o s i t i v e l y g rounded .

The T/R s e t i s n o r m a l l y e q u i p p e d w i t h a m u l t i p o s i t i o n f u n c t i o n s w i t c h a t i e a s t

cne p o s i t i o n o f w h i c h i s t h e s e c o n d a r y ( h i g h v o l t a g e ) g r o u n d . The d e s i g n o f

t h e s w i t c h depends on t h e number o f b u s h i n g s on t h e T/R s e r and w h e t h e r t h e

s e t has b o t h h a l f - w a v e 2nd f u l l - w a v e c a p a b i l i t y .

One t y p e o f g r o u n d s w i t c h d e s i g n p r e v i o u s l y used was a k n i f e - t y p e a i r s w i t c h

mounted i n an e n c l o s u r e on t h e t o p o r s i d e o f t h e T/R s e t . A s m a l l w i ndow may

b e i n c i u d e d i n t h i s e n c l o s u r e so t h a t t h e o p e r a t o r c a n v i s u a l l y c o n f i r m t h a t

t h e g r o u n d s w i t c h c z v t a c t s a r e c l o s e d when t h e e x t e r n a l s w i t c h h a n d l e p o s i t i o n

i n d i c a t e s t h a t t h e y s h o u l d be c l o s e d . Mos t modern T /R s e t s employ an

o i l - s w i t c h d e s i g n such t h a t t h e c o n t a c t s on t h e p o s i t i o n s w i t c h a r e immersed

i n t h e o i l t a n k which, s u r r o u n d s t h e t r a r s f o r m e r . The use s f o i l s w i t c h e s

e n a b l e s a more ccmpac t T /R s e t d e s i g n w h i c h i s a b o u t $1000 p e r b u s h i n g l o w e r

i n c o s t t h a n t h a t o f a T/R s e t u s i n g an a i r s w i t c h d e s i g n . However, s p i t

a r c i n g i n a n i m p e r f e c t l y s e a l e d s w i t c h e v e n t u a l l y c a r b o n i z e s t h e o i l , l e a d i n g

t o pos:, ible t r a n s f o r n e r f a i l u r e . C a r e s h o u l d be t a k e n when c l o s i n g t h e s w i t c h .

I n a d d i t i o n t o T/R sw i t ches , a normal d e s i g n p rocedure i s t o mount a permanent

s a f e t y s w i t c h w i t h a hook o r clamp n e a r t h e penthouse r o o f ha tch . T h i s ground

c o n n e c t i o n i s t i e d d i r e c t l y t o t h e above-grade ground g r i d . The o p e r a t o r

a t t a c h e s t h e c lamp t o t h e exposed h i g h v o l t a g e bus a f t e r t h e h a t c h has been

opened. T h i s p r o v i d e s a second ground c o n n e c t i o n ( i n case t h e T/R ground

s w i t c h has f a i l e d t o o p e r a t e p r o p e r l y ) and g i v e s t h e o p e r a t o r v i s u a l

c o n f i r m a t i o n t h a t t h e bus has been grounded. Due t o t h e n a t u r e o f a s a f e t y

s t i c k ground c o n n e c t i o n , t h e o p e r a t i o n canno t be reasonab ly i n t e g r a t e d i n t o

t h e key i n t e r l o c k system. I n some e x i s t i n g ESP des igns , t h e s a f e t y s t i c k i s

mounted i n a c a b i n e t w i t h t h e c a b i n e t d o o r key i n t e r l o c k e d . T h i s , a t l e a s t ,

r e q u i r e s t h a t t h e c a b i n e t door be opened t o expose t h e s a f e t y s t i c k b e f o r e t h e

penthouse h a t c h i s opened; however, a t tachment o f t h e ground clamp t o t h e h i g h

v o l t a g e bus i s s t i l l a t t h e d i s c r e t i o n o f t h e o p e r a t o r .

Some ESP des igns employ a permanent s a f e t y s t i c k mounted i n a c a b i n e t a t each

access door t o t h e ESP i n t e r i o r . I n t h e s e i n s t a n c e s , t h e ground w i r e

c o n n e c t i o n s a r e u s u a l l y a t t a c h e d t o ESP c a s i n g s o r s t r u c t u r a l s t e e l r a t h e r

t h a n t o e l e c t r i c a l ground g r i d s . The c a b i n e t doors may o r may n o t be i n c l u d e d

i n t h e k e y - i n t e r l o c k sequence.

For l a r g e r ESPs i n wh ich each i n t e r i o r e l e c t r i c a l bus s e c t i o n i s n o t

n e c e s s a r i l y a d j a c e n t t o an access door , p o r t a b l e s a f e t y s t i c k s w i t h s h o r t

c a b l e s may be c a r r i e d i n t o t h e ESP t o ground d i s c h a r g e e l e c t r o d e s t o t h e

c o l l e c t i n g p l a t e s o r s t r u c t u r e .

F o r a71 o p e r a t i o n s r e q u i r i n g m a n u a l l y g r o u n d i n g exposed buses on e l e c t r o d e s ,

g round ing may a l s o be c o n f i r m e d by a p o r t a b l e v o l t m e t e r . One l e a d o f t h e

v o l t m e t e r i s a t t a c h e d t o ground ( u s u a l l y t h e c a s i n g o r s t r u c t u r e ) and t h e

o t h e r t o t h e bus. Bo th l e a d s a r e i n s u l a t e d f o r p r o t e c t i o n o f t h e o p e r a t o r .

Tags may be a t t a c h e d t o access d o o r s t o i n d i c a t e t h a t ma,iual g round

connec t ions have been made and g r o u n d i n g t e s t e d . Tagging s t r a t e g y i s n o t

n e c e s s a r i l y u n i f o r m f o r a l l u t i l i t i e s due t o t h e number o f o p e r a t i o n s which

may be per formed when ESP access doors a r e opened such as e l e c t r i c a l

grounding, v e n t i l a t i o n , and a i r samp l ing f o r oxygen, combus t ib les , and

p o s s i b l y ozone.

An a d d i t i o n a l c o n s i d e r a t i o n when g r o u n d i n g ESPs i s t h e use o f main column

s l i d e b e a r i n g s . Fo r des igns u s i n g s i n t e r e d bronze p l a t e s impregnated w i t h

g r a p h i t e , e l e c t r i c a l con t inu i ty of the column i s e f f e c t i v e l y assured .

S t r u c t u r e grounding by attachment t o t he ground g r i d a t t he column base i s

considered adequate. Newer design bearings may use a t e f l o n s l i d e p l a t e which

i s no t a good e l e c t r i c a l conductor. In t h i s ca se , e l e c t r i c a l c o n t i n u i t y of

t h e column can be achieved by v e r t i c a l l y spanning the bearing wi th a bonding

jumper a t tached t o ground lugs above and below the bearing p lane . The jumper

must be f l e x i b l e and of s u f f i c i e n t length t o accommodate the expansion

movement a t t h e bearing.

Spec i f i ca t i on Requirements

As noted, most ESP-related equipment can be s a f e l y grounded by spec i fy ing

conventional power p l an t design in accordance with National E l e c t r i c Code

p r i n c i p l e s . Cer ta in spec ia l cons idera t ions apply t o the high-voltage

secondary s i d e of t he T/R s e t . The following a r e considered app rop r i a t e f o r

s p e c i f i c a t i o n :

- The high vol tage secondary i s t o be capable of grounding through a t l e a s t two p a r a l l e l paths

- A t l e a s t one of t he grounds should be switch operated and p a r t of t h e key in t e r lock sequence, and a t l e a s t one ground i s t o be v i s i b l y confirmed

- I f t h e u t i l i t y e l e c t s t o use a t h i r d ground with s a f e t y s t i c k s a t access doors , t h e s a f e ty s t i c k s may a l s o be s p e c i f i e d a s permanently i n s t a l l e d in cab ine t s next t o t he doors

- Safe grounding p r inc ip l e s and p r a c t i c e s should be addressed in t h e ESP s u p p l i e r ' s t r a i n i n g program and opera t ing manual.

The preference of a i r - swi tch o r oi l -switch design f o r t h e T/R ground switch i s

n o t c l ea r - cu t . There i s no appreciable f i e l d da ta which would c l e a r l y

ind ica ted t h a t one design type i s supe r io r . However, one element necessary in

any sa fe ty program i s developing sa fe ty minded a t t i t u d e s among ope ra t ions and

maintenance personnel . To t h i s ex t en t , t h e a i r - swi tch design wi th robus t ,

v i s i b l e con tac t s may provide the u t i l i t y with an add i t i ona l f e a t u r e which

promotes worker acceptance of the system. I f a u t i l i t y can reasonably expect

t h e s e b e n e f i t s , then the addi t iona l expense of t h e a i r switch design can be

j u s t i f i e d .

ENCLOSURES

The p r i n c i p l e f u n c t i o n o f e n c l o s u r e s i s t o ease o p e r a t i o n and maintenance by

p r o v i d i n g wea the r p r o t e c t i o n f o r equ ipment and immed ia te l y a d j a c e n t areas.

O the r advantages t o be r e a l i z e d depend upon t h e a rea b e i n g enc losed.

Two m a j o r a r e a s o f an ESP where e n c l o s u r e s a r e o p t i o n a l a r e t h e r o o f and

hopper a r e a s .

ESP Roof

An ESP r o o f may be encTosed p a r t i a l l y o r c o m p l e t e l y depending on t h e

arrangement o f s e t s . Enc losu res a r e n o r m a l l y o f s t e e l f rame c o n s t r u c t i o n w i t h

we ld -a t tached , g a l v a n i z e d s t e e l , o r aluminum roo f -deck ing -pane ls and

g a l v a n i z e d s t e e l s i d e w a l l p a n e l s f a s t e n e d t o g i r t s . S p e c i f i c d e s i g n o f p a n e l s

and d e c k i n g depends on t h e r e q u i r e m e n t f o r i n s u l a t i o n , t h e type o f i n s u l a t i o n ,

and d e s i r e d f i r e r a t i n g . Roof e n c l o s u r e s a r e s t r u c t u r a l l y semi- independent o f

t h e ESP and penthouse w i t h s l i d i n g t y p e column base p l a t e s f o r d i f f e r e n t i a l

expans ion.

Roof e n c l o s u r e s possess a number o f advantages:

* Personnel S a f e t y - There i s l e s s r i s k o f f a l l i n g f rom t h e ESP ( w i t h e n c l o s u r e s i d e w a l l s ) o r s l i p p i n g on w e t o r i c y su r faces .

N o i s e A t t e n u a t i o n - The E n c l o s u r e ( r e g a r d l e s s o f s p e c i f i c c o n s t r u c t i o n d e t a i l s ) reduces e x t e r n a l n o i s e t r a n s m i s s i o n s f r o m T/R s e t s , e x t e r n a l M IGI - t ype rappers , and PA speakers . A l though t h e s e a r e n o t m a j o r sources o f no ise , t h e r e i s some b e n e f i t t o a program o f n o i s e r e d u c t i o n a t m a r g i n a l l o c a t i o n s .

Dust D e p o s i t i o n - Less wind-blow d u s t s e t t l e s on t h e T/R s e t s due t o t h e more c i r c u i t o u s r o u t e ambient c o o l i n g a i r must f o l l o w t o reach T/R s e t s . T h i s b e n e f i t i s a l s o r e a l i z e d i n t h e penthouse i f t h e source o f i n s u l a t o r purge a i r i s w i t h i n t h e e n c l o s u r e . F o r a r e a s o f heavy d u s t l o a d , an e n c l o s u r e w i t h powered v e n t i l a t i o n a l s o o f f e r s t h e d e s i g n o p t i o n o f v e n t i l a t i o n f i l t e r s .

P a i n t P r o t e c t i o n - P a i n t c o a t i n g s w i l l u s u a l l y l a s t l o n g e r w i t h reduced exposure t o s u n l i g h t and weather e lements . However, ESP r o o f equipment (T/R s e t s , c a b i n e t s , e t r . ) i s n o r m a l l y o f o u t d o o r d e s i g n even when enc losed .

Snow - Enc losu re e l i m i n a t e s t h e need f o r manual removal o f deep snow wh ich c o u l d i n t e r f e r e w i t h c o n v e c t i v e c o o l i n g o f T/R s e t s .

A e s t h e t i c s - A e s t h e t i c s a r e c o n s i d e r e d t o be improved b y t h e a r c h i t e c t u r a l c o n t i n u i t y o f a r o o f e n c l o s u r e w i t h an ESP.

Operability - Operator convenience while examining equipment and recording data is improved in an enclosure.

La.yout - An enclosed structure provides convenient attachment and hanger support points for lighting, electrical cable, fire protection piping, and other utilities providing a "cleaner" floor 1 ayout.

Maintainability - The ease of equipment maintenance and maintenance scheduling is enhanced in a weather protected environment.

There are three major disadvantages:

Accessibility - Cranes are precluded from removing equipment from the roof.

Fire Protection - Fire protection cannot be accomplished with grade level hoses from yard hydrants.

Ventilation - A ventilation system is required to remove heat load (primarily T/R set losses) from the area to achieve reasonable temperatures for a work environment.

In a warm or temperate climate, an alternate enclosure design might be a roof

without side walls, which provides most of the advantages of a full enclosure

and a simpler design.

ESP Hopper Areas

An ESP hopper area may be enclosed by extending sidewalls from the ESP casing

to grade. This requires additional framing and girts, side wail panels, and

personnel and equipment removal doors. Many of the advantages of roof

enclosures (improved operability, maintainability, noise attenuation and

aesthetics) also apply to hopper areas.

~ d d i ti onai advantages include:

Dust Contaminant - Dry fly ash emissions from manual cleaning of hoppers and ash handling equipment are prevented from entering the plant area.

Hopper Heating - Convective heat loses from heated/insulated hoppers due to wind are eliminated, with a corresponding reduction i n electrical requirements. Reduced heat loss is also a benefit for ash handling equipment.

The p r i n c i p a l d isadvantages t o an enc losed hopper a rea a r e reduced

a c c e s s i b i l i t y and t h e requ i remen t f o r v e n t i l a t i o n t o p r e v e n t e x c e s s i v e

tempera tu res . S i n c e t h e r e i s a need t o ba lance h e a t i n g and c o o l i n g

requ i remen ts , adequate v e n t i l a t i o n i s b e s t s a t i s f i e d b y a powerseal system

w i t h t h e r m o s t a t i c c o n t r o l .

C o n s i d e r i n g personnel s a f e t y , f i r e p r o t e c t i o n , snow l o a d i n g , and equipment

l a y o u t , t h e r e i s t y p i c a l l y no s i g n i f i c a n t impac t on hopper e n c l o s u r e s .

O t h e r Areas

I n a d d i t i o n t o r o o f and hoppers areas, t h e r e a r e s e v e r a l o t h e r a r e a s w h i c h

may be c o n s i d e r e d f o r enc losu res .

I t i s t y p i c a l i n bag f i l t e r i n s t a l l a t i o n s t o

t h e walkway access t o t h e s i d e c a s i n g d o o r s .

w i n d b low w a t e r c o n t a c t on t h e bags, b u t i t a . I s 0 improves m a i n t a i n a b i l i t y .

i n c l u d e a c a n t i l e v e r e d r o o f o v e r

T h i s i s p r i n c i p a l l y t o p r e v e n t

A l t h o u g h uncommon f o r ESPs because i n t e r n a l s a r e n o t w a t e r s e n s i t i v e , t h e

concep t has c e r t a i n advantages wh ich i n c l u d e :

- I n s u l a t i o n Doors - Water c o n t a c t on i n s u l a t i o n door j o i n t s ( w h i c h may be i l l - f i t t e d ) i s m i n i m i z e d and p r e c l u d e s wet the rma l i n s u l a t i o n . Weather p r o t e c t i o n i s p r o v i d e d f o r equipment w h i c h may b e l o c a t e d a t access d o o r s w h i c h c o u l d i n c l u d e key i n t e r l o c k e d g round s t i c k c a b i n e t s , communicat ion p l u g s i n j a c k o u t l e t s , and e l e c t r i c a l convenience o u t l e t s f o r p o r t a b l e 1 i g h t i ng.

- S t e e l Framing - The s t e e l f r a m i n g a s s o c i a t e d w i t h t h e c a n t i l e v e r e d r o o f p r o v i d e s more a t tachment p o i n t s f o r tempora ry c h a i n h o i s t s o r f o r weather t a r p s t h a t may b e d e s i r e d f o r main tenance.

Permanent e n c l o s u r e s ove r manual samp l ing p o r t s a r e n o t u s u a l l y employed on

ESPs because o f i n f r e q u e n t use and a l s o access requ i remen ts f o r m a n i p u l a t i n g

l o n g sample probes. Temporary p r o t e c t i o n can be p r o v i d e d i n ex t reme c l i m a t e s

by use o f a canvas t e n t s t r e t c h e d ove r a temporary p i p e f rame s u p p o r t .

Enc losed s t a i r w e l l access t o t h e ESP r o o f area i s n o r m a l l y c o n s i d e r e d i n a reas

h a v i n g h a r s h w i n t e r s .

S p e c i f i c a t i o n Requirements

Based upon t h e c o n s i d e r a t i o n s p r e v i o u s l y d e s c r i b e d , d e c i s i o n s a r e made on t h e

degree o f e n c l o s u r e d e s i r e d . I t shou ld be n o t e d t h a t t h e m a j o r i t y o f e x i s t i n g

i n s t a l l a t i o n s do n o t have enc losu re p r o v i s i o n s . Those t h a t do a r e p r i m a r i l y

l o c a t e d i n t h e a c o l d weather env i ronment .

Enc losu res a r e t y p i c a l l y p r o v i d e d by t h e ESP s u p p l i e r . T h i s approach i s n o t

mandatory, b u t i s more conven ien t i n v iew o f d e s i g n c o n s i d e r a t i o n s due t o

d i f f e r e n t i a l expans ion between t h e r o o f e n c l o s u r e and t h e ESP. S p e c i f i c a t i o n

r e q u i r e m e n t s a r e e x t r a c t e d f rom t h e c o n v e n t i o n a l s e t o f a r c h i t e c t u r a l /

s t r u c t u r a l s p e c i f i c a t i o n s f o r an e n t i r e p r o j e c t . These i n c l u d e s t r u c t u r a l

s t e e l , r o o f deck ing , doors , frames, sadd les, hardware, and s i d i n g ( m e t a l , foam

o r f i r e w a l l ) . Design l o a d i n g s f o r se i sm ic even ts , w ind , f i r e , and snow a r e

t h e same as f o r t h e ba lance o f t h e ESP i n s t a l l a t i o n . I f a c e r t a i n t y p e o r

model o f s i d i n g has been s e l e c t e d f o r a r c h i t e c t u r a l c o n t i n u i t y t h r o u g h o u t t h e

p l a n t , t h a n i t must be s p e c i f i e d i n d e t a i l . S u p p l i e r d a t a s u b m i t t a l s i n c l u d e

shop d e t a i l and i n s t a l l a t i o n drawings and computa t ions . R e p r e s e n t a t i v e

p h y s i c a l samples o f a l l m a t e r i a l s a r e g e n e r a l l y s u b m i t t e d i n a d d i t i o n t o

w r i t t e n d e s c r i p t i o n s .

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

The f u n c t i o n o f HVAC systems i s t o p r o v i d e a p r o p e r o p e r a t i n g env i ronment f o r

equipment and personnel th rough h e a t i n g , c o o l i n g , h u m i d i f i c a t i o n , f i l t r a t i o n ,

and p r e s s u r i z a t i o n o f a i r w i t h i n enc losu res . However, n o t a l l such f u n c t i o n s

a re r e q u i r e d a t a l l l o c a t i o n s . The p r i n c i p a l a reas f o r HVAC a p p l i c a t i o n s a r e

t h e T/R s e t c o n t r o l room and t h e roo f /hopper e n c l o s u r e s i f such e n c l o s u r e s a r e

i n c l u d e d i n t h e des ign . Some c a b i n e t mounted s w i t c h g e a r and c o n t r o l equipment

may possess s e l f - c o n t a i n e d v e n t i l a t i o n and h e a t i n g .

ESP C o n t r o l Room

The c o n t r o l room HVAC appara tus i s u s u a l l y compr ised o f a s e l f - c o n t a i n e d ,

roof -mounted u n i t p r o v i d e d by s u p p l i e r s such as C a r r i e r , Trane, o r York .

SAMPLE PORTS

P a r t i c u l a t e Sampl i n q

Two b a s i c methods wh ich a r e w i d e l y used today f o r o b t a i n i n g p a r t i c u l a t e

samples f r o m p r e c i p i t a t o r s . EPA Method No. 5 draws a sample t h r o u g h a n o z z l e

and l o n g p robe i n t h e gas stream and th rough a f i l t e r p l a c e d i n a

hea ted box o u t s i d e t h e f l u e o r s tack . The i n - s t a c k t e s t , f o r y e a r s r e f e r r e d

t o as t h e ASME method, u t i l i z e s a n o z z l e and f i l t e r h o l d e r w i t h i n t h e gas

stream. I n b o t h cases, t h e q u a n t i t y o f gas drawn t h r o u g h t h e n o z z l e i s a t t h e

same v e l o c i t y as t h e l o c a l f l u e gas s t ream, and t h i s p rocedure i s known as

i s o k i n e t i c sampl ing (101).

O p a c i t y Me te rs

R e g u l a t i o n s r e q u i r e t h a t an o p a c i t y m o n i t o r be i n s t a l l e d on a l l new coa l and

o i l - f i r e d steam g e n e r a t o r s w i t h a c a p a c i t y g r e a t e r t h a n 73 megawatts. The

r e g u l a t i o n s c o v e r i n g o p a c i t y p r i m a r i l y p r o v i d e t h e p l a n t o p e r a t o r w i t h a means

o f check ing t he o p e r a t i o n o f t h e p o l l u t i o n c o n t r o l equipment. O p a c i t y

m o n i t o r s on e x i s t i n g sources may be used f o r compl iance purposes, depending

upon s t a t e r e g u l a t i o n s .

I n a d d i t i o n , t h e o p a c i t y m o n i t o r can s e r v e as a process c o n t r o l i n s t r u m e n t by

o p t i m i z i n g combust ion c o n d i t i o n s o r c o n t r o l d e v i c e e f f i c i e n c y (102).

Temperature

The seeming ly s i m p l e measurement o f f l u e gas tempera tu re has caused as many

problems as any o t h e r measurement. S i n g l e p o i n t measurements can be f a r f r o m

t h e average, e s p e c i a l l y i f t h e y a r e o b t a i n e d near t h e s i d e o r t o p s u r f a c e s o f

t h e f l u e . It i s suggested t h a t r e a d i n g s be t a k e n no 7ess t h a n 12 i n . f rom an

o u t e r f l u e w a l l . The thermocouple and e i t h e r a d i r e c t r e a d i n g d e v i c e o r a

p o t e n t i o m e t e r s h o u l d n o t be r e l i e d on i n t h e f i e l d w i t h o u t f r e q u e n t checks

a g a i n s t an a c c u r a t e g l a s s thermometer o r b i m e t a l l i c d i a l thermometer t h a t has

been p r e v i o u s l y c a l i b r a t e d (101).

ACCESS DOORS, PLATFDRMING, STAIRWAYS, INTER-FIELD WALKWAYS

The f u n c t i o n o f access f a c i l i t i e s a r e t o p r o v i d e f o r a s a f e , adequate

approach t o t h e ESP components f o r o p e r a t o r s , maintenance p e r s o n n e l , and

equipment.

Types o f F a c i l i t i e s

ESP access f a c i l i t i e s a r e g e n e r a l l y d e f i n e d t o i n c l u d e t h e f o l l o w i n g t y p e s o f

components:

P l a t f o r m i n g - u s u a l l y g r a t e - t y p e i s used i n t h e hopper a r e a and as l a n d i n g s f o r s t a i r w a y s and pe rsonne l h o i s t s .

Walkways - u s u a l l y g r a t e - t y p e i s used i n t e r n a l l y between f i e l d s , e x t e r n a l l y on c a s i n g s a l o n g s i d e access doors , as access connec t ions between t h e ESP and darnper/sampling p o r t areas, between ESPs a t r o o f l e v e l i n m u l t i p l e ESP arrangement.

S t a i r w a y s - c o n v e n t i o n t h e ESP r o o f a rea , and l o c a t i o n .

Ladders - t h e v e r t i c a l

Handra i 1 s / K i c k p l a t e s - a p p l i e d t o access f a c i r e q u i r e m e n t s .

1 g r a t e - t y p e s t a i r w a y s a r e used from grade t o o c c a s i o n a l l y f rom g rade t o a d u c t sample p o r t

caged des ign i s used t o supplement s t a i r w a y s .

p i p e h a n d r a i l s and i r o n f i a t k i c k p l a t e i s i t i e s i n accordance w i t h OSHA des ign

Access Doors - h inged d o o r s w i t h dog-type o r handwheel r e s t r a i n t s a r e u t i l i z e d . I n some manu fac tu re rs ' des igns , t h e s e may be doub le doors . Under some e l e c t r i c u t i l i t y o p e r a t i n g l a b o r p r a c t i c e s , access doors a r e d e f i n e d as those equipment d o o r s wh ich a re hand o p e r a t e d (do n o t r e q u i r e t o o l s f o r opening and c :os ing) .

Hatchways - b o l t - o n c o v e r s f o r access openings a r e used i n penthouses and h o t r o o f s a l t h o u g h these a p p l i c a t i o n s may a l s o u t i l i z e a h i n g e and d o g - l o c k des ign .

S p e c i a l Walk Sur faces - g e n e r a l l y c h e c k e r - p l a t e e lements a r e l a i d a t o p ESP h o t - r o o f i n s u l a t i n g b l o c k s i n t h e penthouse.

S t r u c t u r a l S t e e l - access p l a t f o r m i n g and walkways may be c a n t i l e v e r e d o f f t h e ESP/ductwork s t r u c t u r a l s t e e l , o r t h e y may be des igned w i t h d e d i c a t e d s t r u c t u r a l s t e e l . D e d i c a t e d s t r u c t u r a l s t e e l i s u s u a l l y d e f i n e d t o be p a r t o f t h e access equipment.

Approach

Because t h e d e s i g n d e t a i l s and g e n e r a l arrangement o f each ESP a p p l i c a t i o n

( i n c l u d i n g duc twork ) a r e d i f f e r e n t , complete r e q u i r e m e n t s f o r access equipment

t o be s u p p l i e d w i t h t h e ESP canno t be i d e n t i f i e d a t t h e s p e c i f i c a t i o n s tage.

The usua l approach i s t o e s t a b l i s h g e n e r i c o r minimum r e q u i r e m e n t s , r e v i e w and

e v a l u a t e s u p p l i e r p r o p o s a l d raw ings , and upgrade t h e d e s i g n a s necessary

th rough d i s c u s s i o n s w i t h s u p p l i e r s f o l l o w e d by p roposa l supplements. A l though

t h i s i s n o t t h e o n l y approach w h i c h can be used, i t i s common p r a c t i c e .

The sca7e used on most s u p p l i e r p r o p o s a l genera l ar rangement , p l a n , and

e l e v a t i o n d raw ings ( I i n c h = 20 f t . o r 1 i n c h = 16 f t .) i s u s u a l l y adequate t o

d e s c r i b e t h e p r i n c i p l e e x t e r i o r access f a c i l i t i e s . T h i s s c a l e , however, i s

n o t s u i t a b l e f o r s m a l l a reas i n v o l v i n g comp l i ca ted geometry such as p l a t f o r m s

around dampers, expans ion j o i n t s , sample p o r t s , r a p p e r d r i v e motors , and

hopper t h r o a t s . These a reas must be accompanied by d r a w i n g s w h i c h have a more

a p p r o p r i a t e s c a l e .

The types of access facilities provided with the ESP are to be listed in

tabular form and supplemented with descriptions on the locations of the

equipment. Quantities are to be listed as numbers of components for

repetitive items, such as access doors, and listed in convenient units for

other items, such as linear feet of walkway or tons of support steel.

Qualitative descriptions such as "one lot" are considered unacceptable for

evaluation and contractual arrangements. Since the supplier has developed

quantities for proposal pricing, these quantities can be easily included in

the proposal.

Specification Requirements

Representative requirements for various components of an ESP include the following:

Internal Walkways - Internal walkways or catwalks should be provided between each physical field near the bottom of the plates. An access door should be in the ESP casing side at each end. In designs employing short fields (six foot depth), one walkway for every two fields is usually provided.

For designs employing plate edge rapping at multiple levels, a walkway is required at each rapper level. Additional access for ease of maintenance may be obtained by specifying a second level of interfield walkways near the top of the plates. This is especially useful for top access to the plates in those designs where overhead clearance between the top of the plates and the ESP hot roof is insufficient to allow a man to stand erect on a plank layed across the top of the plates.

This second level walkway may be complete with side access doors or alternatively with access from a lower walkway via internal caged ladders. This latter design is less common and may not be viable for some ESP internal structural designs, but it does avoid the potential sealing problems associated with access doors.

Internal walkways before the first field and after the last field are uncommon in most existing ESPs but would be considered advantageous for inspection and maintenance. If this feature is specified, the difficulty of coordinating the catwalk design with inlet/outlet distribution plates and internal support members may represent new problems for many suppliers, and proposa7 offerings should be thoroughly reviewed for feasibility.

Dimensions - Many top rapped ESP designs utilize 18 in. internal walkways as a standard design. This narrow width i s generally considered inadequate by those utilities that have had to perform extensive internal maintenance beyond routine inspections. A minimum shoulder-to-shoulder interfield spacing of 30 to 36 i n . is reasonable.

For bot tom-rapped des igns, p l a t f o r m w i d t h i s g e n e r a l l y d i c t a t e d by t h e d e s i g n o f rapper components. As t h i s v a r i e s among s u p p l i e r s , each s u p p l i e r ' s des ign should be e v a l u a t e d on an i n d i v i d u a l b a s i s .

E x t e r n a l Walkways - As a minimum, walkways a r e r e q u i r e d a l o n g t h e c a s i n g s i d e t h a t connects t h e i n t e r f i e l d access d o o r s . A d d i t i o n a l i n t e r c o n n e c t i n g walkways may r e s u l t f r o m t h e s p e c i f i c g e n e r a l arrangement f o r a p r o j e c t . Other a reas t h a t must b e a c c e s s i b l e a r e :

- Sample p o r t s on ductwork

- I n s t r u m e n t connec t ions on duc twork

- Duct and n o z z l e access doors

- Nozz le d i s t r i b u t i o n p l a t e rappers

- Dampers ( d r i v e mechanisms, b e a r i n g s , s t u f f i n g boxes, i n s p e c t i o n p o r t s , c l e a n o u t p o r t s , e t c . )

- Expans ion j o i n t s

There a r e a number o f f e a s i b l e c o n f i g u r a t i o n s f o r access t o t h e s e components. Fo r example, a d u c t access door may b e reached by a s t a i r w a y f r o m grade, by a t o p o f d u c t walkway f rom t h e ESP r o o f , o r by an i n t e r c o n n e c t i n g walkway f rom a n o t h e r ESP component. A p p l i c a t i o n o f t h e s e a l t e r n a t i v e approaches depends on t h e s p e c i f i c r e l a t i o n s h i p o f t h e ESP equipment t o t h e ba lance o f t h e p l a n t equipment as w e l l as o t h e r grade l e v e l genera l ar rangement c o n s t r a i n t s such as roadways.

Conven t iona l minimum d imens ions f o r e x t e r n a l walkways a r e 36 inches w ide w i t h a 7 f o o t c lea rance t o overhead s t e e l . Minimum p l a t f o r m w i d t h a t l a n d i n g s and equipment l o c a t i o n s should be adequate f o r a l ? access, removal and laydown f u n c t i o n s t o be per formed. T h i s minimum depends on t h e s p e c i f i c arrangement b u t g e n e r a l l y does n o t exceed 6 f e e t .

Hopper P l a t f o r m i n q - Gra te - t ype p l a t f o r m i n g shou ld be p r o v i d e d a t t h e hopper t h r o a t l e v e l f o r access t o hopper a c c e s s o r i e s - h e a t e r s , poke h o l e s , a n v i l s , v i b r a t o r s , a e r a t o r s , and t h e hopper access door . I n c o n v e n t i o n a l des igns , t h e p l a t f o r m s u p p o r t i n g s t e e l i s a t t a c h e d t o t h e ESP base suppor t columns r a t h e r t h a n by v e r t i c a l p l a t f o r m co lumns t o grade l e v e l f o o t i n g s . T h i s approach r e t a i n s maximum a c c e s s i b i l i t y t o ash h a n d l i n g equipment. Fo r vacuum-type ash h a n d l i n g systems, t h e hopper e x i t f l a n g e i s t y p i c a l l y 5 f e e t above t h e g r a d e l e v e l mat. The minimum p l a t f o r m e l e v a t i o n shou ld be s e l e c t e d t o p r o v i d e a minimum 7 f o o t c l e a r a n c e f rom t h e mat t o t h e bo t tom o f t h e p l a t f o r m suppor t s t e e l . I n t h i s case, t h e ash v a l v e and p o s s i b l y t h e poke p i p e s a r e a c c e s s i b l e f rom grade and t h e p l a t f o r m / a c c e s s door l e v e l s a r e s e l e c t e d t o a l l o w e n t r y f rom t h e p l a t f o r m w i t h o u t t h e use o f p o r t a b l e l a d d e r s .

For p r e s s u r e - t y p e ash h a n d l i n g systems, t h e hopper e x i t f l a n g e i s t y p i c a l l y 11 t o 14 f t above t h e grade l e v e l mat. I n t h i s case, i t i s more c o n v e n i e n t i f t h e ash h a n d l i n g t o p v a l v e and poke p i p e s a r e

a c c e s s i b l e f r o m t h e hopper p l a t f o r r n i n g . S ince t h i s u s u a l l y r e q u i r e s a ' l o w e r p l a t f o r m , r e l a t i v e t o t h e hopper e x i t f l a n g e , permanent s h o r t s t a i r w a y s w i t h l a n d i n g s may be r e q u i r e d .

Because o f s e v e r a l p o s s i b l e v a r i a t i o n s o f f e a s i b l e hopper p l a t f o r m l a y o u t s , t h i s a r e a i s b e s t e v a l u a t e d by review o f p r o p o s a l d raw ings . The ESP s p e c i f i c a t i o n s h o u l d r e q u i r e t h e submiss ion o f a t y p i c a l hopper d raw ing w h i c h shows t h e access t o t h e hopper d o o r , h e a t e r c o n t r o l s , ash h a n d l i n g v a l v e s , poke p i p e s , and o t h e r hopper components. A c c o r d i n g l y , t h e s p e c i f i c a t i o n u s u a l l y c o n t a i n s a p r e l i m i n a r y s k e t c h o f t h e ash p i p i n g and v a l v e s so t h a t t h e ESP s u p p l i e r can c o o r d i n a t e i t s d e s i g n w i t h t h e ash h a n d l i n g system suppl i e r ' s d e s i g n .

MONORAILS/EQUIPMENT HOISTS

A m o n o r a i l system i s employed on t e h r o o f o f an e l e c t r o s t a t i c p r e c i p i t a t o r t o

p r o v i d e t h e p l a n t s t a f f w i t h an easy way t o l i f t and remove T/R s e t s f o r

maintenance work. There a r e two o p t i o n s f o r a u t i l i t y when i t chooses t o

i n s t a l 1 a monora i l system: 1 i m i t e d and e x t e n s i v e system

L i m i t e d System

T h i s o p t i o n uses one o r two m o n o r a i l s and employs t h e use o f a mule. The

mule may b e used t o s l i d e a T/R s e t c l o s e t o a m o n o r a i l where t h e T/R s e t may

t h e n be l i f t e d and removed t o g rade e l e v a t i o n . T h i s method e l i m i n a t e s t h e

need f o r a crane, wh ich may n o t b e a v a i l a b l e when t h e p l a n t w ishes t o use it.

E x t e n s i v e System

M o n o r a i l s a r e p laced o v e r each T/R s e t . When needed, a h o i s t i s moved t o t h e

T/R s e t where i t i s l owered and t h e T/R s e t l i f t e d o u t .

Access Problems

There a r e severa l access prob lems t h a t a u t i l i t y must c o n s i d e r when s e l e c t i n g

a m o n o r a i l system. I f t h e wea the r e n c l o s u r e has a s l o p i n g r o o f , e x i s t i n g

c l e a r a n c e s must be examined t o d e t e r m i n e whe the r t h e T/R s e t can be l i f t e d

w i t h o u t i n t e r f e r e n c e . A lso , c r o s s b r a c i n g mus t b e des igned so t h a t t h e r e i s no

i n t e r f e r e n c e when equipment i s l i f t e d . Cable t r a y s may a ? s o pose an

i n t e r f e r e n c e problem, and m i n u t e a t t e n t i o n t o d e t a i l i s r e q u i r e d i n p l a n n i n g

them.

I t i s n o t s u f f i c i e n t f o r a u t i l i t y t o m e r e l y s p e c i f y a m o n o r a i l system. A

u t i l i t y must r e v i e w t h e d r a w i n g s t h a t t h e equ ipment s u p p l i e r f u r n i s h e s .

VACUUM CLEANING SYSTEMS

Vacuum c l e a n i n g systems a r e used p r i m a r i l y i n t h e hopper a r e a . T h e i r

f u n c t i o n i s t o p i c k up ash wh ich may have s p i l l e d d u r i n g main tenance

a c t i v i t i e s a s s o c i a t e d w i t h t h e hoppers and ash h a n d l i n g system. One example

o f such ash i s t h a t wh ich s p i l l s t o t h e ground when a p lugged hopper i s

opened.

An advantage o f a vacuum system i s t h a t i t min im izes ash i n f i l t r a t i o n i n t o t h e

p l a n t d ra inage system.

S i z i n g

I n terms o f s i z i n g c r i t e r i a , a u t i l i t y must dec ide how much ash t h e y w i s h t o

be a b l e t o handle . A b e g i n n i n g e s t i m a t e i s t h e amount o f ash t o be c o l l e c t e d

i n one f u l l hopper i n a two o r t h r e e - h o u r p e r i o d .

PERSONNEL H O I S T

P r e c i p i t a t o r s a r e n o t g e n e r a l l y p r o v i d e d w i t h personnel h o i s t s . The reason

f o r t h i s i s t h e d i s t a n c e from grade t o t h e t o p o f t h e p r e c i p i t a t o r i s u s u a l l y

l i m i t e d t o about 100 f e e t . However, a d o u b l e decked p r e c i p i t a t o r , wh ich i s

about 200 f e e t h i g h , may r e q u i r e a pe rsonne l h o i s t .

Access t o t h e p r e c i p i t a t o r i s o f t e n g a i n e d v i a p l a t f o r m i n g w h i c h t i e s i n t o t h e

b o i l e r b u i l d i n g . T h i s a l l o w s f o r t h e use o f t h e p l a n t e l e v a t o r t o p r o v i d e

access v e r y c l o s e t o t h e t o p o f t h e p r e c i p i t a t o r .

Depending on t h e p r e c i p i t a t o r c o n f i g u r a t i o n , some p l a n t s may have p l a t f o r m i n g

on t o p o f ductwork l e a d i n g t o t h e p r e c i p i t a t o r .

WATER WASHING CONSIDERATIONS

A u t i l i t y eng ineer s h o u l d be aware t h a t a l t h o u g h t h e p r e c i p i t a t o r b e i n g

s p e c i f i e d i s supposed t o remain r e l a t i v e l y c l e a n th rough t h e use o f rappers ,

many u t i l i t i e s have found i t necessary t o c l e a n t h e p r e c i p i t a t o r a t r e g u l a r

i n t e r v a l s , t y p i c a l l y r a n g i n g f rom two o r t h r e e months t o two y e a r s . The more

f r e q u e n t c l e a n i n g c y c l e s a r e a s s o c i a t e d w i t h h o t - s i d e p r e c i p i t a t o r s o p e r a t i n g

on low sodium wes te rn c o a l s . i n o r d e r t h a t these h o t - s i d e p r e c i p i t a t o r s have

accep tab le per formance l e v e l s , t h e f u e l i s t r e a t e d w i t h sodium based

compounds. A d d i t i o n a l sodium, a l t h o u g h l o w e r i n g f l y ash

resistivities, can produce a fly ash that tends to be sticky. Sticky fly ash

makes it difficult to remove the ash from the precipitator. The effectiveness

of rapping is reduced and this results i n a growing deposit of fly ash on the

wires. This soon results in the inability to get power to the box, and at

this point, the unit should be taken out of service for cleaning.

Types of Cleaning

Several methods may be used to clean an electrostatic precipitator. They

include mechanical cleaning, sandblasting, and water washing. Mechanical

cleaning involves beating the precipitator internals with hammers and pipes to

shake the dust loose. Sandblasting usually requires an outside contractor and

has the advantage of leaving the ash handling system intact. Water washing

involves spraying the precipitator with high pressure water, and it possesses

the disadvantage of creating wet ash. In terms of the latter two methods, ESP cleaning costs can range from $50,000 to $200,000 for a large ESP installation.

ACOUSTICAL TREATMENT

The sound level criteria that is established for a plant also applies to a

precipitator. The sound level should not exceed 90 dba at a distance of five

feet. Within the gas stream, where noise that is generated comes from rappers

and vibrators, sound level is not a problem because the insulation on the

precipitator casing effectively muffles the sound. However, rappers which are

installed outside the gas stream may require enclosures to contain noise.

Air - Many plants utilize air-driven equipment such as wrenches. If a particular

design requires air driven equipment, air hookups should be located at the

point of use, which will require the installation of an air header system.

Normally, water is not required in the precipitator area. An exception is

water washing. For water washing, an outlet is needed near every entrance way

into the precipitator.

E l e c t r i c a l

Every entrance way i n t o t o a p r e c i p i t a t o r such a s ha tches , hoppers, and hot

roof doors , should be provided with 320 v e l e c t r i c a l power t o provide power

f o r l i g h t s and t o o l s . 120 v o l t power i s a l so needed a t t e s t i n g connect ions

l oca t ed on p r e c i p i t a t o r ductwork. For water washing, 12 or 24 v l i g h t i n g

systems should be used t o reduce e l e c t r i c a l shock hazards.

Welding C i r c u i t s

There i s l i t t l e welding performed once a u n i t i s in opera t ion . However, a

u t i l i t y may want t o provide one or two 480 v welding o u t l e t s a t each end of a

p r e c i p i t a t o r . Also, i n s i d e t he weather enc losure , a welding o u t l e t may be

spaced every 40 o r 50 f e e t .

SPECIAL TOOLS

A spec i a l tool i s any tool t h a t a p l an t does n o t normally s tock . The

requirement f o r spec i a l t o o l s i s determined by s p e c i f i c a t i o n s in which an

equipment supp l i e r s p e c i f i e s required t o o l s ; he a l s o makes provis ions t o

f u r n i s h them. A s u p p l i e r should a l s o provide severa l s e t s of t o o l s in event

of l o s s and breakage.

Types of spec ia l t o o l s a r e those a s soc i a t ed with maintaining the alignment o f

p l a t e s , r epa i r i ng rappers , removal of d i scharge e l e c t r o d e s , and those used f o r

s t r a i g h t e n i n g bowed p l a t e s . Other t o o l s may include multi-purpose d i agnos t i c

appa ra tus f o r t roubleshoot ing microprocessor based AVCs.

MAINTAINABILITY REVIEW OF DRAWINGS

A requirement should be included in a p r e c i p i t a t o r spec i f i ca t i on t h a t

drawings and procedures specifying maintenance procedures be submitted e a r l y

in t h e engineering process so t h a t a u t i l i t y may review these requirements and

determine how they b e s t f i t with the e n t i r e p r o j e c t . Examples a r e

requirements f o r pu l l space , equipment a c c e s s i b i l i t y , and work a r e a s .

LIGHTING

The l i g h t i n g system u s u a l l y c o n s i s t s o f two s e p a r a t e subsystems:

The Normal L i g h t i n g System

The Normal/Emergency L i g h t i n g System.

A l l a r e a s t o which p l a n t pe rsonne l have access s h o u l d be i n c l u d e d i n t h e

1 i g h t i n g system.

The Normal L i g h t i n q System

T y p i c a l minimum ma in ta ined average i l l u m i n a t i o n l e v e l s f o r a p r e c i p i t a t o r and

i t s r e l a t e d areas a r e :

L o c a t i o n

General I n d o o r Area

Minimum Foo tcand les

15

MCC and Sw i t chgear Area 30

P l a t f o r m s : I n d o o r Outdoor

S t a i r w a y s : I n d o o r Outdoor

C o n t r o l Panel 75

Norrnal/Emergency L i g h t i n g System

The Normal/Emergency l i g h t i n g system i s n o r m a l l y e n e r g i z e d and c o n t r i b u t e s t o

t h e normal i l l u m i n a t i o n o f t h e a reas . The l i g h t s f o r t h i s system a r e u s u a l l y

f l u o r e s c e n t and a r e l o c a t e d i n t h e c o n t r o l area, n e a r p o i n t s o f eg ress , and

near e s s e n t i a1 equipment.

ISOLATION DAMPERS

Many u t i l i t i e s may want t o i s o l a t e a s i n g l e p r e c i p i t a t o r c a s i n g d u r i n g p l a n t

o p e r a t i o n i n o r d e r t o p e r f o r m main tenance. Such ma in tenance cannot b e

c o n s i d e r e d as r o u t i n e and o c c u r s o n l y i f a s i g n i f i c a n t number o f

t r a n s f o r m e r - r e c t i f i e r s e t s a r e o u t o f s e r v i c e t h e r e b y p r o d u c i n g excess

emiss ions . Wi th a m u l t i p l e c a s i n g des ign , an i s o l a t i o n p r o v i s i o n w i l l a l l o w a

u n i t t o be m a i n t a i n e d between 50 p e r c e n t and 85 p e r c e n t l o a d . The i s o l a t i o n

a b i l i t y r e q u i r e s a smal l f r o n t end inves tmen t t h a t can r e s u l t i n l a r g e sav ings

l a t e r by reduc ing f o r c e d outages.

I s o l a t i o n dampers should be o f ze ro l eakage , man-safe d e s i g n . I s o l a t i o n

dampers shou ld be v e r t i c a l and possess an a i r p u r g e system, f rame, b lade ,

mo to r o p e r a t o r , and a l l necessary s e a l s and c o n t r o l s .

I t i s suggested t h a t t h a t t h e u t i l i t y e n g i n e e r r e f e r t o E P R i P r o j e c t 2250-1,

e n t i t l e d "Study o f O p e r a t i o n and Des ign o f Dampers i n FGD Systems," i n o r d e r

t o o b t a i n s p e c i f i c o p e r a t i n g case h i s t o r i e s o f dampers. They w i l l p r o v e most

h e l p f u l i n p r e p a r i n g s p e c i f i c a t i o n s f o r i s o l a t i o n dampers.

MAINTENANCE DRAWINGS AND CHECK SHEETS

A s p e c i f i c a t i o n shou ld r e q u i r e t h a t an equipment s u p p l i e r p r o v i d e d e t a i l e d

maintenance drawings o f a l l equipment i n h i s s t a r t - u p and maintenance manual.

I n a d d i t i o n , r o u t i n e c h e c k - o f f sheets shou ld be f u r n i s h e d .

Manual I1 o f t h i s document p r o v i d e s d e t a i l e d i n f o r m a t i o n concern ing check -o f f

shee ts .

7 SPEClFICATION PREPARATION INQUIRY PRQPQSAL EVALUATION AND CONTRACT

ACIMIN ISTRATION

S e c t i o n 7

SPECIFICATION PREPARATION, INQUIRY, PROPOSAL EVALUATION AND CONTRACT ADMINISTRATION

INTRODUCTION

T h i s s e c t i o n p r e s e n t s i n f o r m a t i o n r e g a r d i n g t h e procurement c y c l e f o r and

c o n t r a c t a d m i n i s t r a t i o n o f e l e c t r o s t a t i c p r e c i p i t a t o r s . More s p e c i f i c a l l y ,

t h i s s e c t i o n addresses t h e p r e p a r a t i o n o f s p e c i f i c a t i o n s , commercial

requ i remen ts , b i d d e r q u a l i f i c a t i o n c r i t e r i a , i ssuance o f i n q u i r y packages,

p r o p o s a l e v a l u a t i o n , p r e p a r a t i o n o f c o n t r a c t u a l documents and c o n t r a c t

a d m i n i s t r a t i o n . I t s h o u l d be n o t e d t h a t e l e c t r o s t a t i c p r e c i p i t a t o r s r e p r e s e n t

a s i g n i f i c a n t p o r t i o n o f a modern power p l a n t and, as such, c o n s t i t u t e a m a j o r

c a p i t a l expense. F u r t h e r , when c o n s i d e r i n g t h e a f f e c t o f noncompl iance w i t h

emiss ions r e g u l a t i o n s on p l a n t o p e r a t i o n , i t behooves a u t i l i t y t o purchase

e l e c t r o s t a t i c p r e c i p i t a t o r s t h a t can c o n s i s t e n t l y ach ieve h i g h l e v e l s o f

per formance w h i l e m a i n t a i n i n g h i g h o p e r a t i o n a l a v a i l a b i l i t y . Extreme c a r e and

sound judgement i s r e q u i r e d f o r success fu l p r e c i p i t a t o r i n s t a l l a t i o n and

o p e r a t i o n .

PURCHASING PROCESS

The p u r c h a s i n g p rocess u s u a l l y c o n s i s t s o f t h e f o l l o w i n g even ts :

A l t e r n a t i v e equipment s tudy ( c o n s i d e r i n g h o t - s i d e and c o l d - s i d e p r e c i p i t a t o r s , and f a b r i c f i l t e r s and we t sc rubbers )

P r e p a r a t i o n o f d r a f t t e c h n i c a l s p e c i f i c a t i o n s and d r a w i n g s

P r e p a r a t i o n o f commercia? terms and c o n d i t i o n s

Q u a l i f i c a t i o n o f p o t e n t i a l p r e c i p i t a t o r s u p p l i e r s

Q u a l i f i e d s u p p l i e r r e v i e w o f d r a f t s p e c i f i c a t i o n s , and t e r m s and c o n d i t i o n s

Preparation of final "request for proposal" (RFP) package

Supplier proposa7 preparation

Proposal evaluation

Contract award

- Contract admini stration.

Sequence of Activities

Once a decision is made regarding the level of particulate matter emission

control required for a plant or project, overall schedules and cost estimates

must be developed. In terms of the foregoing sequence, the following generic

schedule requirements are presented:

Alternate equipment study - three to six months, depending upon the depth of the study.

Draft technical specification preparation - up to three months.

Draft commercial terms and conditions - up to two months and should be coincident with specification preparation.

Qualification of potential suppliers - up to two months and should be performed either prior to or coincident with specification preparation.

Qualified supplier review of draft specifications - four to s i x weeks.

Preparation and issuance of RFP - one to four weeks depending upon the nature of qualified supplier comments.

Proposal preparation - two to three months, depending upon scope of supply and proposal activity level o f the qualified suppliers.

Proposal evaluation - three to six months depending upon the number of proposals and the quantity of technical and commercial exceptions.

Contract award including evaluation review - one to two months.

Contract administration through initial performance testing - twenty to forty months, depending upon scope of supply, magnitude of the work, and project schedule requirements.

PERFORMANCE ORIENTED VERSUS DESIGN SPECIFICATIONS

Over the years, two distinct approaches to precipitator specification have

been used. The first, commonly referred to as a performance specification,

sets forth only a desired result and scope of supply. The precipitator

supplier is then charged with the responsibility to use its own standards,

procedures, and judgement in designing the precipitator. Under this concept,

the utility would accept those design features and margins that the supplier

deems necessary. The supplier selects sub-suppliers with the utility having

minimal review and approval priviledges.

A performance specification normally consists of the following:

Design removal efficiency

Fuel characteristics

Scope of supply

Performance warranty statement(s), covering the precipitator system and major sub-systems provided by th precipitator supplier.

The supplier then includes a basic, although limited, description of the

equipment to be provided in its proposal. Major portions of the supplier's

proposal are usually incorporated into the purchase order to provide a

description of the equipment to be furni shed.

The other approach to precipitator specification is termed design or detail

specification. This approach requires a utility to develop a specification

which incorporates all elements of the performance specification but also sets

forth detailed design standards. Detailed design standards include such

features as the minimum number of transformer-rectifier sets, hoppers,

rappers, and most importantly, specific collecting area. This approach

ensures that all proposals are similar in equipment characteristics and meet

minimum design criteria. Proposal evaluation is simplified, and the

probability that the resulting equipment will meet the performance warranties

is greatly enhanced. Utility preferences for sub-suppliers are also addressed in design specifications. Moreover, the supplier's proposal is usually not

incorporated into a

purchase o r d e r , t h u s a v o i d i n g o r m i n i m i z i n g any m i s u n d e r s t a n d i n g s r e l a t i n g t o

what s h a l l be f u r n i s h e d by t h e s u p p l i e r .

I n compar ing performance and d e s i g n s p e c i f i c a t i o n s , t h e d e s i g n s p e c i f i c a t i o n

o f f e r s a u t i l i t y a g r e a t e r degree o f l a t i t u d e i n i n c o r p o r a t i n g i t s own

exper ience and t h e exper ience o f o t h e r s i n t o a p r e c i p i t a t o r d e s i g n . Des ign

s p e c i f i c a t i o n s p r o v i d e b o t h t h e u t i l i t y and equipment s u p p l i e r w i t h a c l e a r

u n d e r s t a n d i n g o f t h e r e s p o n s i b i l i t i e s and d u t i e s o f each p a r t y i n o r d e r t o

comply w i t h t h e p r o v i s i o n s o f t h e c o n t r a c t ; t h i s l e a d s t o s i g n i f i c a n t l y fewer

m isunders tand ings and c o n f l i c t s d u r i n g e x e c u t i o n o f t h e c o n t r a c t .

A c c o r d i n g l y , t h i s manual i s o r i e n t e d t o w a r d t h e d e s i g n s p e c i f i c a t i o n approach.

MATERIAL ONLY VERSUS DELIVER AND ERECT CONTRACTS

A u t i l i t y has a c h o i c e as t o whether a p r e c i p i t a t o r s u p p l i e r s h a l l p r o v i d e

o n l y m a t e r i a l o r t o p r o v i d e b o t h m a t e r i a l and e r e c t i o n . I n te rms o f a

m a t e r i a l o n l y c o n t r a c t , a s u p p l i e r ' s m a t e r i a l w a r r a n t y i s l i m i t e d t o p r o v i d i n g

o n l y f o r t h e r e p a i r o r rep lacement o f a d e f e c t i v e p a r t o r system. The u t i l i t y

i s r e s p o n s i b l e f o r t h e removal and r e i n s t a l l a t i o n o f a f f e c t e d equipment.

Based on y e a r s o f exper ience, t h e c o s t o f removal and r e i n s t a l l a t i o n may be

anywhere f r o m one t o t e n t i m e s t h e c o s t o f t h e d e f e c t i v e m a t e r i a l . There fo re ,

s i g n i f i c a n t and u n a n t i c i p a t e d sums o f money may be spen t by a u t i l i t y f o r

w a r r a n t y r e p a i r o r rep lacement work.

M a t e r i a l o n l y c o n t r a c t s shou ld always r e q u i r e t h a t a r e p r e s e n t a t i v e o f t h e

s u p p l i e r t o be o n - s i t e d u r i n g a l l c o n s t r u c t i o n a c t i v i t i e s a s s o c i a t e d t h e

p r e c i p i t a t o r . T h i s r e p r e s e n t a t i v e i s commonly r e f e r r e d t o as an e r e c t i o n

c o n s u l t a n t o r a d v i s o r . It must be n o t e d t h a t an e r e c t i o n c o n s u l t a n t has no

o n - s i t e e r e c t i o n s u p e r v i s o r y r e s p o n s i b i l i t y and may o n l y a d v i s e t h e u t i l i t y ' s

e r e c t i o n c o n t r a c t o r . An e r e c t i o n c o n s u l t a n t ' s p r i m a r y f u n c t i o n i s t o p r o t e c t

t h e i n t e r e s t s o f t h e s u p p l i e r ; f o r example, he i s r e s p o n s i b l e f o r r e c o r d i n g

d e v i a t i o n s f rom t h e s u p p l i e r ' s e r e c t i o n i n s t r u c t i o n s and t o l e r a n c e s .

There fo re , a u t i l i t y must e x e r c i s e ex t reme c a r e and d i l i g e n c e i n a s s u r i n g t h a t

an e r e c t i o n

c o n s u l t a n t i s exper ienced w i t h t h e s u p p l i e r ' s equipment and t h a t he e x e r c i s e s

p r u d e n t judgement. It i s i m p o r t a n t t h a t t h e e r e c t i o n c o n s u l t a n t works t h e

same hours as t h e c o n s t r u c t i o n crew, even i f i t means o v e r t i m e o r t h e need f o r

two e r e c t i o n c o n s u l t a n t s , one f o r each s h i f t i f t h e work i s t o be per formed on

a m u l t i p l e s h i f t b a s i s . Futhermore, an e r e c t i o n c o n s u l t a n t must be g i v e n

e v e r y o p p o r t u n i t y t o a l e r t a u t i l i t y t o p o t e n t i a l d e f i c i e n c i e s i n e r e c t i o n .

T h i s a l e r t i n g f u n c t i o n should be per formed t h r o u g h r e g u l a r meet ings w i t h a

c o n s t r u c t o r ' s s u p e r v i s o r y pe rsonne l and a u t i l i t y ' s o n - s i t e rep resen ta t . i ves .

I n a d d i t i o n , an e r e c t i o n c o n s u l t a n t shou ld p r o v i d e a week ly r e p o r t t o b o t h t h e

u t i l i t y and p r e c i p i t a t o r c o n t r a c t o r . The s u p p l i e r s h o u l d a l s o p r o v i d e a

" c r i t i c a l i t e m s i g n - o f f " sheet, w h i c h wou ld be used i n t h e f i e l d , w i t h i t s

p r o p o s a l . The e r e c t i o n c o n s u l t a n t must s i g n - o f f and a c c e p t each c r i t i c a l i t e m

o r n o t i f y t h e u t i l i t y ' s management o f unaccep tab le c o n d i t i o n s so t h a t

c o r r e c t i v e a c t i o n may be taken . T h i s p o i n t can n o t be overemphasized s i n c e a

s u p p l i e r may o f t e n c l a i m t h a t f a i l u r e t o a t t a i n per formance and/or f u l f i l l

m a t e r i a l w a r r a n t i e s i s due s o l e l y t o c o n s t r u c t i o n d e f i c i e n c i e s over w h i c h t h e

s u p p l i e r had no c o n t r o l .

On t h e o t h e r hand, a c o n t r a c t w h i c h r e q u i r e s a p r e c i p i t a t o r s u p p l i e r t o e r e c t

t h e m a t e r i a l i t f u r n i s h e s , commonly r e f e r r e d t o as a d e l i v e r - a n d - e r e c t

c o n t r a c t , p r o v i d e s f o r u n i f i e d r e s p o n s i b i l i t y . T h i s u n i f i e d r e s p o n s i b i l i t y

concep t p r e v e n t s a s u p p l i e r f rom c l a i m i n g t h a t t h e u t i l i t y d i d n o t p r o p e r l y

e r e c t t h e equipment shou ld t h e r e be a w a r r a n t y prob lem. In te rms o f t h e

m a t e r i a l war ran ty , i t would b e on a f u r n i s h and i n s t a l l b a s i s , sometimes

r e f e r r e d t o as an i n - p l a c e w a r r a n t y under t h e c o n c e p t o f w a r r a n t y i n k i n d . An

i n - p l a c e w a r r a n t y o f f e r s s i g n i f i c a n t f i n a n c i a l b e n e f i t s t o a u t i l i t y and

m in im izes e x p e n d i t u r e s o f u n a n t i c i p a t e d main tenance f u n d s d u r i n g t h e w a r r a n t y

p e r i o d , wh ich i s t y p i c a l l y f o r one y e a r b u t may be as l o n g as t h r e e y e a r s

a f t e r a u n i t ' s t r i a l o p e r a t i o n . It must be n o t e d t h a t a s u p p l i e r w i l l markup

t h e c o s t o f t h e e r e c t i o n by a sma l l amount t o a c c o u n t f o r overhead, p r o f i t and

w a r r a n t y r e s e r v e .

I n c o n s i d e r a t i o n o f t h e above, d e l i v e r - a n d - e r e c t c o n t r a c t s o f f e r i n g u n i f i e d

r e s p o n s i b i l i t y a r e p r e f e r a b l e because t h e y 1 i m i t a u t i l i t y ' s r i s k .

When e s t a b l i s h i n g a f u e l spec i f i ca t i on f o r t he design and purchase of

e l e c t r o s t a t i c p r e c i p i t a t o r s , a u t i l i t y should always plan f o r u n c e r t a i n t i e s .

These u n c e r t a n t i e s inc lude environmental r egu la t i on changes, v a r i a b i l i t y of

fue l p r o p e r t i e s , domestic economic cond i t i ons , and the e f f e c t o f worldwide

p o l i t i c a l unres t on foreign energy sources. Therefore, when planning new

genera t ing capac i ty o r upgrading the performance of e x i s t i n g f a c i l i t i e s , t he

r e l a t i o n s h i p between f u e l and e l e c t r o s t a t i c p r e c i p i t a t o r performance must be

examined over a wide range of fue l q u a l i t y . (See Parameter Se l ec t ion

d i s c u s s i o n , Sect ion 3 ) .

U t i l i t i e s have t r a d i t i o n a l l y used t h r e e concepts in developing design fue l

c h a r a c t e r i s t i c s f o r p r e c i p i t a t o r s p e c i f i c a t i o n s . They a r e (1) performance

f u e l , (2) narrow range c h a r a c t e r i s t i c s , and ( 3 ) wide range c h a r a c t e r i s t i c s

The performance fue l concept i s sim

s p e c i f i c a t i o n s . A s p e c i f i c fue l i s

i s dependent upon t h i s s ing l e f u e l .

a b s o l u t e l y c e r t a i n t h a t t h i s spec i f

performance t e s t s but t h a t t h i s Cue

l a r t o t h a t employed i n steam genera tor

i d e n t i f i e d , and t h e performance warranty

This idea r equ i r e s t h a t a u t i l i t y be

c fue l i s not only ava i l ab l e dur ing the

o r one s u f f i c i e n t l y s i m i l a r w i l l be

a v a i l a b l e dur ing t h e l i f e of t he u n i t . This concept i s appl icable only t o

cap t ive mining ope ra t ions with ex tens ive ana lyses of known reserves . The

second concept , narrow range c h a r a c t e r i s t i c s , involves i den t i fy ing a s p e c i f i c

geographic region of t h e country from which t h e u t i l i t y p lans t o purchase

f u e l . A range of fue l c h a r a c t e r i s t i c s i s then developed which i s based on a r e l a t i v e l y l a r g e number of mines. The t h i r d concept , wide range

c h a r a c t e r i s t i c s , involves s e l e c t i n g such a broad range of c h a r a c t e r i s t i c s a s

t o f u n c t i o n a l l y inc lude a l l coa l s wi th in a very l a r g e geographic a r e a , f o r

example a l l United S t a t e s coal r e se rves e a s t of t h e Miss i ss ippi River .

I n view of c u r r e n t f u e l market cond i t i ons and based upon p a s t experience, t h e

performance fue l concept i s not p r a c t i c a l due t o t h e p o t e n t i a l u n a v a i l a b i l i t y

of a s p e c i f i c fue l some th ree t o fou r y e a r s a f t e r t h e purchase of a

p r e c i p i t a t o r . A complicating f a c t o r may be a d e s i r e by a u t i l i t y ' s fuel

purchasing group t o obta in t he lowest pos s ib l e fue l c o s t regardTess of a

f u e l ' s e f f e c t on p r e c i p i t a t o r performance. This s i t u a t i o n might be

amel iora ted by a c l o s e working r e l a t i o n s h i p between a u t i l i t y ' s engineering

fue l and purchasing groups.

When c o n s i d e r i n g t h e b e n e f i t s and d isadvantages o f d e s i g n i n g p r e c i p i t a t o r s f o r

e i t h e r a na r row o r w ide range o f f u e l c h a r a c t e r i s t i c s , p l a n t economics must be

cons ide red . Such an e v a l u a t i o n s h o u l d i n c l u d e t h e e f f e c t s on t h e steam

g e n e r a t o r , t h e c o a l and ash h a n d l i n g systems, FO and I D f a n s and t h e

p r e c i p i t a t o r and f l u e gas d e s u l f u r i z a t i o n system. C a p i t a l e x p e n d i t u r e s and

o p e r a t i n g c o s t s shou ld be i n c l u d e d i n t h i s e v a l u a t i o n .

I n t h e f i n a l a n a l y s i s , a u t i l i t y shou ld s e l e c t and e s t a b l i s h t h e range o f f u e l

c h a r a c t e r i s t i c s f o r p r e c i p i t a t o r s i n such a manner as t o p r o v i d e i t s e l f w i t h

t h e g r e a t e s t l a t i t u d e i n responding t o a changing fue; m a r k e t i n a

c o s t - e f f e c t i v e manner.

PREPARATION OF TECHNICAL SPECIFICATIONS

T h i s s e c t i o n p r e s e n t s key concepts as w e l l as an example o f t e c h n i c a l

s p e c i f i c a t i o n s r e q u i r e d i n a r e q u e s t f o r p roposa l and subsequent c o n t r a c t .

There i s no i n t e n t t o p r o v i d e a c t u a l word ing f o r s p e c i f i c a t i o n s b u t r a t h e r t o

p r o v i d e s u f f i c i e n t g u i d e l i n e s so t h a t w e l l w r i t t e n and comp le te s p e c i f i c a t i o n

may be deve loped by a u t i l i t y .

O r q a n i z a t i o n

T e c h n i c a l s p e c i f i c a t i o n s shou ld a lways be p repared and o rgan ized c a r e f u l l y i n

a c l e a r and c o n c i s e manner so t h a t b o t h t h e p r e c i p i t a t o r s u p p l i e r and t h e

u t i l i t y know e x a c t l y what i s t o be p r o v i d e d and by whom. The e f f o r t ex tended

by a u t i l i t y i n p r e p a r i n g s p e c i f i c a t i o n s w i l l be i n v e r s e l y r e f l e c t e d i n t h e

number o f m isunders tand ings and c o n f l i c t s wh ich may a r i s e d u r i n g t h e

a d m i n i s t r a t i o n o f a c o n t r a c t . The need f o r c a r e f u l and complete s p e c i f i c a t i o n

p r e p a r a t i o n c a n n o t be overemphasized.

The f o l l o w i n g i s a l i s t o f t hose documents which should be i n c l u d e d i n a

r e q u e s t f o r p r o p o s a l on a d e l i v e r - a n d - e r e c t b a s i s :

BIDDER INSTRUCTIONS

AGREEMENT

STANDARD TERMS AND CONDITIONS

SUPPLEMENTARY TERMS AND CONDITIONS

SPECIAL CONDITIONS

PRECIPITATOR MECHANICAL INSTALLATION REQUIREMENTS

PRECIPITATOR ELECTRICAL INSTALLATION REQUIREMENTS

ELECTROSTATIC PRECIPITATOR AND ACCESSORIES

DESIGN GUIDES

FIGURES

FORMS GOVERNING REQUIREMENTS FOR INSTRUCTION MANUALS, SELLER'S DRAWINGS, ETC.

MOTOR CONTROL CENTERS FOR USE I N CONTROL POWER STATIONS

ELECTRIC CABLES FOR ELECTRIC GENERATING STATIONS

LIGHTING AND APPLIANCE BRANCH-CIRCUIT PANELBOARDS

MOTORS FOR STATION AUXILIARY SERVICE FURNISHED WITH DRIVE EQUIPMENT RATED UP TO 460 VOLT AND 300 HP

METAL ENCLOSED SWITCHGEAR 6 0 0 VOLT CLASS DRAW-TYPE AND POWER CENTER TRANSFORMERS

ANNUNCIATORS

THERMOCOUPLE, RTD ASSEMBLIES AND THERMDWELLS

ELECTRICAL REQUIREMENTS FOR CONTROL PANELS, BOARDS, AND CABINETS

ELECTRIC MOTOR OPERATORS FOR VALVES, DAMPERS, AND S L I D E GATES

CONTROL SYSTEM DOCUMENTATION REQUIREMENTS

STRUCTURAL STEEL

METAL AND FOAM SIDING

GROUTING FDR EQUIPMENT AND STRUCTURE SUPPORTS

GENERAL ARRANGEMENT AND DESIGN DRAWTNG

A contract should include all o f the foregoing documents except the bidder

instructions, which would no longer be a p p l icable.

More specifically, a precipitator specification may be organized along the

following guidelines:

1.0 1.1 1 . 2 1.3

2.0

3.0 3.1 3 . 2 3 .3 3.4 3 .5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19

4.0

5.0 5.1 5.2 5.3 5 .4

6 .0 6.1 6 .2 6 . 3

7.0 7 . 1 7.2 7.3 7 . 4 7 . 5

APPENDICES

SCOPE Genera l Scope o f Work t o b e P r o v i d e d by S e l l e r Scope o f Work t o be P r o v i d e d by Purchaser

CODES AND STANDARDS

TECHNICAL REQUIREMENTS D e s c r i p t i o n o f S e r v i c e s Des ign Requirements Se ismic Requirements Performance W a r r a n t i e s Des ign and C o n s t r u c t i o n Fea tu res M a t e r i a l s and W e l d i n g O p e r a t i n g Env i ronment Sound C o n t r o l E l e c t r i c a l P r e c i p i t a t o r C o n t r o l System Accessor ies Spare P a r t s and S p e c i a l T o o l s C l e a n l i n e s s S u r f a c e P r e p a r a t i o n and Coa t ing Packaging, S h i p p i n g and Storage Equi pment Mark ing Q u a l i t y Assurance Requi rements F i r e P r o t e c t i o n Requi rements Water Wash System Requi rements

INSTALLATION

TESTS Genera l M a t e r i a l T e s t s Shop Tes ts Fie ld T e s t s

SELLER'S SERVICES AND SCHEDULES Scope o f Serv i ces Types o f Documentat ion Sel l e r ' s Data Submission Schedule

TECHNICAL DATA Scope o f Supply T e c h n i c a l Data by Purchaser T e c h n i c a l Data by S e l l e r T e c h n i c a l Data f o r A l t e r n a t e C o n t r o l Sy.stem by S e l l e r T e c h n i c a l Data f o r C o n t r o l System S i m u l a t o r by S e l l e r

A - Purchaser ' s S tandard Documents and Des ign Guides

B - Purchaser's Design Drawings C - Control System Diagnostics D - Control System Programming E - Seller's General Arrangement and Design Drawings Scope of Supply

It is most important that both a precipitator supplier (Seller) and a utility

(Purchaser) have a clear understanding of the work to be performed. In terms of the precipitator specification, this statement of work is covered in

paragraph 1.0 (Scope) in a general manner and more specifically in paragraph

7.1 (Scope of Supply Statement). An example of a scope of supply statement

section is provided i n Appendix 7A and is for illustration only.

Data Requirements

In order to have a comprehensive proposal prepared by a precipitator supplier, a utility must provide certain information. The following

subsections delineate the type of data required of both a purchaser and seller

Purchaser Provided Technical Data. An example of the quantity and quality of

general design information provided by a purchaser to a seller is illustrated

in Appendix 7B.

Seller Provided Technical Data. An example of t h e type of information

provided by a seller to a purchaser, which describes the equipment to be

furnished and the evaluation thereof, is illustrated in Appendix 7C.

Document Requirements

In addition to the requirement to provide and install the material and

equipment, a seller is also required to provide additional services to ensure

that a technically complete system will be successfully integrated into the

balance of the power plant i n a timely manner. These services normally

include, as a minimum, the following:

E n g i n e e r i n g

Des ign

Procurement

F a b r i c a t i o n

Q u a l i t y compl iance i n s p e c t i o n and t e s t i n g

T r a i n i n g programs

S h i p p i n g , e x p e d i t i n g and f i e l d s e r v i c e s

S e l l e r ' s d a t a s u b m i t t a l schedule

E r e c t i o n

S t a r t - u p o p e r a t i o n s

As an o u t g r o w t h o f these s e r v i c e s , a s e l l e r w i l l p roduce v a r i o u s documents

r e p r e s e n t i n g an i n f o r m a t i o n t r a n s f e r t o a pu rchaser . T h i s i n f o r m a t i o n

t r a n s f e r must be i n accordance w i t h t h e p u r c h a s e r ' s l i m i t a t i o n s as t o t y p e ,

number, f o r m a t , i n f o r m a t i o n c o n t e n t , sequence, schedu le and r e l e a s e . The

f o l l o w i n g i s a l i s t o f t h e documents wh ich shou ld be p r o v i d e d by a s e l l e r o r ,

i n c e r t a i n cases, t ypes o f i n f o r m a t i o n t o be s u p p l i e d by a s e l l e r f o r

i n c o r p o r a t i o n i n t o comparable documents p repared b y a pu rchaser :

Management Documents. The f o l l o w i n g t y p e s o f management documents s h o u l d be

p r o v i d e d by a s e l l e r i n accordance w i t h t h e S e l l e r ' s Data Submission Schedule

n o t e d above:

Procedures Manual

O r g a n i z a t i o n a l C h a r t s

Document L i s t s

Schedules

Prog ress Repor ts

Procedures Manual. A s e l l e r shou ld p repare a p rocedures manual c o v e r i n g

i n t e r f a c e a reas w i t h t he purchaser i n c l u d i n g , b u t n o t l i m i t e d t o :

D e f i n i t i o n s and t e r m i n o l o g y

J o b d e s c r i p t i o n s and r e s p o n s i b i l i t y

D i s t r i b u t i o n o f documents

Procedure f o r changes i n scope o f supp ly o r s p e c i f i c a t i o n

A u t h o r i t y f o r commitment t o v a r i o u s t y p e s o f changes

Procedures f o r e s t a b l i s h i n g and r e p o r t i n g p h y s i c a l accompl

- Procedures f o r maintenance o f i n f o r m a t i o n exchange r e c o r d s

i shment

T h i s document s h o u l d be p r o v i d e d and m a i n t a i n e d by a s e l l e r , w i t h a p p r o p r i a t e

i n p u t f rom a pu rchaser , and shou ld be a v a i l a b l e i n d u p l i c a t e t o t h e

pu rchaser . It must be emphasized t h a t t h e i n t e n t i s t o cover s e l l e r / p u r c h a s e r

i n t e r f a c e s w i t h o n l y min imal i n f o r m a t i o n o r i n t e r f a c e s wh ich a r e s t r i c t l y

i n t e r n a l t o a s e l l e r ' s o r g a n i z a t i o n .

Document L i s t s . A s e l l e r shou ld p r e p a r e and m a i n t a i n l i s t s o f a l l documents

t o be p repared d u r i n g t h e course o f t h e p r o j e c t i n c l u d i n g t h e t y p e o f

i n t e r f a c e w i t h t h e pu rchaser ; i . e . , t r a n s m i t t a l , r e v i e w and comment, approva l

r e q u i r e d f o r r e l e a s e , e t c .

Schedules. A s e l l e r must p r e p a r e and m a i n t a i n a l l necessary schedules and t h e

s t a t u s of d raw ings , s p e c i f i c a t i o n s and o t h e r documentat ion, equipment

procurement , and equipment d e l i v e r y . F a b r i c a t i o n sequences must be deve loped

i n s u f f i c i e n t d e t a i l t o de te rm ine check p o i n t s f o r i n s p e c t i o n and/or t e s t i n g

by a pu rchaser .

P rog ress Repor ts . A s e l l e r must p r e p a r e and submi t p e r i o d i c p rog ress r e p o r t s

on p h y s i c a l accompl ishments, maintenance o f schedules, and f o r e c a s t s o f

component l e a d t i m e s and m a t e r i a l s a v a i l a b i l i t y i n s u f f i c i e n t d e t a i l t o enab le

a purchaser t o a p p r o p r i a t e l y m o n i t o r t h e p r o g r e s s o f t h e p r o j e c t .

Techn ica l Documents. The f o l l o w i n g t y p e s o f t e c h n i c a l documents shou ld be

p r o v i d e d by a s e l l e r i n accordance w i t h t h e S e l l e r ' s Data Submission

Schedule :

Drawings and Diagrams

B i l l s o f M a t e r i a l and L i s t s

Da ta Sheets

C a l c u l a t i o n Sheets

W r i t t e n D e s c r i p t i o n s .

Drawings and Diagrams. A s e l l e r must submi t drawings and diagrams f o r t h e

p u r c h a s e r ' s i n f o r m a t i o n

a s - b u i l t d raw ings f o r a

Schedule . Copies o f a1

p u r c h a s e r ' s r e c o r d . As

and/or r e v i e w and comment. They shou ld i n c l u d e

1 d raw ings l i s t e d i n t h e S e l l e r ' s Data Submission

f i n a l documentat ion should be submi t ted f o r t h e

a r u l e , t h e use o f a s i n g l e drawing (one t i t l e and one

number) t o s a t i s f y a genera l t y p e des

s l i g h t d e v i a t i o n s wou ld n o t be genera

equipment d r a w i n g shou ld have i t s own

d raw ing must have a p u r c h a s e r ' s o r d e r

i d e n t i f i c a t i o n . I t i s r e c o g n i z e d t h a

s e l l e r shou ld be r e q u i r e d t o meet t h e

suggested t h a t p r u d e n t use o f t r a c i n g

A pu rchaser must r e s e r v e t h e r i g h t t o

s e l l e r t o ensure conformance w i t h t h e

gn p r e s e n t a t i o n f o r equipment w i t h

1 y accep tab le . Every p a r t i c u l a r

t i t l e and number. I n a d d i t i o n , each

number and i t e m number f o r easy

d u p l i c a t i o n may be p o s s i b l e ; however, a

i n t e n t o f t h i s paragraph, and it i s

t y p e r e p r o d u c i b l e s be employed.

r e v i e w a71 documents submi t ted by t h e

s p e c i f i c a t i o n ' s .

A pu rchaser must a l s o r e s e r v e t h e o p t i o n t o a u d i t s e l l e r ' s e n g i n e e r i n g and

d e s i g n a c t i v i t i e s a t t h e s e l l e r ' s d e s i g n f a c i l i t y on a p e r i o d i c b a s i s t o

ensure compl iance w i t h s p e c i f i c a t i o n requ i remen ts .

Genera l Arrangement Drawings. General Arrangement drawings must show a l l

equipment, i t s l o c a t i o n , d imens ions, e l e v a t i o n s , p l a t f o r m s e c t i o n cu ts , column

d e s i g n a t i o n s , and a n o r t h ar row. S e c t i o n and D e t a i l d raw ings must a l s o be

i n c l u d e d i n t h e genera l arrangement d raw ing package and must show t h e

same i n f o r m a t i o n as t h e genera l arrangements. Dimensions should i n c l u d e t h e

f i n i s h e d f a c e (such as, b u t n o t l i m i t e d t o , i n s u l a t i o n and l a g g i n g ) o f t h e

equipment, and t h e y s h o u l d a l s o n o t e t h e degree o f thermal expans ion.

Founda t ion Design I n t e r f a c e Drawings. A s e l l e r must p r o v i d e o u t l i n e drawings

f o r a l l equipment and s t r u c t u r e s wh ich r e q u i r e f o u n d a t i o n s t h a t a r e t o be

p r o v i d e d by t h e purchaser . These d raw ings t y p i c a l l y c o n t a i n w e i g h t s ,

d imens ions, and f o u n d a t i o n l o a d i n g i n f o r m a t i o n i n s u f f i c i e n t d e t a i l t o p e r m i t

t h e pu rchaser t o proceed w i t h f o u n d a t i o n d e s i g n . A s e l l e r ' s f o u n d a t i o n

l o a d i n g i n f o r m a t i o n must i n c l u d e a l l dead, s e i s m i c , l i v e , h o r i z o n t a l , v e r t i c a l

and w ind loads .

E r e c t i o n Drawings. A s e l l e r must p r o v i d e d raw ings t h a t show t h e e x t e n t of

shop p r e f a b r i c a t i o n t o be used f o r v a r i o u s components. These d raw ings should

i n d i c a t e t h e l o c a t i o n , t ype , s i ze , and e x t e n t o f a l l f i e l d we lds , t h e number

and s i z e o f subcomponents and shop a t tachment o f s e a l s , and t h e s u p p o r t s and

e n c l o s u r e s i n s u f f i c i e n t d e t a i l t o e n a b l e a pu rchaser t o e v a l u a t e t h e degree

o f r e q u i r e d f i e l d e r e c t i o n shou ld t h e p u r c h a s e r e l e c t t o have t h e equipment

e r e c t i o n per formed by someone o t h e r t h a n t h e s e l l e r .

Equipment and Components Drawings. A s e l l e r must submi t equipment and

component drawings f o r a l l ma jo r p i e c e s o f mechanica l , s t r u c t u r a l and

e l e c t r i c a l equipment. Genera l f e a t u r e s o f these d raw ings a r e as f o l l o w s :

Document i d e n t i f i c a t i o n by t i t l e , number, c h a r a c t e r and d a t a

Component i d e n t i f i c a t i o n b y i t e m number

Dimensional d a t a - d imens ioned o u t l i n e d r a w i n g i n c l u d i n g motor o u t l i n e and motor nameplate i f a p p l i c a b l e

Envelope d imens ions r e q u i r e d f o r c l e a r a n c e , access and d isassembly

Flange p r e p a r a t i o n d e t a i l s

L i f t i n g and p u l l i n g p r o v i s i o n s i n c l u d i n g equipment w e i g h t s

Connect ion d imens iona l d a t a a t i n t e r f a c e s w i t h the Purchaser s u p p l i e d equipment

A l l o w a b l e c o n n e c t i o n r e a c t i o n s and moments

Basep la te and s u p p o r t d e t a i l s i n c l u d i n g f o u n d a t i o n l o a d i n g

L o c a t i o n and s i z i n g o f t e r m i n a l boxes and c a b ? e / c o n d u i t e n t r y

Complete per formance/charac ter i s t ic d a t a and c u r v e s

Any r e s t r i c t i o n s o r l i m i t a t i o n s t o t h e i n s t a l l a t i o n of t h e S e l l e r f u r n i s h e d equipment i n t h e P u r c h a s e r ' s scope o f supp ly

Transformer high v o l t a g e t e r m i n a t i o n d e t a i 1 s .

A s e l l e r m u s t a1 s o

c a b i n e t d rawings .

One-Li ne E l e c t r i c a

submit ins t rument o u t l i n e d r a b

1 Diagrams. One-1 i ne e l e c t r i c a

n g s , and c o n t r o l board and

d iagrams should show a l l

s e l l e r s u p p l i e d buses from t h e t r a n s f o r m e r s down th rough ?20/208 wye v o l t

p a n e l s . A d d i t i o n a l l y , t h e s e diagrams shou ld show d c buses and p a n e l s .

G e n e r a l l y , one - l ine diagrams show b u d p a n e l c o n t i n u o u s and s h o r t c i r c u i t

r a t i n g s , bus and equipment i n s t r u m e n t a t i o n end p r o t e c t i v e r e l a y i n g ; 6 . 9 kV t o

480v and 480 t o 120/208 wye v o l t t r a n s f o r m e r r a t i n g s ( i . e . , kVA and

impedance); c a b l e s i z e s of a l l motor ; t r a n s f o r m e r and pane l f e e d e r s ; and

grounding r e s i s t o r r a t i n g s . These d iagrams u s u a l l y r e f l e c t a twin bus d e s i g n

such t h a t t h e f a i l u r e of e i t h e r bus w i l l n o t r e s u l t i n a t o t a l l o s s of power

t o t h e p r e c i p i t a t o r .

Communication and L igh t ing Drawings. Communication and l i g h t i n g drawings

shou ld show t h e p h y s i c a l l o c a t i o n of r e s p e c t i v e equipment i n r e l a t i o n t o

e l e c t r o s t a t i c p r e c i p i t a t o r sys tem components. A d d i t i o n a l l y , a symbols l i s t

shou ld be i n c l u d e d t o i d e n t i f y t h e components shown on d rawings . A

communication system i n t e r c o n n e c t i o n b l o c k diagram must a l s o be p repared .

Tray and Condui t Drawings. Tray and c o n d u i t d rawings s h o u l d show t r a y and

c o n d u i t r o u t i n g i n r e l a t i o n t o sys tem components and /o r s t r u c t u r e s . As a

minimum, t r a y s and c o n d u i t s should be s e p a r a t e d and i d e n t i f i e d i n such a

manner t o e n s u r e t h a t 6 .9 kV power, c o n t r o l , and low l e v e l c a b l e r o u t e s a r e

n o t mixed. Drawings should a l s o i d e n t i f y t h e d i a m e t e r and c o n s t r u c t i o n of

c o n d u i t s , t r a y s i z e s and whether t h e t r a y s a r e a l a d d e r t y p e o r a r e s o l i d w i t h

c o v e r s .

Tray and c o n d u i t p lan drawings of a p a r t i c u l a r e l e v a t i o n shou ld show a l l

equipment on t h a t e l e v a t i o n i n c l u d i n g f l o o r embedments up t o t h e bottom of t h e

n e x t f l o o r e l e v a t i o n . Glass f l o o r d rawings a r e u s u a l l y n o t d e s i r a b l e .

Cabling I n t e r f a c e Diagram. A cabl ing i n t e r f a c e diagram should must be prepared

t o show a s e l l e r ' s terminal block arrangement and the l oca t ion f o r i n t e r f a c e

with a pu rchase r ' s power and cont ro l cab l e s .

Grounding System I n t e r f a c e Diagram. A grounding system i n t e r f a c e diagram

should be prepared t o show a s e l l e r ' s i n t e r f a c e l oca t ion with a pu rchase r ' s

grounding system. This diagram should i d e n t i f y grounding cab le s i z e ,

q u a n t i t y , and loca t ion dimensions.

Tray and Conduit System In t e r f ace Diagram. A t r a y and conduit system

i n t e r f a c e diagram should be prepared t o show a s e l l e r ' s i n t e r f a c e l oca t ion

with a pu rchase r ' s t r a y and conduit system. This diagram should i d e n t i f y

condui t and t r a y s i z e , e l eva t ion , ' locat ion dimensions, and quan t i t y .

Equipment In t e rna l Wiring Diagrams. Equipment i n t e rna l wir ing diagrams should

be prepared f o r a71 swi tchgear , the motor cont ro l c e n t e r , t he control cab ine t ,

cont ro l boards , and s i m i l a r types of equipment. In genera l , t he se diagrams

show poin t - to-poin t wi r ing of e l e c t r i c a l devices l oca t ed in o r on t h e

enc losu re s . S p e c i f i c requirements f o r t h e s e diagrams a r e usua l ly contained in

at tachment s p e c i f i c a t i o n s .

Control Wiring Diagrams. A s e l l e r should prepare and submit control wir ing

diagrams f o r t h e p r e c i p i t a t o r cont ro l system and i t s a s soc i a t ed support ing

systems such a s e l e c t r i c power d i s t r i b u t i o n system, f i r e pro tec t ion system,

and h e a t i n g , v e n t i l a t i n g , and a i r condi t ion ing systems.

The func t ion of t he cont ro l wir ing diagrams i s t o show both l o g i c func t ions

f o r s p e c i f i c equipmeniddevice operat ion and p ro t ec t ion , including personnel

s a f e t y f e a t u r e s , and complete wir ing and cabl ing informa' LI ' on.

Two b a s i c types of cont ro l wir ing diagrams (CWDs) can be prepared depending

upon t h e type of hardware used t o implement cont ro l func t ions . One

type may be microprocessor or solid-state logic system CWDs and another type

may be relay system CWDs of the elementary schematic type. The primary

purpose of the CWDs is to provide t h e following:

Cable identification information

Cable termination information

MCC or breaker identification information

Control switch information

Microprocessor input/output point identification

Control cabinet identification information

Microprocessor patch panel or programming information

Input/output device wiring information

Relay or solid state wiring information identification

Control loop operation information

Used and spare device contact information

Alarm information.

Instrument Location and Arrangement Drawings. A seller should prepare and

submit instrument location and arrangement drawings. They should be prepared

from general arrangement type drawings and should use the approved general

arrangement information as a background. The primary purpose of the

instrument location and arrangement drawings is to provide instrument tap

location information, instrument mounting location information, instrument air

piping header location, and diagrammatic routing information to the instrument

installer. A secondary function is to provide location information for local

electrical control stations and cabinets.

Instrument Installation and Instrument Support Details. A seller must prepare

specific instrument installation and support details for each instrument in

its scope of work. Detailed design drawings should be complete working

drawings of each installation, and should show a Bill of Materials, final

dimensions, and, where pertinent to the installation design, the correct

s p a t i a l r e l a t i o n s h i p o f a l l components. The d e t a i l e d i n s t a l l a t i o n d e s i g n

d raw ings s h o u l d a l s o s p e c i f i c a l l y i d e n t i f y a l l p o r t s on i n s t r u m e n t a t i o n ,

c o n t r o l v a l v e s , and a s s o c i a t e d d e v i c e s t o wh ich a s e l l e r has made

c o n n e c t i o n s . A l l p i p e and tube connec t ions p r o v i d e d by an equipment

m a n u f a c t u r e r o r w i t h i n t h e scope o f a d i f f e r e n t i n s t a l l a t i o n c o n t r a c t s h o u l d

be n o t e d as "by manufacturer1 ' o r "by o t h e r s , " as a p p r o p r i a t e . Each

i n s t r u m e n t , c o n t r o l va l ve , o r a s s o c i a t e d d e v i c e t o which a d r a w i n g a p p l i e s

shou ld be s p e c i f i c a l l y i d e n t i f i e d on each d raw ing u s i n g a p u r c h a s e r ' s

i n s t r u m e n t i d e n t i f i c a t i o n number.

Key I n t e r l o c k System Drawings. A s e l l e r must p repare a s p e c i f i c key i n t e r l o c k

d r a w i n g t h a t d e t a i l s t h e l o g i c and o t h e r r e q u i r e m e n t s o f t h e system.

Log ic Diagrams. A s e l l e r must p repare and submi t f u n c t i o n a l l o g i c d iagrams

f o r each c o n t r o l system and/or subsystem d e s c r i b e d i n t h e p r e c i p i t a t o r c o n t r o l

system p o r t i o n o f t h e s p e c i f i c a t i o n . C o n t r o l system l o g i c d iagrams may be

deve loped on a system b a s i s o r on an i n d i v i d u a l c i r c u i t o r equipment b a s i s .

The d raw ings should c o n s i s t o f t h r e e forms as a p p l i c a b l e :

I n t e r l o c k Log ic Diagrams

Analog F u n c t i o n a l Log ic Diagrams

Computer Flow Char ts .

I n t e r l o c k l o g i c diagrams shou ld show i n f o r m a t i o n e s s e n t i a l t o u n d e r s t a n d i n g

t h e p rocess . These d raw ings shou ld d e l i n e a t e between i n s t r u m e n t s and d e v i c e s

t h a t p e r t a i n t o t h e process and t h o s e t h a t a r e p r o v i d e d f o r o p e r a t o r use .

Log ic d iag rams should c o n s i s t p r i m a r i l y o f l o g i c symbols w i t h i n p u t and o u t p u t

s i g n a l l i n e s i n t e r c o n n e c t i n g t h e i n i t i a t i n g f u n c t i o n s and consequent a c t i o n s .

In g e n e r a l , a l o g i c d iagram shou ld be drawn showing t h e p r i m a r y i n i t i a t i n g

i n p u t c o n d i t i o n ( o r d e v i c e ) a t the l e f t hand s i d e , t h e consequent equipment

o p e r a t i on

( o r end c o n d i t i o n ) a t t h e r i g h t hand s i d e , and t h e i n t e r c o n n e c t i n g l o g i c

symbols i n t h e i n t e r v e n i n g space.

Analog f u n c t i o n a l l o g i c d iagrams shou ld be p r e p a r e d i n accordance w i t h SAMA

s t a n d a r d s .

Computer F low Char ts shou ld d e t a i l t h e l o g i c o p e r a t i o n f o r each system,

d i s r e g a r d i n g t h e a c t u a l e l e c t r i c a l o r i n s t r u m e n t a t i o n equ ipment . The

f o l l o w i n g i n f o r m a t i o n shou ld be i n c l u d e d as p a r t o f t h e computer f l o w c h a r t

documenta t ion package:

Complete i n p u t l i s t f o r each system

Complete o u t p u t l i s t f o r each system

Complete f l a g l i s t f o r each system

A l i n e l i s t o f eve ry program s tep

C o n t r o l System So f tware Documentat ion. A s e l l e r must p r e p a r e and submi t a

comp le te and comprehensive s o f t w a r e documentat ion package d e s c r i b i n g t h e

o p e r a t i o n and maintenance o f m ic rop rocessor based c o n t r o l systems. T h i s

c o n s i s t s o f a documentat ion c o n s i s t s o f s tep-by-s tep commented l i s t i n g s o f

each program on p r i n t e d copy and a l s o a magne t i c t a p e copy s u i t a b l e f o r e n t r y

i n t o t h e m ic rop rocessor system. The p r i m a r y purpose o f t h e documenta t ion i s

t o f u l l y d e s c r i b e t h e o p e r a t i o n o f each m ic rop rocessor and i t s a s s o c i a t e d

i n p u t / o u t p u t hardware.

P r e c i p i t a t o r S i z e S e l e c t i o n Documentat ion. A s e l l e r s h o u l d p r e p a r e t h e i n p u t

d a t a and submi t t h e d a t a t o an independent r e s e a r c h o r g a n i z a t i o n so t h a t t h e

EPA computer p r e c i p i t a t o r s i z i n g program f o r v e r i f i c a t i o n o f t h a t s e l l e r ' s

p r e c i p i t a t o r s i z e s e l e c t i o n . A s e l l e r must t h e n submi t a l l i n p u t d a t a and t h e

program o u t p u t t o a pu rchaser so t h a t t h i s i n f o r m a t i o n can b e i n t u r n

s u b m i t t e d t o t h e r e g i o n a l EPA o f f i c e t o supplement a p u r c h a s e r ' s P r e v e n t i o n o f

S i g n i f i c a n t D e t e r i o r a t i o n Perm i t .

C o n t r o l System C o n f i q u r a t i o n Drawings. A s e l l e r shou ld p r e p a r e and submi t

c o n t r o l system c o n f i g u r a t i o n drawings showing t h e p h y s i c a l c o n f i g u r a t i o n ,

communicat ion channels , f u n c t i o n a l hardware c o n f i g u r a t i o n , and power s u p p l y

d i s t r i b u t i o n o f t h e c o n t r o l system. The purpose o f these d r a w i n g s i s t o

convey t h e o v e r a l l l a y o u t and des ign p h i l o s o p h y o f t h e c o n t r o l system t o a

p u r c h a s e r .

I n s t r u m e n t Schematics. A s e l l e r shou ld p repare and s u b m i t i n s t r u m e n t

schemat ics f o r a l l p rocess systems and subsystems i d e n t i f i e d i n t h e c o n t r a c t .

Schematics s h o u l d f o l l o w a p i p i n g and i n s t r u m e n t d iag ram (P&ID) f o r m a t b u t

shou ld n o t r e p e a t mechanica l system d e s i g n i n f o r m a t i o n n o r m a l l y f o u n d on t h e

system f l o w d iagrams such as l i n e number, l i n e s i z e s , ex t raneous p i p i n g ,

i n s t r u m e n t r o o t v a l v e s , and v a l v e numbers f o r manua l l y opera ted v a l v e s wh ich

a r e n o t i n v o l v e d w i t h e l e c t r i c a l c o n t r o l c i r c u i t s . The purpose o f t h e

i n s t r u m e n t schemat ic s h o u l d be t o p r o v i d e a pu rchaser w i t h a document wh ich

p r e s e n t s t h e c o n t r o l c i r c u i t o f t h e system, system i n s t r u m e n t a t i o n f o r

m o n i t o r i n g and process a l a r m i n g , and t h e f u n c t i o n a l i n t e r r e l a t i o n s h i p between

t h e v a r i o u s c o n t r o l d e v i c e s w i t h i n t h e system and between systems.

I n s t r u m e n t schemat ics s h o u l d show t h e f o l l o w i n g i n f o r m a t i o n :

Main p rocess p r e s e n t e d on a system b a s i s c o n s i s t e n t w i t h system f l o w d iagrams as p r e p a r e d by t h e S e l l e r .

Secondary p rocesses o n l y t o t h e e x t e n t necessary t o d e s c r i b e t h e i n t e n d e d pu rpose o f i n s t r u m e n t a t i o n and c o n t r o l equipment f o r t h a t system.

A l l p rocess r e l a t e d v a l v e s and p i p i n g s p e c i a l t i e s wh ich a r e c o n t a i n e d i n t h e p r i m a r y and secondary p r o c e s s f l o w s shown on t h e schemat ic .

F a i l u r e modes f o r a l l c o n t r o l v a l v e s , ga tes , dampers, e t c

A p p r o p r i a t e number o f i n s t r u m e n t c o n n e c t i o n s on tanks , v e s s e l s , h e a t e r s h e l l s , e t c .

M o t o r s a s s o c i a t e d w i t h pumps, f a n s , va l ves , e t c .

A l l i n s t r u m e n t s and c o n t r o l d e v i c e s d i r e c t l y a s s o c i a t e d w i t h t h e p rocess .

The f o l l o w i n g i n f o r m a t i o n s h o u l d be exc luded f rom i n s t r u m e n t schemat ics s i n c e

t h i s i n f o r m a t i o n i s shown on f l o w d iagrams and i s n o t r e q u i r e d t o unders tand

t h e a p p l i c a t i o n o f i n s t r u m e n t a t i o n and c o n t r o l d e v i c e s t o t h e system:

I n s t r u m e n t r o o t v a l v e s and l o c a l i s o l a t i o n v a l v e s

P i p i n g l i n e numbers

Extraneous secondary p rocess f l o w l i n e s , and fea tu res such as v e n t s and d r a i n s w h i c h do n o t i m p a i r u n d e r s t a n d i n g o f t h e system

P i p i n g r e d u c e r s and o t h e r ex t raneous p i p i n g i n f o r m a t i o n

E x t e r n a l I n t e r c o n n e c t i o n Diagrams. A s e l l e r must p repare and submi t e x t e r n a l

i n t e r c o n n e c t i o n d iagrams f o r a l l e l e c t r i c a l equ ipment s u p p l i e d by a s e l l e r o r

i t s subvendors. The p r i m a r y purpose o f e x t e r n a l i n t e r c o n n e c t i o n d iagrams i s

t o p r o v i d e c a b l e t e r m i n a t i o n i n f o r m a t i o n f o r c o n s t r u c t i o n and maintenance.

Te rm ina l b l o c k s shou ld be shown i n r e l a t i v e p h y s i c a l l o c a t i o n w i t h t e r m i n a l

b l o c k number and t e r m i n a l p o i n t numbers shown.

Each e x t e r n a l c a b l e shou ld be shown t e r m i n a t e d on i t s a p p r o p r i a t e t e r m i n a l

b l o c k s . C o l o r code, c a b l e number, spare conduc to rs , and d e s t i n a t i o n s h o u l d be

shown.

These d raw ings shou ld a l s o i n c l u d e c r o s s - r e f e r e n c e d raw ing i n f o r m a t i o n t o

o t h e r w i r i n g d raw ings , i n c l u d i n g i n t e r n a l c a b i n e t w i r i n g diagram's, so t h a t t h e

w i r i n g i n f o r m a t i o n f o r a complete c i r c u i t can be f o l l o w e d th rough t h e

documenta t ion package.

B i l l s of M a t e r i a l and L i s t s . A s e l l e r shou ld p r o v i d e v a r i o u s l i s t s and b i l l s

o f m a t e r i a l as i n d i c a t e d i n t h e f o l l o w i n g pa rag raphs .

Cab le and C o n d u i t L i s t (CCL). A Cable and C o n d u i t L i s t (CCL) must be p repared

t o show a l l c a b l i n g w i t h i n t h e p r e c i p i t a t o r system enve lope. T h i s document

d e f i n e s c a b l e r o u t e s f r o m o r i g i n t o d e s t i n a t i o n , c a b l e t y p e , and l e n g t h o f

r u n . Cable t r a y s and c o n d u i t s on p h y s i c a l d raw ings must be numbered and r o u t e

i d e n t i f i c a t i o n must c o r r e l a t e t o t h e p h y s i c a l d raw ings . A d d i t i o n a l l y , t r a y and

c o n d u i t f i l l d a t a must be p r o v i d e d . The c a b l e and c o n d u i t 1 i s t shou ld :

I d e n t i f y equ ipment a t b o t h c a b l e t e r m i n a t i o n s .

I d e n t i f y t h e c a b l e by r e f e r e n c e t o i t s a s s o c i a t e d c o n t r o l c i r c u i t number wherever p o s s i b l e .

Identify cable routing including cab1 e tray numbers, conduit numbers, manhole numbers and junction box numbers. These numbers should appear on the electrical physical drawings.

Identify the type o f cable, length of each pull and the cumulative total length for each type of cable for the entire contract.

A subsection of the CCL called the "conduit list" should list in numerical order each conduit number, its s ize and type, and the identifying number of any cables routed through that conduit. It should also list "from" and "to" for each conduit.

No more than one control circuit's associated cables should appear on each CCL sheet.

Instrument Data Base Information. A seller must prepare and submit instrument

data base information covering all instruments and control devices within its

scope of work. The instrument data base will be used by a purchaser to store

and manage pertinent information about plant instrumentation. Each instrument

should have pertinent design, engineering, procurement, and computer

input/output and operating information stored in the data base. The

information related to each instrument should be grouped by type according to

the end user of the information.

The following is a list of instrument information that should be contained in

a data base arranged by information groups.

A - Design and Engineering Information

1 - Tag Number 2 - Service Description 3 - Flow Diagram Number

4 - Instrument Schematic Number

5 - Connection From 6 - Connection To

7 - Control Wiring Diagram Number 8 - Typical Installation Detail Number

9 - Specific Installation Detail Number

10 - Instrument Location and Arrangement Drawing Number I1 - Mounting Location

12 - Instrument Support Detail Number

13 - Primary Function

14 - Piping Diagram Number

B - Procurement Information

1 - Manufacturer 2 - Manufacturer's Model Number 3 - Procurement Contract Number 4 - Operating Range

5 - Vendor Tag Number

6 - Output Signal

7 - Foreign File Numbers for Certified Drawings (Outline & Electrical)

C - Computer Input/Output Information

1 - Computer Point I D

2 - Point Type 3 - lower Reasonable Limit

4 - Upper Reasonable Limit

5 - Input/Output Terminal Numbers

D - Operating Information 1 - Set Point

2 - Dead Band

3 - Operation

Not all of the listed information will be applicable to each instrument. When

a specific piece of information is not applicable for a particular instrument,

"NA" should be entered in the appropriate data field.

Bill of Material. Bills of material should correlate components to outline

drawings and diagrams. Components may be identified by the original

manufacturer's name and catalog numbers. If the catalog reference does not

contain all operating characteristics, such as in an auxiliary relay, for

example, the following should be supplied:

Nominal voltage

- Operating vo1 tage range

Minimum pick-up voltage

Drop-out voltage

Pick-up time at minimum pick-up voltage

Inrush VA and pf if ac at minimum pick-up voltage

Continuous VA ac, coil resistance - dc

Number and kind of contacts

Contact ratings: making, continuous, interrupting AC/DC

Since all parameters for all devices cannot be listed in a specification, the

foregoing should be considered as illustrating the data required to enable a

purchaser to analyze circuits under various conditions. Billing material

should include all electrical equipment including wire types (no lengths)

mounted on the board, and it should state whether the purchaser or seller will

furnish that equipment. Bills of material should identify each item by name,

with its associated quantity on order, manufacturer's name, and catalog number.

A seller should submit data sheets for motors and instruments in accordance

with the requirements set forth in referenced specifications that are included

as attachments to the precipitator specification.

C a l c u l a t i o n Shee ts . A s e l l e r must u s u a l l y pe r fo rm t h e s t u d i e s and

c a l c u l a t i o n s d e s c r i b e d i n t h e f o l l o w i n g paragraphs and s h o u l d submi t c o p i e s o f

t h e s t u d i e s and c a l c u l a t i o n shee ts t o a purchaser f o r i n f o r m a t i o n and/or

rev iew.

E l e c t r i c a l Load S t u d i e s . Load s t u d i e s shou ld be deve loped f o r each

swi t chgear , 1 i g h t i n g , power, hopper h e a t i n g , and dc p a n e l . A p r e l i m i n a r y l o a d

s tudy, p r o v i d e d w i t h a p r o p o s a l , s h o u l d i d e n t i f y t h e t o t a l maximum power

requ i remen t w h i c h w i l l n o t be exceeded.

S h o r t C i r c u i t C a l c u l a t i o n s . S h o r t c i r c u i t c a l c u l a t i o n s must be per formed and

submi t ted t o v e r i f y t h a t equipment s h o r t c i r c u i t r a t i n g s w i l l n o t be exceeded

f o r any bus and/or panel wh ich were s e l e c t e d on an impedance b a s i s . Vo l tage

d rop c a l c u l a t i o n s shou ld be p e r f o r m e d t o ensure t h a t mo to rs a r e purchased w i t h

p roper v o l t a g e t o l e r a n c e . R e g u l a t i o n s t u d i e s should a l s o be per formed t o

v e r i f y t h a t v o l t a g e f l u c t u a t i o n s ( i . e . , no l o a d v o l t a g e t o s t a r t i n g l a r g e s t

motor w i t h bus f u l l y l oaded minus s t a r t i n g motor ) would n o t r e s u l t i n damage

t o equipment due t o o v e r v o l t a g e o r d r o p o u t o f c o n t r o l s due t o v o l t a g e d r o p

based on t r a n s f o r m e r impedances and a v a i l a b l e t a p s .

W r i t t e n D e s c r i p t i o n s . W i t h i t s p r o p o s a l , a s e l l e r s h o u l d p r o v i d e and m a i n t a i n

th roughou t t h e d u r a t i o n o f t h e p r o j e c t a thorough w r i t t e n d e s c r i p t i o n o f t h e

system i n c l u d i n g t h e f o l l o w i n g areas:

System C r i t e r i a

- O p e r a t i n g r e q u i r e m e n t s

- Des ign requ i remen ts and parameters

System D e s c r i p t i o n

- O v e r a l l system d e s c r i p t i o n

- Component d e s c r i p t i o n

System C o n t r o l

- C o n t r o l o f m a j o r components (sequencing, p r o t e c t i v e

- c i r c u i t s , e t c . )

- Process c o n t r o l (ana log c o n t r o l l oops , e t c . )

- System m o n i t o r i n g and a la rms

System O p e r a t i o n

- Normal o p e r a t i o n

- Abnormal o p e r a t i o n , ( l o a d changes, s ta r tup -shu tdown)

- Emergency o p e r a t i o n (emergency shutdown procedures)

System Maintenance

- Maintenance approva l and p r o v i s i o n s

- P r e v e n t a t i v e maintenance

- C o r r e c t i v e main tenance

- Maintenance schedule .

The i n f o r m a t i o n c o n t a i n e d i n t h i s w r i t t e n d e s c r i p t i o n i s u s u a l l y q u i t e s i m i l a r

t o t h a t i n an i n s t r u c t i o n manual, and i t i s l i s t e d he re as a s e p a r a t e document

i n o r d e r t o emphasize t h a t i t i s u s u a l l y r e q u i r e d as one o f t h e e a r l i e s t

documents produced by a s e l l e r on a p r o j e c t .

A s e l l e r shou ld a l s o p r o v i d e a w r i t t e n d e s c r i p t i o n f o r a i l h e a t i n g ,

v e n t i l a t i n g , a i r c o n d i t i o n i n g , f i r e p r o t e c t i o n , e l e c t r i c a l power d i s t r i b u t i o n ,

and s e a l a i r systems c o n s i s t e n t w i t h t h e f o r e g o i n g requ i remen ts .

S e l l e r ' s Data Submission Schedule, I n a d d i t i o n t o t h e i n f o r m a t i o n r e q u i r e d by

the f i l l - i n sheets , a s e l l e r shou ld submi t t h e f o l l o w i n g d r a w i n g s and d a t a

with a p r o p o s a l . These d raw ings must show t h e t e r m i n a l p o i n t s o f a s e l l e r ' s

scope o f supp ly .

Data Submission Schedule. T y p i c a l d a t a and d raw ing schedule r e q u i r e m e n t s a r e :

Submittal Requirements

Submittal Purpose Item Description

1 Fill-in Data Sheets With Proposal For Eval uation

2 Detailed Project Schedule which includes engineering, fabrication, tests, sequence of shipment, technician training and all key dates

30 Days After Award

20 Days After Review/Comment Award

3 Drawing submittal schedule

4 Instruction Manuals 90 Days Before Review/Comment Completion of Material Shipment

With Proposal 5 Recommended spare parts and special tools 1 ist

For Eval uati on

6 Storage and preservation procedure applicable to site storage

120 Days Prior to any shipment

Information

7 Electrostatic precipitator and associated ductwork outline, plan and sectional views

With Proposal Review/Comment/ Evaluation

8 Certified electrostatic precipitator support steel plan

60 days after award

Review/Comment/ Eval uation

9 Electrostatic precipitator support steel detai 1 s

90 Days After Award

10 Certified electrostatic precipitator and associated ductwork foundation loading and anchor bolt location drawing

60 days after award

Review/Comment/ Eval uation

11 Inlet ductwork 60 Days After Award

12 Interconnecting ductwork 60 Days After Award

Subrni t t a l Requi remen t s

S u b m i t t a l Purpose Item D e s c r i p t i o n

O u t l e t ductwork 60 Days A f t e r Award

60 Days A f t e r Award

I n s t a l l a t i o n drawings, d e t a i l s and p rocedures

Rev

Rev Eva

Rev Eva

Rev Eva

Rev Eva

P l a t f o r m s and s t a i r w a y s P l a n

W i t h P roposa l ew/Comment/ u a t i o n

P l a t f o r m s and s t a i r w a y s s e c t i o n s

W i t h Proposa l ew/Cornment/ u a t i o n

W i t h Proposa l ew/Comment/ u a t i o n

C o l l e c t i n g e l e c t r o d e s s u p p o r t s and gu ides

D i scharge e l e c t r o d e s u p p o r t s and gu ides

W i t h Proposa l ew/Comrnent/ u a t i o n

Review/Comment/ Eva1 u a t i o n

H i g h v o l t a g e bus, s u p p o r t s and e n c l o s u r e

W i t h Proposa l

Thermal i n s u l a t i o n d e t a i l s

150 Days P r i o r t o F a b r i c a t i o n

T rans fo rmer r e c t i f i e r s e t o u t 1 i ne


T rans fo rmer r e c t i f i e r s e t c o n t r o l c a b i n e t o u t l i n e


Rapper c o n t r o l c a b i n e t o u t l i ne


Rapper c o n t r o l c a b i n e t i n t e r n a l w i r i n g



Hopper c o n t r o l c a b i n e t o u t l i ne

Hopper c o n t r o l c a b i n e t i n t e r n a l w i r i n g

120 Rays A f t e r Award

Key i n t e r l o c k system d iag ram and o p e r a t i n g d e s c r i p t i o n


Wi th Proposa l E l e c t r i c a l one 1 i n e d iagrams

Communicat ion and L i g h t i n g d raw ings


S u b m i t t a l S u b m i t t a l Requirements Purpose I t e m D e s c r i p t i o n

30 C o n t r o l W i r i n g Diagrams 300 Days A f t e r Revi ew/Comrnent Award

3 1 T r a y and C o n d u i t Drawings 120 Days A f t e r I n f o r m a t i o n Award

32 I n s t r u m e n t Data Sheets P r e l i m i n a r y Review/Comment w i t h Proposa l , F i n a l 30 Days A f t e r Award

O u t l i n e d raw ings o f a l l components and accessor ies i n c l u d i n g b u t n o t l i m i t e d t o fans , dampers, mo to rs , sw i t chgear , MCC's, e t c .


M o t o r Data Sheets 120 Days A f t e r Award

I n f o r m a t i o n

As Necessary O t h e r Drawings as may be r e q u i r e d t o cover t h e com- p l e t e equipment i n s t a l l a t i o n

As necessary

C o r r e c t i o n F a c t o r vs Gas Volume Curve

W i t h Proposal

C o r r e c t i o n F a c t o r vs I n l e t G r a i n Loading Curve

W i t h Proposa l

C o r r e c t i o n F a c t o r vs Gas Temperature Curve

W i t h Proposa l Review/Comment/Evaluat

Rev i ew/Comment/Eval u a t

i o n

i o n C o r r e c t i o n F a c t o r vs S u l f u r Content i n Fuel Curve

W i t h Proposa l

C o r r e c t i o n F a c t o r vs Bus- S e c t i o n De-energ iza t ion Curve

W i t h P r o ~ o s a l

Power Consumption C o r r e c t i v e F a c t o r

W i t h Proposa l

W i t h Proposal

For E v a l u a t i o n

Review/Cornment Grounding System I n t e r f a c e Diagram

S u b m i t t a l Requirements

S u b m i t t a l Purpose I t e m D e s c r i p t i o n

43 Cab1 i n g I n t e r f a c e Diagram

W i t h Proposa l

44 T ray and C o n d u i t System I n t e r f a c e Diagram

W i t h P r o ~ o s a l

45 E l e c t r i c a l Load Study 60 Days A f t e r Award

Rev i ew/Comment

46 W r i t t e n D e s c r i p t i o n s

47 S h o r t C i r c u i t S tudy

W i t h Proposa l Review/Comment

I n f o r m a t i o n 60 Days A f t e r Award

48 I n s t r u m e n t I n s t a l l a t i o n and I n s t r u m e n t Suppor t D e t a i 1 s


49 I n s t r u m e n t L o c a t i o n and Arrangement Drawings


Revi ew/Comment

50 Cable and C o n d u i t L i s t 240 Days A f t e r Award

I n f o r m a t i o n

51 I n s t r u m e n t Data Base i n f o r m a t i o n


52 B i l l s o f M a t e r i a l As necessary As necessary

Review/Comment 53 Procedures Manual 60 Days A f t e r Award

54 Document L i s t s 60 Days A f t e r Award

Rev i ew/Comrnent

55 Log ic Diagrams 60 Days A f t e r Award

56 C o n t r o l System So f tware Documentat ion


57 P r e c i p i t a t o r S i z e S e l e c t i o n Documentat ion


58 C o n t r o l System C o n f i g u r a t i o n Drawings


Rev i ew/Comrnent

S u b m i t t a l Submi t t a l I t e m D e s c r i p t i o n Requirements Purpose

59 I n s t r u m e n t Schematics 90 Davs A f t e r Review/Comment

60 E x t e r n a l I n t e r c o n n e c t i o n 120 Day Award

Performance Warranty

I f a17 p r e c i p i t a t o r s met d e s i g n emiss ion l e v e

A f t e r Review/Comment

s, t h e r e would be no need

f o r a s u p p l i e r t o o f f e r per formance assurances, and u t i l i t i e s would have

a b s o l u t e c o n f i d e n c e i n mee t ing emiss ion s tandards. However, i n f a c i n g t h e

r e a l i t i e s o f t h e e l e c t r o s t a t i c p r e c i p i t a t i o n p rocess , i t i s apparent and

necessary t h a t a s u p p l i e r make s p e c i f i c a s s e r t i o n s as t o t h e performance o f

i t s equipment. T h i s a s s e r t i o n i s commonly r e f e r r e d t o as a performance

w a r r a n t y . A performance w a r r a n t y r e f l e c t s t h e degree o f conf idence a

s u p p l i e r has i n i t s t e c h n o l o g y and a l e v e l o f commercial r i s k t h a t i t i s

w i l l i n g t o accep t t o o b t a i n an o r d e r .

U s u a l l y , a per formance w a r r a n t y w i l l cove r parameters such as c o l l e c t i o n

e f f i c i e n c y , o u t l e t emiss ion, o p a c i t y , f l u e gas p r e s s u r e d r o p , power

consumption, and u n i t a v a i l a b i l i t y . A per formance w a r r a n t y must be c l e a r l y

s t a t e d and p r o v i d e a s t r a i g h t f o r w a r d and reasonab le mechanism f o r i t s

a d m i n i s t r a t i o n .

Guaranty C o r r e c t i o n Curves. P r e c i p i t a t o r s a r e des igned t o ach ieve a

s p e c i f i c c o l l e c t i o n e f f i c i e n c y a t a p a r t i c u l a r s e t o f process c o n d i t i o n s ,

sometimes r e f e r r e d t o as a d e s i g n p o i n t . A d e s i g n p o i n t u s u a l l y ( b u t n o t

a lways) r e p r e s e n t s t h e wors t -case comb ina t ion o f parameters . Worst-case

pa ramete rs c o n s i s t o f maximum f l u e gas f l o w , maximum f l u e gas temperature ,

maximum f u e l ash c o n t e n t , minimum f u e l s u l f u r c o n t e n t , and minimum f u e l

h e a t i n g v a l u e . A wors t -case d e s i g n p o i n t i s f r e q u e n t l y a f a b r i c a t e d

c o n d i t i o n wh ich , i n a l l p r o b a b i l i t y , . m a y never be exper ienced . F u r t h e r , i t

wou ld be a lmos t i m p o s s i b l e t o produce a wors t -case d e s i g n p o i n t d u r i n g

per formance t e s t s . Consequent ly , s u p p l i e r s a r e r e q u e s t e d t o p r o v i d e

p r o j e c t i o n s o f p r e c i p i t a t o r per formance f o r a range o f c o n d i t i o n s .

P r o j e c t i o n s a r e u s u a l l y p r e s e n t e d i n g r a p h i c form and a r e r e f e r r e d t o as

guaranteed

performance co r r ec t ion curves whose purpose i s t o i n s p i r e confidence in t h e

equipment by p red i c t i ng improved performance l e v e l s f o r o the r than design

poin t condi t ions . For example, i f an emission level a t 80 percent of design

flow coinc ides with t h e emission level pred ic ted by the co r r ec t ion curve ,

then i t would be presumed t h a t should t h e maximum gas flow be encountered,

the designed emission leve l would be met.

A bas i c problem wi th performance curves i s t h a t although they may be based on

technica l p r i n c i p l e s , t he curves a r e r e a l l y commercial in na tu re and must be

t r e a t e d a s such. These curves represent a c e r t a i n perceived r i s k leve l t h a t

a supp l i e r i s w i l l i n g t o accept f o r a p a r t i c u l a r p r o j e c t , and they can vary

d rama t i ca l ly with each supp l i e r . This va r i a t i on i s i l l u s t r a t e d in Figure

7-1, which r e l a t e s an emission cor rec t ion f a c t o r t o gas flow.

I f t he se curves represented a purely technica l r e l a t i o n s h i p between gas flow

and performance, t hey would co inc ide . However, Figure 7-1 r e v e a l s t h a t

s u p p l i e r ' A ' i s engendering the l e a s t r i s k while supp l i e r ' E l i s assuming t h e

most r i s k . From a u t i l i t y ' s s tandpoin t , supp l i e r ' E ' i s o f f e r i n g t h e most

a t t r a c t i v e performance curve because i t s t a t e s t h a t a t lower gas f lows, t h e r e

i s cons iderable margin in t he design. The added design margin reduces a

u t i l i t y ' s r i s k in meeting design emission l e v e l s and/or i t s a b i l i t y t o

achieve acceptable emission l e v e l s under adverse opera t ing cond i t i ons .

U t i l i t i e s should a l s o be aware of the e f f e c t of an o u t l e t s t oppe r and how i t

r e l a t e s t o t h e performance warranty curves. An o u t l e t s topper s t a t e s t h a t

when a c e r t a i n emission level i s achieved, t h e warranty i s deemed t o have

been s a t i s f i e d in f u l l a l though the p r e c i p i t a t o r i s not producing t h e

c o l l e c t i o n e f f i c i e n c y s t a t e d in the con t r ac t o r a s ad jus ted by t h e co r r ec t ion

curves. The o r i g i n a l reason given f o r t he o u t l e t s topper concept was t h a t

one could not r e l i a b l y measure emissions l e s s than 0 . 1 pounds/miliion BTU.

Many p r e c i p i t a t o r s i n t h e 1960s t o e a r l y 1970s e r a passed performance t e s t s

by meeting t h e o u t l e t s topper . The drawback t o t h i s concept i s revealed when

performance curves a r e compared t o the o u t l e t s topper . A u t i l i t y may be l ed

t o be l ieve t h a t i t i s ob ta in ing a un i t with a c o l l e c t i o n e f f i c i e n c y of 99.8

percent o r higher a t non-design poin t cond i t i ons , but an outlet s topper

- SUPPLIER "E"

- -

C - - -

30 40 50 60 70 80 90 100 110

PERCENT OF DESIGN GAS FLOW

Figure 7-1. Guarantee Performance Curve-Gas F low vs. Emission Correction Fac to r

may be s a t i s f i e d with e f f i c i e n c i e s i n t h e low 99 percent range. Hence, the

performance curves become wor th less and may border on mi s rep re sen ta t i on .

Therefore, i f an o u t l e t s topper i s t o be accepted by a u t i l i t y , i t must be

s e t a t a level t h a t i s low enough t o i n s p i r e confidence t h a t t h e u n i t could

meet performance requirements a t t h e design poin t . Should a s u p p l i e r fee l

t h a t an o u t l e t s topper i s needed f o r p r o t e c t i o n , then an o u t l e t s topper may

be incorporated i n t o t h e performance curve , a s supp l i e r ' A ' has done in

Figure 7-1. A u t i l i t y must be ca re fu l i n determining the exac t na tu re of

the performance warranty.

The app l i ca t i on of t he se performance co r r ec t ion curves t o f i e l d t e s t

condi t ions must be s e t f o r t h within t h e s p e c i f i c a t i o n in o rde r t o avoid

confusion a t a l a t e r d a t e . Normally, co r r ec t ion curves a r e provided fo r

such parameters a s gas f low, gas tempera ture , i n l e t dus t loading and fuel

s u l f u r content . The d a t a po in t s de r ived from these curves a r e then used t o

modify t e s t r e s u l t s ( i . e . , o u t l e t d u s t loading) which a r e then compared t o

t he performance warranty value. In o r d e r t o accomplish t h i s malfunction of

t e s t s r e s u l t s , var ious forms of t h e fol lowing equation have been used:

where:

LC = correc ted o u t l e t dus t loading

La = measured o u t l e t d u s t loading

C f l = co r r ec t ion f a c t o r a t measured gas temperature

CF = co r r ec t ion f a c t o r a t measured gas temperature 2 CF = co r r ec t ion f a c t o r f o r measured i n l e t d u s t loading 3 CF = co r r ec t ion f a c t o r f o r measured fue l s u l f u r coqtent 4

CFu = various o t h e r co r r ec t ion f a c t o r s a s needed

Of course , t he number of c o r r e c t i ~

des ign requirements, such a s t h e

of sodium l e v e l s in t h e f l y ash.

genera tor has two o r more prec ip i

on curves can vary according t o s p e c i f i c

i nc lus ion of a curve r e l a t i n g t h e e f f e c t s

For those s i t u a t i o n s where a steam

t a t o r s arranged i n p a r a l l e l and emission

t e s t i n g i s conducted on each c a s i n g , t h e n t h e composi te o u t l e t d u s t l o a d i n g

can be determed by t h e f o l l o w i n g e q u a t i o n :

where:

LC t o t a l = c o r r e c t e d compos i te o u t l e t d u s t l o a d i n g

LC,, Lcb = c o r r e c t e d o u t l e t l o a d i n g s f o r p r e c i p i t a t o r cas ings "aii

and "b" as i n d i v i d u a l l y determined b y e q u a t i o n 7-1

Fa' Fb = f l u e gas v o l u m e t r i c f l o w s f o r each p r e c i p i t a t o r cas ing .

I n t h e e v a l u a t i o n o f per formance c o r r e c t i o n curves, t h e u t i l i t y may w i s h t o

c o n s i d e r a s s i g n i n g a l i m i t e d mone ta ry v a l u e t o improved per formance l e v e l s

f o r e v a l u a t i o n purposes. Shou ld t h a t ass ignment be made, t h e u t i l i t y

s h o u l d communicate t h i s e v a l u a t i o n f a c t o r t o t h e b i d d e r s p r i o r t o p roposa l

submi ss ion .

Nhen e v a l u a t i n g performance c o r r e c t i o n c u r v e s f o r emiss ion w a r r a n t y

purposes, c a r e must a l s o be e x e r c i s e d i n e v a l u a t i n g power consumption

w a r r a n t i e s and t h e r e l a t i o n s h i p between them. It has been found t h a t

sometimes when t h e s u p p l i e r p r e p a r e s i t s emiss ion c o r r e c t i o n curves, t h e

p r e c i p i t a t o r power i n p u t t h r o u g h t h e T-R s e t s may be c o n s i d e r e d a t a

maximum l e v e l o v e r t h e range o f t h e c u r v e s . However, w i t h t h e use o f

energy management concepts , t h e s e h i g h power l e v e l s may n o t be exper ienced

d u r i n g t e s t i n g , t h u s a f f e c t i n g measured emiss ions . As such, t h e u t i l i t y

and s u p p l i e r may be f a c e d w i t h t h e s i t u a t i o n o f meet ing e i t h e r one o f t h e

w a r r a n t i e s b u t n o t b o t h . T h e r e f o r e , t h e p roposa l e v a l u a t i o n s must n o t o n l y

f u l l y i n v e s t i g a t e t h e n a t u r e o f t h e per formance c o r r e c t i o n cu rves and

w a r r a n t y s ta temen ts b u t a l s o examine t h e assumptions upon wh ich t h e y a r e

based.

Power Consumption Warranty. The consideration and evaluation of power

consumption warranties requires that utilities exercise the utmost care.

Care is required because to date, there is yet to be developed a reliable,

publicly available method for correlating power consumption with fuel

properties, collection efficiency, and internal precipitator

configuration. For the most part, the data developed by a supplier tends

to be discrete and limited in its scope and applicability. Predicting

power consumption becomes more difficult when dealing with specific fuels

for which a supplier has no data. Therefore, a utility must investigate

the basis and logic of supplier claims and warranties.

Power consumption warranties have been a major evaluation factor in

determining which supplier receives a contract award. Each supplier

calculates its power consumption in a particular manner with certain

assumptions. The methodology and assumptions can create situations where

power consumption levels vary by a factor o f five. Yet it is apparent that

such great differences cannot really exist. Therefore, extensive

discussions with each supplier must be undertaken to determine the bases of

the consumption levels. When modern specifications establish minimum

precipitator sizing and other feature related criteria, bids will be

extremely close in physical configuration, and power consumption levels

should not dramatically vary.

Precipitator electrical loads may be broken down into those associated with

(1) transformer-rectifier sets, (2) hopper heating, (3) insulator purge and

heating, (4) control room heating and air conditioning, and (5) 7ighting.

Principal loads are associated with the transformer-rectifier sets and

hopper heating. Other loads, in a practical sense, are minor. When a

specification establishes the minimum number of hoppers and their

capacities, all bids should have essentially the same power requirements.

The only remaining variable load is that of the transformer-rectifier

sets. Considering that power consumption will be a function of discharge

electrode geometry, gas and particle electrical properties, automatic

v o l t a g e c o n t r o l l e r s , and e l e c t r o d e c l e a n l i n e s s , a t t e n t i o n must be d i r e c t e d

t o p o t e n t i a l d i f f e r e n c e s i n equipment t o s u b s t a n t i a t e power consumpt ion

l e v e l s .

Should one c o n s i d e r v a r i o u s b i d s , and presume, due t o advances i n equ ipment

des ign , t h a t d i s c h a r g e e l e c t r o d e c o n f i g u r a t i o n w i l l

f a c t o r i n power consumption, t r a n s f o r m e r - r e c t i f i e r

l e v e l s shou ld n o t v a r y by more than 25 p e r c e n t f o r

course, a l l o f t h e f o r e g o i n g would n o t s u p p o r t v a r i ,

be t h e p redominan t

s e t power consumpt ion

t h e same c o n d i t i o n s . O f

a t i o n s i n power

consumption o f up t o 500 p e r c e n t ; t h e r e f o r e , a u t i l i t y can t a k e one o f t h e

f o l l o w i n g approaches: (1) i g n o r e power consumption w a r r a n t i e s , ( 2 )

e s t a b l i s h a minimum consumption l e v e l under wh ich t h e b i d d e r wou ld r e c e i v e

no c r e d i t , o r ( 3 ) p r o r a t e t h e consumption l e v e l s o f a11 b i d d e r s so t h a t t h e

d i f f e r e n c e between h i g h and low i s on t h e o r d e r o f 25 t o 50 p e r c e n t .

I n t h e f i n a l a n a l y s i s , a u t i l i t y must e x e r c i s e p ruden t judgment i n

e v a l u a t i n g power consumpt ion w a r r a n t i e s i n l i g h t o f t h e l a c k o f a c o h e s i v e

and r e l i a b l e d a t a base. A u t i l i t y must a l s o t a k e ca re n o t t o p l a c e

s u p p l i e r s i n a p o s i t i o n such t h a t m i s r e p r e s e n t a t i o n o r unwar ran ted r i s k i s

encouraged.

Performance T e s t s . C u r r e n t l y , a t w o - t e s t concept i s u t i l i z e d t o d e t e r m i n e

whether a p r e c i p i t a t o r can f u l f i l l i t s per formance w a r r a n t y . The f i r s t

t e s t , ' A ' , i s n o r m a l l y conducted w i t h i n t h r e e months o f a u n i t ' s

commercial d a t e . A t t h i s t i m e , v a r i o u s t e s t s a r e per formed t o d e t e r m i n e

compl iance w i t h c o n t r a c t c o l : e c t i o n e f f i c i e n c y , o u t l e t em iss ion , o p a c i t y ,

power consumption, and f l u e gas p r e s s u r e d r o p w a r r a n t i e s . T h i s t e s t

c h a r a c t e r i z e s p r e c i p i t a t o r per formance i n an as-new c o n d i t i o n . The second

t e s t , ' 5 ' . u s u a l l y i s conducted 12 t o 24 months a f t e r a p r e c i p i t a t o r has

passed t e s t ' A 1 . T e s t '8 ' addresses o n l y c o l l e c t i o n e f f i c i e n c y , o u t l e t

em iss ion , and o p a c i t y . I n o r d e r t h a t t e s t 'B' b e e n f o r c e a b l e i n te rms o f

t h e per formance w a r r a n t y , i t i s i m p e r a t i v e t h a t t h e m a t e r i a l w a r r a n t y

e x t e n d th rough t e s t ' B ' .

Ano the r aspec t o f a performance w a r r a n t y i s t h e requ i remen t t h a t a s u p p l i e r

p r o m p t l y and d i l i g e n t l y pursue c o r r e c t i v e a c t i o n s r e q u i r e d under t h e

m a t e r i a l and per formance w a r r a n t i e s . The concept r e q u i r e s t h a t a

cumulative period of time; e.g., 550 elapsed calendar days, be established

i n which a supplier can complete any and all warranty repairs. The elapsed

time for each event is computed from the time the supplier is notified in

writing that a condition exists which requires corrective action and until

such time as corrections are effected and the utility so notified in

writing. Delays in making equipment avai-lable to a supplier would be

excluded from the time accounting. Should a supplier fail to complete

corrections in the allotted time, the supplier would forfeit a sum of

money. Forfeiture of money would not relieve a supplier from its

responsibilities under the contract but rather acts to encourage responsive

action from the supplier.

Qualified Suppliers Review and Comment of Draft Specifications

Developing a precipitator specification is a significant undertaking.

Moreover, proposal preparation may require a supplier to expend upwards of

$250,DDO for a major project. Consequently, it behooves both utility and

supplier to ensure that a specification accurately reflects the utility's

needs, desires, and requirements, which will then reduce the incidence of

alternate equipment quotations or re-bidding with the preparation of

entirely new proposals

In order that specifications reflect a utility's requirements, it is suggested that qualified precipitator suppliers be given an opportunity to

review specifications prior to their release in a request for proposal.

This review by a qualified supplier should address the following as a

minimum:

Minimum specific collecting area (SCA)

Maximum collecting electrode height

Maximum gas velocity through the precipitator

Minimum aspect ratio

Minimum treatment time

Minimum number of mechanical fields

Minimum number of electrical fields and bus sections

Number of precipitators and chambers

Precipitator general arrangement

Precipitator control system

Ideally, a qualified supplier would review all specifications, not only the

precipitator specification but also attachment specifications, should schedule

allow. Usually, due to time constraints, a utility must consider itself

fortunate to have only the precipitator specification reviewed. A supplier may use two techniques in reviewing a specification. The first involves an

in-depth analysis based upon the cost-effective benefit considerations of each

of the significant design requirements. This technique requires a significant

effort on the part of a supplier. The second technique involves reviewing the

specification from the standpoint of identifying those requirements which

would make the suppliers proposal uncompetitive in terms of its standard or

normal design practices or scope of supply. These uncompetitive requirements

wou7d have to be individually studied and evaluated in terms of whether (1)

the requirement is a physical impossibility, (2) the requirement is not part

of the manufacturer's original equipment design concept, or (3) the

requirement has proved to be ineffectual on previous designs.

Qua1 if ied suppl iers'

identifying potentia

request for proposal

reviews of the specification may prove beneficial i n

1 problems and resolving them prior to the issuance of a

. This will benefit a supplier because it will have to prepare only one proposal, and a utility by simplifying its evaluation. The

latter enables a utility to concentrate its efforts on the evaluation of the

real issues.

SUPPLIER QUALIFICATION

One of the most critical aspects in purchasing an electrostatic precipitator

is the selection of suppliers who will offer various proposals from which a

utility must choose. Although the supplier selection process is often seen as

nothing more than gathering the names of all the companies engaged in

manufacturing precipitators, the selection process has far reaching

implications regarding necessary fulfillment of performance warranties. Some

view the process as a way to ensure competitive pricing. The questions which

must be asked are "How many suppliers are needed to assure competitive

prices?" and "Which suppliers have demonstrated a clear cut track record of

reliable equipment, prudent sizing criteria, commercial commitment to

resolving problem jobs, and a continuing effort in developing precipitator

technology?" This section presents concepts which, when applied by a utility,

should provide realistic grounds on which to select a limited number of

qualified precipitator suppliers for a particular project.

Assembly of Vendor Experience

In order to obtain necessary information for implementing a rational qualification procedure, a meeting should be held with each prospective

bidder. These meetings enable an exchange of information relative to a

project. Usually, utility personnel from both the engineering and purchasing

staffs w i l l describe the project in terms of its technical requirements such

as flyash removal efficiency and scope of supply, and commercial requirements

such as limitations on escalation or lump sum fixed pricing, extended material

and performance warranties, and liquidated da

should usually be requested to provide the fo

Review of equipment design features

Discussion of sizing philosophy and

Presentation of current research an

Installation 1 ist

ages and schedule. A supplier

lowing information:

hi story

development projects

Performance test reports on similar projects

Discussion of problem jobs

Quality assurance program

Staff qualifications

Schedule adherence analyses of previous projects

I d e n t i f i c a t i o n o f m a n u f a c t u r i n g f a c i l i t i e s

F i n a n c i a l v a l u e o f r e c e n t c o n t r a c t s

Annual f i n a n c i a l r e p o r t

Bank r e f e r e n c e s

U t i 1 i t y r e f e r e n c e s

L i s t i n g o f any pending l i t i g a t i o n .

T h i s i n f o r m a t i o n w i l l se rve as t h e b a s i s f o r an e v a l u a t i o n conducted b y a team

o f u t i l i t y pe rsonne l , w h i c h n o r m a l l y c o n s i s t s o f personnel f rom t h e u t i l i t y ' s

e n g i n e e r i n g , pu rchas ing , l e g a l , c o n s t r u c t i o n , and q u a l i t y assurance

depar tmen ts . A team e f f o r t i s encouraged i n o r d e r t o b r i n g s p e c i a l i z e d

t a l e n t s and p e r s p e c t i v e s t o b e a r and t o l i m i t t h e t i m e spent i n t h e s e l e c t i o n

p r o c e s s .

Commercial E v a l u a t i o n

Each u t i l i t y n o r m a l l y has i t s own commercial c r i t e r i a f o r d e t e r m i n i n g

q u a l i f i c a t i o n s f o r a b i d d e r s l i s t . C o n s i d e r i n g t h e c o s t and r e g u l a t o r y

s i g n i f i c a n c e o f a p r e c i p i t a t o r , i t i s p r u d e n t t o employ sc reen ing p rocedures

t h a t t e n d t o c e n t e r abou t a s u p p l i e r s ' a b i l i t i e s t o assume a new l i a b i l i t y and

how t h e y have d i s c h a r g e d t h e i r r e s p o n s i b i l i t i e s on p r e v i o u s c o n t r a c t s .

A Dun and B r a d s t r e e t r a t i n g o f a s u p p l i e r i s o f t e n t h e s t a r t i n g p o i n t o f an

e v a l u a t i o n . Depending upon a u t i l i t y ' s c o r p o r a t e p o l i c i e s and t h e p o t e n t i a l

v a l u e o f t h e p r o j e c t , a minimum o f an "AM r a t i n g may be r e q u i r e d as a f i r s t

s c r e e n i n g l e v e l . T h i s t y p e o f sc reen ing i s based on a "go/no go" concep t . A

second l e v e l o f s c r e e n i n g i s an a n a l y s i s o f p a s t annual r e p o r t s , bank

r e f e r e n c e s , and p o s s i b l y a c u r r e n t f i n a n c i a l s ta temen t . Again, t h i s a n a l y s i s

wou ld e s t a b l i s h a "go/no go" l e v e l wh ich t h e s u p p l i e r must pass i n o r d e r t o b e

c o n s i d e r e d f u r t h e r . A t h i r d l e v e l o f sc reen ing i s t o determine whether a

s u p p l i e r has r e c e n t l y comp le ted a c o n t r a c t w i t h a v a l u e s i m i l a r t o t h a t o f t h e

proposed p r o j e c t . A f o u r t h l e v e l o f sc reen ing i n v o l v e s an assessment o f t h e

l i a b i l i t y o f a s u p p l i e r c o n c e r n i n g any o u t s t a n d i n g l i t i g a t i o n i n w h i c h i t i s

i n v o l v e d . A u t i l i t y ' s l e g a l s t a f f shou ld n o r m a l l y be i n c o n t a c t w i t h a

s u p p l i e r ' s counse l t o de te rm ine t h e e x a c t n a t u r e and s t a t u s o f l i t i g a t i o n . A

d e t e r m i n a t i o n would have t o be made on t h e p remise t h a t s h o u l d a s u p p l i e r l o s e

a l l o r a ma jo r p o r t i o n o f l i t i g a t i o n , i t wou ld n o t b e s i g n i f i c a n t l y i m p a i r e d

i n f u l f i l l i n g f u t u r e c o n t r a c t s . A f i n a l sc reen ing l e v e l , and p o s s i b l y one o f

t h e more i n f l u e n t i a l , i s t h e u t i l i t y ' s p a s t h i s t o r y w i t h a p a r t i c u l a r s u p p l i e r

i n terms o f comp ly ing w i t h schedu le requ i remen ts , t r e a t m e n t o f m a t e r i a l and

per formance w a r r a n t i e s , c o n t r a c t e x t r a s , and t h e r e s o l u t i o n o f problem j o b s .

Supplement ing t h e f o r e g o i n g , a u t i l i t y may w i s h t o i n v e s t i g a t e a s u p p l i e r ' s

manu fac tu r ing f a c i l i t i e s , s u b c o n t r a c t o r f a c i l i t i e s , and q u a l i t y assurance

programs. A u t i l i t y may a l s o h o l d d i s c u s s i o n s w i t h o t h e r u t i l i t y use rs o f t h e

s u p p l i e r ' s equipment and p o s s i b l y v i s i t o t h e r p l a n t s i t e s .

I t shou ld be recogn ized t h a t commercial e v a l u a t i o n f a c t o r s must be judged

a g a i n s t t h e economic c o n d i t i o n s e x i s t i n g a t a s p e c i f i c . t i m e and a r e s u b j e c t i v e

i n na tu re ; however, i t i s more a p p r o p r i a t e t o use s u b j e c t i v e s c r e e n i n g

procedures i n t h e b i d d e r q u a l i f i c a t i o n phase r a t h e r t h a n i n t h e p roposa l

e v a l u a t i o n stage. Proposa l e v a l u a t i o n s r e q u i r e a d o l l a r e v a l u a t i o n f a c t o r f o r

a l l s u b s t a n t i a l i s s u e s . Many o f t h e f o r e g o i n g concep ts a r e n o t r e a d i l y

arneanable t o such d o l l a r v a l u a t i o n w i t h o u t b e i n g s u b j e c t e d t o charges o f

f a v o r i t i s m o r a r b i t r a r y a c t i o n s , and i t i s suggested t h a t t h i s procedure be

used t o ensure t h a t a b i d d e r s l i s t c o n t a i n s o n l y t h o s e s u p p l i e r s f rom whom t h e

u t i l i t y would be happy t o purchase equ ipment .

C r i t e r i a f o r Vendor S e l e c t i o n

Once a commercial e v a l u a t i o n has been comp le ted and a t e n t a t i v e b i d d e r s l i s t

e s t a b l i s h e d , a t e c h n i c a l e v a l u a t i o n s h o u l d b e pe r fo rmed . T h i s e v a l u a t i o n

concerns i t s i l f w i t h t e c h n i c a l f e a t u r e s o f p r e c i p i t a t o r s , s i z i n g t r a c k

reco rds , number o f u n i t s i n s e r v i c e and/or under c o n t r a c t , o p e r a t i o n a l

f l e x i b i l i t y , and r e l i a b i l i t y . Each t e n t a t i v e b i d d e r i s e v a l u a t e d in te rms o f

p r e c i p i t a t o r exper ience and t e c h n i c a l m e r i t r e g a r d i n g s p e c i f i c d e s i g n f e a t u r e s .

The f i r s t exper ience sc reen ing l e v e l o f t h e t e c h n i c a l e v a l u a t f o n must

de te rm ine whether t h e p o t e n t i a l s u p p l i e r has an i n s t a l l a t i o n t h a t r e f l e c t s t h e

i n t e r n a l d e s i g n components wh ich i t m i g h t propose f o r a c u r r e n t p r o j e c t . The

q u a l i f i c a t i o n s ta tement m i g h t s t a t e t h a t t h e p o t e n t i a l s u p p l i e r "have a r i g i d

d i s c h a r g e e l e c t r o d e des igned p r e c i p i t a t o r i n o p e r a t i o n w i t h a s p e c i f i c t y p e o f

f u e l on a Mw ( a s a minimum) domes t i c e l e c t r i c u t i l i t y u n i t by t h e end o f

t h e - q u a r t e r o f 19-." T h i s sc reen ing l e v e l ensures t h a t a u t i l i t y wou ld

n o t be p u r c h a s i n g an u n t e s t e d des ign w i t h a l l o f t h e p r o d u c t development

prob lems t h a t wou ld e n t a i l . P o t e n t i a l s u p p l i e r s who c o u l d n o t meet t h i s

c r i t e r i a would be e l i m i n a t e d from f u r t h e r c o n s i d e r a t i o n .

The second l e v e l o f exper ience sc reen ing e v a l u a t e s a s u p p l i e r ' s t o t a l

exper ience i n t e r m s o f a summation o f t h e megawatt r a t i n g s o f a l l c o l d - s i d e

p r e c i p i t a t o r s on domest ic c o a l - f i r e d p l a n t s i n o p e r a t i o n s i n c e 1970 and/or

c u r r e n t l y on o r d e r . T h i s t i m e frame r e p r e s e n t s t h e exper ience i n terms o f

r e c e n t emiss ion r e q u i r e m e n t s , s i z i n g p h i l o s o p h y , and f u e l c h a r a c t e r i s t i c s .

Each s u p p l i e r ' s i n s t a l l a t i o n l i s t i s t h e n c r e d i t e d i n te rms o f megawatts i n

accordance w i t h t h e f o l l o w i n g c r i t e r i a :

I - R i g i d D ischarge E l e c t r o d e Des ign

F u l l c r e d i t f o r those u n i t s wh ich have passed guaran teed per formance l e v e l s .

H a l f c r e d i t f o r those u n i t s wh ich a r e i n o p e r a t i o n b u t have n o t been t e s t e d t o d a t e .

O n e - t h i r d c r e d i t f o r those u n i t s wh ich a r e i n o p e r a t i o n b u t have f a i l e d t o pass per formance guarantees.

One-quar ter c r e d i t f o r those u n i t s under c o n s t r u c t i o n .

One-e ighth c r e d i t f o r those u n i t s which a r e i n t h e e n g i n e e r i n g phase b u t n o t y e t under c o n s t r u c t i o n .

I1 - Weighted Wi re Design

O n e - t h i r d c r e d i t f o r o n l y those u n i t s which have passed per formance t e s t s w i t h a minimum c o l l e c t i o n e f f i c i e n c y o f 98 p e r c e n t .

These c r i t e r i a a t t e m p t t o p u t t h e s u p p l i e r s exper ience i n t o a p r o p e r

p e r s p e c t i v e r e l a t i v e t o t h e t o t a l range o f a c t i v i t i e s f rom t h e e n g i n e e r i n g

phase th rough t h e o p e r a t i o n a l phase. Each phase o f t h e work demons t ra tes a

c e r t a i n c a p a b i l i t y and i s accorded some c r e d i t , w i t h u n i t s h a v i n g passed t h e i r

performance guaran tees g e t t i n g t h e ma jo r p o r t i o n o f t h e c r e d i t . It must be

ncted t h a t weighted wire u n i t s a r e given some c r e d i t due t o t he va luab le da ta

the supp l i e r has obtained r e l a t i v e t o o t h e r p r e c i p i t a t o r aspec ts such a s gas

d i s t r i b u t i o n , automatic vo l t age c o n t r o l l e r s , cons t ruc t ion techniques , e t c .

The c r i t e r i a f o r c r e d i t i n g megawatts can be modified t o r e f l e c t a u t i l i t y ' s

concern o r special requirements . Typical modifying f a c t o r s a r e :

* Consider only those p r e c i p i t a t o r s opera t ing on a p a r t i c u l a r type of f u e l .

Consider only t hese p r e c i p i t a t o r s w i t h a c e r t a i n minimum c o l l e c t i o n e f f i c i e n c y .

Consider those p r e c i p i t a t o r s with t e s t e d o u t l e t emissions of a c e r t a i n level o r l e s s .

Consider those p r e c i p i t a t o r s which have f a i l e d t h e i r performance guarantees only i f they r ep re sen t a small percentage of those p r e c i p i t a t o r s which have passed t h e i r performance guarantees .

Consider only those p r e c i p i t a t o r s appl ied t o a c e r t a i n megawatt s i z e o r l a r g e r .

Apply a mult iplying f a c t o r t o those p r e c i p i t a t o r s where t he supp l i e r had r e s p o n s i b i l i t y f o r both mater ia l and e r ec t ion a s opposed t o mater ia l only c o n t r a c t s .

This second experience screening leve l w i l l r e s u l t i n e s t a b l i s h i n g a c r e d i t e d

megawatt r a t i n g f o r each s u p p l i e r . The r a t i n g l e v e l s can range from a few

hundreds t o approximately 10,000 c r e d i t e d megawatts. A u t i l i t y w i l l have t o

decide what s p e c i f i c level of experience i s app rop r i a t e t o t h e proposed

p r o j e c t . On a p r ac t i ca l b a s i s , t h i s leve l could range from t h e 2,000 t o 5,000

c r ed i t ed megawatts. Only t hose p o t e n t i a l s u p p l i e r s who meet some s p e c i f i c

experience leve l should then be considered f o r f u r t h e r eva lua t ion .

A f i n a l screening i s a t echn ica l one involving eva lua t ion of t he remaining

po ten t i a l supp l i e r s from t h e a spec t of t h e technica l mer i t of t h e i r r e spec t ive

designs in r e l a t i onsh ip t o p r o j e c t requirements . A t yp i ca l technica l mer i t

eva lua t ion format c o n s i s t s o f t he fol lowing:

Maxi m u m I - Discharge Elec t rodes Ratings

Electrode con f igu ra t ion (round, square , 3 needle, punched)

I - Discharge Elec t rodes

Type of e l ec t rode mounting (p ipe frame or mast)

Type of e l ec t rode support (two o r four po in t s )

Po ten t i a l f o r e l e c t r o d e and support expansion o r d i s t o r t i o n

In t e rna l e l ec t rode assembly bracing

Type of rapper (mechanical , e l e c t r o - mechanical, pneumatic)

Rapper l oca t ion ( i n o r ou t of gas stream)

Adjustable rapper i n t e n s i t y

Rapper r e p a i r without removing u n i t from se rv i ce

Off power rapping c a p a b i l i t y

Rapper segrega t ion and ene rg i za t ind iv idua l t r a n s f o r m e r - r e c t i f i e r

Type of automatic vol tage cont ro

ion on an b a s i s

l l e r

I1 - ColTecting Elec t rodes

P l a t e t h i ckness (18 o r 16 gauge)

Upper p l a t e support ( s p r i n g , bo l t ed , tongue)

Bottom p l a t e spacers and bracing

P l a t e spacing experience ( 9 , 1 0 , o r 1 2 inch)

Type of rapper (mechanical, e l e c t r o - mechanical, pneumatic)



Rapper r e p a i r without removing u n i t from se rv i ce

Off power rapping c a p a b i l i t y

Maxi mum Ratings

A

A

A

A

C

C

B

'3

C

8

A

D

C

C

D

C

C

B

B

C

I1 - C o l l e c t i n g E l e c t r o d e s

Number o f p l a t e s rapped b y any one r a p p e r (one, two, t h r e e , o r f o u r )

Rapper s e g r e g a t i o n and e n e r g i z a t i o n on an i n d i v i d u a l t r a n s f o r m e r - r e c t i f i e r b a s i s

I11 - S i z e S e l e c t i o n

Data base

Methodology A

Refuse f i r i n g e x p e r i e n c e C

O i l f i r i n g e x p e r i e n c e C

O f cou rse , parameters can b e m o d i f i e d t o s u i t t h e u t i l i t y ' s needs; however,

t h e y s h o u l d r e f l e c t r e a l concerns and t h e r e l a t i v e impor tance o f i n d i v i d u a l

pa ramete rs i n terms of enhanced p r e c i p i t a t o r performance. U s u a l l y , maximum

r a t i n g s a r e c o n v e r t e d t o a numer i ca l system f o r ease i n e s t a b l i s h i n g an

o v e r a l l r a t i n g . I t i s suggested t h a t a minimum r a t i n g o f 50 p e r c e n t o f t h e

t o t a l t h e o r e t i c a l maximum r a t i n g would be r e q u i r e d f o r a suppl

q u a l i f i e d t o b i d on a p r o j e c t .

The a p p l i c a t i o n o f b o t h commercial and t e c h n i c a l e v a l u a t i o n c r

p r o b a b l y r e s u l t i n a b i d d e r s f 1 i s t c o n s i s t i n g o f approx ima te l y

t e r i a w i l l

f i v e

s u p p l i e r s . T h i s number o f s u p p l i e r s s h o u l d ensure c o m p e t i t i v e p r i c i n g y e t

r e c o g n i z e t h a t t h e p e r i o d o f t i m e p e r m i t t e d f o r e v a l u a t i o n i s u s u a l l y l i m i t e d

r e g a r d l e s s o f t h e number o f b i d d e r s . When t h e r e i s a c e r t a i n minimum p e r i o d

o f t i m e and e f f o r t a s s o c i a t e d w i t h r e v i e w i n g and p r o p e r l y e v a l u a t i n g each

p r o p o s a l , t h e need f o r a l i m i t e d number o f b i d d e r s i s mandatory, and c o u r t e s y

b i d s do n o t serve t h e i n t e r e s t s o f t h e u t i l i t y o r s u p p l i e r . The g u i d i n g r u l e

i n e s t a b l i s h i n g a b i d d e r s t l i s t i s t o s e l e c t o n l y those s u p p l i e r s f rom w h i c h a

u t i 1 i t y wou ld c o n f i d e n t l y purchase equipment.

PREPARATION OF COMMERCIAL TERMS AND CONDITIONS

T h i s s e c t i o n d i scusses the o r g a n i z a t i o n o f commercial te rms and c o n d i t i o n s f o r

a r e q u e s t f o r p roposa l (RFP) r e g a r d i n g t h e t y p e o f terms t o be s p e c i f i e d f o r

d e l i v e r and e r e c t c o n t r a c t s .

O r g a n i z a t i o n

Commercial te rms and c o n d i t i o n s shou ld be p repared and o rgan ized i n a manner

t h a t c l e a r l y and c a r e f u l l y d e l i n e a t e s t h e requ i remen ts t o wh ich t h e b i d d e r , as

a c o n t r a c t o r , must adhere f o r t h e des ign , e n g i n e e r i n g , f a b r i c a t i o n , and

e r e c t i o n o f an e l e c t r o s t a t i c p r e c i p i t a t o r . I t i s n o t t h e i n t e n t o f t h i s

s e c t i o n t o p r o v i d e a c t u a l word ing t o be used i n an RFP, b u t t o be i l l u s t r a t i v e

o f t h o s e concepts t h a t shou ld be addressed. A c t u a l word ing shou ld be

deve loped b y a u t i l i t y ' s l e g a l counse l c o n s i s t e n t w i t h p r o j e c t commercial

t e rms and c o n d i t i o n s . I t must be noted t h a t te rms and c o n d i t i o n s shou ld be

c o n s t r u c t e d

i n such a manner as t o p r o t e c t a u t i l i t y ' s r i g h t s and i n t e r e s t s w h i l e

p r o v i d i n g f o r t h e e q u i t a b l e r e s o l u t i o n o f m isunders tand ings between a u t i l i t y

and p r e c i p i t a t o r m a n u f a c t u r e r .

The f o l l o w i n g l i s t s a r e examples o f t y p i c a l o r g a n i z a t i o n s o f commercial t e rms

and c o n d i t i o n s . Tab le 7-1 i l l u s t r a t e s t h e o r g a n i z a t i o n o f m a t e r i a l supp ly

c o n t r a c t s , and Tab le 7-2 d e a l s w i t h t h e o r g a n i z a t i o n o f e r e c t i o n c o n t r a c t s .

D e t a i l s o f t h e c o n t r a c t u r a l te rms and c o n d i t i o n s a r e g i v e n i n Appendix 7D.

TREATMENT OF EXCEPTIONS AND NEGOTIATIONS

Once a p r e c i p i t a t o r s u p p l i e r ' s p r o p o s a l s a r e r e c e i v e d , a u t i l i t y eng ineer must

t h e n deve lop a p l a n t o r e v i e w and e v a l u a t e t h e p r o p o s a l s . An e v a l u a t o r must

unders tand t h a t i t becomes d i f f i c u l t f o r a s u p p l i e r t o comply w i t h each

r e q u i r e m e n t o f t h e b i d d i n g documents; t h e r e f o r e , p a r t o f t h e p l a n must be t o

e s t a b l i s h c r i t e r i a f o r t h e d i s p o s i t i o n o f e x c e p t i o n s . I n a d d i t i o n , an

e v a l u a t i o n p l a n shou ld c o n t a i n a p r e c i s e procedure f o r t h e a p p l i c a t i o n o f

monetary e v a l u a t i o n f a c t o r s .

P roposa l Review

A p roposa l r e v i e w c o n s i s t s o f comparing an o f f e r i n g t o t h e requ i remen ts o f

t h e RFP and t h e n t o t h e o t h e r o f f e r i n g s . The comparison i s u s u a l l y

accomp l i shed by t a b u l a t i n g t h e s u p p l i e r f i l l - i n d a t a p o r t i o n s o f t h e RFP,

w h i c h p r o v i d e s a q u i c k and easy way t o i d e n t i f y and h i g h l i g h t d i f f e r e n c e s

among v a r i o u s o f f e r i n g s . Once d i f f e r e n c e s a r e i d e n t i f i e d , a u t i l i t y must

e v a l u a t e t h e s i g n i f i c a n c e o f t h e d i f f e r e n c e s . I t ems o f substance must be

d i s c u s s e d w i t h t h e b i d d e r s t o de te rm ine t h e bases f o r d i f f e r i n g . Many

Table 7 - 1

O r g a n i z a t i o n o f Material Supply C o n t r a c t s

D e f i n i t i o n s C o n t r a c t Documents Ubl i g a t i o n s o f C o n t r a c t o r O b l i g a t i o n s o f Owner D e i i v e r y , T i t l e and S to rage R i s k o f Loss Taxes W a r r a n t i e s L i m i t a t i o n s o f L i a b i 1 i t y Repor ts and S c h e d u l i n g Pa ten ts T e r m i n a t i o n f o r Convenience T e r m i n a t i o n f o r D e f a u l t Suspension o f Work I n s p e c t i o n s and T e s t s Force Ma jeu re L iens Compliance w i t h Codes, P e r m i t s , Laws and L i censes A p p l i c a b l e S t a t e Law Changes and E x t r a Work Assignment and S u b c o n t r a c t s P r o p r i e t a r y I n f o r m a t i o n Nonwaiver N o t i c e s and Correspondence Equal Employment O p p o r t u n i t y , and A f f i r m a t i v e A c t i o n Occupationa7 S a f e t y and H e a l t h A c t Role o f Engineer C o n t r a c t o r ' s Drawings and I n s t r u c t i o n Manuals P h y s i c a l Damage t o J o b s i t e P r i c e P o l i c y i n v o i c i n g and Payment Terms Owner's P r e s c r i b e d Forms Complete Agreement E f f e c t o f S e c t i o n Headings I n d e m n i f i c a t i o n Subcon t rac ts Schedule U n i t O p t i o n C o n t r a c t Bonds Cancel l a t i o n Charges

Tab le 7-2

O r g a n i z a t i o n o f E r e c t i o n C o n t r a c t s

D e f i n i t i o n s O b l i g a t i o n s o f C o n t r a c t o r Obl i g a t i o n s o f Owner D e l i v e r y and S to rage C o n t r a c t o r Respons ib le f o r Work U n t i l Accepted Personal A t t e n t i o n o f C o n t r a c t o r C o n t r a c t o r ' s R e p r e s e n t a t i o n s Insu rance Requirements P lann ing , Cost , Schedu l ing and C o n t r o l Independent C o n t r a c t o r and Key Personnel C o n t r a c t o r ' s Employees Tes ts and I n s p e c t i o n s ; Access t o t h e Work Turnover C o n t r a c t o r ' s Records Suspension o f Work Force Majeure P a r t i a l U t i 1 i z a t i o n o f Work Changes i n t h e Work Subcon t rac ts Labor Requirements and F r i n g e B e n e f i t s - J o b s i t e

A c t i v i t i e s On ly Waiver o f C la ims Temporary F a c i l i t i e s Perm i t s , Fees, N o t i c e s H e a l t h and S a f e t y P u b l i c a t i o n s , Photographs and Commercial A c t i v i t i e s T i t l e o f M a t e r i a l s Found P r o t e c t i o n o f P r o p e r t y o f O t h e r s P r o t e c t i o n o f Env i ronment C lean ing Up C o n t r a c t o r ' s P l a n t and Equipment Emergency I n s t r u c t i o n s L i n e s and Grades Time and O r d e r o f Complet ion and Coopera t ion I n v o i c i n g and Payment Terms C o n t r a c t Bonds Bomb T h r e a t Procedure

d i f f e r e n c e s w i l l be a f u n c t i o n o f s u p p l i e r s p e c i f i c des ign c h a r a c t e r i s t i c s ;

o t h e r s may r e s u l t f r o m d i f f e r e n t i n t e r p r e t a t i o n s o f t h e RFP. A u t i l i t y

e n g i n e e r , t h e r e f o r e , must have a c l e a r unders tand ing o f t h e o r i g i n a l

s p e c i f i c a t i o n i n t e n t , t h e s u p p l i e r ' s d e s i g n c h a r a c t e r i s t i c l i m i t a t i o n s , and

t h e s p e c i f i c f e a t u r e s o f t h e o f f e r i n g s . Only then can he e v a l u a t e t h e

n e c e s s i t y and/or r i s k a s s o c i a t e d w i t h a p a r t i c u l a r i t e m o f d i f f e r e n c e .

Some u t i l i t i e s have rev iewed t h e p r o p o s a l s under a two phase approach. The

f i r s t phase i s an a b b r e v i a t e d economic e v a l u a t i o n which examines base p r i c e ,

e s c a l a t i o n , and performance guarantee v a l u e s f o r p ressure d rop and power

consumption. Depending upon t h e d e p t h o f t h e e v a l u a t i o n , b i d d e r e x c e p t i o n s

a r e n o t n o r m a l l y cons ide red . The a b b r e v i a t e d economic e v a l u a t i o n ranks t h e

b i d d e r s i n monetary terms.

A t t h i s p o i n t , a u t i l i t y may dec ide t o l i m i t f u t u r e e v a l u a t i o n a c t i v i t i e s t o

t h e two o r t h r e e b i d d e r s wh ich had t h e l o w e s t e v a l u a t e d b i d s . I t must be

p o i n t e d o u t t h a t an a b b r e v i a t e d e v a l u a t i o n may o v e r l o o k c r i t i c a l a reas i n

te rms o f b i d d e r s ' e x c e p t i o n s , wh ich may t h e n have a s i g n i f i c a n t e f f e c t on

p r i c i n g . A b i d d e r who had an a t t r a c t i v e o f f e r i n g i n t h e a b b r e v i a t e d

e v a l u a t i o n may n o t be v i a b l e once a l l o f t h e excep t ions have been r e s o l v e d .

I n a d d i t i o n , a b i d d e r who f a i l e d t o pass t h e f i r s t phase, m igh t i n f a c t , have

a v e r y a t t r a c t i v e o f f e r i n g i f he were g i v e n an o p p o r t u n i t y t o r e s o l v e i t s

e x c e p t i o n s . I n o r d e r t o p r o v i d e a u t i l i t y w i t h t h e b e s t chance t o o b t a i n t h e

most a t t r a c t i v e p i e c e o f equipment, c o n s i d e r a t i o n should be g i v e n t o f u l l y

e v a l u a t i n g a l l p r o p o s a l s and r e f r a i n f r o m s h o r t c u t s .

U t i l i t i e s must m a i n t a i n t h e c o n f i d e n t i a l n a t u r e o f each b i d d e r s ' p r i c i n g

s t r u c t u r e i n o r d e r t o be f a i r t o a l l b i d d e r s . it i s suggested t h a t p r i c i n g

i n f o r m a t i o n be l i m i t e d t o personnel who demonst ra te a need-to-know. Should a

u t i l i t y d e c i d e t o e v a l u a t e a l l p r o p o s a l s , p r i c i n g i n f o r m a t i o n shou ld be sea led

and k e p t by t h e u t i l i t y ' s p u r c h a s i n g depar tment . Sealed p r i c e s s h o u l d then be

opened o n l y a f t e r t h e e v a l u a t i o n p rocess i s complete. Fur thermore, t h e

u t i l i t y may w i s h t o r e c e i v e t h e p r o p o s a l i n two p a r t s : (1) t e c h n i c a l and

commercial and (2) p r i c i n g . T h i s p e r m i t s t e c h n i c a l and commercial e v a l u a t i o n s

t o b e g i n e a r l i e r t h a n normal w h i l e a f f o r d i n g a b i d d e r a g r e a t e r t h a n normal

p e r i o d o f

t i m e t o o b t a i n t h e b e s t a v a i l a b l e p r i c i n g f rom h i s s u b c o n t r a c t o r s . I n

a d d i t i o n , i t i s suggested t h a t a b i d d e r be g i v e n an o p p o r t u n i t y t o submi t a

n e t p r i c e a d j u s t m e n t a t t h e c o n c l u s i o n o f t h e n e g o t i a t i o n s so t h a t f i n a l

n e g o t i a t e d p o s i t i o n s , b o t h t e c h n i c a l and commercial , can be f a c t o r e d i n t o a

p r o p o s a l . The n e t p r i c e ad jus tmen t a l s o a l l o w s a b i d d e r t o base i t s p r i c e on

t h e l a t e s t and b e s t p r i c i n g f rom i t s s u b c o n t r a c t o r s , w h i l e e l i m i n a t i n g t h e

need f o r a u t i l i t y t o t r a c k m y r i a d i n d i v i d u a l ad jus tmen ts and a l s o reduces t h e

r i s k o f m i s c a l c u l a t i o n .

P r e p a r a t i o n o f E x c e p t i o n / N e g o t i a t i o n Book

As a u t i l i t y ' s p roposa l e v a l u a t i o n team proceeds w i t h an e v a l u a t i o n , i t w i l l

become a p p a r e n t t h a t a t r a c k i n g method must be deve loped t o handle b i d d e r s '

e x c e p t i o n s , n a t u r e o f t h e e x c e p t i o n and i t s r e s o l u t i o n . It i s suggested t h a t

an e x c e p t i o n / n e g o t i a t i o n book be p r e p a r e d t o p r o v i d e t h i s t r a c k i n g method.

An e x c e p t i o n / n e g o t i a t i o n book c o n s i s t s o f a number o f 11x17 i n . s i z e sheets o f

paper w i t h t h e o r i g i n a l t e x t o f a s p e c i f i c s e c t i o n o f t h e RFP on t h e l e f t s i d e

and b i d d e r s ' e x c e p t i o n s on t h e r i g h t s i d e . Ample room i s a f f o r d e d f o r

i n d i c a t i o n o f a u t i l i t y ' s i n i t i a l n e g o t i a t i n g p o s i t i o n and f i n a l r e s o l u t i o n o f

t h e comment. An example o f t h i s p r o c e d u r e i s p r e s e n t e d i n F i g u r e 7-2. A l l o f

t h e b i d d e r s e x c e p t i o n s a r e c o m p i l e d i n a book fo rm and a copy i s g i v e n t o a

b i d d e r p r i o r t o n e g o t i a t i o n s . D u r i n g n e g o t i a t i o n s , r e s o l u t i o n s a r e r e c o r d e d

i n b o t h u t i l i t y and b i d d e r books and s igned by a p p r o p r i a t e r e p r e s e n t a t i v e s .

Consequent ly , t h e e x c e p t i o n / n e g o t i a t i o n book becomes t h e s o l e source o f a l l

agreements r e l a t i n g t o c o n t r a c t p r e p a r a t i o n , the reby r e d u c i n g the p o s s i b i l i t y

o f m isunders tand ings .

C l a r i f i c a t i o n Mee t ings

A f t e r d a t a t a b u l a t i o n sheets and e x c e p t i o n / n e g o t i a t i o n books a r e p repared and

p r o p o s a l s read , i t i s suggested t h a t mee t ings be h e l d w i t h each b i d d e r . The

purpose o f t h e mee t ings i s t o d i s c u s s a reas o f concern t o t h e p roposa l . Care

s h o u l d be t a k e n n o t t o n e g o t i a t e e x c e p t i o n s b u t t o e l i c i t i n f o r m a t i o n upon

w h i c h a u t i l i t y can form an o p i n i o n r e g a r d i n g t h e d i s p o s i t i o n o f t h e

e x c e p t i o n . I f a t a l l p o s s i b l e , u t i l i t y personnel shou ld have ques t ions

p r e p a r e d i n w r i t i n g p r i o r t o a m e e t i n g i n o r d e r t o p r o v i d e b i d d e r s w i t h an

o p p o r t u n i t y t o p r e p a r e w r i t t e n responses.

Supplementary Terms 6 Conditions Project Iden t i f i ca t ion Ho.

Revision

27.0 HEALTH M D SAFETY

The importance of the safety of a l l personnel on the Project shal l be recognized by Contractor, and accident prevention shal l be an in tegra l pa r t OF Contractor's operations. Contractor shal l take a l l precautions necessary and shall bear sole responsib i l i ty for the Safety of the Wrk and the safety and adequacy Of the methcds and mans i t enploys i s performing the m r k .

Contractor shal l take a l l precautions fo r the safety and health of, and shall provide a l l protection necessary t o prevent danage, in ju ry o r loss to:

(a) A l l enployees an the Work and a l l other persons who may be affected thereby;

( b l A11 Work and a l l materials and e q u i m n t to be incorporated therein, whether i s storage on o r o f f the Jobsite, under the cars, custody o r control of Contractor o r Subcontractors.

Contractor shal l carply wi th a l l applicable federal, state and local laws. ordinances, rules and regulations pertaining to the health and safety o f persons o r property. including those pranulgated pursuant to OSW. Contractor shal l erect and m i n t a i n as required by ex is t ing conditions and progress o f the Work a l l safeguards for safety and protection including, without l imitat ions. pasting danger signs and other uarnjngs against hazards, enforcing applicable safety and health and f i r e regulations and not i fy ing owners and users o f adjacent u t i l i t i e s .

Contractor shal l maintain a safety progran, including a weekly c r a f t safety meeting, on the Jobsite. The purpose o f such safety progran shal l be t o maintain a safe work place and to ensure carpliance wi th the safety regulations and standards adopted pursuant t o OSHA together wi th a l l other applicable rules and regulations.

Contractor shal l cooperate with Owner, ~ng ineer and a11 other contractors i n t h e i r respective safety p r o g r m . Contractor's safety progrm shal l con fon t o to the Project safety progrm and shal l be subject t o coordination and m n i t o r i n g by Engineer. Contractor's representative shall attend the weekly Project Safety C m i t t e e meetings.

(PlI l-29) 27.0 Health L Safety

27.3 Line 4: After word "OSHA" add "provided however the Contract Price shall be adjusted for any increased costs incurred by Seller as a resu l t o f changes and/or additions thereto subsequent to Noumber 20. 1981"

W E R POSITION

U ACCEPTABLE

0 UNACCEPTABLE

NEGOTIABLE

Withdrawn by l e t t e r O f

Figure 7-2. Sample Sheet From Exception/Negotiation Book

N e g o t i a t i o n Meet i n s

N e g o t i a t i o n meet ings must be t h e mechanism by wh ich i s s u e s a r e r e s o l v e d i n a

fo rma l manner. Represen ta t i ves o f a u t i l i t y ' s e n g i n e e r i n g and pu rchas ing

s t a f f s must a t t e n d these meet ings s i n c e many o f t h e i s s u e s i n v o l v e b o t h

t e c h n i c a l and commercial aspects t h a t may be i n t e r r e l a t e d . A u t i l i t y ' s

r e p r e s e n t a t i v e s must have t h e a u t h o r i t y t o a c t on b e h a l f o f it. A b i d d e r mus t

a l s o have personnel p r e s e n t w i t h a u t h o r i t y t o a c t on t h e b i d d e r ' s b e h a l f .

Lega l counse l i s n o t u s u a l l y p r e s e n t a t n e g o t i a t i o n s , a l t h o u g h each p a r t y may

sometimes d i s c u s s key i s s u e s w i t h counse l p r i o r t o t h e mee t ing . Should one o f

t h e p a r t i e s have o r r e q u e s t l e g a l counse l a t n e g o t i a t i o n s , i t would b e p r u d e n t

t h a t t h e o t h e r p a r t y a1 so be r e p r e s e n t e d by counse l .

I n o r d e r t o p r o p e r l y manage t h e n e g o t i a t i o n process, each p a r t y shou ld

d e s i g n a t e a team l e a d e r who would p r e s e n t h i s p a r t y ' s i n t e r e s t s t o t h e o t h e r .

As d i scussed above, t h e e x c e p t i o n / n e g o t i a t i o n book p r o v i d e s a road map f o r t h e

p rocess and e s t a b l i s h e s a permanent, u n i f i e d r e c o r d o f t h e p roceed ings .

INVESTMENT EVALUATION

D u r i n g an e v a l u a t i o n , a u t i l i t y must c o n s i d e r a l l o f t h e c o s t s a s s o c i a t e d w i t h

each o f t h e o f f e r i n g s . Costs a s s o c i a t e d w i t h a b i d d e r ' s scope o f s u p p l y a r e

known t h r o u g h h i s p r i c i n g s t r u c t u r e . P roposa ls n o r m a l l y comply w i t h t h e scope

o f supp ly reques ted i n t h e RFP. Shou ld t h i s n o t be t h e case, a u t i l i t y may

e i t h e r r e q u e s t a b i d d e r t o i n c l u d e t h e m i s s i n g work i n i t s p r i c e , o r t h e

u t i l i t y may e s t i m a t e t h e v a l u e o f t h e m i s s i n g work. It i s p r e f e r a b l e t h a t a

b i d d e r i n c l u d e a p r i c e f o r t h e m i s s i n g work so t h a t a l l p r o p o s a l s can be

compared on an equal b a s i s .

C u r r e n t p r a c t i c e s t e n d t o i n c l u d e n o t o n l y p r e c i p i t a t o r c a s i n g s i n a b i d d e r ' s

scope of supp ly , b u t a l s o ductwork , s u p p o r t s t e e l , access p l a t f o r m s ,

i n s u l a t i o n , and e l e c t r i c a l power s u p p l i e s . Commonly, f o u n d a t i o n s , f l y ash

h a n d l i n g equipment, a r e a pav ing , and power supp ly feeds a r e e s t i m a t e d by a

u t i l i t y and i n c l u d e d i n an e v a l u a t i o n . Depending upon a b i d d e r ' s scope o f

supp ly , a u t i l i t y may f i n d t h a t t h e d i f f e r e n t i a l c o s t s a s s o c i a t e d w i t h u t i l i t y

s u p p l i e d equipment o r f a c i l i t i e s w i l l have l i t t l e o r no e f f e c t on

m a j o r new p r o j e c t s whereas sma l l o r r e t r o f i t p r o j e c t s a r e more s e n s i t i v e t o

t h e s e i t e m s . T h e r e f o r e , i t i s necessary f o r t h e u t i l i t y t o e s t a b l i s h t h e

a p p r o p r i a t e e v a l u a t i o n f a c t o r s and be a b l e t o a p p l y them i n an e x p e d i t i o u s

manner.

PERFORMANCE WARRANTY EVALUATION

As p r e v i o u s l y d i scussed , per formance w a r r a n t y v a l u e s can have a s i g n i f i c a n t

impac t on p roposa l e v a l u a t i o n . The u t i l i t y must d e c i d e whether t h e v a r i o u s

per formance w a r r a n t y l e v e l s o f f e r e d by t h e b i d d e r s a r e reasonable (e.g.,

p r e s s u r e d r o p s w i t h 0 .5 i n c h H20 d i f f e r e n t i a l between h i g h and low v a l u e s ,

power consumpt ion l e v e l s w i t h a 25 t o 50 p e r c e n t spread between h i g h and

low) . Shou ld t h e l e v e l s n o t pass t h e t e s t o f reasonableness, t h e u t i l i t y can

o p t t o d i s r e g a r d t h e v a l u e s and n o t p e r f o r m t h i s p o r t i o n o f t h e e v a l u a t i o n , o r

r e q u e s t t h e b i d d e r s t o f u l l y e x p l a i n t h e b a s i s o f t h e v a l u e s o r p r o r a t e t h e

v a l u e s so t h e f a l l w i t h i n t h e rea lm o f reason. i n a d d i t i o n , shou ld t h e

u t i l i t y f i n d t h a t t h e s e economic f a c t o r s so i n f l u e n c e t h e e v a l u a t i o n i n an

u n r e a l i s t i c a l manner, t h e u t i l i t y may o p t t o d e - s e n s i t i z e t h e e v a l u a t i o n t o

t h e s e f a c t o r s . T h i s can be accompl ished b y p e r f o r m i n g d i s c r e t e e v a l u a t i o n s a t

p r o j e c t e d o p e r a t i n g p o i n t s and t h e n p r o r a t i n g them on t h e number o f o p e r a t i n g

h o u r s p e r y e a r . T h i s t e c h n i q u e can e f f e c t i v e l y reduce t h e impac t o f t h e

pe r fo rmance w a r r a n t y e v a l u a t i o n by o n e - h a l f . It wou ld be advantageous f o r t h e

u t i l i t y t o e x p l a i n t h e a p p l i c a t i o n o f e v a l u a t i o n f a c t o r s t o t h e b i d d e r d u r i n g

t h e p r o p o s a l p r e p a r a t i o n phase. T h i s w i l l p e r m i t t h e b i d d e r t o o p t i m i z e t h e i r

o f f e r i n g s by f o c u s i n g t h e p r o p e r a t t e n t i o n on t h e e v a l u a t i o n f a c t o r s .

TECHNICAL MERIT EVALUATIONS

I n a d d i t i o n t o t h e t r a d i t i o n a l economic e v a l u a t i o n approaches, u t i l i t i e s may

w i s h t o p e r f o r m a t e c h n i c a l m e r i t e v a l u a t i o n o f t h e p roposa ls . The concept o f

t h i s e v a l u a t i o n t e c h n i q u e i s t o i d e n t i f y s p e c i f i c t e c h n i c a l f e a t u r e s o f t h e

p r o p o s a l s and r a t e t h o s e f e a t u r e s on a s u b j e c t i v e b a s i s . T y p i c a l f e a t u r e s

w h i c h can b e e v a l u a t e d a r e :

D ischarge E l e c t r o d e s

E l e c t r o d e c o n f i g u r a t i o n

Type of e l ec t rode mounting

Type of e l ec t rode support (two o r four poin ts )

Po ten t i a l f o r e lec t rode and support expansion o r d i s t o r t i o n

In t e rna l e l e c t r o d e assembly brac ing

Type of rapping system



Rapper maintenance f e a t u r e s

Rapper segrega t ion and ene rg i za t ion

Type of automatic vol tage c o n t r o l l e r

Number of t ransformer- rec t i f i e r s e t s

Number of f i e l d s

Number of bus s ec t ions

Col l ec t i nq Elec t rodes

P l a t e t h i c k n e s s (18 or 16 gauge)

Upper p l a t e support

Bottom p l a t e spacers and brac ing

P l a t e spacing experience (9,10, or 1 2 inch)

Type of rapping

Rapper l oca t ion ( i n o r o u t of gas s tream)

Adjus tab le rapper i n t e n s i t y

Rapper maintenance f ea tu re s

O f f power rapping c a p a b i l i t y

Number of p l a t e s rapped by a apper (one, two, t h r e e , o r four )

Rapper segrega t ion and ene rg i za t ion

P l a t e a r e a rapped a t any i n s t a n t of time

P l a t e he igh t

Size Se lec t ion

Spec i f ic c o l l e c t i n g p l a t e a rea

Aspect r a t i o

Col lec t ing p l a t e a rea per t r a n s f o r m e r - r e c t i f i e r s e t

Collect ing p l a t e a rea per bus sec t ion

Corona power d e n s i t y (rated/expected)

P r e c i p i t a t o r gas ve loc i ty

Number of t r ans fo rmer - r ec t i f i e r s e t s per hopper

Of course , these parameters should be modified t o s u i t t h e u t i l i t y ' s

s p e c i f i c needs. However, t he parameters should r e f l e c t r e a l i s t i c concerns

and t h e r e l a t i v e importance of ind iv idua l parameters in terms of enhanced

p r e c i p i t a t o r performance. Typica l ly , t h e r a t i n g s a r e converted t o a numerical system f o r ease in e s t a b l i s h i n g an o v e r a l l r a t i ng f o r each

proposa l . I t must be noted t h a t once these r a t i n g s a r e appl ied , the

u t i l i t y w i l l probably be faced with a s i t u a t i o n where t he lowest eva lua t ed

b idde r , on a monetary b a s i s , may not be highly r a t e d t e c h n i c a l l y . As such,

t h e u t i l i t y may wish t o explore t he concept of ass igning some monetary

value t o t h e technical mer i t eva lua t ion . This monetary value could range

from very small values which would probably have very l i t t l e a f f e c t on the

eva lua t ion , whereas l a rge va lues may r a d i c a l l y swing t h e outcome of t h e

eva lua t ion . Therefore, t h e u t i l i t y may wish t o cons ide r prora t ing t h e

d i f f e r e n c e i n evaluated p r i c e between high and low b idder w i t h the

d i f f e r e n c e between high and low technica l meri t r a t i n g s . In any e v e n t , t he

u t i l i t y must approach t h e use of technica l mer i t eva lua t ions wi th g r e a t

c a r e i f t hey are t o be of value.

COMMERCIAL EVALUATION

In add i t i on t o a technica l eva lua t ion of t he proposa ls , a commercial

eva lua t ion must a l s o be performed. Under the presumption t h a t t he b idde r s

have s a t i s f i e d t he minimum requirements o f t he t e c h n i c a l requi rements , t he

commercial evaluat ion becomes paramount.

Terms and Conditions

A t t h e conclusion of t h e negot ia t ion process , t h e b idders ' except ions

would have been resolved i n one of four ways ( 1 ) exception withdrawn, (2)

exception i s acceptable , (3) s a t i s f a c t o r y wording has been accepted , o r (4 )

no r e so lu t ion can be reached. In terms of t he commercial eva lua t ion , t he

f i r s t t h r ee methods of reso lu t ion pose no problems and do not a f f e c t t h e

ove ra l l eva lua t ion . However, in t he s i t u a t i o n where no s a t i s f a c t o r y

r e so lu t ion can be reached, the u t i l i t y can t ake one of two approaches (1)

dec l a r e t h e bidder non-responsive o r (2 ) a s s e s s a monetary penal ty a g a i n s t

t h e b idder . Ul t imate ly , t he se two approaches may be he lpfu l i n reso lv ing

t h e i s s u e . I t should be noted t h a t t he app l i ca t i on of e i t h e r of t he

approaches may be d i f f i c u l t and should be used a s a l a s t r e s o r t .

Terms of Payment

The eva lua t ion of terms of payment ( i . e . , cash flow requirements) can have

a s i g n i f i c a n t impact on the eva lua t ion . As such, t h e u t i l i t y must be aware

t h a t t he es t imated cash flow could be misrepresented by a b idder i n order

t o obta in an evaluat ion advantage. Rea l i s t i ca : l y , should t h e mater ia l

d e l i v e r y and e r e c t i o n schedules be e s s e n t i a l l y t he same f o r a l l b idders ,

then t h e r e would be very l i t t l e d i f f e r ence in pro jec ted cash flow s ince a l l

b idders should execute t h e work in a s i m i l a r manner. Should t h e r e be a

s i g n i f i c a n t d i f f e r e n c e among pro jec ted cash f lows , t h e u t i l i t y may opt t o

e i t h e r d i s r ega rd the cash flows a s an eva lua t ion f a c t o r or develop i t s own

cash flow schedule and equal ly apply i t t o a l l bidders . These approaches

should be considered so a s t o not give an u n f a i r advantage t o a p a r t i c u l a r

b idder who might be misrepresent ing t h e s i t u a t i o n . I t should be noted t h a t

usua l ly pro jec ted cash flows are not made p a r t of t he c o n t r a c t , so a s not

t o l i m i t both t he u t i l i t y and supp l i e r from ava i l i ng themselves of t h e

b e n e f i t s of e a r l y de l ive ry or e r ec t ion .

Esca l a t i on

The terms f o r how esca l a t i on i s t o be app l i ed i n t h e c o n t r a c t a r e s t a t e d

in t h e R F P . Usually, only minor c l a r i f i c a t i o n i s required by t h e b idders

but t he bas ic p r i n c i p l e s remain i n t a c t . The r ea l ques t ions t h e u t i l i t y

must address i s how much e sca l a t i on wi l l occur over t h e l i f e of t he

p r o j e c t and how much w i l l i t cos t . The eva lua t i on can then s e l e c t an

e s c a l a t i o n r a t e which i s a p p l i e d f o r e n t i r e p r o j e c t f inanc ing , and apply i t

t o a l l b i dde rs . Th i s concept , a long w i t h t h a t o f ana lyz ing p ro jec ted cash

f lows, would no t f avo r any p a r t i c u l a r b i dde r s ince

based on t h e b idders base p r i c e . Hence, t he r e l a t

b idders would no t be r a d i c a l l y a f f ec ted .

Cance l l a t i on Charqes

I n t oday ' s c l ima te o f u n c e r t a j n t y r e l a t i v e t o requ

i t would t r a c k and be

ve standings o f t he

red capac i ty growth

ra tes , t h e u t i l i t i e s must be prepared t o deal w i t h p r o j e c t c a n c e l l a t i o n .

I n t he pas t , c a n c e l l a t i o n charges were r a r e l y , i f ever , evaluated.

However, shou7d a u t i l i t y w i s h t o evaluate c a n c e l l a t i o n charges, i t can

reques t t h a t each b idde r p r o v i d e a cumulat ive, n o t t o exceed c a n c e l l a t i o n

schedule. Th i s schedule would be based on t h e percentage o f t h e c o n t r a c t

p r i c e f o r each month of t h e p r o j e c t which would be p a i d t o t he p r e c i p i t a t o r

s u p p l i e r i n t he event o f c a n c e l l a t i o n . The eva lua t i on o f t he schedule

would i n v o l v e us ing a s l i d i n g p r o b a b i l i t y sca le as a f u n c t i o n o f p r o j e c t

du ra t i on . I n o rder f o r t h i s eva lua t i on t o be meaningfu l , i t i s necessary

t h a t t h e c o n t r a c t con ta in t h e b idders schedule. T h i s would overcome the

problems assoc ia ted w i t h " p r o j e c t e d cash f lows".

L i m i t a t i o n o f L i a b i l i t y t o F i x Nonperforming Equipment

Consider ing today 's l i t i g a t i o n prone environment, t h e ques t ion o f how much

money w i l l t he s u p p l i e r be r e q u i r e d t o spend i n o r d e r t o make the

p r e c i p i t a t o r operate p r o p e r l y must be addressed. I n essence, c u r r e n t

p r a c t i c e i s t o l i m i t t h i s va lue t o t h e value o f t h e esca la ted con t rac t .

The u t i l i t y and b idder should d iscuss what a re t h e r i s k s and b e n e f i t s o f

h igher and lower l i a b i l i t y l i m i t s when upgrading t h e equipment t o meet t h e

requ i red emission l i m i t a t i o n s .

L i qu ida ted Damages

L iqu ida ted damages have been used t o compensate t h e u t i l i t y f o r delays i n

schedule and f a i l u r e t o meet c e r t a i n aspects o f t h e performance guarantee.

I n terms o f app ly ing t h e l i q u i d a t e d damage concept t o scbedule t h e ac tua l

assessment o f t he damage and t h e de te rmina t ion o f wh ich p a r t y a c t u a l l y

caused of t h e delay can become q u i t e d i f f i c u l t . As such, t h e b idde rs

w i l l p e r c e i v e t h a t t h e i r r i s k s a r e h i g h e r i n terms o f mee t ing t h e schedule ,

and consequent ly i n c r e a s e t h e i r p r i c e a c c o r d i n g l y . The u t i l i t y may be b e t t e r

adv ised t o adopt an i n c e n t i v e approach t o e a r l y c o m p l e t i o n o f c e r t a i n c r i t i c a

phases o f t h e p r o j e c t as a means o f m a i n t a i n i n g o r i m p r o v i n g p r o j e c t schedu le

System p ressure d r o p and e l e c t r i c a l power consumpt ion a r e i t e m s where

assessment o f l i q u i d a t e d damages a r e most a p p r o p r i a t e . I n essence, t h e

u t i l i t y may be f a c e d w i t h t h e s i t u a t i o n where e m i s s i o n s a r e i n accordance w i t h

t h e guarantee b u t power consumption i s t o o h i g h . The s u p p l i e r and u t i l i t y a r e

then f a c e d w i t h a di lemma, as m e e t i n g b o t h o f t h e guaran tees s i m u l t a n e o u s l y

may be i m p o s s i b l e . Hence, a p p l y i n g a l i q u i d a t e d damage t o power consumption

becomes most a p p r o p r i a t e . The v a l u e o f t h e l i q u i d a t e d damage should be t h e

same

t h e

1 jab

used

SUPP

as t h a t o f t h e e v a l u a t i o n f a c t o r used i n t h e b i d e v a l u a t i o n . F u r t h e r ,

i q u i d a t e d damages should be e x c l u s i v e o f a l l o t h e r l i m i t a t i o n s on

l i t i e s . One p o i n t o f concern i s t h a t l i q u i d a t e d damages shou ld n o t be

when t h e equipment f a i l s t o meet o u t l e t e m i s s i o n guarantee l e v e l s ; t h e

i e r shou ld t h e n do whatever i s needed t o a c h i e v e t h e s p e c i f i e d l e v e l o f

performance.

Qua1 i t y Assurance

The e v a l u a t i o n o f b i d d e r q u a l i t y assurance p rocedures i s somewhat s u b j e c t i v e

and must be v iewed from t h e s t a n d p o i n t o f whe the r t h e program i s a c c e p t a b l e o r

n o t accep tab le . A t t e m p t i n g t o r a t e o r grade t h e a c c e p t a b l e programs w i l l i n

a l l p r o b a b i l i t y be f r u i t l e s s a n d have no r e a l impac t on

t h e o v e r a l l e v a l u a t i o n . For t h o s e programs wh ich a r e j udged unacceptab le , t h e

u t i j i t y shou ld work w i t h t h e b i d d e r t o c o r r e c t t h e d e f i c i e n c i e s .

Insu rance and Bonds

Insu rance and bond requ i remen ts a r e m a t t e r s o f u t i l i t y c o r p o r a t e p o l i c y and

a r e n o t u s u a l l y s u b j e c t t o change. T h e r e f o r e , t h e b i d d e r must meet these

minimum requ i remen ts o r have i t s p r o p o s a l deemed non-respons ive. Of cou rse ,

p roper b i d d e r q u a l i f i c a t i o n p rocedures w i l l u s u a l l y a v o i d t h i s i ssue . Hence,

i nsu rance and bond requ i remen ts wou ld n o t e n t e r i n t o t h e commercial e v a l u a t i o n .

Retent ion

Usual u t i l i t y p r a c t i c e i s t o r e t a i n a small percentage (up t o ten percent )

of each of the b idders invoices t o a s su re t h a t t he supp l i e r wi l l provide

proper a t t e n t i o n t o t h e p r o j e c t during the warranty period. This small

percentage may r e s u l t i n the u t i l i t y withholding severa l mi l l i ons of

d o l l a r s on a major p r o j e c t . This u t i l i t y r e t a ined c a p i t a l p resents t he

b idder wi th t he problem of having t o bu i ld i n t o i t s p r i c e t h e cos t of t h a t

c a p i t a l over t he l i f e of the con t r ac t . I t has become a p r a c t i c e on the

p a r t of some b idders t o o f f e r performance bonds o r f e t t e r s of c r e d i t i n

l i e u o f r e t e n t i o n in o rde r t o reduce t h e equipment purchase p r i ce . By and

l a r g e , t h e value of performance bonds and l e t t e r s of c r e d i t w i l l be based

upon t h e s p e c i f i c terms and condi t ions contained t h e r e i n . Each u t i l i t y has

i t s own po l i cy i n dea l ing with t he r e t e n t i o n i s sue and t h e award of a

p r e c i p i t a t o r c o n t r a c t would have t o be i n accordance with these p o l i c i e s .

I t should be noted t h a t t he purpose of r e t e n t i o n i s t o a s su re t h a t t h e

u t i l i t y has t he s u p p l i e r ' s a t t e n t i o n concerning warranty problems and t h a t

they a r e resolved i n an expedi t ious manner.

Cont rac t Award

Once t h e eva lua t ion has been completed and a dec i s ion made, t he u t i l i t y

n o t i f i e s t he successful bidder with a l e t t e r of i n t e n t . The con t r ac tu ra l

documents woutd then be prepared using t h e b idde r s ' f i l l - i n technica l da ta

shee t s along with t h e except ion/negot ia t ion book. I t i s suggested t h a t the

b i d d e r ' s r e p r e s e n t a t i v e s review a17 documents f o r accuracy. Once t h i s i s

done, then the f i n a l c o n t r a c t document can be s en t f o r s igna tu re .

Cont rac t Administrat ion

Once t h e con t r ac t has been p laced , u t i l i t y personnel a r e assigned t o

admin i s t e r i t . Schedule adherence and drawing d e l i v e r y then become

paramount f o r execution of t h e p ro j ec t . This i s where t he incent ive

approach t o schedule can provide g r e a t b e n e f i t s t o t h e p r o j e c t . An area of

concern i s change o r d e r s which open up t h e p o s s i b i l i t y of schedule de lays

and exces s ive markuos on mater ia l and t abo r .

T h e r e f o r e , t h e g u i d i n g p r i n c i p l e o f c o n t r a c t admini s t r a t i o n i s " i f i t

works, d o n ' t change i t". Even w i t h t h i s approach, changes w i l l occur and

i t wou ld be t o t h e u t i l i t y ' s advantage t o have a s e c t i o n i n t h e c o n t r a c t

wh ich p l a c e s l i m i t a t i o n s on markups f o r such changes.

ECONOMIC EVALUATION

Genera l

I n t h e f i n a l a n a l y s i s , once t h e adequacy o f t h e performance i s assured, a

comparison o f t h e o v e r a l l economics a s s o c i a t e d w i t h each o f t h e p r o p o s a l s i s

conducted.

A u t i l i t y e n g i n e e r who i s p e r f o r m i n g p roposa l e v a l u a t i o n s w i l l have t o assess

c a p i t a l o u t l a y s and annual o p e r a t i n g c o s t s a s s o c i a t e d w i t h each p r o p o s a l , and

he shou ld use a u n i f o r m and e c o n o m i c a l l y sound ( i . e . , de fendab le ) method t o

make comparisons. I n a l l cases, i t i s necessary t o e v a l u a t e t h e o v e r a l l

economic e f f e c t o f each p r o p o s a l . The f o l l o w i n g d i s c u s s i o n p r e s e n t s examples

o f seve ra l s y s t e m a t i c approaches t o t h e economic e v a l u a t i o n p rocess . Many

u t i l i t i e s have e s t a b l i s h e d t h e i r own s t a n d a r d c r i t e r i a f o r economic

e v a l u a t i o n s , as has E P R I i n i t s T e c h n i c a l Assessment Guide (EPRI P-2410-SR,

May 1982). S tandards may be s i m i l a r , o r t h e y may d i f f e r s l i g h t l y . However,

i t i s most i m p o r t a n t t h a t evaTuat ions b e conducted i n a l o g i c a l , o r d e r l y

manner.

A l t e r n a t i v e Economic Comparison Methods

A number o f economic c h a r a c t e r i s t i c s s e t t h e e l e c t r i c u t i l i t y i n d u s t r y a p a r t

f r o m most o t h e r i n d u s t r i e s .

1. I t i s c a p i t a l i n t e n s i v e ; f o r some u t i l i t i e s , over h a l f of t h e

revenue f r o m t h e s a l e o f e l e c t r i c i t y i s a l l o c a t e d t o pay o b l i g a t i o n s

t h a t a r e r e l a t e d t o c a ~ i t a l i nves tmen t .

2. I t s i n v e s t m e n t i t ems u s u a l l y a r e l o n g - l i v e d , o f t e n f rom 30 t o 50

y e a r s .

3. It has a r e l a t i v e l y u n i f o r m f l o w o f annual revenue d o l l a r s

4 . I t i s required t o supply product demand, and usage i s determined by

the customers of i t s s e r v i c e t e r r i t o r y ; i t may not s e l e c t t h e

markets t h a t i t chooses t o e n t e r .

5. I t i s regulated by government agencies and i s mandated t o provide

r e l i a b l e , low-cost e l e c t r i c i t y in an environmental ly accep tab l e

manner.

In the bus iness community, t h e r e a r e several methods f o r conducting economic

ana lyses of a l t e r n a t e choices. Among these a r e :

Spec ia l ized methodologies f o r p a r t i c u l a r i n d u s t r i e s , e s p e c i a l l y i ndus t r i e s with r e l a t i v e l y shor t - l ived p l a n t items o r wi th rap id technological obsolescence

Oi scounted cash f 1 ow

Return on investment

Cost /benefi t r a t i o

Payback period

Revenue requirement.

Revenue requirement methodology i s gene ra l ly regarded a s most a p p r o p r i a t e f o r

t h e e l e c t r i c u t i l i t y i ndus t ry . With t h i s approach, t he revenue r equ i r ed t o

sus t a in a given a l t e r n a t i v e i s determined and compared t o s i m i l a r l y der ived

revenue requirements of i t s a l t e r n a t i v e s . This method determines t h e revenue

r equ i r ed from the ra tepayer and, t h e r e f o r e , i s c o n s i s t e n t wi th t h e p r i n c i p l e

of ensuring e l e c t r i c i t y supplied a t t h e lowest pos s ib l e p r i c e s i n c e i t enables

determining a lowest revenue required from ra t epaye r s (within r egu la to ry

g u i d e l i n e s on adequate r2turn t o i nves to r s ) r a t h e r than maximizing r e tu rn t o

i n v e s t o r s .

Because revenue requirement i s t he method usua l ly used in t he e l e c t r i c u t i l i t y

i ndus t ry f o r the economic comparison of a l t e r n a t i v e s and because t h e E l e c t r i c

Power Research I n s t i t u t e has adopted t h i s methodology t o eva lua t e

a l t e r n a t i v e s , t h e revenue requirement method has been se l ec t ed f o r

p r e s e n t a t i o n i n t h i s manual. Much o f t h e f o l l o w i n g d i s c u s s i o n on economic

a n a l y s i s was taken f rom EPRI 's Techn ica l Assessment Guide ( E P R I P-2410-SR, May

1982) wh ich shou ld be used as a r e f e r e n c e f o r a d d i t i o n a l d e t a i l s .

F i n a n c i a l Mathematics

Numer ica l a n a l y s i s f o r t h e e v a l u a t i o n o f equipment a l t e r n a t i v e s i n v o l v e s t h e

use o f seve ra l r e l a t i v e l y s t r a i g h t f o r w a r d mathemat ica l f o r m u l a s and symbols.

A b r i e f r e v i e w o f t h e f i n a n c i a l mathematics needed t o p e r f o r m such economic

comparisons i s p resen ted be1 ow.

P r e s e n t Value o f a S i n g l e Sum. The d i s c o u n t r a t e 1, i s t h e t i m e v a l u e o f

money i n t h e t i m e p e r i o d n. The p r e s e n t v a l u e fi o f a s i n g l e amount 5 made 2

t i m e p e r i o d s i n t h e f u t u r e a t a d i s c o u n t r a t e 2 p e r t i m e p e r i o d i s de te rm ined

b y t h e fo rmu la

n PV = xv

where 1 v n = -

( l + i ) n

The use o f t h i s f o r m u l a i s il

o c c u r s 5 y e a r s i n t h e f u t u r e ,

a t t h e b e g i n n i n g o f t h e f i r s t

PV

l u s t r a t e d b y a t i m e diagram. Suppose t h a t x and we a r e t o de te rm ine t h e p r e s e n t v a l u e o f 5

y e a r .

0 1 2 3 4 5 Years

P V = xv 5 ( 7 - 5 )

The p r e s e n t v a l u e n y e a r s i n t h e f u t u r e o f a s i n g l e amount t o d a y i s determined

by m u l t i p l y i n g t h e d o l l a r s today by t h e r e c i p r o c a l o f yn.

Present Value of a Uniform S e r i e s . The present value P V of a uniform s e r i e s 5 - per time per iod t h a t ex tends 1 t ime periods i n t he f u t u r e a t a r a t e of 1 per

time per iod i s determined by t h e formula

where

o r

o r

o r

The use i s i l l u s t r a t e d by a t ime diagram. Suppose t h a t t h e r e i s a uniform

s e r i e s c o n s i s t i n g of an amount x a t t he end of each y e a r f o r 5 yea r s and we

a r e t o determine the p re sen t va lue a s of t he uniform s e r i e s a t t he beginning

of t he f i r s t yea r .

0 1 2 3 4 5 Years

Note t h a t t h e present value of a uniform s e r i e s using the a n f a c t o r i s

always a t a po in t in time t h a t i s one time period p r i o r t o t h e f i r s t

t r ansac t ion in t he s e r i e s .

To conver t a s ing l e sum a t one po in t i n the time s e r i e s , use the rec iproca l of

t he a,, f a c t o r . In t h i s c a s e , t h e f i r s t term of t he s e r i e s w i l l always occur

one time per iod a f t e r t h e s i n g l e sum.

E s c a l a t i o n and I n f l a t i o n . The annual i n f l a t i o n r a t e ei i s t h e r a t e i n r i s e

i n p r i c e caused b y an i n c r e a s e i n a v a i l a b l e c u r r e n c y and c r e d i t w i t h o u t a

p r o p o r t i o n a t e i n c r e a s e i n a v a i l a b l e goods and s e r v i c e s o f equal v a l u e . The

r e a l e s c a l a t i o n r a t e e i s t h e annual r a t e o f i n c r e a s e o f an e x p e n d i t u r e r

t h a t i s due t o f a c t o r s such as resource d e p l e t i o n , i n c r e a s e d demand, o r

improvements i n t h e s t a t e o f t h e a r t ( n e g a t i v e r a t e ) . Real e s c a l a t i o n i s

i ndependen t and e x c l u s i v e o f i n f l a t i o n .

The apparen t annual e s c a l a t i o n r a t e e i s t h e t o t a l annual r a t e o f i n c r e a s e a

i n p r i c e l e v e l and i n c l u d e s t h e e f f e c t s o f b o t h i n f l a t i o n and r e a l

e s c a l a t i o n . I t i s equal t o :

The use i s i l l u s t r a t e d by a t i m e diagram. Suppose t h a t t h e r e i s an amount x a t t h e b e g i n n i n g o f t h e f i r s t y e a r , s u b j e c t t o an apparen t e s c a l a t i o n r a t e ,

1 1 a t t h e end o f t h e f i f t h y e a r . and we de te rm ine t h e p r i c e l e v e

Y = x(

Note t h a t t o e x p r e s s a sum o f money s u b j e c t t o e s c a l a t i o n i n terms o f d o l l a r s

a t ano the r p o i n t i n t i m e t h e apparent e s c a l a t i o n r a t e e i s used. To a e x p r e s s a sum o f money i n a d i f f e r e n t r e f e r e n c e y e a r t h e d i s c o u n t r a t e 1 i s

used.

L e v e l i z a t i o n and E s c a l a t i o n . The l e v e l i z a t i o n f a c t o r in determines t h e

e q u i v a l e n t l e v e l i z e d v a l u e a o f a s e r i e s o f n payments t h a t i s u n i f o r m o v e r

t i m e excep t f o r a c o n s t a n t apparen t e s c a l a t i o n r a t e . The p r i c e l e v e l o f t h e

s e r i e s a t t h e b e g i n n i n g o f t h e f i r s t y e a r i s y .

where

The i n i

the beg

and

e = apparent annual e sca l a t i on r a t e a e = r ea l annual e sca l a t i on r a t e r e . = annual i n f l a t i o n r a t e 1

i = annual d i scount r a t e

n = number of y e a r s .

t i a l monetary amount t h a t i s mul t ip l i ed by t he f a c t o r Ln i s s t a t e d

inn ing o f f i r s t year d o l l a r s , even though a l l t r a n s a c t i o n s a r e made

the end o f t h e i r respec t ive y e a r s .

The use of t h i s formula i s i l l u s t r a t e d by a time diagram.

Investments and Expenses

An investment i s an expenditure which r e s u l t s in a u n i t of p l an t t h a t i s of

long term use. I n a revenue requirement a n a l y s i s , t h e money t o pay f o r an

investment must come from o u t s i d e debt and equi ty f inanc ing .

Investments include, but a r e not l im i t ed t o , t he physical p l an t of a u t i l i t y ,

such a s genera t ing u n i t s , and t h e t ransmission and d i s t r i b u t i o n systems.

Expenses a r e a l l of t he expenditures t h a t a r e not c l a s sed a s investment items

including opera t ing and maintenance charges and fue l c o s t . Expenses a r e paid

d i r e c t l y from revenue. While investments a r e paid from new debt and equ i ty

s e c u r i t i e s , t he re turn t h a t i s due t o deb t and equi ty s e c u r i t y holders , book

d e p r e c i a t i o n , income taxes , l o c a l p r o p e r t y t a x e s , and i n s u r a n c e a r e a l s o t a k e n

f r o m revenue.

Revenue Requirements

The revenue requ i remen t i s t h e amount o f revenue t h a t must be c o l l e c t e d f r o m

customers t o compensate a u t i l i t y f o r a l l e x p e n d i t u r e s a s s o c i a t e d w i t h t h e

i m p l e m e n t a t i o n o f an a l t e r n a t i v e d e c i s i o n i n v o l v i n g money. I n t h e l o n g run ,

revenue must pay f o r a l l o f t h e c o s t s o f d o i n g b u s i n e s s as d e f i n e d by

r e g u l a t o r y a c t i o n .

Revenue requ i remen ts i n c l u d e two components, c a r r y i n g charges ( o f t e n r e f e r r e d

t o as f i x e d charges) and expenses. C a r r y i n g charges a r e a g e n e r a l d e s i g n a t i o n

f o r charges t h a t a r e r e l a t e d t o c a p i t a l i nves tmen t . They c o n s t i t u t e t h e

o b l i g a t i o n i n h e r e n t i n an inves tmen t d e c i s i o n and a r e i n c u r r e d r e g a r d l e s s o f

how much t h e p a r t i c u l a r i nves tmen t i s used o r may be used. Expenses u s u a l l y

a r e made t o c o v e r t h e way i n wh ich a f a c i l i t y i s o p e r a t e d o r m a i n t a i n e d and

i n c l u d e f u e l , o p e r a t i n g , and maintenance c o s t s .

Expenses a r e sometimes r e f e r r e d t o as o p e r a t i n g c o s t s and, i n accordance w i t h

e s t a b l i s h e d ra temak ing p r a c t i c e s , a r e p a i d f o r d i r e c t l y f rom revenue. Thus, a

d o l l a r o f expense i s equal t o and r e q u i r e s a d o l l a r o f revenue. Expenses

u s u a l l y a r e made f o r goods and s e r v i c e s t h a t a r e u t i l i z e d i n a s h o r t p e r i o d o f

t i m e , u s u a l l y one y e a r o r l e s s . N o r m a l l y a t l e a s t 60 p e r c e n t o f t h e t o t a l

revenue c o l l e c t e d a n n u a l l y by an e l e c t r i c u t i l i t y pays t h e expenses.

Remaining revenue pays t h e c a r r y i n g charge o b l i g a t i o n a s s o c i a t e d w i t h an

i n v e s t m e n t (an inves tmen t i s sometimes r e f e r r e d t o as a c a p i t a 1 i t e m o r a

p l a n t i t e m ) . The i n s t a l l e d c o s t o f an inves tmen t i s n o t t a k e n f r o m revenue

when i n c u r r e d because (1) t h i s wou ld r e q u i r e p r e s e n t customers t o pay f o r

i t e m s t h a t wou ld be used t o supply customers as f a r as 60 y e a r s i n t h e f u t u r e

and (2) as a p r a c t i c a l m a t t e r , t h e r e l a t i v e l y u n i f o r m f l o w o f revenue d o l l a r s

wou ld n o t be adequate f o r a pay-as-you-go c o n s t r u c t i o n program t h a t may have

w i d e l y v a r y i n g monetary requ i remen ts t h r o u g h t i m e .

The money t o c o v e r t h e t o t a l c a p i t a l requ i remen t o f an inves tmen t comes f r o m

new f i n a n c i n g t h r o u g h t h e s a l e o f bonds and deben tu res r e f e r r e d t o as " d e b t

f i n a n c i n g , " and f o r i nves to r -owned u t i l i t i e s f rom t h e s a l e o f common and

p r e f e r r e d s t o c k , r e f e r r e d t o as " e q u i t y f i n a n c i n g . ' ' An a n a l y s i s o f t h e

r e l a t i v e amounts o f d e b t and e q u i t y money i s beyond t h e scope o f t h i s manual,

b u t most i nves to r -owned u t i l i t i e s m a i n t a i n d e b t r a t i o s ( r a t i o o f d e b t

f i n a n c i n g t o t o t a l f i n a n c i n g ) i n t h e ne ighborhood o f 50 p e r c e n t .

The r e t u r n , o r money t h a t t h e u t i l i t y must pay t o i n v e s t o r s f o r t h e use o f

b o t h d e b t and e q u i t y money, i s a component o f t h e revenue requ i remen t and is

p a r t o f t h e o b l i g a t i o n a s s o c i a t e d w i t h an inves tmen t . O the r components o f

c a r r y i n g charges i n c l u d e book d e p r e c i a t i o n (annual c h a r g e t o repay t h e

o r i g i n a l amount o b t a i n e d f rom i n v e s t o r s ) and Federa l and l o c a l income taxes .

Loca l p r o p e r t y t a x e s and i n s u r a n c e a r e a l s o i n c l u d e d as c a r r y i n g charges.

As o u t l i n e d be low, t h e breakdown o f revenue r e q u i r e m e n t s i s as f o l l o w s :

REVENUE REQUIREMENTS

C a r r y i n g Charges

R e t u r n on d e b t

Expenses

Fue l

R e t u r n on e q u i t y c 1 ' O p e r a t i n g

Book d e p r e c i a t i on Maintenance

Income Taxes

L o c a l p r o p e r t y t axes

I n s u r a n c e

"' D i v i d e n d p a i d o u t

The revenue requ i remen t t e c h n i q u e r e q u i r e s t h e d e t e r m i n a t i o n o f a l l a p p l i c a b l e

annual c a r r y i n g charges and expenses f o r each y e a r o v e r t h e l i f e o f t h e

p l a n t .

A l s o o f concern i s t h e "Minimum Accep tab le Return" , w h i c h i s equal t o r e t u r n

on d e b t and r e t u r n on e q u i t y . T h i s i s t h e l o w e s t amount t h a t i n v e s t o r s w i l l

accep t i n o r d e r t o make a v a i l a b l e t h e funds needed b y t h e u t i l i t y f o r t h e

inves tmen t .

The revenue requ i remen t o f an a l t e r n a t i v e i s t h e d i s c r e t e charge a s s o c i a t e d

w i t h t h a t a l t e r n a t i v e and i s used f o r comparing t h a t a l t e r n a t i v e w i t h o t h e r

a l t e r n a t i v e s .

D iscoun t Ra te f o r P resen t Va lue A n a l y s i s

The d i s c o u n t i n g r a t e i f o r p r e s e n t v a l u e c a l c u l a t i o n s i s t h e we igh ted c o s t o f

c a p i t a l and i s equa l t o t h e sum o f t h e r e t u r n on d e b t and t h e r e t u r n on

e q u i t y .

The E f f e c t o f I n f l a t i o n on t h e D i s c o u n t Rate

C o n t i n u i n g t h e d i s c u s s i o n o f e s c a l a t i o n and i n f l a t i o n , t h e i n f l a t i o n r a t e has

a d i r e c t r e l a t i o n s h i p on t h e d i s c o u n t r a t e I. I f ei i s t h e i n f l a t i o n r a t e

and c i s t h e we igh ted c o s t o f c a p i t a l i n t h e absence o f i n f l a t i o n , then :

I t i s p o s s i b l e t h a t h i g h r a t e s o f i n f l a t i o n may change t h e v a l u e o f t h e

c o n s t a n t d o l l a r d i s c o u n t r a t e , c , s i n c e t h i s v a l u e i s based on a c e r t a i n l e v e l

of i nves tmen t r i s k and h i g h i n f l a t i o n r a t e s may change t h e l e v e l o f r i s k .

However, f o r most economic a n a l y s e s i t may be assumed t h a t an i n c r e a s e i n t h e

i n f l a t i o n r a t e ei causes a c o r r e s p o n d i n g i n c r e a s e i n t h e d i s c o u n t r a t e i, and t h e v a l u e o f c remains c o n s t a n t .

A p r e s e n t v a l u e a n a l y s i s may be pe r fo rmed u s i n g c u r r e n t d o l l a r s i n w h i c h

investments , b e f o r e t h e y a r e c a p i t a l i z e d , and expenses i n f l a t e a c c o r d i n g t o

t he i n f l a t i o n r a t e ei. The c a r r y i n g charges do n o t i n f l a t e because t h e s e

charges a r e f i x e d once t h e i n v e s t m e n t i s c a p i t a l i z e d . A c u r r e n t d o l l a r

a n a l y s i s r e q u i r e s t h e use o f a d i s c o u n t r a t e equal t o t h e c o s t o f money a t t h e

p r e v a i l i n g r a t e o f i n f l a t i o n .

On t h e o t h e r hand, i f c o s t s a r e k e p t i n c o n s t a n t d o l l a r s r a t h e r t h a n a l l o w e d

t o i n f l a t e , t h e d i s c o u n t r a t e must be t h e we igh ted c o s t o f c a p i t a ? i n t h e

absence o f i n f ? a t i on.

Occurrence of Payments

For convenience in making economic s t u d i e s , i t may be assumed t h a t a l l

investments w i l l be made a t t he beginning (January 1) of a year based on c o s t

e s t ima te s referenced t o December 31 of t he previous yea r , and a l l car ry ing

charges, and unless otherwise s t a t e d a l l expense item a r e made a t t h e end o f

t he y e a r .

Present Value of Revenue Requirements

The concepts of p re sen t value a r i t hme t i c and revenue requirements t h a t have

been presented e a r l i e r i n t h i s sec t ion a r e combined t o obta in t h e p re sen t

value of revenue reauirements .

Book L i f e Analysis . The present value of car ry ing charges V i s t h e sum m,n

of t he present value of each of t he annual car ry ing charges over t h e book l i f e

of an investment:

where 2 i s the tax recovery c l a s s and n i s the book l i f e . The p re sen t value

"m.n can be l e v e l i z e d by d iv id ing by t h e a n fac tor .

Thus,

where P i s t h e l e v e l i z e d car ry ing charges of a p l a n t item wi th an m year m , n

t a x recovery c l a s s and n y e a r book l i f e .

A book l i f e a n a l y s i s i s t he present value of revenue requirements o r t he

l eve l i zed revenue requirement over t he book l i f e of an a l t e r n a t i v e ( ca r ry ing

charges p lus expenses) .

F o r a t y p i c a l A l t e r n a t i v e A,

P r e s e n t Va lue Revenue Requirement (PVRRA)

PVRRA = ( Inves tmen t ) ( V ) + X(Expenses) (Ln)(an) (7-22) m,n

Leve l i z e d Revenue Requirement ( LRRA)

LRRA = ( Inves tmen t ) P + Z(Expenses)(Ln) m, n

where:

I n v e s t m e n t = T o t a l c a p i t a l requ i remen t

Expenses = A l l a p p r o p r i a t e e x p e n d i t u r e s

"m,n and P = A p p r o p r i a t e f a c t o r s f o r a p l a n t i t e m w i t h an m, n

m y e a r t a x r e c o v e r y c l a s s and n y e a r book l i f e -

Ln = L e v e l i z i n g f a c t o r based on an a p p r o p r i a t e r e a l

e s c a l a t i o n r a t e e and i n f l a t i o n r a t e ei f o r r ' each expense

a n = Present wor th f a c t o r f o r a u n i f o r m s e r i e s .

An example o f t h i s t y p e a n a l y s i s f o r a t y p i c a l a l t e r n a t i v e i s p r e s e n t e d i n

T a b l e 7-3 . Economic i n p u t d a t a f o r use i n t h e example is p r e s e n t e d i n T a b l e

7-4.

Year-by-Year A n a l y s i s . The mechanics o f t h e book l i f e c a l c u l a t i o n o f t h e

s e c t i o n above i s such t h a t a c t u a l revenue requ i remen ts i n any p a r t i c u l a r y e a r

canno t be i d e n t i f i e d . S i g n i f i c a n t d i f f e r e n c e s i n revenue requ i remen ts on a

year-by-year b a s i s t h a t m i g h t weigh h e a v i l y on t h e d e c i s i o n making p rocess a r e

n o t addressed. The year-by-year a n a l y s i s , i n which a c t u a l revenue s t reams a r e

compared on an annual b a s i s overcomes t h i s problem.

G e n e r a l l y , i t i s b e s t t o a r range a year-by-year a n a l y s i s i n c

each a l t e r n a t i v e .

An example o f t h i s t y p e a n a l y s i s f o r a t y p

Tab le 7-5. Economic i n p u t d a t a f o r use i n

i c a l a l t e r n a t i v e i s

t h e example i s i n c

lumnar f o r m f o r

p r e s e n t e d i n

uded.

Table 7-3

Economic Evaluation Data

Capital Costs (Per One Dollar of Direct Construction Cost)

Direct Material and Equipment

Direct Construction and Erection

Total Direct Construction Cost

Indirect Costs (Assumes 26% of Item 1.2)

Administrative Costs (Assumes 7% of Item 1.3)

Capital Cost at Contract Award Date Per One Dollar of

Direct Construction Cost

Escalation (Assumes 38 mos. from Contract Award to Construc-

tion Midpoint (C.M.) 8 8%): (({1.08)~'~~)~~-1)(1.174)=

Subtotal

Interest During Construction (Assumes 16 mos. from

C.M. to Commercial Operation Date (C.O.D.) @18%)(((1.18)~/~~)~~-l)(l. 498) =

Subtotal

Contingency

Total Capital Cost at Commercial Operation Date Per

One Dollar of Direct Construction Cost at Contract Award

Date

Capital Costs at Commercial Operation Date

D i r e c t Material and Equipment 8 Contract Award

Date (C.A.D.)

Direct Construction and Erection @ C.A.D.

Subtotal

Total Capital Cost @ C.O.D. Multiplier (1.12)

Capital Cost

Capacity Charge (Assumes 2200 kW P $1000/kW)

Replacement Power Cost During Installation Outage

(Assumes Concurrent with Boiler Repairs; i.e.,

Not Chargeable)

Total Capital Cost at Commercial Operation Date

Tab le 7-3 (Con t inued)

F i xed Charge Rates

I n t e r e s t (Assumes 50% Debt 8 14%) 0.07000

A f t e r Tax R e t u r n on E q u i t y (Assume 50% E q u i t y

@ 14%) 0.07000

A m o r t i z a t i o n (Assumes 10 Year Economic L i f e )

( . S O ) ( . 14) / ( ( (1 . 1 4 ) ' ~ ) - 1 ) = 0.02586

D e p r e c i a t i o n o f E q u i t y (Assumes 10 Year Remaining Economic L i f e )

(.50)(.14)/(((1.14)10)-1) =

Federa l and S t a t e Income Taxes (Assumes 52% o f B e f o r e Tax

Return on E q u i t y ) : (0.14)(0.50)(0.52)/(1.0-0.52) =

P r o p e r t y Taxes (Assumes 1.5%)

Insu rance (Assumes 1.5%)

C a p i t a l A c q u i s i t i o n s (Assume 0.2%)

F i x e d Charge Rate

Annual F i x e d Charges

(57262OOO)(O. 29955)

Annual O p e r a t i n g Costs a t Commercial Opera t ing Date

Opera t ing Labor (Assumes 1 O p e r a t o r / S h i f t , 5 S h i f t s ,

$30,00O/yr. i n c l u d i n g f r i n g e s , s u p e r v i s i o n , e t c . )

Maintenance Labor (Assumes 10,000 hours d i r e c t

l a b o r p e r y e a r , $15/hr i n c l u d i n g f r i n g e s , overheads,

s u p e r v i s i o n , e t c . )

Maintenance M a t e r i a l (Assumes 82% o f d i r e c t

maintenance l a b o r )

Power Consumption (Assumes 75% a v a i l a b i l i t y , 90% 6 l o a d f a c t o r , 10,000 B W k W h r , $2.00/10 B t u T o t a l )

a) P r e c i p i t a t o r Consumption (Assumes 90% o p e r a t i o n a l ,

1800 kW w i t h a l l o p e r a t i o n a l )

b ) Fan Consumption (Assumes 2 .5 i n . WC drop on 6 1 . 8 ~ 1 0 ACFM 8 100% l o a d , 70% avg. l oad , e f f i c i e n c i e s :

68% f a n , and 92% motor )

c ) A u x i l i a r i e s (Assumes 400 kW) 6 Heat Loss (Assumes 10°F drop, 5 .200 x 10 l b / h r

6 f l u e gas, S2/10 B t u t o t a l , s p e c i f i c h e a t o f

0.24 B t u / l b )

T o t a l Annual O p e r a t i n g Cost a t C.O.D.

T o t a l Annual Owning and O p e r a t i n g Cos t a t C.O.D.

3,633,000 + 17,153,000 = 20,786,000

Table 7-4

Present Value A n a l y s i s

1.0 + E s c a l a t i o n Rate + E s c a l a t i o n Rate

1.0 + D iscoun t Rate + D i s c o u n t Rate 1 ""'1 0 - [ 1.0 + E s c a l a t i o n Rate

1.0 + D i s c o u n t Rate

FIXED CAPITAL CHARGES ($1000)

ESCALATING ANNUAL COSTS ($1000)

Annual F i x e d Charges

Base F i x e d Charges

17,153

Presen t Value F a c t o r (Annual S e r i e s ) = an

= (((1.0 + D i s c o u n t Rate) Year) - l.O)/(Di scount Rate(l.O + D i s c o u n t

l Ia te lYear)

= (((1.0 + 0.14) lo) - 1.0)/(0.14 (1.0 + 0.14) lo) = 5.2161

Presen t Value o f F i x e d Charges

17153 (5.2161) = 89,472

Annual O p e r a t i n g Cos ts

4 . 1 Base O p e r a t i n g Costs a t C.Q.

3633

4.2 E s c a l a t i o n Rate

0.08 o r 8%

E s c a l a t i n g Presen t Va lue F a c t o r (Annual Ser ies )= (L,)(an)


PRESENT VALUE ANALYSIS

FIXED CAPITAL CHARGES ($1000)

ESCALATING ANNUAL COSTS ($1000)

6.0 P r e s e n t Worth o f Annual Opera t ing C o s t s

3633 (7.5176) = 25,998

7.0 P r e s e n t Va lue Revenue Requirement (PVRR)

89,472 + 25,998 + 115,470

Tab le 7-5

Commulat7ve Annual Cash F l o w A n a l y s i s

FIXED ANNUAL CAPITAL CHARGES ($1000)

ESCALATING ANNUAL OPERATING COSTS ($1000)

Years Annual Annual f r o m C a p i t a l Operate . COD Chgs . ( l ) Cs t . (2 ,7 )

0 17,153 3,633

1 17,153 3,924

2 17,153 4,238

3 17,153 4,577

4 17,153 4,943

5 17,153 5,338

6 17,153 5,765

7 17,153 6,226

8 17,153 6,724

9 17,153 7,262

10 17,153 7,843

Cumula t i ve T o t a l s

T o t a l Annual Costs

20,786

21,077

21,391

21,730

22,096

22,491

22,918

23,379

23,877

24,415

24.996

P r e s e n t Value F a c t o r (3)

0

0.8772

0.7695

0.6749

0.5921

0.5194

0.4556

0.3996

0.3506

0.3075

0.2697

5.2161

Presen t P r e s e n t Value o f Va lue o f ACC (4) AOC (5)

T o t a l P r e s e n t Va lue

0

18,488

16,460

14,667

13,082

11,681

10,441

9,343

8,370

7,508

6,742

103,583

Notes :

1) Annual F i x e d Charges: Base: 17,153,000 @ C .O .D .

2) Annual O p e r a t i n g Costs : Base: 3,633,000 8 C . O . D . E s c a l a t i o n : 8% ( C o n s t a n t )

3 ) Present Value Factor ( S i n g l e Year a t D iscoun t Rate o f 14%):

= l.O/((l.U + D i s c o u n t Rate) Year)

4) Present Va lue o f Annual F i x e d Charges

= PVF Year X AFC

5) Present Va lue o f Annual O p e r a t i n g Cost

= PVF Year X AOC

Table 7-5 (Continued)

6) Tota l s may n o t agree due t o roundoff

7) Usually, d i f f e r e n t e sca l a t i on f a c t o r s a r e used f o r f u e l , l abo r ,

m a t e r i a l s , e t c . and a separa te column i s prepared f o r each c o s t . For

s i m p l i c i t y , one column was used f o r presenta t ion here.

Capita? Charges

General. For a major construction project, capital costs may be readily

subdivided as follows:

Direct Material and Equipment Cost, Including:

- Fill, piling and soil stabilization

- Concrete, rebar and forms

- Structure, siding, roofing and insulation

- Mechanical equipment auxiliaries, ancillaries, pumps, piping, valves, fittings, flanges, supports and hangers

- Motors, transformers, control centers, switchgear, lighting, distribution panels, power cable, control wiring, controls, computers, instrumentation, etc.

Direct Construction Cost, Including:

- Force account labor and supervision

- Subcontractors

Indirect Construction Costs, Including:

- Cranes, dozers, pans, tools, etc.

- Temporary buildings

- Parking

Administrative Costs, Including:

- Envi ronmental/Regulatory

- Engineering, design, and procurement

- Construction management

- Start-LIP

Capital Charges f o r Lost Capab i l i t y :

- Capacity charge f o r a u x i l i a r y power

- Charges f o r replacement power during outage (u sua l ly a p p l i e s t o r e t r o f i t s ) .

These individual cap i t a l c o s t s a r e sub jec t t o c e r t a i n economic e f f e c t s ,

including:

Real e sca l a t i on

I n f l a t i o n

I n t e r e s t during cons t ruc t ion

The cap i t a l c o s t s a s ad jus ted t o r e f l e c t economic e f f e c t s a r e subjec t t o t h e

following "f ixed charges" a s d iscussed in the sec t ion on revenue requirements:

Return on debt

Return on equi ty

Book dep rec i a t i on

Income and property t a x e s

Insurance.

In developing t h e c a p i t a l charges a s soc i a t ed with each proposa l , each o f t he

above-l is ted parameters must be cons idered c a r e f u l l y . P e r t i n e n t

cons idera t ions a r e discussed below.

Direc t Material and Equipment. The conf igura t ion of t h e equipment and t h e

proposed scope of s e rv i ce s can both l ead t o adjustments t o t he c a p i t a ? c o s t s

i n t he proposal .

I t should be made c l e a r t o a l l t h e prospec t ive bidders t h a t

Any add i t i ona l items which expand with t he scope beyond t h a t s p e c i f i e d in t he reques t f o r proposal must be pr iced separa te ly from the "base" p r i c e .

All proposals must o f f e r , a s a minimum, t o f u r n i s h t he e n t i r e scope exac t ly a s s p e c i f i e d in t h e reques t f o r proposa l .

All proposals must c l e a r l y spec i fy t he scope of s e rv i ce s which w i l l be provided f o r t he "base" p r i c e .

During the proposal evaluation, all proposals must be carefully reviewed to

assure that all of the above-listed requirements are met. If a noncomplying

proposal is offered, or a proposal takes exception to the specifications, it

may be resolved as follows:

Reject the noncomplying proposal.

Reject all proposals and request a rebid.

Request the bidder to offer a supplemental proposal to adjust the scope to comply with the request for proposal. On sealed-bid proposals, it may not be possible to do this if the bids have already been opened publicly.

Estimate the cost adjustment associated with correcting the proposal scope to that specified in the request for proposal.

When all the proposals to be evaluated are compliant, the proposed

configurations may be comparatively evaluated.

Both the proposal evaluation and the clear assignment of performance

responsibility can be made easier by specifying a "full servicet' scope in the

request for proposal, i . e . , one which covers both the major equipment item

and its associated foundations, electrical, auxiliaries, ancillary equipment, - etc. The decision to take this approach should be based on consideration of

both the impact on performance warranty enforcement and the impact on total

capital cost. If the decision is made to go "full service", it will be

helpful to clearly specify the configuration and location of all interfaces

between the major equipment item and all connecting equipment and supports.

If this approach is taken, the economic evaluation of configuration

differences is minimized, if not avoided. If not, the following areas should all be investigated in greater detail:

Fill, Soil Stabilization, Piling, Concrete, Rebar and Forms

- If the fill, soil stabilization, piling and concrete foundations are not in the bidder's scope of services, these areas must be explored unless it i s clear that all the proposed configurations are so similar that there would be no measurable differences.

- Foundation loading due to equipment weight, thermal expansion, and also due to overturning moments from wind loads should be considered.

S t r u c t u r e , S i d i n g , Roo f ing , and I n s u l a t i o n

- I f these a reas a r e n o t e n t i r e l y i n c l u d e d i n t h e scope, t h e y must be cons ide red , u n l e s s i t i s c l e a r t h a t a l l t h e proposed c o n f i g u r a t i o n s a r e so s i m i l a r t h a t t h e r e wou ld be no measurab le d i f f e r e n c e s .

- U n i t p r i c e s p e r i n s t a l l e d square f o o t may be used i n most a r e a s e x c e p t s t r u c t u r a l s t e e l .

- i f t h e s u p p o r t i n g s t r u c t u r a l s t e e l i s n o t i n c l u d e d i n t h e m a j o r equipment b i d d e r ' s p r o p o s a l , i t should be c a r e f u l l y e s t i m a t e d .

- S i d i n g and i n s u l a t i o n c o s t s may be c o n s i d e r a b l y h i g h e r f o r t h o s e c o n f i g u r a t i o n s wh ich a r e complex i n d e s i g n .

* Mechanica l Equipment, A u x i l i a r i e s , A n c i l l a r i e s , E t c .

- Any a s s o c i a t e d equipment n o t i n c l u d e d i n t h e proposed scope s h o u l d be l i s t e d and p r i c e d u n l e s s i t i s c l e a r t h a t a l l t h e proposed c o n f i g u r a t i o n s are so s i m i l a r t h a t t h e r e would be no measurab le d i f f e r e n c e s .

- Equipment i n t e r f a c e s may s e v e r e l y impact c o s t s , e.g. , t h e number o f p r e c i p i t a t o r hoppers can impact f l y ash h a n d l i n g system c o s t s . I n t e r f a c e s which do n o t i n t e r f a c e can be c o s t l y , e .g . , connec t ing duc twork and expansion j o i n t s between m a j o r components.

E l e c t r i c a l Equipment, E t c

- I f t h e t r a n s f o r m e r s , sw i t chgear , c o n t r o l c e n t e r s , power c a b l e , mo to rs , d i s t r i b u t i o n pane ls , l i g h t i n g , c o n t r o l w i r i n g , e t c . a r e n o t i n c l u d e d i n t h e proposed scope, t h e y must be l i s t e d and p r i c e d , u n l e s s a l l t h e proposed c o n f i g u r a t i o n s a r e so s i m i l a r t h a t t h e r e would be no measurable d i f f e r e n c e s .

- U n i t p r i c e s may be used f o r power cab le , f o r i n s t r u m e n t a t i o n and c o n t r o l w i r i n g m a t e r i a l s .

- I f t h e c o n t r o l i n s t r u m e n t a t i o n w i r i n g i s m u l t i p l e x e d , a c o n s i d e r a b l e r e d u c t i o n i n c o s t may be a n t i c i p a t e d . Converse ly , h a r d - w i r i n g would be more c o s t l y .

M i s c e l l a n e o u s

I f t h e r e i s g r e a t e r u n c e r t a i n t y i n any o f t h e m a t e r i a l o r equipment c o s t

ad jus tments , i t s c o n t i n g e n c y shou ld be a d j u s t e d a p p r o p r i a t e l y .

D i r e c t C o n s t r u c t i o n and E r e c t i o n Cost. Again, b o t h t h e p r o p o s a l e v a l u a t i o n

and t h e c l e a r ass ignment o f per formance r e s p o n s i b i l i t y can be made e a s i e r b y

s p e c i f y i n g a " f u l l serv ice1 ' scope i n t h e r e q u e s t f o r p r o p o s a l , i . e . , one w h i c h

covers b o t h t h e ma jo r equ ipment i t e m and a s s o c i a t e d equipment, and t h e

e r e c t i o n o f t h e equipment and t h e a s s o c i a t e d s u p p o r t i n g c o n s t r u c t i o n . T h i s

d e c i s i o n shou ld be based, a s d i s c u s s e d above, on a c a r e f u l e v a l u a t i o n o f t h e

a l t e r n a t i v e s . I f t h e d e c i s i o n i s made t o go " f u l l s e r v i c e " o r t o make t h e

b i d d e r r e s p o n s i b l e f o r p a r t o f t h e c o n s t r u c t i o n o r e r e c t i o n , i t w i l l b e

h e l p f u l t o deve lop a precedence d iagram, m a j o r t a s k d u r a t i o n s and a c r i t i c a l

e v e n t schedule f o r those a r e a s i n t h e c o n s t r u c t i o n schedule w h i c h may be

i n v o l v e d i n t h e e r e c t i o n o f t h e m a j o r equ ipment i t e m and t h e s u p p o r t i n g

o f t h e f i n a l n e g o t i a t e d c o n t r a c t

r o a c h i s taken, t h e economic

i o n c o s t d i f f e r e n c e s i s m in im ized ,

i t e m s shou ld be i n v e s t i g a t e d i n

c o n s t r u c t i o n . T h i s schedu le s h o u l d be p a r t

w i t h t h e b i d d e r . I f t h e " f u l l s e r v i c e " app

e v a l u a t i o n o f d i r e c t c o n s t r u c t i o n and e r e c t

i f n o t avo ided . I f n o t , a l l t h e f o l l o w i n g

g r e a t e r d e t a i l :

* D i r e c t M a t e r i a l and Equipment

- A l l of t h e a r e a s e x p l o r e d i n t h e above s e c t i o n on d i r e c t m a t e r i a l and equipment s h o u l d be i n v e s t i g a t e d f o r p o t e n t i a l impact on d i r e c t c o n s t r u c t i o n and e r e c t i o n c o s t .

Module S i z e

- M a j o r equipment i t e m s a r e n o r m a l l y preassembled i n modules t o maximize shop f a b r i c a t i o n and m i n i m i z e f i e l d c o n s t r u c t i o n and the reby c o n s t r u c t i o n c o s t . The r e q u e s t f o r p roposa l s h o u l d s p e c i f y t h a t t h e modules be as l a r g e as p r a c t i c a l , w i t h i n t h e l i m i t a t i o n s o f t h e l a r g e s t c ranes and l i f t i n g g e a r a t t h e s i t e , and t h e l i m i t a t i o n s o f t h e a v a i l a b l e means o f t r a n s p o r t . The proposed module s i z e s s h o u l d be e v a l u a t e d f o r c o n s t r u c t i o n c o s t impac t , u n l e s s a l l t h e proposed module s i z e s a r e so s i m i l a r t h a t t h e r e w o u l d be no measurable d i f f e r e n c e s .

- A l though t h e l a r g e r modules a r e g e n e r a l l y p r e f e r r e d , t h e reduced f i e l d c o n s t r u c t i o n t i m e shou ld be ba lanced a g a i n s t any a d d i t i o n a l t r a n s p o r t a t i o n c o s t s due t o o v e r s i z e d loads , and a d d i t i o n a l c o s t s f o r e x t r a l a r g e c ranes and l i f t i n g g e a r .

S u b c o n t r a c t o r s

- If t h e b i d d e r p l a n s t o use a s u b c o n t r a c t o r o r s u b c o n t r a c t o r s t o e r e c t t h e m a j o r equipment i t e m o r any s u p p o r t i n g equipment, t h e b i d d e r shou ld i d e n t i f y t h e s e s u b c o n t r a c t o r s .

- S u b c o n t r a c t o r s s h o u l d be s u b j e c t t o t h e same s c r u t i n y as t h e p r ime b i d d e r .

I f t h e r e i s g r e a t e r u n c e r t a i n t y i n any o f t h e d i r e c t c o n s t r u c t i o n o r e r e c t i o n

c o s t ad jus tmen ts , i t s c o n t i n g e n c y shou ld be a d j u s t e d a p p r o p r i a t e l y .

Indirect Construction Costs. Indirect construction costs may be potentially

impacted in a number of ways. Two common areas are discussed below:

Special Handling Equipment

- As discussed above, special hand1 ing equipment may be required if the major equipment item is furnished in oversized modules. This must be balanced against savings which may be realized from reduced direct construction cost.

Special Storage Requirements

- Certain instrumentation, controls, computers, etc., may require protection from the elements and therefore may not be suitable for outside laydown. Warehousing costs for this equipment may be considerable.

- This and other equipment (particularly computers and other electronics) may require special environmental controls on humidity and airborne particulate.

If there is greater uncertainty in any of the indirect costs, its contingency should be adjusted appropriately.

Administrative Costs. It is usual that Administrative costs are relatively

constant, regardless of the bidder selected, if a71 bidders have essentially

the same scope. If not, an allowance for additional administrative costs

should be comouted.

Capacity Charges for Lost Capability. The capacity charges for lost

capability fall into two categories: the incremental capita7 cost of

additional new installed capacity as needed to replace installed capacity lost

to service auxiliary power requirements, and the cost of replacement power

needed to meet generation requirements during the outage required to implement

the major equipment item or during an incremental delay in commercial

operation due to a schedule extension required to implement the major

equipment item. These are discussed below:

Incremental Charge for Lost Capability

- The incremental cost per kilowatt of lost capacity may be defined as the slope of a curve expressing the installed capital cost of similar power plants of varying sizes and the same commercial operating date versus the net capacity in kilowatts of these similar power plants operating at maximum continuous rating. It is not the quotient of the estimated

c a p i t a l c o s t o f t h e p l a n t i n q u e s t i o n d i v i d e d by i t s i n s t a l l e d c a p a c i t y . For example, a l a r g e two u n i t c o a l - f i r e d power p l a n t w i t h a commercial o p e r a t i n g d a t e i n 1986 would p r o b a b l y c o s t abou t $ 1 8 0 D / k i l o w a t t , b o t t o m l i n e . The i n c r e m e n t a l c o s t o f one a d d i t i o n a l k i l o w a t t however would be a b o u t $ 1 1 0 0 / k i l o w a t t .

- Inc rementa l a u x i l i a r y power requ i remen ts f a l l i n t o two c a t e g o r i e s : c o n s t a n t l o a d s which a r e i n s e n s i t i v e t o p l a n t o u t p u t , and p r o c e s s - r e l a t e d l o a d s wh ich shou ld be e v a l u a t e d a t t h e u n i t maximum c o n t i n u o u s r a t i n g when d e t e r m i n i n g t h e c o s t o f l o s t c a p a c i t y .

- When e v a l u a t i n g a u x i l i a r y horsepower f o r t h e c o s t o f l o s t c a p a c i t y , c o n s i d e r a t i o n s h o u l d be g i v e n t o t h e t h e o r e t i c a l horsepower r e q u i r e d , t h e mechanica l e f f i c i e n c y o f t h e d r i v e n equipment, t h e mechanica l e f f i c i e n c y o f t h e r e d u c t i o n gear and/or f l u i d c o u p l i n g , t h e e f f i c i e n c y o f t h e e l e c t r i c motor , t h e e f f i c i e n c y o f t h e v a r i a b l e speed e l e c t r i c a l c o n t r o l system, and l o s s e s i n t h e power c a b l e , t r a n s f o r m e r s , and sw i t chgear .

C o s t o f Replacement Power

- When e v a l u a t i n g t h e c o s t o f rep lacement power as it a p p l i e s t o a p a r t i c u l a r m a j o r equipment i t e m p r o p o s a l , t h e a c t u a l rep lacement power requ i remen t must be p r o j e c t e d on t h e b a s i s o f t h e a n t i c i p a t e d l o a d f a c t o r o f t h e a f f e c t e d u n i t and t h e a n t i c i p a t e d ou tage d u r a t i o n chargeabfe t o t h e s p e c i f i c m a j o r equipment i t em. I f t h e m a j o r equipment i t e m i s n o t on t h e c r i t i c a l pa th , m i n o r v a r i a t i o n s i n d u r a t i o n t h a t a r e a i l o c a b l e t o t h e s p e c i f i c m a j o r equipment i t e m w i t h i n t h e l i m i t s o f t h e f l o a t i n t h e p r o j e c t scheduie would have l i t t l e measureable impac t . V a r i a t i o n s exceeding these l i m i t s would e i t h e r e x t e n d t h e outage d u r a t i o n o r mandate a p r o j e c t schedule a c c e l e r a t i o n w i t h a d d i t i o n a l c o s t s due t o premium pay, e t c .

The p r o d u c t o f t h e l o a d f a c t o r , t h e a c t u a l chargeable i n c r e a s e i n outage d u r a t i o n , and t h e n e t u n i t o u t p u t a t 100 p e r c e n t r a t e d l o a d wou ld approx imate t h e power w h i c h must be rep laced , i f t h e d u r a t i o n i s ex tended. i n t e r e s t d u r i n g c o n s t r u c t i o n f o r t h e e n t i r e p r o j e c t wou ld a l s o i n c r e a s e .

The u n i t c o s t s o f t h e rep lacement power may be based on two sources, purchase f rom o t h e r u t i l i t i e s o r i nc reased o u t p u t f rom o t h e r u n i t s on t h e system. A l though t h e e s t i m a t e d c o s t may b e de te rm ined q u i t e q u i c k l y u s i n g l o a d f o r e c a s t i n g and c o s t i n g programs, i f t h e s e a r e n o t r e a d i l y a v a i l a b l e , a good approx ima t ion may be deve loped by assuming t h a t rep lacement power a t l e v e l s above p i a n t r a t e d c a p a c i t y ( e . g . , VWOP) must be o b t a i n e d by purchase f r o m n e i g h b o r i n g u t i l i t i e s , and t h a t power a t l e v e l s a t p l a n t r a t e d c a p a c i t y and be low may be o b t a i n e d by " t u r n i n g up t h e w i c k " on t h e o t h e r u n i t s owned by t h e u t i l i t y .

- To summarize, p o t e n t i a l i n c r e a s e s i n t h e p r o j e c t schedule d u r a t i o n t h a t a r e a t t r i b u t a b l e t o a g i v e n ma jo r equipment p r o p o s a l may be r e s o l v e d u s i n g one o r more o f t h e f o l l o w i n g :

"Reducing t h e f l o a t * A c c e l e r a t i n g t h e schedule w i t h (ove r t ime , e t c . ) * S l i p p i n g t h e comp le t ion d a t e

I f t h e c o m p l e t i o n d a t e i s s l i p p e d , t h e c o s t impac t w o u l d i n c l u d e t h e f o l l o w i n g :

*Purchased rep lacement power *Replacement power f rom o t h e r u n i t s * Inc reased i n t e r e s t d u r i n g c o n s t r u c t i o n .

I n t e r e s t d u r i n g c o n s t r u c t i o n i s d i s c u s s e d be low.

Economic E f f e c t s , I n c l u d i n g Apparent E s c a l a t i o n , and I n t e r e s t D u r i n g

C o n s t r u c t i o n . These e f f e c t s may be s u b d i v i d e d i n t o two c a t e g o r i e s :

Economic e f f e c t s d i r e c t l y a s s o c i a t e d w i t h t h e ma jo r equipment p roposa l :

- Apparent e s c a l a t i o n o f c o s t s a s s o c i a t e d w i t h each scheduled payment

- I n t e r e s t d u r i n g c o n s t r u c t i o n a s s o c i a t e d w i t h each scheduled payment.

Economic e f f e c t s a s s o c i a t e d w i t h t h e a d d i t i o n a l c a p i t a l c o s t s o f a f f e c t e d a u x i l i a r y and a n c i l l a r y equipment, and a s s o c i a t e d c o n s t r u c t i o n and e r e c t i o n , e t c . :

- Apparent e s c a l a t i o n o f t h e a d d i t i o n a l c o s t s t o t h e c o n s t r u c t i o n m i d p o i n t

- I n t e r e s t d u r i n g c o n s t r u c t i o n o f t h e a d d i t i o n a l c o s t s f r o m c o n s t r u c t i o n m i d p o i n t t o t h e commercial o p e r a t i o n d a t e .

The d e t a i l s o f t h e o r i g i n o f t h e s e economic e f f e c t s a r e covered be low

E v a l u a t i o n o f Terms o f Payment and Other C a p i t a l Costs o f M a j o r Equipment

P roposa ls . Wh i le e s c a l a t i o n and i n t e r e s t d u r i n g c o n s t r u c t i o n a r e o f t e n

e v a l u a t e d i n terms o f t h e c o n s t r u c t i o n m i d p o i n t , t h e c o s t s d i r e c t l y a s s o c i a t e d

w i t h each ma jo r equipment p roposa l shou ld be e v a l u a t e d more r i g o r o u s l y based

on t h e a c t u a l te rms o f payment proposed.

U s u a l l y t h e proposed terms o f payment w i l l i n c l u d e t h e f o l l o w i n g i m p o r t a n t

d a t a :

A " f i r m ' p r i c e

A d a t e a t wh ich t h e " f i r m " p r i c e b e g i n s t o e s c a l a t e *

An e s c a l a t i o n t a b l e , s p e c i f y i n g :

- The Bureau o f Labor S t a t i s t i c s o r s i m i l a r e s c a l a t i o n i n d i c e s t o be a p p l i e d t o each c o s t c a t e g o r y

- The f r a c t i o n o f t h e f i r m p r i c e ( o r a c t u a l d o l l a r amount) t o b e a p p l i e d t o each c o s t c a t e g o r y

- The esca l a t i o n "cap" (maximum e s c a l a t i o n )

- I f e s c a l a t i o n will be p a i d p e r i o d i c a l l y o r w i t h t h e r e t a i n a g e

A payment schedule, s p e c i f y i n g :

- A l i s t o f m a j o r m i l e s t o n e s w h i c h r n u s t b e m e t b e f o r e e a c h payment i s made*

- The d a t e f o r each m i l e s t o n e *

- The f r a c t i o n o f t h e f i r m p r i c e ( o r a c t u a l u n e s c a l a t e d d o l l a r amount) t o be b i l l e d on each c o s t c a t e g o r y on each m i l e s t o n e d a t e

- The amount o f r e t a i n a g e *

- The b i l l i n g i n t e r v a l between t h e m i l e s t o n e d a t e and the d e l i n q u e n t d a t e

- The i n t e r e s t cha rged on d e l i n q u e n t payments.

( I t ems marked " may be s p e c i f i e d by t h e U t i l i t y . )

TO a c c u r a t e l y e v a l u a t e t h e te rms o f payment, t h e above l i s t e d d a t a must be

supplemented w i t h t h e f o l l o w i n g U t i l i t y da ta :

P r o j e c t e d apparent e s c a l a t i o n r a t e s f o r each o f t h e i n d i c e s t o be a p p l i e d t o each c o s t c a t e g o r y

I n t e r e s t d u r i n g c o n s t r u c t i o n

- P r o j e c t schedule f o r a l l work p o t e n t i a l l y i m p a c t i n g t h e imp lementa t ion o f t h e m a j o r equipment i t e m , i n c l u d i n g * " :

- Precedence d iag ram

- D u r a t i o n s .

(*"The schedule must be rev iewed t o a s s u r e t h a t t h e m i l e s t o n e s used i n t h e payment schedule a r e "do-able," e.g., w i l l o t h e r p r o j e c t a c t i v i t i e s s u p p o r t t h e imp lementa t ion o f t h e m a j o r equ ipment i t em?)

An a b b r e v i a t e d example o f proposed terms o f payment f o r a " f a b r i c a t e , d e l i v e r

and check-out " p roposa l w i t h t h e terms o f payment and t h e s u p p o r t i n g U t i l i t y

d a t a appears i n Tab le 7-6 . The case shown assumes equipment e r e c t i o n b y

o t h e r s .

An a n a l y s i s o f t h e terms o f payment i n Tab le 7-6 i s t a b u l a t e d on T a b l e s 7-7

t h r o u g h -9. To s i m p l i f y t h e a n a l y s i s , t h e te rms i n c l u d e o n l y two c o s t

c a t e g o r i e s , " M a t e r i a l " and "Labor . " Ac tua l t e rms may i n c l u d e many more

c a t e g o r i e s .

I n e v a l u a t i n g terms o f payment, s p e c i a l ca re shou ld be t a k e n t o r e s o l v e t h e

f o l l o w i n g i s s u e s :

S ince a p p l i c a b l e e s c a l a t i o n i n d i c e s a r e p u b l i s h e d a f t e r t h e f a c t , e s c a l a t i o n may n o t be a c c u r a t e l y c a l c u l a t e d a t t h e moment a p r o g r e s s payment i s b i l l e d . To r e s o l v e t h i s prob lem, e s c a l a t i o n i s u s u a l l y e s t i m a t e d and b i l l e d w i t h each p r o g r e s s payment, t h e n a d j u s t e d a f t e r t h e i n d i c e s a r e p u b l i s h e d . E s c a l a t i o n may a l s o be b i l l e d a f t e r t h e i n d i c e s a r e p u b l i s h e d , o r b i l l e d w i t h t h e r e t a i n a g e a f t e r j o b c o m p l e t i o n .

The method o f p r o v i d i n g f o r t h e d e f e r r e d b i l l i n g o f e s c a l a t i o n must be c l e a r l y d e f i n e d . A l t h o u g h compound i n t e r e s t a t a s t i p u l a t e d r a t e i s u s u a l l y s p e c i f i e d , some c o n t r a c t s p r o v i d e f o r c o n t i n u o u s e s c a l a t i o n up t o t h e p o i n t t h a t t h e payment i s p a i d i n f u l l .

N e i t h e r e s c a l a t i o n n o r i n t e r e s t s h o u l d be p a i d i n p rog ress payments n o t made due t o f a i l u r e t o meet p r o g r e s s m i l e s t o n e s ( u n l e s s t h e d e l a y i s n o t t h e f a u l t o f t h e equipment s u p p l i e r ) , n o r on r e t a i n a g e h e l d due t o f a i l u r e t o meet performance.

M i l e s t o n e s f o r p r o g r e s s payments must be c l e a r l y d e f i n e d . "Engi- n e e r i n g 15% Complete" i s u n c l e a r . "Founda t ion Loads and B o l t i n g P lans Complete'' i s more conc ise .

B i l l i n g and payment p rocedures a r e v e r y i m p o r t a n t . For example, i f t h e b i l l i s p r e s e n t e d 30 days a f t e r m e e t i n g t h e m i l e s t o n e , and p a i d 60 days a f t e r r e c e i p t o f t h e b i l l , a f u l l q u a r t e r o f i n t e r e s t i s a p p a r e n t l y avo ided b y t h e U t i l i t y . Converse ly , i f t h e b i l l i s p r e s e n t e d 30 days i n advance o f t h e a n t i c i p a t e d m i l e s t o n e , and p a i d by e l e c t r o n i c funds t r a n s f e r on t h e m i l e s t o n e d a t e ( g i v e n

Table 7-6

Terms o f Payment Data MILESTONES AND PAYMENTS TABLE

Elapsed Unesca la ted Unescal a t e d Time From M a t e r i a l Cost Labor Cost

L i n e F i r m D a t e Payment Payment L i n e No. (Weeks ) M i l e s t o n e D e s c r i p t i o n ( F r a c t i o n ) ( F r a c t i o n ) No.

1 0 C o n t r a c t Award-Star t E n g i n e e r i n g - - 1

2 25 E n g i n e e r i n g 50% Complete - 0.025 2

3 50 E n g i n e e r i n g 100% Complete - 0.025 3

4 6 0 Release F a b r i c a t i o n - P u r c h a s e

M a t e r i a l 0.10 0.05 4

5 65 M a t e r i a l 50% Purchased 0.10 0.05 5

6 9 5 Equipment 50% F a b r i c a t e d and

De l i v e r e d 0.30 0.05 6

7 125 Equipment 50% E r e c t e d and

Checked Out 0.10 0.05 7

8 155 M a t e r i a l 100% Purchased 0.10 0.05 8

9 185 Equipment 100% F a b r i c a t e d and

Del i v e r e d - 0.05 9

10 215 Equipment 100% E r e c t e d and

Checked Out 0.025 0.05 10

11 220 S t a r t u p Complete (C.D.D.) 0.025 0.025 1 I. 12 230 Performance T e s t Successful ly - - 0.025 12

Compi e t e d

TOTALS 0.55 0.45

PROJECTED ESCALATION OF COST

L i n e No. -

13

14

15

16

17

18

19

20

2 1

D u r a t i o n Labor E s c a l a t i o n M a t e r i a l E s c a l a t i o n (Weeks) Rate ( F r a c t i o n ) Rate ( F r a c t i o n )

0-52 0.065 0.055

53-104 0.067 0.060

105-156 0.063 0.065

157-230 0.060 0.070

COST DATA

F i r m P r i c e on Purchase Da te 14,922,400

A d m i n i s t r a t i v e Costs A l l o c a t i o n *1,044,570

T o t a l Cost on F i rm Da te 15,966,970

E s c a l a t i o n Cap (0.14) 14%

B i l l i n g Procedure

B i l l i n g Date: 30 days p r i o r t o due d a t e

Payment Date: On o r b e f o r e due d a t e

P e n a l t i e s : 18% p e r annurn compounded d a i l y i f l a t e

E s c a l a t i o n : E s t i m a t e d and b i l l e d w i t h each b i j l . Updated t o

r e f l e c t i n d i c e s when p u b l i s h e d .

*Assumes 7% p r o j e c t a d m i n i s t r a t i v e c o s t

PRECAUTION

These d a t a a r e f o r d e m o n s t r a t i o n purposes o n l y . A c t u a l payment schedules may

l i s t a s e r i e s o f 50 payments o r more.

Table 7-7

Elapsed Time From

Line. Firm Date

2 25

3 50

4 60

5 65

6 95

7 125

8 155

9 185

10 215

I I 220

12 230

13 TOTAL

Terms o f Payment Ana lys is

LABOR ESCALATION

Unescal a t ed Payment

(F rac t ion ) ( c )

0 .0

0.025

0.025

0.05

0.05

0.05

0.05

0.05

0.05

0.05

0.025

0.025

0.45

Labor Costs P ro j ec t Esca l a t i on

Rate Factor Esca la t ion ( Frac t ion ) (Mul t i p l i e r ) ( C x e )

( d l ( e l ( f )

NOTES :

( a ) Line Number

(b) Time from Contract Award t o Line Number

( c ) Unescalated Payment from Table 7-6

(d) Escala t ion Rate from Table 7-6

( e ) Esca la t ion Factor:

EF = (1 .0 + Escala t ion ~ a t e ) ~ - l

where N = (Number of weeks from c o n t r a c t award t o payment)/52 weeks per

y e a r

( f ) ( c ) x ( e l

T a b l e 7-8

Terms o f Payment A n a l y s i s

MATEFlIAL ESCALATION

Elapsed Time From

Line F i r m Date No. (Weeks) ( a ) (b)

1 0

2 25

3 50

4 60

5 6 5

6 95

7 125

8 155

9 185

10 215

11 220

12 230

13 TOTAL

Unescal a t e d Payment

( F r a c t i o n ) ( c )

0.0

0.0

0.0

0.10

0.10

0.10

0.10

0.10

0.0

0.025

0.025

0.0

0.55

M a t e r i a l Costs P r o j e c t E s c a l a t i o n

Rate F a c t o r E s c a l a t i o n ( F r a c t i o n ) ( M u l t i p l i e r ) ( C x e )

( d l ( e ) ( f )

NOTES :

( a ) L i n e Number

( b ) Time from C o n t r a c t Award t o L i n e Number

( c ) Unesca la ted Payment f rom Table 7-6

( d ) E s c a l a t i o n Rate f rom Table 7-6

( e ) E s c a l a t i o n F a c t o r : N EF + (1.0 + E s c a l a t i o n Rate) -1

where N = (Number o f weeks f rom c o n t r a c t award t o payment)/52 weeks p e r

y e a r

f (c) X ( e l

Table 7-9

Terms o f Payment Analysis INTEREST DURING CONSTRUCTION

TERMS OF PAYMENT:

Payments, E lapsed Time Cumu la t i ve T o t a l o f E s c a l a t i o n

Time From To E s c a l a t i o n Payments & I D C L i n e F i rm Date C . O . D . (From Co7 F & E s c a l a t i o n t o C.O.D. & (Weeks) (Weeks) ~ a b l e s 7-7 & 7-8) ( F r a c t i o n ) ( F r a c t i o n ) ( a ) (b) ( c ) ( d ) ( e l ( f )

0 220

25 195

5 0 170

6 0 160

6 5 155

9 5 125

125 9 5

155 65

185 35

215 15

220 0

230 -10

TOTALS :

COSTS ($1000)"

0.0008

0 .0024

0.0127

0.0239

0.0408

0.0637

0 .0930

0 .1054

0 .1271

0 . 1 4 ( l i m i t )

0 . 1 4 ( l i m i t ) -

0.1400

2,235

"Ease = 15,966,970 f rom T a b l e 7-6

NOTES : -

( a ) L i n e Number

( b ) Time from C o n t r a c t A w a r d t o L i n e Number

( c ) Time f rom L i n e Number t o C.O.D.

(d ) Cumulat ive Sum o f E n t r i e s i n Column ( f ) f r o m Tab les 7-7 and 7-8

Tab le 7-9 (Ccn t inued)

( e ) T o t a l o f E n t r i e s i n Columns (c ) and ( f ) f r o m Tab les 7-7 and 7-8

( f ) E n t r y i n Column ( e ) , m u l t i p l i e d b y t h e f o l l o w i n g I . D . C . F a c t o r ( I F ) :

IF = ( 1 . 0 + D i s c o u n t ate)^ = 1.18 N

where N = (Number o f weeks f r o m payment t o C .O .D . ) / 52 weeks p e r

y e a r

confirmation that the mjlestone is met) then the Utility apparently avoids no interest. It should be understood; however, that although the interest is apparently paid by the Seller, i t is actually paid by the Utility as part of the purchase price. If the SeTier's short-term paper carries a higher discount rate than the Utility's (usually the case) it may be in the best interest of the Utility to agree to pay promptly. This may be evaluated by requesting alternative payment plans.

Although a proposal with a "firm" price to completion appears to avoid the payment of escalation and the evaluation of its economic effects, the progress payment schedule, escalation factors, and applicable indices must still be defined in the proposal so that unavoidable delays (not the fault of the Supplier) can be handled without renegotiation of the Contract.

Evaluation of Economic Effects on Associated Auxiliary and Ancillary Equipment

and Construction Costs. The economic effects associated with the escalation

of costs and the interest during construction can be accurately projected for

those costs covered in major equipment proposals based on the proposed

sequence of payments. This is covered i n the section above. There is usually

no readily available project cash flow tabulation applicable to the analysis

of these economic effects as they apply to cost of a major piece of

equipment's auxiliary and ancillary equipment and in the construction which is

usually associated with the implementation o f a major piece of equipment. For

these costs, a more simplistic approach may be taken to approximate the actual

cash flow, as follows:

Adjust the direct costs of material, equipment, construction and erection for indirect and administrative costs.

Establish the date construction will begin at the site (usually specified in the licensing and permitting documents) and the Commercial Operation Date.

Assume that the economic centroid of the project cash flow occurs at the mid-point (Construction Mid-Point) between the Initial Construction Date and the Commercial Operation Date.

Escalate the adjusted additional costs of ancillary and auxiliary equipment and construction from the date estimated to the Construction Mid-Point using the projected, apparent escalation rate.

Apply interest during construction to the additional costs from the Construction Mid-Point to the Commercial Operation Date.

A simple example appears in Table 7-10

T a b l e 7-10

A s s o c i a t e d A u x i l i a r y and A n c i l l a r y M a t e r i a l , Equipment, C o n s t r u c t i o n and E r e c t i o n Costs, and Economic E f f e c t s

DIRECT COSTS:

I t e m No. -

D e s c r i p t i o n o f Cost ($1000)

E r e c t i o n o f Major Equipment I t e m

I n s u l a t i o n and Lagging Not Covered

on Proposa l

Foundat ions

B u i l d i n g s and Enc losu res

S t r u c t u r a l S tee l No t Covered i n

Proposa l

E l e c t r i c a l Equipment and W i r i n g Not

Covered i n Proposa l

A d d i t i o n a l Ductwork

S u b t o t a l : D i r e c t C o n s t r u c t i o n Cost

OTHER COSTS:

I tern No.

D e s c r i p t i o n o f Costs

M a t e r i a l & Equipment

-

130

1,200

420

238

508

190

2,686

9 I n d i r e c t Costs (Assumes 26% o f I t e m 8 - C o n s t r u c t i o n and E r e c t i o n )

1 0 A d m i n f s t r a t i v e Costs (Assumes 7% o f I t ems 8 & 9)

11 Cont ingency (Assumes 10% o f I t e m s 8, 9, & 10)

1 2 S u b t o t a l ( I t e m s 8 t h r o u g h 11)

I t e m D e s c r i p t i o n

No. o f Event -

1 3 S t a r t o f P r o j e c t

1 4 Ma jo r Equipment C o n t r a c t Award

C o n s t r u c t i o n & E r e c t i o n

6,193

150

1,400

210

218

1,040

115

9,326

Cos ts (%1000)

Time From T i m e t o

P r o j e c t S t a r t C.O.D.


I t e m

No.

15

16

17

18

D e s c r i p t i o n

o f Event

A s s o c i a t e d Equipment and

C o n s t r u c t i o n E s t i m a t e

S t a r t o f C o n s t r u c t i o n

C o n s t r u c t i o n M i d - P o i n t

Commercial O p e r a t i o n

Time From Time t o

P r o j e c t S t a r t C.O.D.

ECONOMIC EFFECTS:

I t e m Economic Cos t No. - E f f e c t $1000

19 E s c a l a t i o n (Assumes 9% E s c a l a t i o n f o r 38 rnos. f r o m

C o n s t r u c t i o n E s t i m a t e t o C o n s t r u c t i o n M i d - P o i n t ) :

( ( 1 . 0 9 ) ~ ~ / ' ~ - 1 ) ( 1 6 9 9 3 ) 5,332

20 I n t e r e s t D u r i n g C o n s t r u c t i o n (Assumes 18% I.D.C.

f o r 16 rnos. f r o m C o n s t r u c t i o n M i d - P o i n t t o C.O.D.):

( (1. 18)16"2-1)(16993+5332) 5,513

21 E s c a l a t e d Cos t w i t h I .D .C . B C.O.D. 27,838

T o t a l ( I t e m s 12, 19, and 20)

Annual F i x e d Charge Rates . Once t h e t o t a l c a p i t a l c o s t a t Commercial O p e r a t i o n Date i s e s t a b l i s h e d , i t must be c o n v e r t e d i n t o an annual c o s t f o r f u r t h e r e v a l u a t i o n . The most c o n v e n i e n t means t o a c c o m p l i s h t h i s i s t o c o n v e r t a71 o f t h e c a p i t a l charges i n t o an annual f i x e d cha rge r a t e . These charges u s u a l l y c o n t a i n t h e f o l l o w i n g f a c t o r s :

D i s c o u n t r a t e on t h e l o n g - t e r m bonded d e b t

A m o r t i z a t i o n o f t h e l o n g - t e r m bonded d e b t o v e r t h e economic l i f e o f t h e p l a n t . T h i s may be accomp l i shed by means o f a s i n k i n g fund s t r u c t u r e d t o r e t i r e t h e bonded d e b t a t m a t u r i t y .

A f t e r t a x r e t u r n on i n v e s t m e n t on t h e e q u i t y

S i n k i n g funds f o r renewal and rep lacemen t

Payments i n l i e u o f t a x e s

A d m i n i s t r a t i v e c o s t s

i n s u r a n c e

D e p r e c i a t i o n on t h e d e p r e c i a b l e p o r t i o n o f t h e e q u i t y

S t a t e , f e d e r a l , and l o c a l income t a x e s

S t a t e and l o c a l p r o p e r t y t a x e s

Cost o f c a p i t a l a c q u i s i t i o n .

The e v a l u a t i o n o f t h e a b o v e - l i s t e d f a c t o r s r e q u i r e s t h a t t h e f o l l o w i n g d a t a be

made a v a i l a b l e t o t h e i n v e s t i g a t o r : = The c a p i t a l recove ry p e r i o d t o be used i n t h e a m o r t i z a t i o n o f t h e

d e b t , e t c . T h i s p e r i o d may be l e s s t h a n t h e o p e r a t i o n a l l i f e o f t h e equipment eva lua ted ; p a r t i c u l a r l y if a r e t r o f i t t o an o l d e r p l a n t i s i n v o l v e d .

= A d m i n i s t r a t i v e c o s t s

The d i s c o u n t r a t e on t h e l o n g - t e r m d e b t

A n t i c i p a t e d sa lvage a1 lowance

- R a t i o o f t o t a l i n t e r e s t d u r i n g c o n s t r u c t i o n t o t o t a l c a p i t a l c o s t a t commercial o p e r a t i o n d a t e

Federa l and s t a t e t a x p r o v i s i o n s

Incentive tax credit and portion of investment to which it applies

State and local property tax rates

Insurance rates.

This detailed economic data can then be used to generate a fixed charge rate

that is appropriate.

The annual fixed chargerate must be determined for each project based on data

procedures obtained from the accounting department o f the utility.

Annual Operating Costs

General. Annual costs of operation may be readily subdivided into the

following categories:

Auxiliary Powercost

- Power consumption

*Precipitator transformer rectifier and sets

*Precipitator auxiliaries

"Induced draft fans

- Power cost

*Wholesale system busbar cost

"Energy cost based on unit heat rate and fuel cost.

Replacement Power Cost

- Plant economics

*Rated capacity

*toad factor

- Equipment a v a i l a b i l i t y

- Net power c o s t

* U n i t c o s t o f rep lacement power

"Energy c o s t based on u n i t h e a t r a t e and f u e l c o s t .

Heat Losses

- Heat l o s s e s

*Temperature d r o p

*F lue Gas F low

* I n f i l t r a t i o n

- Energy c o s t based on b o i l e r e f f i c i e n c y and f u e l c o s t .

O p e r a t i n g Labor Cost

- S t a f f requ i remen ts

- U n i t c o s t , i n c l u d i n g f r i n g e s , b e n e f i t s , s u p e r v i s i o n , e t c .

Main tenance Labor

- S t a f f requ i remen ts

- U n i t c o s t .

Maintenance M a t e r i a l s and Spares.

A u x i l i a r y Power Cos ts . Accurate p r o j e c t i o n s o f a u x i l i a r y power c o s t s may b e

deve loped based on t a b u l a t i o n s o f t o t a l u n i t h e a t r a t e and o f p l a n t a u x i l i a r y

l o a d s o v e r a range o f s i x n e t p l a n t l o a d s ; e.g., 25%, 50%, 75%, 100%, VWO

( v a l v e s w ide open), and VWOP ( v a l v e s w i d e open ove rp ressure ) .

Power Consumption. The ma jo r consumers o f e l e c t r i c power a r e l i s t e d as

f o l l o w s :

E l e c t r o s t a t i c P r e c i p i t a t o r s

E l e c t r o s t a t i c p r e c i p i t a t o r power may be p r o j e c t e d based on t h e f o l l o w i n g parameters :

- Constant power to supporting equipment

- Power proportional to flue gas volumetric flow

- Power proportional to flue gas temperature

- Power proportional to inlet ash loading

- Power proportional to fuel sulphu; content

- Power losses from busbar to precipitator

These may be analyzed based on the anticipated performance fuel to determine

the power consumption of the electrostatic precipitator and its supporting

equipment over the specified load range. These correlations must be

guaranteed by the manufacturer, and form part of its proposal. Precipitator

power must be determined at each of the six plant loads listed above.

Induced Draft Fans

Induced draft fan power is profoundly affected by electrostatic precipitator pressure drop, air infiltration, and heat loss. I . D . fan power must be determined over the specified range of operating load, and is usually analyzed based on the anticipated performance fuel. Design horsepower should not be used here, as it usually includes large margins. I.D. fan power calculations should consider design excess air, air infiltration (usually greater than guaranteed), temperature drop across precipitator, and the flue gas analysis.

When turning down the fans for lower outputs at reduced loads, the following

areas should be checked carefully:

Excess air requirements may increase at reduced loads to control convection pass heat fluxes

Infiltration may vary, depending on duct pressures

Flue gas temperatures will vary

Temperature drop will change.

On the basis of the projected I.D. fan flow pressure drop, fan horsepower may

be estimated for each load.

A s t h e f a n power changes, t h e d r i v e changes, t o o . There a r e s e v e r a l t y p e s o f

I . D . f a n d r i v e c o n t r o l s i n common use: I n l e t vane c o n t r o l , v a r i a b l e speed

wound r o t o r motor , d u m p / f i l l h y d r a u l i c c o u p l i n g , v a r i a b l e speed /va r iab le

f requency motor and steam t u r b i n e d r i v e s . The f o l l o w i n g f a n d r i v e f a c t o r s

must be e v a l u a t e d a t t h e v a r i o u s s p e c i f i e d loads:

D i r e c t f a n horsepower under each l o a d c o n d i t i o n

Reduct ion gear l o s s e s

F l u i d c o u p l i n g l o s s e s a t l o a d

Moto r l o s s e s

V a r i a b l e speed d r i v e l o s s e s a t l o a d

Power l o s s e s f rom busbar t o f a n s .

I . D . f a n power l e v e l s must be computed a t each s p e c i f i e d l o a d , and c o r r e c t e d

t o r e f l e c t t h e f a c t o r s l i s t e d above.

U n i t A u x i l i a r y Power Cost. The u n i t a u x i l i a r y power c o s t may b e c a l c u l a t e d i n

a number o f ways, s u b j e c t t o t h e i n d i v i d u a l u t i l i t y ' s s i t u a t i o n . These a r e as

f o l l o w s :

Uni t -Generated Energy

Based on n e t u n i t h e a t r a t e a t each s p e c i f i e d power l e v e l , and e s c a l a t e d f u e l c o s t

System Wholesale Generated Energy Cost

Based on system r a t e f o r who lesa le power i n t h e u t i l i t y system

Combined U n i t & System Generated Enerqy Cost

Based on n e t u n i t hea t r a t e and e s c a l a t e d f u e l c o s t a t each s p e c i f i e d power l e v e l f rom 25% t o VWD (normal p r e s s u r e ) , and on t h e system who lesa le r a t e f o r power t r a n s f e r i n t h e system f o r a u x i l i a r y power used a t VWOP. (Note : Some u t i l i t i e s a p p l y emergency rep lacement power c o s t s t o l o s t c a p a c i t y a t VWOP.)

T o t a l A u x i l i a r y Power Costs. T o t a l a u x i l i a r y power l e v e l s may b e t a b u l a t e d a t

each l o a d , t h e n m u l t i p l i e d b y t h e a p p r o p r i a t e u n i t c o s t a t each load . A

s i m p l e example appears on Table 7-11.

T a b l e 7-11

Auxi I i a r y Power Cost

I tern No.

1

2

3

4

5

6

7

Gross Output Auxi l ia ry Power (kW)

(MW) Precip. I.D. Fan T o t a l

660 2230 9062 11486

T o t a l Annual Cost B C.O.D.

Heat Rate

(Btu/kW-hr)

Annual Duration Cos t B C . O . D . (hrs/yr) ($/yr)*

6 * Sase p r i c e 92/10 B t u , 78 mos. e sca l a t i on @ 8%

Heat Loss Energy Cost

Heat Losses. Thermal energy l o s t from t h e f l u e gas ductwork and the

e l e c t r o s t a t i c p r e c i p i t a t o r must be returned t o t he a i r en t e r ing the cyc le .

The minimum average cold end temperature maintained in t he regenera t ive a i r

h e a t e r may not f a l l below t h e ac id dewpoint. I f t h e thermal energy l o s t

through the i n s u l a t i o n and lagging causes t h e f l u e gas temperature t o drop

below the ac id dewpoint, then add i t i ona l cyc l e hea t must be added t o t h e a i r

s i d e t o avoid severe cor ros ion .

Cost of Heat Losses. The impact on the cyc l e of t h e ex t rac t ion steam used t o

b r ing i n l e t a i r temperatures up t o an acceptable leve l can be based on t h e

c a l c u l a t i o n s shown in Table 7-12. B a s i c a l l y , t h e approach compares two

s imp l i f i ed hea t ba lances , one with and one without t he ex t r ac t ion supply t o

the a i r p rehea t ing system. The column showing "Average Ext r . 106 BTU/hrl'

i s based on normal meteorological cond i t i ons .

Operating and Maintenance Labor

There a r e two types of Q&M personnel : permanently assigned operat ing and

roving , par t - t ime ope ra to r s . For a b r i e f explana t ion of t h e economics of

e a c h , see Table 7-13.

S ince power p l a n t s usua l ly schedule f i v e s h i f t s of ope ra t ion , maintaining an

opera t ion on a s t a t i o n a t a l l t imes r equ i r e s r e t a in ing f l v e opera tors f u l l

t ime . Cycling a roving opera tor through t h e major equipment item

p e r i o d i c a l l y i s more economical in t h a t only a por t ion of a worker 's time i s

chargeable each s h i f t . I t i s assumed t h a t t he workers would have o ther

d u t i e s which would be charged aga ins t o t h e r appropr ia te accounts . I t i s

q u i t e d i f f i c u l t t o develop approximations of the ac tua l c o s t s incurred by

par t - t ime l a b o r , p a r t i c u l a r l y when comparing between a l t e r n a t i v e s .

GENERAL:

I tern

1

2

3

4

5

6

7

8

CASE I :

10

11

Tab le 7-13

Opera t ing and Maintenance Labor Costs

D e s c r i p t i o n

Base Annual Wages

S a l a r y R e l a t e d Cos ts

T o t a l D i r e c t Costs

S u p e r v i s i o n , G&A, e t c .

T o t a l Annual Labor Cost

T o t a l Average Annual Charged Hours

U n i t Cost ($ /h r )

I n c l u d i n g Mark-ups

U n i t Cost D C.O.D . (78 mos. e s c a l a t i o n @ 8%) $24.69 B C . O . D .

U t i l i z a t i o n : One r o v i n g o p e r a t o r , one work h o u r / s h i f t , e i g h t

h o u d s h i f t (one work h o u r / s h i f t ) ( 2 0 0 0 h r d s h i f t y r ) ( e i g h t t o t a l

hours /sh i f t ) = 250 h r / y r

Annual Cos t (250)(24.69) = $6173 B C.O.D.

8 FUELS OTHER THAN COAL

Section 8

FUELS OTHER THAN COAL

I N T R O D U C T I O N

Coal is he predcrninant fuel for electricity production in the United States;

it produced 53.4 percent of the total electricity generated in 1982 (Figure

8 ) . Another 40.1 percent came from nuclear power plants, hydro-electric

plants, and gas-fired boilers, applicarions vhich do n o t require use of

electrostatic precipitators. Included in the remaining 6.5 percent share of

the electricity generated that year were oil-fired boilers, which provided a

6.1 percent share of the electricity generated, and refuse derived fuel (RDF), which has been co-fired with coal in the utility industry since 1972.

Electrostatic precipitators are the most comrnon7y used particulate control

devices on oil-fired b o i l e r s . In 1378, a taka1 of 43 stations were i ? e n t i f i e d

i n an EPRI study as having one or more oil-fired generating units equipped with electrostatic precipitators (110).

Only two RDF installations, a 150 ton-per-day installation operated by an

Ames, Iowa municipal utility and a 200 ton-per-day installation at Madison Gas

& Electric in Madison, Wisconsin, were in commercial operation at the end o f

1982. Eoth instzllations have electrostatic precipitators in service far

particulate removal. Two other installations started up in 1983, and one

additional installation began operation in 1984.

In recent years, interest h a s developed in the conversion of existing

oil-fired equipment to coal firing. Coal-oil mixture (COM) and coal-water

slurry (CWS) firing systems may make a significant contribution towards the

rapid, cost effective substitution of coal for oil.

Combustion testing at several sites has demonstrated tbat a 50 percent coal

and 50 percent No. 6 oil mixture could be fired in some utility boilers in

place of 100 percent No. 6 oil. I n 1981, Flcrida Power and Light complezed a successful demonstration wich 53 percent CON at Sanford Stacion Unit 4, a 400

NUCLEAR 9.5%-

COAL 43.0% I HYDRO 11.7% i i - r

CAPABlLiTY GENERATION 586,142 M W 2,216,821 GWh

*OTHER includes pumped storage capacity. The net negative generation from pumped storage results in reducing generation OTHER to 0.4%.

""The difference between the sum of the parts and 100% represents the share by sources not shown, including ner pumped.

Figure 8-1. Actual C a p a b i l i t y v e r s u s Generation i n t h e

Uni ted S t a t e s for 1982' (109)

MW boiler designed to fire oil (113). For a permanent conversion to COM,

electrostatic precipitators are required for particulate removal. There is

great concern over the use of fabric filter collectors, because unburned

carbon soot in the COM ash could blind fabric filter bags.

Early work sponsored by EPRI and DOE demonstrated that pumpable, relatively stable slurries containing 60 to 70 percent pulverized coal in 30 to 40

percent water could be prepared. An EPRI study which began in 1979 determined that slurries containing 65 to 75 percent (dry weight) "clean"

coal i n water were transportable, storable, and fireable 1 ike No. 6 fuel

oil. Combustion tests, performed in 1982, further determined that CWS

burned stably without requiring supplementary fuel firing (114).

CWS feasibility studies and test burns continue, but to date there are no

utility boilers commercially firing CWS. Babcock and Wilcox estimates that

there are about 20,000 MW of utility boiler capacity, which were originally designed for coal-firing and that could be modified to fire CWS quickly,

that now burn other fuels (G). After conversion to CSW these units will require electrostatic precipitators or fabric filters for particulate

removal .

The purpose of this chapter is to build upon and modify the methodologies

developed for sizing and designing coal-fired boiler electrostatic

precipitators and extend these to the following applications:

Oil-fired boilers

Refuse derived fuel (RDF)

Coal-oil mixture (COM)

Coal-water slurry (CWS)

Topics covered include:

Estimation of process parameters such as flue gas flow rate, ash concentration, ash particle size distribution, the electrical resistivity of the ash, and stack cpacity.

Techniques for precipitator size selection

Specification of unique mechanical and electrical features which may be needed to collect and process these ashes in an electrostatic precipitator.

01 L-FIRED BOILERS

Electrostatic precipitators are the most commonly used particulate removal

devices on oil-fired boilers. This can be attributed partly to the fact that

many oil-fired utility boilers were at one time burning coal and have since

converted to fuel oil. In order that these preci2itators perform adeq~ately,

special equi

El ectrostati particulate

stack emissi

usually the

meet a 0.13

merit modifications were made

c precipitators are capable of reducing oil-fired boiler

emissions by about 50 to 99 percent and can eliminate visible

o n s . Plhen oil firilg, the visible stack emissions reculation is

ccntrolling factor. From a purely .?uantitatiue standpoint. to

lb/xExu emissions limita~ion, it is unlikely tnat a cci ;ection

efficiency higher than 60 percent wouid be needed, even ~ n d e r high fuel

additive rate and high oil ash content conditions. To meet a stack visible

emissions requirement of 20 percent opacity (particularly with higher sulfur

fuel oils which require additives to minimize fireside corrosion), a

precipitator efficiency of about 90 percent would be required. Use of high

efficiency precipitators also reduces stack visible emissions during

sootblowing ( 1 2 0 ) . -

A reduction of oil-fired boiler particuiate emissions by over 90 percent may

be zchieved with correctly sized precipitators designed specifically for oil

ash collection, or by coal-fired boiler precipitators which have been

specially modified to c o l l e c t oil ash (118). Generally speaking, a new or

modified precipitator with the capability for 99 percent fiyash collection

efficiency wili collect oil ash with about 90 percent effic!ency (E). Special modifications for oil ash collection include increased

transformer-rectifier set power, variable intensity rapping to n i n $ m i z e ash

re-entraiawnt, and ad2i:ional heatlns and thermal insulation to keep stjcky

oil ;sh from 5,~i:ding up on i?terior surfaces.


,'i i:jt+t zo2;, ++:: 5:.. c~ . . . - fsS f2 , - c 2 : c G ~ , c ; ~ i i 3 ; y c p ~ - - ,-.. ! ? lor

oil-fired boilers is a representative fuel analysis. Fuel oil i s classified

into two m j 3 r types: residual and distillate. Fuel oils are further

classified by grades: grades No. 1 and No. 2 (disti:late); No. 5 and No. 6

(residual); and No. 4 (a bicnd). The pri~ary diffsrerces between residval oil

and distillate 3il are the higher ash and sulfur content of residcal oil and

t h e f a c t t h a t i t i s more v i s c o u s and hence more d i f f i c u l t t o burn

p r o p e r l y (125). ASTM s t a n d a r d s p e c i f i c a t i o n s f o r f u e l o i l s a r e l i s t e d i n

Tab le 8-1, and t y p i c a l ranges o f a n a l y s e s f o r t h e No. 2 and No. 6 g r a d e s o f

fue l o i l a r e l i s t e d i n Table 8 - 2 . The most f r e q u e n t l y burned f u e l o i l i n

u t i l i t y b o i l e r s i s g rade N o . 6 ; much lower q u a n t i t i e s o f N o . 5, No. 4 and No.

2 a r e used . Very few u t i l i t y b o i l e r s burn crude o i l r a t h e r than t h e s e r e f i l e d

p r o c u c t s (118).

Combustion d a t a f o r a t y p i c a l No. 6 f u e l o i l i s shown i n T a b l e 8-3 . The

gaseous p r z d u c t s o f combustion a r e c a l c u l a t e d f o r t h e o r e t i c a l a i r and 20

;p rcen t e x c e s s a i r l eve l :

A comparison o f a "c l ean" No. 6 f u e l o i l v e r s u s a " d i r t y " No. 6 f u e l o i l i s

p r e s e n t e d i n Tab le 8-4. Inc luded i n t h i s Table a r e f u e l u l t i m a t e a n a l y s e s ,

f u e l h e a t i n g v a l u e s , and two p a r a m e t e r s which can be d e t e r m i n e d by use o f

combustion c h e m i s t r y c a l c u l a t i o n s : t h e t o t a l f l u e g a s produced p e r pound of

f u e l o i l , and i n o r g a n i c a sh e m i s s i o n s . The former can be used t o a c c u r a t e l y

d e t e r m i n e f l u e g a s f low r a t e ; however, i n o r g a n i c a s h i s o n l y one of s e v e r a l

3 t h ~ r i m p o r t a n t ~ o r c p c n e n t s a r e :

Carbon r e s i d u e , which i s s o o t y , o r g a n i c m a t e r i a l , f r e q u e n t l y c o n s i s t i n g of l a r g e unburned carbonaceous p a r t i c l e s t e n d i n g t o be s t i c k y and hygroscop ic . The p a r t i c u ! a t e d i s c h a r g e from o i l - f i r e d b o i l e r s u s u a l l y c o n t a i n s between 30 p e r c e n t and 80 p e r c e n t ca rbon c o n t e n t .

* F i l t e r a b l e s u l f a t e s , formed by low ternperz ture and /o r high e x c e s s a i r o p e r a t i o n and by :he u;e o f f u e l o i l and f i r o s i d s z d d i t i v e s . Alumina, d o i o n i t e , magnesia and a m ~ o n i a a d d i t i v e s a r e f r e q u e n t l y used t o improve b o i l e r h e a t t r a n s f e r and t o r e d a c e c o r r o s i o n . When t h e s e a d d i t i v e s a r e used w h i l e b u r n i n g high s u l f u r f u e l o i l , s u l f a t e s c o n s t i t u t e approx ima te ly 35 t o 50 p e r c e n t o f t h e p a r t i c u l a t e e n i s s i o n s cz'ch.

Acid s m ~ t , which i s 2 c c n b i n a t i o n of condensed a c i d ;cd cz rbon tkia: y i e l d s g r e a s y , c o r r o s i v e p a r t i c l e s . Acid smut i s c r e a t e d by t n e f o r m a t i o n and/or c o l l e c t i o n o f s u l f u r i c a c i d upon p a r t i c u l a t e d e p o s i t s which l i e on f u r n a c e and d u c t s u r f a c e s . Although some a c i d smut i s p e r i o d i c a l l y r e l e a s e d by aerodynamic r e e n t r a i n n e n t and d u c t

, - v j ~ r ~ : ~ g n ~ , t h s .-,,.-.. s , L ' - i:cT 2 ~ i l SIC>; 2: ; ; : S S ; ' O C S ? ~ 3 d ~ l i j S S P L ~ Y O Z . : ~ ~ S

d u r i n g s o o t blowing. Acid smut i s t h u s g e n e r a l l y r e l e a s e d a s l a r g e , f l a k y p a r t i c i e s .

T a b l e 8-1

A Z T i i Standard Specifications for

Fuel O i 1 s (124)

Yo. I A d i ~ t i l l a t e a i l intended for vaporizing p~ t - t ype burners and other burners requiring this grade of fuel Yo. 2 A d i s t i l l a t e o i l f o r general purpose W 1 t i c heating for use i n burners not r q u i r i n g Yo. 1 fuel o i l M. 4 Pmheatiw not usually required fo r handling o r burning Yo. 5 (Light) Preheating m y be r e q u i d depndinp on climate and equipnent No. 5 (Heavy) Preheating nay be w u i r d for burning and, i n cold c l imtes. m y be required f o r handling (Bunker 8 ) Yo. 6 Preheating requlrCd for h r n i n g and Mndl ing (8mnrer C)

Wter Carbon Dis t i l l a t i on Cnde Flash Pour and residue t-ratwes, K i n m t i c viscosity. mPper of p i n t , point redimnt. on 101 Ash *fIC) M W ) t viscosity, rec centistmkes Gravity s t r i p

1 *F OF % by b o t t a . %.by IET 90Z Universal a t Fvmt at I t IW'F At 122'F dep mr- o i l ( C l (d l vol- % ~ l a h t point point IWDF(3BC) 122'F ( 5 K I (38C) ( 9 x 1 RPI msion

B i n )Lb. M x Pax *dl x l l in b nin Par nm Tax n m Par r i n *ax ain nm

No. 1 1W or 0 trace 0.15 - 4 2 0 - 5 5 0 - - - 1.4 2.2 - - 35 Ilo. 3 legal (215) (2881 (381

Ilo. 2 lo0 or mC 0.10 0.35 540' 640 (32.61' (37.94) - - 2.0e 3.6 - - 311 legal 1-71 (ZBZ (3381

(381

Ho. 4 l 3 D o r 20 0.50 0.10 - - - 45 125 - - 15.81 (26.1) - - legal ( - 71 1551

M. 5 130 or - l .W 0.10 - - - l i gh t legal

1551

a. Rescgnizing the necerrTty for I n -su l fu r o l l r used i n connection with hedt-trealmnt, nonfcrmur metal, glass, and c e r m i c furnaces and other special uses. d sulfur reqvtrnrelrt may be specifled i n accordance wi th the fo l lov ing table:

Grade of fuel o i l Sulfur. nax. I

No. 1 0.5 Ho. 2 0.7 No. 6 no l i m i t Ho. 5 no l i m i t M. h no l i m i t

b. It i s thc intent of there classif ications that failure t o met any r w u i r m n t s of a given grade doel not a u t m t i c a l l y place an o i l i n the next larcr grade unless i n fact i t m e t s a l l m q u i r m n t r o f the lpnr grade.

c. 1-r or higher pour polntr m y be specified Menever required by conditions of storage o r use.

d. The 10% d i s t i l l a t i o n tenpcratwe point may be r p e c i f i d a t W'F t226CI mrmm for use i n other than a tm i r i ng burners

f. Yi remi ty valuer i n parentheses are for infomation only and not necessarily l imi t ing

g . me m u n t of water by d ~ r t i l l a t i o n pIur the sediment by extraction shall m t ei& 2 . a . The a r u n t of sediment by extraction shall not exceed 0.m. A deduction i n quantity shall be mde for a l l ra ter a d sediocnt in ezces~ o f 1.m.

T a b l e 8-2

Typical Ranges o f Analyses of No. 2 a n d No. 6 Grade Fuel O i 1 s (Adapted from (118) , (724) )

Grade of 'Fuel O i l

Weight, Percent

S u l f u r

Hydrogen

CarSon

h'lcrogen

Oxygen

Ash

G r a v i t y , OA?1

?our P o i n t , " F

V i s c o s i t y , Centistrokss @ 100°F

Uater & Sediment, Volume percent

Carbon R e s i d u e , Weight percenti*

Heating v a l u e , B t u / l b jgr@ss)**"

No. 2

0.004 - 1.0

11.8 - 1 3 . 9

8 6 . 1 - 88.2

Nil - 0.1

No. 6

** CARBON RESIDUE OX 10% BOTTOXS FOR SO. 2 ALQ ON 100 PERCENT BOTTOMS FOR KO. 6

*** CALCULATED VALL'ES

Tab le 8-3

Combustion Data Summary f o r a Typical No. 6 Fuel Oil (127)

Analysis

Carponent

Gross heating value

X by weight

Carbon Hydrogen Sul fur Water Ash

Catbustion a i r requirement (dry)

88.3 9.5 1.6 0.05 0.10

lb / lb Theoretical -Ti3 10% excess 193.9 14.8 20% excess 211.6 16.1 100% excess 352.6 26.9

Products o f cmtwstion, per l b o f fuel o i l Assune a i r a t 40% RH, 60°F

Conponent

Total 1 186.7 1 14.49 1 222.5 1 17.22

* 2

Hzo so 2

u2

02

At theoret ical a i r At 207, excess a i r

27.9 sc f 19.3 0.2

139.3 -

3.24 I b 0.92 0.03

10.30 --

27.9 scf 19.5 0.2

167.5 7.4

3.24 l b 0.93 0.03

12.38 0.66

Parameter

Carbon (%)

Hydrogen (%)

Oxygen (%)

Nitrogen (%)

Sulfur (%)

Ash (%)

Heat Value (Btu/lb)

Table 8-4

Comparison o f a Clean No. 6 Fuel O i l versus a Dirty No. 6 Fuel O i l

"Clean" N o . 6 Fuel O i l

8 6 . 5

11.9

0.4

0 . 2

1 .o

0 .01

18,800

Tor 1 Flue Gas Produced 3 (ft gas / lb fue1,wet b a s i s ) * 223.1

"Dirty" No. 6 Fuel 011

86.5

9.5

0.8

0.4

2 . 4 5

0.35

18,500

Inorganic ash emissions (lb/mBtu) **

* A t 6 0 ' ~ and 30.0 i n Hg. Assumes 2.5% excess a i r and 10% a i r heater in leakage.

** Assumes 80% ash carryover from b o i l e r .

Fuel o i l and f i r e s i d e a d d i t i v e s which have not reac ted t o produce s u l f a t e s . This catagory inc ludes unreacted a d d i t i v e a s well a s a d d i t i v e which has coupled with sodium-vanadium complexes.

Carbon soo t , which i s e s s e n t i a l l y i den t i ca l i n composition t o carbon r e s idue but i s formed by vapor phase condensation. Soot p a r t i c ? s s a r e very uniform in s i z e , 0 . 0 1 t o 0 . 1 0 micrometer in d iameter , and a r e t hus d i s t i ngu i shab le from carbon residue p a r t i c l e s wnich a r e 1 0 t o 100 microns in diameter (=).

S u l f u r i c ac id mi s t , which i s comprised of f i n e l y d ispersed l i q u i d d r o p l e t s of H,SO,.

The mixture of p a r t i c u l a t e mat te r emissions components can be estimate^ but

not t h e o r e t i c a l l y determined. The types of p a r t i c u l a t e mat te r ercissions rnd

q u a l t i t i e s of each type a r e dependent upcn many f a c t o r s , inc luding:

* Condition and type of equipment

Bo i l e r r a t i n g

F i r ing cond i t i ons , e spec i a l l y combustion excess a i r l eve l

Use of fuel o i l o r f i r e s i d e a d d i t i v e s

Percentage by weight o f inorganic p a r t i c u l a t e ma t t e r , s u l f u r and carbon res idue in t he fue l o i l .

The type of t h e combustion equipment and i t s condit ion usua l ly play a

secondary r o l e in t he u t i l i t y s e c t o r but can, under extreme cond i t i ons , have a

s i g n i f i c a n t e f f e c t on p a r t i c u l a t e emissions. P a r t i c u l a t e emissions may be

decreased by:

Longer combustion region residence times

Proper cont ro l o f t he degree of comhustion a i r sw i r l i ng in t he combustion region

Use of modern o i l burners and con t ro l s t h a t a l low a f i n e r degree of o i l a tomizat ion and operat ion a t optimized combustion excess a i r l e v e l s

Frequently cleaning the f i r ebox , ductwork, and ash hoppers, and continuous sequent ia l soot blowing of heat t r a n s f e r s u r f a c e s .

A l o n g e r c o m b u s t i o n r e g i o n r e s i d e n c e t i m e d e c r e a s e s p a r t i c u l a t e e m i s s i o n s b u t

i n c r e z s e s NO e m i s s i o n s . F i g u r e 8-2 p r e s e n t s t h e r e s u l t s o f one X

i n v e s t i g a t o r ' s f i n d i n g s on t h e b e n e f i c i a l e f f e c t o f o p t i m i z i n g c o m b u s t i o n a i r

s w i r l ; howeve r , F n c r e a s i n g c o m b u s t i o n a i r s w i r l a l s o p r o m o t e s a f i n e r

p a r t i c u l a t e s i z e d i s t r i b u t i o n and i n c r e a s e d NOx e m i s s i o n s . H i g h e r

p a r t i c u l a t e e m i s s i o n s r e s u l t f r o m t o o f i n e o r t o o c o a r s e an o i l a t o m i z a t i o n ;

f i n e r a t o m i z a t i o n l e v e l s a l s o i n c r e a s e NO e m i s s i o n s . Combus t i on e x c e s s a i r X

l e v e l , a s d e m o n s t r a t e d i n F i g u r e 8 -3 , s t r o n g l y i n f l u e n c e s p a r t i c u l a t e

e m i s s i o n s . Modern o i l b u r n e f s and b u r n e r c o n t r o l s a l l o w s t a b l e o p e r a t i o n a t

b e l o w 5 p e r c e n t excess a i r l e v e l s o v e r a w i d e b o i l e r l o a d r a n g e . A 1975 s t u d y

on p a r t i c u l a t e c o n t r o l s t r a t e g y b y t h e Bos ton E d i s o n Company c o n c l u d e d t h a t

r e d u c t i o n s o f up t o 30 p e r c e n t can b e a c h i e v e d on l a r g e u t i l i t y b o i l e r s

t h r o u g h u s e o f t h e f o l l o w i n g o p e r a t i n g and m a i n t e n a n c e p r o c e d u r e s ( 131 ,118 ) :

C o n t i n u o u s s e q u e n t i a l o p e r a t i o n o f s o o t b l o w e r s .

R o u t i n e d i s a s s e m b l y and c l e a n i n g o f f u e l o i l b u r n e r s , a n d r e n e w a l o f wo rn p a r t s as soon as wear i s d e t e c t e d .

A b o i l e r shutdown e v e r y t h r e e months t o p u r g e c l e a n t h e b u r n e r s and t o c l e a n t h e f i r e s i d e s o f b o i l e r s , d u c t w o r k , and a s h h o p p e r s .

Comp le te o v e r h a u l o f a l l e q u i p c e n t d u r i n g each a n n u a l o u t a g e .

T h i s r e s u l t i s i n t e r e s t i n g because i t d e m o n s t r a t e s t h a t w e l l - m a i n t a i n e d

e q u i p m e n t c a n b e even f u r t h e r o p t i m i z e d by e x t r a o r d i n a r y m a i n t e n a n c e measures .

B o i l e r r a t i n g i n f l u e n c e s t h e amount o f p a r t i c u l a t e e m i s s i o n s , a s shown i n

F i g u r e 8-4 ( f o r u n c o n t r o l l e d b o i l e r s w i t h no a d d i t i v e s employed) a n d F i g u r e

8-5 ( f o r u n c o n t r o l l e d r e s i d u a l o i l - f i r e d b o i l e r s , w i t h and w i t h o u t a d d i t i v e s

employed) . As seen i n F i g u r e 8-4, a l a r g e d e g r e e o f d a t a s c a t t e r i s a p p a r e n t

b e l o w t h e 150 MW b o i l e r r a t i n g , w h i l e f r o m 150 MW t o 600 MW u n c o n t r o l l e d

p a r t i c u l a t e e m i s s i o n s r a n g e be tween a b o u t 0 . 0 3 and 0 .06 l b /mB tu . T h i s t r e n d

e x i s t s i n p a r t because l a r g e u t i l i t y b o i l e r s a r e g e n e r a l l y w e l l m a i n t a i n e d and

o p e r a t e d a n d u s u a l l y emp loy s t a t e o f t h e a r t c o m b u s t i o n e q u i p m e n t .

F i r i n g c o n d i t i o n s nave a v e r y s i g n i f i c a n t e f f e c t . I n c r e a s i n g f u e l '~.7CPl.a',." Z . - ' "."' ? - .-., b u . L , , lL p , . - _ s l i r e , .r I ;me t e m p e r a - a r e , and s t a c k g a s t e m p e r a t u r e a l l

s e r v e t o d e c r e a s e t h e a n 3 u n t o f p a r t i c u l a t e e m i s s i o n s . P a r t i c u l a t e e m i s s i o n s

r i s e w i t h an i n c r e a s e d r a t e o f f l u e g a s r e c i r c u l a t i o n , a l t h o u g h t h i s p r a c t i c e

0J t I f 9 I I I 1 f I 0.6 0.7 0.8 0.9 1.0

TANGENT OF SWIRL AIR ANGLE

Figure 8-2. T e s t Resul t s Showing the Ef fec t s o f Combustion Air Swirl on P a r t i c u l a t e Emissions from an Oil-Fired Boi le r ( l 2 9 ) , (110) -- -

OXYGEN IN BOILER FLUE GAS. %

Figure 8-3. Variat ion of P a r t i c u l a t e Emissions from Oi l -F i red Boilers w i t h Oxygen Content i n Flue Gas (110, 132)

BOILER OPERATING CAPACITY, Mw

Figure 8-4. Uncontrolled Electric U t i l i t y Oil-Fired Boiler Emissions versus Boi 1 er Operati nq Capacity (No Addi ti v ies Employed) (fl, Q)

0 CONTROLLED SYSTEMS USrNG ADDITIVES

0 CONTROLLED SYSTEMS NOT USING ADDITIVES

BOILER OPERATING CAPACITY, M w

Figure 8-5. Controlled E l e c t r i c U t i l i t y Residual Oil-Fired Boi le r Emissions ( A f t e r ESP) versus Boi le r Operating Capacity (With and Without MgO Addit ive Employed) (87) -

i s favored f o r the cont ro l of NOx emissions. A t yp i ca l va r i a t i on in

p a r t i c u l a t e emissions wi th oxygen content in t he b o i l e r f l ue gas i s shown in

Figure 8-3. This r e l a t i o n s h i p was developed f o r a d i r t y No. 6 fue l o i l burned

i n a l a r g e b o i l e r . Higher emission r a t e s a s soc i a t ed with lower l e v e l s of

excess a i r a r e caused by increased carbon l o s s , while t he increase in

emissions a t higher excess a i r l e v e l s i s caused by acce lera ted conversion of

s u l f u r d ioxide t o s u l f u r t r i o x i d e which in t u rn promotes a n i nc rease in

f i l t e r a b i e s u l f a t e s and s u l f u r i c ac id mis t (132) . - Figure 8-6 p re sen t s

add i t i ona l t e s t da ta which adds i n s igh t i n t o t h i s carbon/acid r e l a t i o n s h i p .

A t low excess a i r l e v e l s , most of the SO, produced i s absorbed by carbon

p a r t i c l e s ; an ana lys i s of t he f i i t e r ca t ch showed 57 percent carbon and 24

percent a c i d . Stack opac i ty was bclow 20 percent , with a whi:e/S*own'sh

plume. A t high excess a i r l e v e l s , t h e r e i s more SO, ava i l ab l e than t h e r e

i s carbon t o absorb i t ; an a n a l y s i s of t h e ca tch showed 15 percent carbon and

50 percent a c i d . Stack opac i ty increased , occas iona l ly exceeding 20 pe rcen t ,

with an acid-blue haze plume (126 ) . -

Fuel o i l and f i r e s i d e a d d i t i v e s a r e f r equen t ly used t o reduce ac id cor ros ion

and t o improve b o i l e r hea t t r a n s f e r c h a r a c t e r i s t i c s . Addit ives reduce ac id

cor ros ion by coupling wi th s u l f u r t r i o x i d e t o form s u l f a t e s , and hea t t r a n s f e r

i s improved by the conversion of s t i cky ash components, which adhere t o hea t

exchanger su r f aces , i n t o powdery-like compounds t h a t can be removed by

sootblowing (133, m),. Alumina, dolomite and magnesia a r e f r equen t ly used

a d d i t i v e s in u t i l i t y o i l - f i r e d b o i l e r s . Carbon s m u t and acid mi s t have a l s o

been succes s fu l ly c o n t r o l l e d by adding ammonia t o t he f l u e gas j u s t upstream

of the a i r hea t e r . Ammonia combines with s u l f u r t r i o x i d e t o produce a fume of

(NH,),SO,, which can then be co l l ec t ed in a p a r t i c u l a t e control

device.

The e f f e c t of a d d i t i v e s on the quan t i t y and composition of p a r t i c u l a t e

emissions can be s i g n i f i c a n t . Addit ives u sua l ly increase emissions bu t , in

some c a s e s , can decrease o r have a neg l ig ib l e e f f e c t on the q u a n t i t y of

p a r t i c u l a t e matter emi t ted from o i l - f i r e d b o i l e r s . Typica l ly , use of alumina,

dolomite, magnesia, o r ammonia w i l l increase emissions by a f a c t o r of about

1 . 5 t o 2 .5 , with s u l f a t e s c o n s t i t u t i n g approximately 35 t o 50 percent of t he

f i l t e r a b l e p a r t i c u l a t e emiss ions when f i r i n g a high s u l f u r fue l o i l .

- SQ3, PPm

r r r r m H +Q4 possible in emissions

om-- Actual H2S04 emissions

Total emissions

yields high- acid plume

0 1 .O 2.0 3.0 4.0

O2 LEVELS, %

Figure 8-6. Carbon/Acid Relationship in Oil-Fired Boiler Particulate

Emissions (126 ) -

Figure 8-4 when using

effect of aium'na and

ash deposits is graph

magnesia additives are readily explainable (m). The

dolomite additives on the composition of superheater oil

cally illustrated in Figure 8-7. The indicated

particulate removal efficiency, the higher particulate emission rates shown in

1

troublesome constituents (sodium-vanadium complexes) are highly corrosive when

deposited i n a molten state on h i g h temperature metal surfaces. In addition

to this, vanadium also acts as a good catalyst for conversion of SO, to

SO,, hence giving low temperature corrosion an undesired boost. Alumina,

e for b:-h-- --..--A . , . . , L;,e , s,,.~,. = i d ~ r ccrrosion ci::r3;, C ~ E i ;L. , .Live is t l ied t; - -

vanadjum co7tent of the fuel at a ratio normally of about 2 : l of magnesium and aluminum oxijes to vanadium. The additives raise the melting point of the ash deposit, rendering it a powdery substance which can be removed by soatblowing and collected in a particulate control device.

* For lsw temperature corrosion control, additives c3uple with sulfur trioxide to form sulfates, which can be collected in a particulate control device.

The distjllate oil add:tj)!es 1<:;:?2 $5 T;t:z 2-5 .,,:re i ~ ~ ~ ~ - j f ~ ~ ~ by

irvesti~atgr 2 s k i n g c2~227e cf reducing particulate emissions by 30 to 50

percent ( 1 3 7 ) . - The importance of additive concentration on particulate

emissions rate is demonstrate2 in Figure 8-8; this relationship was determined

during a test arcgram evaluating usage of Ethyl CI-2, one of the additives

listed oo Table 8-5.

Figure t i -9 shows pr~iculate emissions frorc industrial oi:-fired hollers as a

fgnction of the inorganic ash content of the fuel oil. Mezsured emissions are

on the order of one to two times the theoretically deternined enissions if

fuel zsh were csnsiderdd xo be the oniy emissions compo!lenx. Considering Lhat

oil ;sh carryover ranges between 30 TO 100 percect, this resclt demonstrates

that unburned carbon ranges from 30 to 80 percent, or on the order of one to

five times the inorganic a s h emissions ( 1 3 5 ) . When considering atility cil

f i r e d boi7ers, fuel ash content i s not a $srtic~;lar!y useful indicatsr of the

quantity of prticulate emissions due to widespread usage of additives and ash

reinjection. Ash reinjection typically adds 3e tweSn 50 a ~ d 100 percent to the

T a b l e 8-5

Seven Distillate Fuel Oil Additives Found to Substantially Reduce Par t i cu l a t e Emissions (118, 137)

Additive

-- Arapahoe Ferrocene

Ethyl C1-2

Comercial Chemical Improsoot

Gaml en DP231

Fuel Combustion Corp. Fuel co SOj

Ccmwcial Chemical Formula L S D

Industrial Chemicals Watcs 130

b ~ i l l imoles per kilogram

Concentrat ion

Ye igh t ! b

Total p a r t i c u l a t e with addi t i v e / t o t a l par t fcula te without

add i t ive

WITHOUT

5 TROUBLESOME CONSTITUENTS

DOLOMITE

Figure 8 - 7 . Effect o f Fuel Oi l Add i t i ves on t he Composition o f Superheater Oil Ash Deposit (Adapted fromlllO), - (124)) -

ADDITIVE, W T %

Figure 8-8. Particui ate Ratio (Particulate 5~issions with Additive/Particulat? Emissions without Additive) versus Ethyl CI-2 Additive Concentration (118), (137) - --

WT% ASH IN FUEL

F i g u r e 8-9 . Uncontrolled I n d u s t r i a l Oil-Fired Boiler P a r t i c u l a t e Emissions versus Weight-Percent Ash in Fuel Oil (UJ, 135)

i n o r g a n i c d u s t l o a d i n g (135). F i g u r e 8-10 demonstates t h e l a c k o f a

r e l a t i o n s h i p between f u e l ash c o n t e n t and p a r t i c u l a t e e m i s s i o n s f o r c o n t r o l l e d

r e s i d u a l o i l - f i r e d u t i l i t y b o i l e r s o f 70 MW c a p a c i t y and above.

C o n t r o l l e d and u n c o n t r o l l e d p a r t i c u l a t e e m i s s i o n s f o r r e s i d u a l , o i l - f i r e d

u t i l i t y b o i l e r s o f 70 MW c a p a c i t y and above i s shown a s a f u n c t i o n o f f u e l o i l

s u l f u r c o n t e n t i n F i g u r e 8-11. A l t h o u g h t h e r e i s a s l i g h t t r e n d toward h i g h e r

emiss ions w i t h h i g h e r f u e l s u l f u r c o n t e n t , t h e d a t a i s t o o s c a t t e r e d t o d e f i n e

a u s e f u l r e l a t i o n s h i p (119). Hence, a l t h o u g h a d d i t i o n a l s u l f u r i n t h e f l u e

gas c o u l d l e a d t o a d d i t i o n a l f i l t e r a b l e s u l f a t e s , a c i d smut and s u l f u r i c a c i d

m i s t , and ocher f u e l p r o p e r t i e s ( s u c h as i n o r g a n i c ash c o n t e n t and r a r b o n

r e s i d u e c o n ~ e n t ) , b o i i e r r a t i n g and c o n b u s t i o n f i r i n g c o n d i t i o n s a r e

o v e r r i d i n g f a c t o r s .

P a r t i c u l a t e e m i s s i o n s have been found t o i n c r e a s e when t h e ca rbon r e s i d u e i n

t h e f u e l o i l i n c r e a s e s ( F i g u r e 8-12) . A s p h a l t e n e (naptnenes and s i m i l i a r

h y d r o c a r b o n s ) , found i n Venezue l ian , G u l f Coas t , C a l i f o r n i a and some Rocky

Moun ta in r e s i d u a l o i l s , c o n s t i t u t e a l a r g e p o r t i o n o f t h i s ca rbon r e s i d u e .

A1 though F i g u r e 8-12 i s based on i n d u s t r i a l b o i l e r t e s t s , s i r n i l i a r r e s u l t s

have been o b t a i n e d f o r l a r g e u t i l i t y r e s i d u a l o i l - f i r e d b o i l e r s .

Comprehensive mass ba lances o f t h e p a r t i c u l a t e emissYons f r o m o i l - f i r e d

b o i l e r s a r e n o t a v a i i a b l e i n t h e open l i t e r a t u r e ; however, an i n t e r e s t i n g

e s t i m a t e was r e p o r t e d on by one i n v e s t i g a t o r (Tab le 8-6). T h i s e s t i m a t e i s

based on t h e f o l l o w i n g assumpt ions ( 1 3 5 ) : -

O i l ash c a r r y o v e r v a r i e s f rom 30 t o 100 p e r c e n t , w i t h an a d d i t i o n a l 10 t o 20 p e r c e n t e m i t t e d d u r i n g s o o t b l o w i n g .

A d d i t i v e s a r e t r e a t e d as an e q u i v a l e n t amount o f o i l ash. T h e i r r e a c t i o n w i t h o t h e r e m i s s i o n s components i s i g n o r e d i n t h i s e s t i m a t e .

On t h e o r d e r o f 1 t o 5 p e r c e n t o f t h e f u e l s u l f u r i s c o n v e r t e d t o s u l f u r t r i o x i d e , w h i c h c o u l d t h e n combine w i t h w a t e r vapor i n t h e f l u e gas t o f o r m s u l f u r i c a c i d m i s t . The So3 t o H 2 SO c o n v e r s i o n r a t e i s dependent upon gas t e m p e r a t u r e ( r e l a t i v e t o t h e a c i d d e w p o i n t ) i n accordance w i t h F i g u r e 8-13. I t i s assumed :hat t h e a i r h e ~ t e r o u t i e t t ~ m p e r a t u r e r a n g e s f r o m 250 t o 27O0F, w i t h a duc twork g r a d i e n t o f + 50°F.

Carbon r e s i d u e i s assumed t o be between 0 .02 and 0 .10 gns /ac f . The lower end v a l u e i s i n acco rdance w i t h t h e r u l e o f thumb t h a t 0 . 0 5 t o

.20

3 .IS o - Uncontrolled G 5 x -Boilers Controlled

.16 by Electrostatic 9 vi

.I4 0 V)

2 .12 z w I- .10 5 3 2 .08 I- er a L .06 o A m 2 .04 w + i .02

PERCENTAGE O f SULFUR IN OIL 19149-5

F i g u r e 6-11. C o n t r o l l e d and Uncon t ro l l ed P a r t i c u l a t e Emiss ions as a Funct ion o f Fuel S u l f u r Content f o r Residual Oil F i r e d Base-Loaded U t i l i t y B o i l e r s a t o r Above 70 MW Capac i ty (No A d d i t i v i e s Employed) (E)

Table 8-6

Total Emiss ions w i t h Ash

R e i n j e c t i o n , g n s / a c f

Estimated Particulate Emiss ions for Three Different Fuel Oils F i r e d i n a U t i l i t y Boiler (Adapted from ( l a )

Fue l A Fuel B Fuel C

Oil Analys i s

Ash Conten t , % weight

Vanadium, ppm

Sulfur Conten t , % weight

A d d i t i v e (MgO + A10) , X weight

Emission Components, gns/acf

I n o r g a n i c Ash 0.008 t o 0.025 0.008 t o 0.025 0.012 t o 0.038

A d d i t i v e s - 0.003 t o 0.010 0.006 t o 0.020

Sulfuric Acid M i s t 0 t o 0.003 0 t o 0.01 0 t o 0.03

Carbon Res idue 0.02 t o 0.10 0.02 t o 0.10 0.02 t o 0.10

Carbon Soot 0.003 0.003 0.003

T o t a l Emiss ions , gns/acf 0.031 t o 0.13 0.034 ta 0.15 0.041 t o 0.19

2 4 6 8 10 12 14

FUEL OIL CARBON RESIDUE. PERCENT

F i g u r e 8-12. Effect o f Fuel O i l Carbon Residue on

P a r t i c u l a t e E~! i i s s i ons fro111 Indus t r i a l O i l Fired

b o i l e r s (118, 136) - -

GAS TEMPERATURE (UNIFORM)*F

Figure 8-13. Sulfuric Acid Mist Loading versus Flue Gas Temperature for Oil Fired Boilers (110, 135) -

0.10 percent of the heating value of the fuel is lost as carbon. The upper end value is representative of boilers operating with low excess combustion air, on the order of 5 percent or less.

Carbon soot is assumed to be 0.003 gns/acf, based on available distillate fuel oil test data.

Acid smut formation is ignored in this estimate.

Based on available test data, an increase in organic ash loading of 50 to 100 percent is assigned to ash reinjection.

The range of total emissions estimated for each of the three fuels listed on

Table 8-6 varies by a factor of between 4 and 5. This reflects the high

degree of uncertainty associated with predicting oil ash carryover and the

amount of carbon residue in the emissions, and also the wide range of additive

rates employed by boiler operators.

Of interest is the use of emission factors for predicting emissions from

uncontrolled oil-fired boilers. The U.S. Environmental Protection Agency

compiles emission factors for all stationary sources for which sufficient

information exists to establish realistic relationships. Emission factors

relate the quantity of pollutants emitted to some indicator, usually boiler

size or quantity of fuel burned, while empirical data on process parameters

(temperature, excess air, etc.) is not considered (125). - U.S. Environmental

Protection Agency emissions factors for the determination of uncontrolled

emissions from oil-fired power plants are summarized on Table 8-7. For a

typical No. 6 fuel oil, the particulate emissions factor of 8 lb

pollutants/1O3 gal of fuel oil is approximately equivalent to 0.053 lb/mBtu

emissions. A slightly more refined approach was developed by the GCA

Corporation in 1974. Based on the uncontrolled emissions data plotted in

Figure 8-3, the following regression equation was developed (119):

where: y = filterable particulate emissions (tb/rnBtu) x = boiler capacity (MW).

This equation is useful for preliminary estimates of oil-fired boiler

emissions when additives are not utilized.

Table 8-7

U.S. Environmental Protection Agency Emissions Factors for Determination of Uncontrolled

Emissions from Oil Fired Power Plants (Adapted from (G))

P o l l u t a n t

P a r t i c u l a t e

S u l f u r Dioxide (SO2)

S u l f u r T r i o x i d e (SO3)

Carbon Monoxide (CO)

Hydrocarbons

N i t r o g e n Oxides (NO2)

Aldehydes (HCHO)

U n c o n t r o l l e d Emiss ions

f l b p o l l u r a n t s / l ~ ~ g a l f u e l o i l )

8*

* E q u i v a l e n t t o 0.053 lb/mBtu f o r t y p i c a l No. 6 f u e l oil

** Use 50 f o r t a n g e n t i a l l y f i r e d u n i t s

S = p e r c e n t by we igh t of s u l f u r i n f u e l oil

An i m p o r t a n t process parameter w i t h r e s p e c t t o t h e d e s i g n and per formance o f

e l e c t r o s t a t i c p r e c i p i t a t o r s i s t h e p a r t i c l e s i z e d i s t r i b u t i o n o f t h e

e f f l u e n t . F o r o i l - f i r e d b o i l e r s , p a r t i c l e s i z e d i s t r i b u t i o n depends on t h e

f o l l o w i n g f a c t o r s :

Degree o f a t o m i z a t i o n o f t h e o i l

Degree o f m i x i n g i n t h e combust ion r e g i o n

Flame temperature

Furnace des ign

The f l u e gas pa th t h r o u g h t h e b o i l e r t o t h e s t a c k ( " t i m e a t tempera tu re p r o f i l e " ) .

P a r t i c l e s i z e d i s t r i b u t i o n v a r i e s c o n s i d e r a b l y f r o m one u n i t t o t h e n e x t , b u t

f o r t h e most p a r t , o i l - f i r e d b o i l e r emiss ions can be c h a r a c t e r i z e d as b e i n g

v e r y f i n e . Each p a r t i c u l a t e e m i s s i o n s component has a unique p a r t i c l e s i z e

range, as l i s t e d on Table 8-8. Carbon soo t c o n t r i b u t e s t h e f i n e s t p a r t i c l e s ,

and carbon r e s i d u e c o n t r i b u t e s t h e c o a r s e s t ( t y p i c a l l y up t o 50 microns

d iamete r b u t o c c a s i o n a l l y as l a r g e as 100 m i c r o n s ) . When a c i d smut i s

p r e s e n t , t hese l a r g e p a r t i c l e s a r e capab le o f s t a y i n g e n t r a i n e d i n t h e gas

stream t h r o u g h t o t h e s t a c k due t o t h e i r t h i n f l a k y shape. Three t y p i c a l

o a r t i c l e s i z e d i s t r i b u t i o n s showing t h e f i n e p a r t i c l e s i z e o f o i l e m i s s i o n s

b u l k e l e c t r i c a l r e s i s t i v i t y o f o i l - f i r e d b o i l e r

i c a l l y low. Because o f t h e r e l a t i v e l y l o w quant

1 o i l , t h e r e i s u s u a l l y s u f f i c i e n t SO, a v a i l a b l e

a r e

The

t Y p f ue

shown i n F i g u r e 8-14 (110, 139).

p a r t i c u l a t e emiss ions i s

i t y o f i n o r g a n i c ash i n

f o r n a t u r a l

c o n d i t i o n i n g , even w i t h f u e l o i l s h a v i n g a v e r y l o w s u l f u r c o n t e n t (132). I n

a d d i t i o n , 30 t o 80 percen t o f t h e e m i s s i o n s c o n s i s t s o f unburned carbon, wh ich

i s always a h i g h l y conduc t i ve m a t e r i a l . T h e r e f o r e , t h e r e s i s t i v i t y o f

o i l - f i r e d b o i l e r p a r t i c u l a t e emiss ions i s a lmos t a lways l e s s than t h a t f o r

caa

coa

bo i

r e s

con

, l o 7 t o 10' ohm-cm f o r o i l v e r s u s lo9 t o 1 0 1 3 ohm-cm f o r

(119). A t y p i c a l r e s i s t i v i t y v e r s u s t e m p e r a t u r e curve, f o r an o i l - f i r e d

e r b u r n i n g a No. 6 f u e l o i l , i s shown i n F i g u r e 8-15. Measured ash

s t i v i t y c u r v e s , f o r ash produced d u r i n g combust ion o f a v e r y l ow s u l f u r

e n t f u e l o i l , a r e p resen ted i n F i g u r e 8-16.

Table 8-8

P a r t i c l e Size Range o f Oil Fired B o i l e r Pa r t i cu la te Emiss ions Components (Adapted from (1 l o ) , (135) , (138))

Par t icu la te Emissions Component

Inorganic Ash

A d d i t i v e s

S u l f u r i c Acid M i s t

Carbon Residue

Carbon Soot

Acid Smut

P a r t i c u l a t e Size Range

1 t o 5 microns

l t o 5 microns

O . S t o 5 microns

10 t o 100 microns

0.01 t o 0.10 microns

1/8 t o 114 inch f l a k e s

20

10

V) Z

0 - Z r x - 5 UI !- W

5 - 0 W -I

0 C LT

2

1 80 90 99

CUMULATIVE % LESS THAN SIZE INDICATED

F i g u r e 8-14. T y p i c a l P a r t i c l e S ize L i s t r i b u t i o n s o f O i l F i r e d B o i l e r Emiss ions Based on u'ata Prov id by t h e U.S. Department o f Hea l th , Educa t ion and We l fa re , Long I s l a n d L i g h t i n g Company and Bech te l C o r p o r a t i o n (110, 121 ) - -

led

GAS TEMPERATURE -OF

F i g u r e 8-1 5. Typical Resistivity versus Gas Temperature Curve f o r a No. 6 Fue: Oil Fired Boiler (f10, 121)

FLUE -GAS TEMPERATURE, OF

Figure 8-1 6 . Typical Oil Ash R e 5 i s t i v i ty Measurements, f o r Very Low-Sulfur Content Fuel O i l Ash ( 1 10, 132) --

Stack v i s i b l e emission i s a c r i t i c a l parameter f o r o i l - f i r e d b o i l e r s . As

s t a t e d i n the previous s e c t i o n , s t ack opac i ty i s usua l ly t he ove r r id ing f a c t o r

when determining cont ro l requirements . I t has a l s o been e s t a b l i s h e d t h a t

o i l - f i r e d b o i l e r p a r t i c u l a t e emissions a r e a mixture of components, each

component having i t s own unique physical and chemical p r o p e r t i e s . Hence, in

order t o understand the b a s i s f o r p a r t i c u l a t e removal device s e l e c t i o n , we

must f i r s t understand how t h e var ious components o f o i l - f i r e d b o i l e r emissions

c o l l e c t i v e l y impact s t ack opac i ty . A s imp l i f i ed , genera l ized approach

fo l lows; although somewhat i nconc lus ive , t h i s exe rc i s e provides a framework

f o r understanding the mechanisms a v a i l a b l e f o r p red i c t i ng opac i ty (135).

I t i s gene ra l ly accepted t h a t opac i ty can be descr ibed by the fo l

equat ions :

% Opacity = 100 (1 - - 1 ) 1,

1 owi ng two

where: 1, = i n t e n s i t y of i nc iden t l i g h t

I = i n t e n s i t y of t r ansmi t t ed l i g h t

W = p a r t i c u l a t e mass concent ra t ion (gm/m , ac tua l cond i t i ons

p = p a r t i c l e d e n s i t y (gm/cm3)

L = i l l umina t ion path l eng th ; i . e . , s t ack diameter (m)

K = e x t i n c t i o n c o e f f i c i e n t (cm3/rnz)

For low l e v e l s of opac i ty (20 pe rcen t o r l e s s ) , t h e above equat ions can be

approximated q u i t e we1 1 by:

% Opacity = 100 ( LW )

Values of K have been computed and repor ted in t he l i t e r a t u r e , and a r e

pr imar i ly dependent upon t h e index of r e f r a c t i o n and diameter of t h e p a r t i c l e .

I l l umina t ion path l eng th , i n t h i s case t h e s t ack d iameter , i s an important

v a r i a b l e . For example, with a l l o t h e r f a c t o r s being equal , an 800 MW u n i t

wou ld produce t w i c e t h e o p a c i t y o f a 200 MV u n i t because t h e s tack d i a m e t e r i s

t w i c e as l a r g e . T h i s r e l a t i o n s h i p i s i m p o r t a n t ; c o r r e l a t i o n between o p a c i t y

and p a r t i c u l a t e g r a i n l o a d i n g must be r e f e r r e d t o a p a t h l e n g t h so t h a t i t can

b e c o r r e c t e d f o r d i f f e r e n t s i z e u n i t s .

U s i n g p u b l i s h e d va lues o f e x t i n c t i o n c o e f f i c i e n t s , maximum va lues o f g r a i n

l o a d i n g c o n s i s t e n t w i t h t h e s t a c k o p a c i t y r e g u l a t i o n o f 20 p e r c e n t a r e shown

i n F i g u r e 8-17. These cu rves were deve loped f o r a p a t h l e n g t h o f 20 f t .

Three cu rves a r e g i v e n f o r o i l - f i r e d b o i l e r emiss ions components w i t h

d i f f e r e n t r e f r a c t i v e indexes: carbon ( e i t h e r carbon soo t o r carbon r e s i d u e ) ,

i n o r g a n i c ash, and s u l f u r i c a c i d m i s t . It i s apparent t h a t p a r t i c l e s i z e has

a pronounced e f f e c t on t h e c o r r e l a t i o n between o p a c i t y and g r a i n l o a d i n g .

T h i s i s shown g r a p h i c a l l y i n F i g u r e s 8-18 and 8-19, which p r e s e n t e s t i m a t e d

o p a c i t y l e v e l s v e r s u s p a r t i c u l a t e g r a i n l o a d i n g , assuming t h a t carbon r e s i d u e

p a r t i c l e s a r e 10 t o 50 m ic romete rs and i n o r g a n i c ash p a r t i c l e s a r e 1 t o 5

micrometers . Note t h a t l a r g e p a r t i c l e s make a min imal c o n t r i b u t i o n t o s t a c k

o p a c i t y ; f o r t h i s reason, a c i d smut emiss ions can be i g n o r e d i n t h i s a n a l y s i s .

U s i n g t h e p a r t i c u l a t e l o a d i n g s f o r o i l - f i r e d b o i l e r emiss ions shown on Tab le

8-6, a carbon r e s i d u e emiss ion o f 0.02 t o 0 . 0 3 gns/acf would y i e l d an o p a c i t y

o f 1 t o 8 p e r c e n t . T h i s would i n c r e a s e t o 4 t o 26 p e r c e n t f o r t h e extreme

l o a d i n g o f 0.10 gns /ac f . The c o n t r i b u t i o n f rom t h e i n o r g a n i c ash cannot be

de te rm ined i n so s t r a i g h t f o r w a r d a manner. I f t h e ash has been r e l e a s e d f rom

carbon r e s i d u e p a r t i c l e s , a l o a d i n g o f 0 . 0 1 gns/acf would produce 4 t o 22

p e r c e n t o p a c i t y . However, i f t h e ash i s r e t a i n e d i n t h e carbon p a r t i c l e s i t

w o u l d behave l i k e t h e l a r g e carbon p a r t i c l e s and o n l y i n c r e a s e s t a c k o p a c i t y

by 2 t o 4 p e r c e n t . The a c t u a l s i t u a t i o n i s p r o b a b l y i n t e r m e d i a t e t o these two

cases. I f 0.005 gns /ac f o f ash i s p r e s e n t as 1 t o 5 mic ron p a r t i c l e s w h i l e

t h e r e m a i n i n g 0.005 gns /ac f i s s t i l l i n t h e carbon r e s i d u e , o p a c i t y would

p r o b a b l y i n c r e a s e by abou t 2 t o 12 p e r c e n t . I t i s apparent t h a t t h e r e s u l t a n t

o p a c i t y f rom t h e carbon r e s i d u e and ash c o u l d range from v e r y l ow ( l e s s than 5

p e r c e n t ) t o v e r y h i g h (20 t o 30 p e r c e n t ) depending on assumptions made abou t

t h e d i s t r i b u t i o n o f ash and i t s s i z e . The d a t a r e q u i r e d t o e l i m i n a t e

guesswork a s s o c i a t e d w i t h these assumpt ions i s n o t r e a d i l y a v a i l a b l e .

PARTICULATE LOADING GNSIACF

F i g u r e 8-19. Stack Opacity versus Par t i cu la te Loading fo r Sulfur ic Acid Mist Emissions from Oil-Fired Boilers (135)

The s i t u a t i o n f o r carbon s o o t i s o p p o s i t e t o t h a t f o r i n o r g a n i c ash and ca rbon

r e s i d u e because t h e p a r t i c l e s i z e d i s t r i b u t i o n i s w e l l known b u t t h e

p a r t i c u l a t e l o a d i n g i s no t . Carbon s o o t i s p r e s e n t as s p h e r i c a l p a r t i c l e s

0 . 0 1 t o 0.1 micrometers i n s i z e ; a more e x a c t e s t i m a t e i s n o t r e q u i r e d s i n c e

t h e e x t i n c t i o n c o e f f i c i e n t i s c o n s t a n t o v e r t h i s range. The r e s u l t a n t

o p a c i t y i s shown i n F i g u r e 8-18 f o r a reasonab le range o f 0.001 t o 0 .003

gns /ac f . Soot has a more pronounced e f f e c t on o p a c i t y t h a n e i t h e r ash o r

carbon r e s i d u e , and t h e r e s u l t a n t o p a c i t y f o r t h e above range i s 6 t o 19

p e r c e n t . The Shel l -Bacharach smoke t e s t , deve loped f o r d i s t i l l a t e f u e l

combust ion, can p r o v i d e a rough e s t i m a t e o f soo t emiss ions, b u t t h i s t e s t has

n o t been r o u t i n e l y per formed on r e s i d u a l f u e l combust ion systems. The range

o f 0 .001 t o 0.003 gns/acf r e p r e s e n t s a l e v e l e a s i l y o b t a i n e d f o r d i s t i l l a t e

f u e l s ; however, i t i s n o t known i f r e s i d u a l f u e l u n i t s a r e n o r m a l l y o p e r a t e d

i n a s i m i l a r range. There i s p r o b a b l y no i n h e r e n t reason why a u n i t c o u l d n o t

b e opera ted a t l e s s t h a n 0 .001 gns /ac f s o o t emiss ion, b u t exper imen ta l d a t a t o

c o n f i r m t h i s a r e n o t a v a i l a b l e .

B o i l e r a d d i t i v e s a r e n o r m a l l y o f s m a l l s i z e , 1 t o 5 m i c r o n s , and t h e y

presumably t e n d t o r e t a i n t h

Inadequate d i s p e r s i o n i n t h e

i n c r e a s e p a r t i c l e s i z e . The

t h a t some would be r e t a i n e d

i f t h e unburned carbon emi ss

s s i z e d i s t r i b u t i o n as an e m i s s i o n component.

f u e l o r a g g l o m e r a t i o n o f p a r t i c l e s would p r o b a b l y

a d d i t i v e wou ld behave s i m i l a r t o t h e f u e l ash i n

n t h e l a r g e r carbon r e s i d u e p a r t i c l e s , e s p e c i a l l y

on i s h i g h . The emiss ion r a t e f o r a d d i t i v e s ,

when used, c o u l d range from 0.004 t o a b o u t 0 .02 g n s / a c f . T h i s would

cor respond t o an o p a c i t y o f l e s s t h a n 2 p e r c e n t t o g r e a t e r t h a n 22 p e r c e n t .

S u l f u r i c a c i d m i s t has been r e p o r t e d t o f o r m a t p a r t i c l e s i z e s o f 0.5 t o 5.0

m ic romete rs , depending on t h e wa te r vapor c o n t e n t o f t h e gas. I n a combust ion

system, some o f t h e a c i d c o u l d c o n c e i v a b l y condense on t h e s u r f a c e o f ash

p a r t i c l e s , r a t h e r than fo rm ing separa te d r o p l e t s , e s p e c i a l l y i f t h e ash i s

a l k a l i n e . I f t h e f l u e gas were 5 t o 10°F be low i t s a c i d dewpo in t , s u l f u r i c

a c i d m i s t l o a d i n g c o u l d range f rom 0.005 t o 0.05 gns /ac f , wh ich cor responds t o

an o p a c i t y range o f 4 p e r c e n t t o s u b s t a n t i a l l y g r e a t e r t h a n 20 p e r c e n t . There

i s l i t t l e exper imen ta l d a t a on c o r r e l a t i o n s between o p a c i t y and s t a c k

tempera tu re , b u t i t i s conce ivab le t h a t s u l f u r i c a c i d m i s t c o u l d be t h e

c o n t r o l l i n g f a c t o r f o r u n i t s w i t h r e l a t i v e l y l ow s t a c k tempera tu res . It i s

a l s o poss ib l e f o r s u l f u r i c ac id mist t o form a t t he s tack e x i t due t o mixing

of f l u e gas with cold ambient a i r t o produce a mixture which i s below t h e ac id

dewpoint. In t h i s c a s e , a p r e c i p i t a t o r w i l l not s u b s t a n t i a l l y a l t e r t h e

opac i ty because t he a c i d mi s t i s farmed a f t e r t h e p a r t i c u l a t e c o l l e c t i o n

device .

T h e r e s u l t a n t opac i ty from these various emissions components a r e l i s t e d on

Table 8-9. Estimated opac i ty ranges from a low of about 10 pe rcen t , i f

s u l f u r i c ac id mis t i s not p r e sen t , t o s u b s t a n t i a l l y more than 20 percent . For

a given p a r t i c u l a t e l oad ing , carbon soot has t he g r e a t e s t e f f e c t o n opac i ty

w i ~ h only 0.023 gns/acf y i e i d i n g 20 percent opaci:y. I t c2n be s t a t e d

t h e r e f o r e t h a t whenever the p a r t i c u l a t e lozding i s c - e s t e r than 0.003 gns/acf

t h e r e i s t he p o t e n t i a l f o r opac i ty g rea t e r than 20 percent . However,

depending on the emission composition, a h igher loading wi l l not neces sa r i l y

cause t he opac i ty s tandard t o be exceeded. Considering the minimum l e v e l s of

each emissions component and neglect ing t h e e f f e c t of s u l f u r i c ac id m i s t , a

minimum opaci ty level of 11 percent can be a s soc i a t ed with an emissions

concent ra t ion of 0.035 gn/acf . This opac i ty leve l i s achieved when carbon

soot emissions a r e l im i t ed t o 0.001 gn/acf .

P r e c i p i t a t o r S i ze Se l ec t ion

E l e c t r o s t a t i c p r e c i p i t a t o r s a r e capable of reducing o i l - f i r e d b o i l e r

p a r t i c u l a t e emissions by 50 t o 99 percent , on t h e average. When o i l - f i r i n g ,

s t ack v i s i b l e emissions i s usual ly the c o n t r o l l i n g f a c t o r ; t o meet a s t ack

v i s i b l e emissions requirement of 20 percent opac i ty ( p a r t i c u l a r l y with higher

s u l f u r fuel o i l s which r e q u i r e a d d i t i v e s ) , a p r e c i p i r s t o r e f f i c i ency of a b o u t

90 percent would be r equ i r ed . P r e c i p i t a t o r design e f f i c i e n c i e s have t y p i c a l l y

ranged from 90 t o 95 pe rcen t f o r b o i l e r s f i r i n g high s u l f u r res idua l fue l o i l .

The d a t a bank upon which o i l - f i r e d b o i l e r precipitator s i z ings a r e based i s

not a s well def ined a s f o r coa l - f i r ed b o i l e r p r e c i p i t a t o r s . This i s due t o

severa l f a c t o r s , inc luding the following:

Boi 1 e r emiss ions , and hence a1 so p r e c i p i t a t o r performance, i s highly dependent upon b o i l e r f i r i n g condi t ions ( i . e . , combustion excess a i r l e v e l , f i r ebox c l e a n l i n e s s , f l u e gas tempera ture , e t c . ) . Far example, f i e l d t e s t s have demonstrated t h a t while maintaining an oxygen l eve l i n t h e f l u e gas of about 2 percent tends t o minimize

Table 8-9

Resultant Opacity Levels from Various Emissions Components o f an Oil-Fired Boiler (1 - 35)

Emiss ions Component 4 Opac i ty *

I n o r g a n i c Ash 2-22

Carbon Residue 1-26

Carbon Soot 6-19

S u l f u r i c A c i d M i s t ( i f p r e s e n t ) 4-20 o r g r e a t e r

B o i l e r A d d i t i v e s 2-22

T o t a l 15, t o much g r e a t e r t h a n 20**

Corresponding P a r t i c u l a t e

Emissions (gn/acf )

* For a 20 f e e t d i a m e t e r s tack

** O p a c i t i e s a r e n o t d i r e c t l y a d d i c i v e f o r v a l u e s g r e a t e r than 20 p e r c e n t .

uncontrolled oil-fired boiler emissions (Figure 9-5), reducing combustion excess air to the lowest practical levels tends to minimize sulfur trioxide and precipitator outlet particulate emissions.

Because of the low electrical resistivity of oil ash, substantially more'power must be delivered to the precipitator. Coal-fired boiler precipitators are typically energized to levels of 0.5 to 2 watts/square foot of collecting electrode area, compared to 1.5 to 3 watts/ft2 C.E. for oil-fired boiler precipitators. This imp1 ies that precipitator power supply, automatic voltage controls, and electrode alignment are critical factors. For example, two oil-fired boiler precipitators, each performing under identical conditions including electrode specific collecting area (SCA), can have significantly different collection efficiency levels if electrode misalignment or an electrical energization problem prevents one of them from achieving maximum corona power. Although this can also be a fzctor with coal-fired boiler precipitarsrs, the hlshzr operating corona power levels required of oil-fired precipitators magnifies the effect.

The data base, at least here i n the United States, is primarily comprised of weighted wire type precipitators. In some installations weighted wire discharge electrode system have suffered wire breakage probl ems.

A data base for oil-fired boiler precipitators may be found on Table 8-10.

The listed design and test data were assembled from an industry survey

conducted as part of a previous EPRI study (G), and also private communications with Research-Cottrell, inc. (139) and Long Island Lighting Company (140). Missing information was filled in where possible with data

from Power Magazine's annual "Plant Design Report" (141). Uhen extracting

data from the EPRI study, the published industry survey questionnaires were first checked for completeness and consistency; if missing information or

contradictory responses could not be resolved beyond reasonable doubt, the

information from the questionnaire was left out of the data base. The final

data base is comprised of 24 units from 16 different power stations.

When examining precipitator sizing standards practiced by the industry, the

design data on Table 8-10 adds little insight until those precipitators

designed speciffcally for oil are segregated from those that were converted

from coal to oil (Figure 8-20), When this is lone it is appzrent that, with

only one exception, an SCA between 224 to 264 ftz/lOOO acfm was installed

Converted to Oil Designed for Oil

SPECIFIC COLLECTION AREA, ft2/kcfm

Figure 8-20. Design Collection Eff iciency versus Specific Collecting Data f o r Precipi ta tors on Oil-Fired Boilers

f o r a des ign e f f i c i e n c y o f 90 p e r c e n t , and between 250 t o 365 f t z / l O O O acfm

f o r a des ign e f f i c i e n c y o f 95 p e r c e n t ( a l l a r e we igh ted w i r e t y p e

p r e c i p i t a t o r s w i t h n i n e i n c h spac ing between c o l l e c t i n g e l e c t r o d e p l a t e s ) .

Des ign m i g r a t i o n v e l o c i t i e s (unmod i f i ed ) f o r these p r e c i p i t a t o r s range f rom

8.21 f p s t o 11.14 f p s , w i t h a mean o f 9 . 6 4 f p s . P r e c i p i t a t o r v e l o c i t i e s range

f r o m 4.25 f p s t o 5.00 f p s , w i t h a mean o f 4 .64 f p s ; p r e c i p i t a t o r aspec t r a t i o s

( e l e c t r o d e t o t a l l e n g t h d i v i d e d by h e i g h t ) range f rom 0.70 t o 1.20, w i t h a

mean o f 0.94.

Des ign and t e s t e d per formance f o r we igh ted w i r e p r e c i p i t a t o r s a t f i v e

o i l - f i r e d b o i l e r i n s t a l l a t i o n s i s compared i n F i g u r e 8-21. I t would appear

t h a t none o f t h e s e u n i t s l i v e d up t o t h e i r d e s i g n e x p e c t a t i o n s ( a l t h o u g h

d e s i g n c o l l e c t i o n e f f i c i e n c i e s a r e n o t a v a i l a b l e f o r t h e Danskammer

p r e c i p i t a t o r s ) . Measured per formance v a r i e s o v e r a w ide range a t Danskammer

U n i t s 1 and 2 and N o r t h p o r t U n i t 3; b o t h o f t h e s e i n s t a l l a t i o n s have

p r e c i p i t a t o r s w i t h SCA 's o f s l i g h t l y l e s s t h a n 200 f t 2 / 1 0 0 0 acfm. The

h i g h l y v a r i a b l e per formance o f these smal l p r e c i p i t a t o r s i s an i n d i c a t i o n o f

d i f f i c u l t y exper ienced i n m a i n t a i n i n g h i g h o p e r a t i n g corona power l e v e l s and

t h e wide v a r i a t i o n i n i n l e t p a r t i c u l a t e l o a d i n g (up t o a f a c t o r o f f o u r a t t h e

N o r t h p o r t U n i t 3 i n s t a l l a t i o n ) . Never the less , when good e l e c t r i c a l

e n e r g i z a t i o n was ach ieved a t N o r t h p o r t U n i t 3, a m i g r a t i o n v e l o c i t y

( u n m o d i f i e d ) o f 21.95 fpm was measured d u r i n g h i g h i n l e t l o a d i n g c o n d i t i o n s .

T a k i n g i n t o account a71 o f t h e t e s t s r e p o r t e d i n F i g u r e 8-21, m i g r a t i o n

v e l o c i t y ranged f r o m 5.36 fpm t o 21.95 fpm, w i t h a mean o f 11.37 fpm.

D e t a i l e d p r e c i p i t a t o r d e s i g n d a t a i s shown on Tab le 8-11 f o r f i v e

w e i g h t e d - w i r e p r e c i p i t a t o r s des igned f o r o i l - f i r e d b o i l e r s (139). Design

c o l l e c t i o n e f f i c i e n c i e s range f rom 90 t o 95 p e r c e n t by we igh t , i n s t a l l e d

s p e c i f i c c o l l e c t i n g p l a t e a r e a f rom 224 t o 323 f t 2 / 1 0 0 0 acfm, and gas

t r e a t m e n t t i m e v a r i e s f r o m 5.03 t o 5 .78 seconds. A l l t h e p r e c i p i t a t o r s have

30 f t h i g h c o l l e c t i n g e l e c t r o d e p l a t e s w h i l e t h e number o f mechanica l f i e l d s

v a r i e s f rom two t o f o u r .

S p e c i f i c a t i o n o f Mechanica l and E l e c t r i c a l Fea tu res

O i l - f i r e d b o i l e r emiss ions have severa l u n d e s i r a b l e c h a r a c t e r i s t i c s which

mus t be t a k e n i n t o accoun t when d e s i g n i n g an e l e c t r o s t a t i c p r e c i p i t a t o r . The

Design

A Testing 1 Salem Harbor 4 2 New Haven Harbor 3 Cokeworks 1 4 Danskarnmer 1 4 5 Northport 3

SPECt FIC COLLECTION AREA/1000 cfrn

Figure 8-21. Design and Tested Collection Efficiency versus Specific Collecting Area for F i v e Oil-Fired Boiler Precipitator Install ations

?do =I J r L n I.?

P.

2<- = N

0 2 5

ua

high percentage of combustibles in o i l a s h , t h e s t i c k i n e s s of t h e a sh , t he

f i nenes s of the a sh , and the co r ros ive na tu re of the e f f l u e n t g ive r i s e t o t he

following areas of spec i a l concern:

The a s h ' s low r e s i s t i v i t y r e q u i r e s a high degree of e l e c t r i c a l ene rg i za t ion . i n s t a l l e d r a t e d corona power f o r o i l - f i r e d b o i l e r p r e c i p i t a t o r s t y p i c a l l y range from 1.8 w a t t s / f t 2 of c o l l e c t i n g p l a t e a rea up t o 3 . 5 w a t t s / f t 2 . Use of modern, automatic vol tage c o n t r o l l e r s with a f a s t response cu r r en t l i m i t p rovis ion i s recommended (121). Elec t rode alignment i s c r i t i c a l f o r achievement of a high degree of e l e c t r i c a l ene rg i za t ion , e s p e c i a l l y f o r weighted wire type p r e c i p i t a t o r s with nine inch spacing between c o l l e c t i n g e l ec t rode p l a t e s . Smaller bus s ec t ions (on the order of 10,000 f t z of c o l l e c t i n g p l a t e a r e a ) a r e more s u i t a b l e f o r maintaining high l e v e l s of e l e c t r i c a l e n e r g i z a t i o n .

A medium t o high a spec t r a t i o and a low p r e c i p i t a t o r v e l o c i t y a r e required f o r c o l i e c t i o n of f ine :y d iv ided , low r e s i s t i v i t y p a r t i c l e s .

The high combustible content of t h e ash may cause i t t o become pyrophoric - t h a t i s , s u b j e c t t o spontaneous combustion in t h e presence of oxygen. Air leakage i n t o the hopper from t h e ash handling system, or any o t h e r opening, can cause l o c a l i z e d combustion of t he s t o r e d ash. This may r e s u l t in t h e formation of c l i n k e r s , which can plug the hopper o u t l e t or cause s t r u c t u r a l damage t o t h e hoppers (132). I t was f ea red a t one time t h a t t he high combustible content of o i l ash would cause a f i r e hazard. To d a t e , t h i s has not proved a s e r i o u s concern; however, i t i s recommended t h a t hoppers be emptied on a continuous cyc l e which wil l prevent t h e ash from reaching a leve l where spark-over from the d ischarge e l e c t r o d e frame t o the c o l l e c t e d ash might occur , possibly causing i g n i t i o n (121).

The r a t i o of t h e amount of s u l f u r i c acid in t he f l u e gas t o t h e amount of ash i s higher in o i l - f i r e d b o i l e r s than i n c o a l - f i r e d b o i l e r s . Therefore , ope ra t ion a t f l u e gas temperatures near t h e ac id dewpoint causes o i l ash t o become s t i cky and co r ros ive . When t h i s condit ion i s severe , rappers cannot remove the ash from c o l l e c t i n g e l e c t r o d e s , and hoppers become plugged (132) . When extended low temperature opera t ion i s a n t i c i p a t e d , ex t r a thermal i n s u l a t i o n and special m a t e r i a l s of cons t ruc t ion such as Cor-Ten s t e e l can be provided f o r minizing co r ros ion , and sharper rapping blows may be needed t o c l ean c o l l e c t i n g p l a t e s . I t should be noted t h a t t he manufacturers of Cor-Ten S t e e l do not guarantee i t a g a i n s t cor ros ion .

P r e c i p i t a t o r hoppers near ly always c r ea t e problems when c o l l e c t i n g o i l ash . Extra hopper hea t ing ( a t l e a s t 20 w a t t s / f t 2 of hopper sur face) and addi t iona l thermal i n su l a t i on help keep the o i l ash from becoming too viscous t o f low. I f t h e wind-chill index f o r t h e a rea i s low, a weather enc losure should be provided t o p r o t e c t t h e hoppers (121). Steep hopper v a l l e y angles a l s o he lp prevent pluggages from occurr ing . Some manufacturers recommend double angle hoppers, having a 55" v a l l e y ang le t op sec t ion and a 60 t o 65' val ley angle bottom sec t ion .

H i g h v o l t a g e s u p p o r t i n s u l a t o r s , t h r o u g h w h i c h t h e h i g h v o l t a g e s u p p l y i s connec ted t o t h e d i s c h a r g e e l e c t r o d e f rame i n s i d e t h e p r e c i p i t a t o r chamber, r e q u i r e s p e c i a l a t t e n t i o n . D e p o s i t s o f o i l ash on t h e i n s i d e o f t h e s e i n s u l a t o r s c o u l d promote e l e c t r i c a l breakdown o r t r a c k i n g t o ground a t peak p o t e n t i a l s o f 70 kV o r more. It i s t h e r e f o r e necessary t o p r o v i d e i n s u l a t o r p r e s s u r i z i n g a i r and h e a t i n g . P r e s s u r i z i n g a i r , from 25 t o 100 f t 3 / m i n o f c l e a n a i r p e r i n s u l a t o r , p r e v e n t s o i l ash l aden gases f rom s e t t l i n g on t h e i n s i d e s u r f a c e o f t h e i n s u l a t o r . E l e c t r i c h e a t e r s , a p p r o x i m a t e l y 3 kW r a t i n g p e r i n s u l a t o r , warm t h e a i r t o above t h e dewpoin t o f t h e gas (121) .

The e l e c t r o d e r a p p i n g system must be f l e x i b l e enough t o cope w i t h b o t h s t i c k y , hard- to- remove ash p a r t i c l e s and carbon p a r t i c l e s w h i c h can e a s i l y r e e n t r a i n and cause r a p p i n g p u f f s . V a r i a b l e i n t e n s i t y r a p p e r s , and modern, p rog ramab le r a p p e r c o n t r o l l e r s , a r e recommended.

Many o i l - f i r e d b o i l e r p r e c i p i t a t o r s a r e equ ipped w i t h t o p spray w a t e r wash-down systems. These a l l o w t h e c o n v e n i e n t removal o f s t i c k y e l e c t r o d e b u i l d u p s d u r i n g ou tages .

N e a r l y a l l o f t h e o i l - f i r e d b o i l e r p r e c i p i t a t o r s i n t h e U n i t e d S t a t e s a r e o f

t h e w e i g h t e d w i r e t y p e ; r i g i d f rame p r e c i p i t a t o r s domina te i n b o t h Europe and

Japan. The most s u i t a b l e p r e c i p i t a t o r d e s i g n f o r t h i s a p p l i c a t i o n shou ld

f u l f i l l t h e f o l l o w i n g c r i t e r i a :

The p r e c i p i t a t o r s h o u l d have sma l l bus s e c t i o n s , t o enab le o p e r a t i o n a t h i g h co rona power l e v e l s .

The p r e c i p i t a t o r s h o u l d be equ ipped w i t h v a r i a b l e i n t e n s i t y r a p p i n g systems, so as t o p r e v e n t p a r t i c u l a t e r e e n t r a i n m e n t .

The p r e c i p i t a t o r chamber s h o u l d be o f medium t o h i g h aspec t r a t i o d e s i g n , w h i l e s t i l l m a i n t a i n i n g compactness (an i m p o r t a n t c o n s i d e r a t i o n f o r r e t r o f i t a p p l i c a t i o n s ) .

The p r e c i p i t a t o r s h o u l d have a s u p e r i o r degree o f e l e c t r o d e a l i g n m e n t ; f r o m t h i s s t a n d p o i n t , t w e l v e i n c h spac ing between c o l l e c t i n g e l e c t r o d e p l a t e s i s more f o r g i v i n g t h a n n i n e i n c h spac ing .

The d i s c h a r g e e l e c t r o d e s s h o u l d be d u r a b l e ( r e s i s t a n t t o corona w i n d i n d u c e d movement, f a t i g u e f a i l u r e , and corona d i s c h a r g e bu rn - th rough f a i 1 u r e ) .

Seve ra l m a n u f a c t u r e r s i n t h e U n i t e d S t a t e s now o f f e r p r e c i p i t a t o r s w i t h r i g i d

mast - type e l e c t r o d e s h a v i n g t w e l v e i n c h c o l l e c t i n g e l e c t r o d e p l a t e spac ings

and equ ipped w i t h v a r i a b l e i n t e n s i t y r a p p i n g systems. I n d i v i d u a l bus s e c t i o n s

can be s i z e d a s sma l l as 10,000 f t Z o f c o l l e c t i n g e l e c t r o d e . A l t h o u g h t h i s

p a r t i c u l a r d e s i g n wou ld appear t o be b e s t s u i t e d f o r o i l - f i r e d b o i l e r

application, experience is limited because of the newness of the design and

the limited importance of oil as a utility fuel i n recent years.

REFUSE DERIVED FUEL ( R D F )

High on the priority list of potential nonconventional fuels for utility

boilers is refuse derived fuel (RDF), which is a processed form of municipal

solid waste (MSW). Table 8-12 summarizes current electric utility experience

with co-firing RDF.

There are two predominant waste-to-electricity technologies:

Mass-burning, which is the combustion of unprocessed solid wastes in either a waterwall incinerator, a waste-heat boiler or a combination of both, thus generating steam to drive a turbine-generator set. Practically no preparation of the garbage is required (only the largest non-combustibles are removed) (146).

Co-firing, which is the firing of processed RDF along with coal, oil or natural gas in a modified conventional boiler. RDF is produced by removing metals, glass and other non-combustible matter from MSW, and shredding and sizing the remaining combustible matter. Most of the utility RDF facilities co-fire 10 to 15 percent RDF in suspension in conventional pulverized coal-fired boilers. Some utilities have retrofitted dump grates to support the RDF for more complete combustion, a modification which has permitted up to 20 percent RDF co-firing at the Ames Unit 7 facility.

The first mass-burn waste-to-electricity project i n the United States began

commercial operation in May, 1983. It is a 2100 tons/day facility erected in

Clearwater, Florida, owned by Pinellas County, and operated by UOP, Inc. The

electricity produced by this 50 MW unit i s sold to the Florida Power

Corporation. This arrangement is typical of the s i x mass-burn projects

currently i n operation or under construction in the United States; the

facilities are owned and operated by either a municipality or a private

corporation, and the electricity is sold to a local investor-owned electric

uti 1 i ty (112).

RDF facilities in the United States are also owned and operated by

municipalities or private corporations; however, they are typically located at

an investor-owned utility's electric generating station, where RDF is co-fired

with coal in a modified conventional boiler. RDF has been co-fired along with coa: by the electric utility industry since April, 1972, when the city of

Tab le 8-12

Summary o f E l e c t r i c U t i l i t y Experience w i t h C o - F i r i n g RDF w i t h Coal (Adapted from ( I l l ) , (144))

RDF FACILITY. L O ~ A T I O N , O * N E R A O P E A T P _ R . --

AMES, IOWA S O L I D HASTE RECOVERY SYSTEM, OWtlED AND OPERRTED BY THE C I T Y .

PROJECT STATUS

RDF P n r n u c r l o ~ CAPACITY I $ 150 TPD N O M I N A L . MF F A C I L I T Y COST $ 6 . 3 M I L L I O N I N 1 '375 DOLLARS.

B A L T IMOREI MARYLAND - OWNED BY B A L T I M O R E COUNTY. OPERATED BY TLLEDYNE N A T I O N A L

T E S T BURN AT B A L T l n O R E GAS 8 E L E C l R l C 200-MU U N I T AT CRANE S T A T I O N OF 230D TONS DF RDF OVER 60 DAYS. 20% RDF F I R I N G R A T E .

1200 TPD THROUGHOUl C A P A C I T Y . COST $10 H I L L I O N I N 1975,

STARTED OPERATING I N 1976. L A N D - F I L L I N G RDF. I F BCUE CONVERTS CRANE S T A T I O N TO COAL. I T COULD CONSUME UP TO H A L F THE RDF, S T A R T l N G I N 1984

CHICAGO, OWNED AND OPERATED BY C l T Y OF CHICAGO.

RDF USED A s SUPPLEMENT T o COAL I N COHMONWEALTH E D I S O N CO. ' S 200-MW CRAWFORD U N l T 7 RDF USED AT 1 0 % RATE:

3500 TONS RDF PER WEEK. COST $16 M I L L I O N (1975).

PRODUCED RDF FROM L A T E 1978 TO D E C E W E R , 1979. OPERATES AS COM- PACTOR ONLY, P E N D I N G F U N D I N G FOR M O D I F I C A T I O N S TO RDF PLAHT AND B O I L E R

LAKELAND, F L O R I D A . TO BE JOlJiTLY OWNED BY C l T Y OF L A K E L A N D AlK! THE ORLANDO, F L A . U T I L I T I E S COMMISSION.

300 TPD. C O S T $186 n l L L I o N . SCHEDULED FOR 1983 OPERATION.

MADISOl4, WISCONSIN. OWNED AND OPERATED BY C l T Y O f MAD I SON,

RDF I S BURNED I N T w o 5 0 - l l w B O I L E R S AT M A D I S O N GAS 8 E L E C - T R I C C O . ' S BLOUNT S T . S T A T I O N . RDF USED AS 11% S u P P t E n F N T .

400 TPD. C o s r $2.4 M l L l l o r r . STARTUP IN JULY 1979. SINCE THEN, SYSTEM HAS OPERATED WELL, CONSUMING 15,000 TONS OF TRASH, DISPLACING 7000 TONS o f COAL.

MILWAUKEE W I S C O N S I N . OWNED AND OPERATED BY AMERICAN CAN COMPANY.

RDF WAS 0URNED I N W l S C O N S r N E L E C T R I C POWER C 0 . ' 5 310-w UNITS 7 AND 8 AT OAK C R S E K STATION, AT RATES UP TO 151,

1200 TPD. COST $21 H I L L I O N I N 1975. (PLUS $4 M I L L I O N FOR POWER PLAHT W D l T I C C T l O U S , )

STARTUP I N MARCH 1977. SHUT DOWN S I N C E AUGUST 1 9 8 0 ,

I T I S I N T E N D E D TO BURN THE RDF AT ROCHESTER GAS 1 ELEC- T R I C C O . ' S RUSSELL STATION, 4 B O I L E R S T O T A L I N G 235 tW.

ZOO0 TPD ( 1 3 2 0 TPD OF R D F ) . COST $ 5 3 M I L L I O H . POHER PLANT F A C l L l T Y COST I S 112 M I L L I O N .

STARTUP I N S t P T E R B E R 1979, con- B U S T I B L E S L A N D F I L L E D . P L A N TO START BURNING RDF AT RGBE I N 1983, U P l o H A L F THE RDF n a y u L T l M A T r L v BE t o# -

RDF H A S BURNED A 1 U N I O N ELEC- T R I C CO.'S MERAHEC S T A T I O N TN A 1 2 5 . ~ 1 C O A L - F I R E C U N I T .

300 T P D S T . L O U I S . OPERATED BY C I T Y . DEMONSTRATION PROJECT FU?4DED BY C I T Y , U N I O N E L E C T R I C CO. AND ENVIRONMENTAL PROTECTION AGENCY.

DEHONSTRATION U N l T STAPTUP I N 1972. SHUT DOWN I N 1975. PLANNED L A I G E - SCALE SYSTEM WAS DROPPED I N 1976.

St.Louis/Union E l e c t r i c Company RDF demonstration p ro j ec t commenced a t Meramec

S t a t i o n . Of the e i g h t c o - f i r i n g p r o j e c t s l i s t e d on Table 8-13, on ly two

p r o j e c t s , Ames, Iowa and Madison, Wisconsin, a r e p re sen t ly in commercial

opera t ion . The Lakeland, F lor ida and Rochester, New York f a c i l i t i e s a r e

cu r r en t ly in a s t a r t -up mode, and the Balt imore, Maryland f a c i l i t y was

pro jec ted f o r s t a r t u p in 1984.

The s t a r t i n g material f o r R D F i s MSV, which i s t y p i c a l l y composed of 60 t o 90

percent combustibles ( i nc lud ing organic food was te , paper , p l a s t i c , wood,

rubber, l e a t h e r and t e x t i l e s ) with the remainder being g l a s s , meta ls and

miscel laneous ma te r i a l s . As a f u e l , MSW in t he United S t a t e s g e n e r a l l y has an

as-received heating value of from 3500 t o j u s t over 5000 Btu/lb. The makeup

of MSW can vary widely depending upon geographical l o c a t i o n , time of y e a r ,

weather-related f a c t o r s , e t c . , which in t u r n a f f e c t s t h e c h a r a c t e r i s t i c s of

t he end-product RDF. Preprocessing s t e p s such a s shredders , a i r c l a s s i f i e r s ,

sc reens , magnetic s e p a r a t o r s , and aluminum removal systems a r e used t o prepare

RDF (144). The end product i s a RDF " f l u f f " m a t e r i a l , with a hea t ing value

range of from 4,500 t o j u s t below 8000 Btu/ lb, which can be co-f i red along

with coal in a modified conventional b o i l e r .

For t he most p a r t , modern e l e c t r o s t a t i c p r e c i p i t a t o r s opera t ing on l a r g e

pulverized coa l - f i red b o i l e r s co - f i r i ng with RDF should be adequate t o control

p a r t i c u l a t e s . However, co - f i r i ng can cause a drop in p r e c i p i t a t o r performance

because of increased f l u e gas volume flow r a t e s due t o l a r g e r excess a i r

requirements , and a l so due t o higher f l ya sh loading and/or increased unburned

combustibles i n the f l y a s h . Accordingly, t he t r a d i t i o n a l design of

p r e c i p i t a t o r s must be somewhat modified t o r e f l e c t t he c h a r a c t e r i s t i c s of RDF

and i t s combustion ( 1 4 4 ) . -

Calculat ion of Process Parameters

The usual desc r ip to r s f o r s o l i d f u e l s have been measured fo r RDF, inc luding

heat ing value, proximate and u l t ima te a n a l y s i s , composition, and s i z e . Tables

8-13 through 8-15 show average as-received RDF p r o p e r t i e s reported by t h e

various l o c a t i o n s , e i t h e r from b o i l e r t e s t s conducted by the e l e c t r i c u t i l i t y

o r from t e s t s conducted a t t he RDF processing p l a n t . These t a b l e s a r e

organized from highest t o lowest values of the major property l i s t e d in each

T a b l e 8-:3

Location

Bridgeport

Balt imore

b d i s o n

k S

Chicago

M i luaukee

S t . Louis

Average Properties of Refuse Derived

Fuel ( R D F ) as Repor te~ a t Various Fac i l i t i e s (x)

Test Descr ipt ion

ROF p lan t sarples ROF trucks t o u t i l i t y

ROF p lan t sanples, 1979 ROF p lan t test . 1980-81 B o i l e r test , 1980

B o i l e r tes t , 1979 Monthly average, 1980-81 ROF p l a n t s m l e s . 1979

B o i l e r tes t , 1982 Yeekly average. 1979 ( I h P s data a f te r 1978 d isc screen i n s t a l l a t i o n ;

RDF p lan t data, 1979 B o i l e r tes t , 1979

RDF p lan t data Monthly average. 1979-80 B o i l e r tes t . 1979

U t i l i t y d a i l y sanples, 1973-75 ROF p lan t tests, 1974-75

As Received Heating Value m i s t u r e Ash Sul fur Chlor ine (Btullb) ( X by wt ) j X by wt) ( X by wt) ( X by w t l

a F i f t y sanples heating value only. tb i s tu re , ash, and s u l f u r nurber o f sarples unknown.

b ~ w n t y - t h r e e m i s t l r r e and ash s m l e s .

'Five s u l f u r and ch lo r ine sanples.

d ~ h i c a g o reported t h a t 30 b o i l e r tes ts were conducted. Ass- one s w p l e per tes t .

N u h e r o f swp les

As received ROF Heating value, B W l b Proximate analysis, X by w t

Hoisture Ash

03 V o l a t i l e matter Ln m Fixed carbon

Ul t imate analysis. X by ut Carbon Hydrogen Nitrogen Oxygen Su l fu r Chlorine Hoisture and ash

Bal t i m r e RDF Plant

Sarrples 1979

13

7,692

10.6 7.6

69.4 12.4 100.0

T a b l e 8-14

Average RDF Prox ima te and U l t i m a t e

Ana lyses a s Repor ted a t V a r i o u s F a c i l i t i e s (111)

%a1 timore B o i l e r Test

1980

3

6,296b

28.0 12.2

Amesa B o i l e r Test

1982

3

6,356

22.5 8.5

a~ l l &nes data a f t e r 1978 d i sc screen i n s t a l l a t i o n .

m s a Yeekly

Averages 1979

8

6,113

18.4 9.6

56.1 15.9 -

100.0

29.9 6.0 0.2

35.5 0.2 0.2

28.0 100.OC

Chicago 8oi l e r Test

1979

30

5,231

24.8 20.8 46.7 7.7 -

100.0

29.7 3.9 0.6

19.9 0.3 -

45.6 w

100.0

H i 1 uaukee ROF Plant

Data

N A

5,190

31.0 19.5 41.2

8.3 - 100.0

28.2 3.8 0.6

16.2 0.3 0.4

50.5 100.0

M i lwaukee B o i l e r Test

1979

3

4,800

31.3 15.5 45.5

7.7 100.0

27.7 3.1 0.4

21.3 0.1 .-

46.8 - 100.0

S t . Louis ROF Plant

Test 1974-15

97

4,576

26.6 21.7 43.6 8.1 -

100.0

26.0 3.8 0.5

21.2 0.2 -

48.3 - 100.0

b ~ h r e e sarrpres f o r u l t ima te analysis. Heating value was 6,396 f o r the average o f 39 swp les dur ing t h i s t e s t per iod.

C ~ l t i m a t e analysis reported on d r y basis and ca lcu la ted here t o as received basis.

Average RDF Composition and

Size as Reported a t Various Fac i l i t i e s (m)

B a I t i m r e RDF Plant

Test 198041

As received RDF Ccnposition, X by wt

Paper and cardboard 91.1 P las t ic

Paper and cardboard - plus p las t i c 91.1

bod - Glass 0.3 Ferrous metal 0.1 Monferrous metal 0.6 Inorganic other 0.1 organ i csb 4.1 Miscel laneous and

f ines 3.7 loa.0C

Bulk density, I b / f t 3 3.7

X by Ut Larger than Stated Screen Size.

Square Screen Size (in.)

?mesa Meekly

Averages 1979

8

78.8 5.1

- 83.9

4.3 1.4 0.1 0.6 -

3.1

6.6 - 100.0

2.6

- 4.8 -

18.7 -

51.9

Note: Dash mark indicates no measurement nude.

'Arnes data af ter 1978 disc screen ins ta l la t ion .

Chicago RDF Plant

Ddta

30

60.5 5.3

- 65.8

2.5 2. l 0.3

.- 22.3

7 .O - 100.0

S t . Louis RDF Plant

Test 1974-75

97

58.2 4.9

- 63.1

3.4 2.6 0.3 0.5 -

4.7

25.4 - 100.0

6.8

Mdison Milwaukee RDF Plant RDF Plant Test

Data 1979

b~ rgan i cs include yard wastes, food wastes, cloth, t e x t i b s , tar , rubber, and leather.

C8altimore corposit ion a i r dr ied basis.

t a b l e . B r i d g e p o r t had t h e h i g h e s t h e a t i n g v a l u e because o f t h e RDF's l o w

m o i s t u r e c o n t e n t . O f t h e l o c a t i o n s r e p o r t i n g composi t ion, t h e RDF a t

B a l t i m o r e had t h e h i g h e s t paper and p l a s t i c c o n t e n t .

P e r c e n t ash b y w e i g h t ranged f rom 7.6 t o 21.7, and p e r c e n t s u l f u r b y w e i g h t

was g e n e r a l l y low, r a n g i n g f rom 0.1 t o 0.7. The l a r g e s t RDF p a r t i c l e s i z e s

a r e o f most i n t e r e s t because t h e l a r g e r s i z e s have more p o t e n t i a l f o r

p luqgage o f m a t e r i a l h a n d l i n g systems and a l s o r e q u i r e l o n g e r combust ion

t i m e . Values l a r g e r t h a n 0.75 i n . a r e r e p o r t e d i n Tab le 8-16 because

d i f f e r e n t screen s i z e s were used i n measurement a t d i f f e r e n t l o c a t i o n s , and

0.75 i n . i s t h e s i z e above which a l l l o c a t i o n s r e p o r t e d d a t a (111).

The m a j o r components o f RDF ash ( T a b l e 8-16) a r e s i l i c o n , aluminum, and

c a l c i u m . A p p r o x i m a t e l y h a l f o f t h e RDF ash i s s i l i c o n . Of t h e l o c a t i o n s

r e p o r t i n g RDF ash a n a l y s i s , B a l t i m o r e had t h e h i g h e s t s i l i c o n c o n t e n t and

Ames t h e l o w e s t (111). Sodium, an i m p o r t a n t c h a r g e - c a r r i e r f o r

e l e c t r o s t a t i c p r e c i p i t a t i o n , v a r i e d f r o m 0 t o 8 . 2 p e r c e n t by w e i g h t .

Un favo rab le RDF ash r e s i s t i v i t y does n o t appear t o be a s i g n i f i c a n t f a c t o r

when c o - f i r i n g RDF w i t h c o a l . F l y a s h f r o m c o a l can v a r y f r o m l o w

r e s i s t i v i t y t o v e r y h i g h r e s i s t i v i t y depending on t h e c h e m i s t r y o f t h e

p a r t i c u l a r ash. I n g e n e r a l , RDF ash has a l ower r e s i s t i v i t y t h a n most c o a l

ashes p r i m a r i l y due t o a h i g h e r pe rcen tage o f carbonaceous m a t e r i a l i n t h e

ash (149).

Exper imen ta l t e s t i n g conduc ted a t t h e Arnes U n i t 7 f a c i 1 i t y (148) i s t h e

most d e t a i l e d t e s t d a t a on RDF c o - f i r i n g c u r r e n t l y a v a i l a b l e i n t h e open

l i t e r a t u r e . Tab le 8-17 i n c l u d e s combust ion a i r , feedwater , steam, and f l u e

gas c h a r a c t e r i s t i c s measured d u r i n g t h e exper imen ta l t e s t program. Heat

i n p u t f r o m ROF f i r i n g v a r i e d f r o m 0 t o 20 .8 p e r c e n t . F i u e gas

c h a r a c t e r i s t i c s were measured a t a sampl ing l o c a t i o n i n t h e smokestack.

Wh i le f l u e gas f l o w r a t e ( a t s t a n d a r d c o n d i t i o n s ) did n o t change

s i g n i f i c a n t l y d u r i n g RDF c o - f i r i n g when compared t o 100 p e r c e n t c o a l

f i r i n g , gas t e m p e r a t u r e i n c r e a s e d b y 49°F a t 80 pe rcen t l o a d and by 18OF a t

100 p e r c e n t l o a d . T h i s i n c r e a s e i n f l u e gas temperature has a d e t r i m e n t a l

e f f e c t on p r e c i p i t a t o r performance by f o r c i n g coal/RDF ash r e s i s t i v i t y and

a c t u a l gas f l o w r a t e

Table 8-16

Ash analysis. X by utC Silicon, SiO,

Alunintm, A120, Calciun, CaO

Copper. CuO Iron, Fe,O, Lead. PbO Rgnesiun, ?4g0 hnganese. WnO, Phosphorus, P205 Potdssiun, K,O Sodiun, Na,O Sulfur, SO, Tin, SnO, Titaniun, TiO, Zinc, ZnO Chlorine, C1

Average RDF Ash Properties As Reported a t Var ious F a c i l i t i e s (111)

Baltinore Boiler Test 1980

N A ~

57.0

17.8 10.7

2.5

1.7

2.2 2.2 2.2 1.8

St. Louis Mil ity Daily Sanples 1973-75

65 1

55.5

8.8 11.9

0.2 5.3 0.2 1.5

1.3 1.7 8.2 1.5 0.03 1 .o 0.3

akms data after 1978 disc screen installation.

b~ypical average value. Htrber of sqles unknown.

f i i luaukee Bailer Test 1979

3

54.2

9.3 14.5

4.5 0.2 2.9

1.7 5- 1 2.3 0.1 1.0 0.5 3.1 99.4

Bridgeport ROF Plant Data

NAb

M.7

11.3 8.0

18.6

1.2

Chi cago Boiler Test 1979

30

49.3

7.4 12.9

3.6

3.1

1.9 0

- 78.2

m s a Boiler Test 1982

3

47.7

18.3 12.3

4.7

2.4 0.3 0.3 2.3 4.0 4.4

3.3

- 100.0

CValues are shown for those analyses that uere conducted. In nust cases ash analysis does not total 100% because a carplete analysis uas not conducted.

Table 8-17

Average A i r , Feedwater, and Steam

C h a r a c t e r i s t i c s f a r Experimental Runs

a t Ames Boiler Unit (E)

upward. Fuel ana lyses , b o t h RDF and c o a l , a r e l i s t e d on Tab le 8-18. The

RDF has a mean h e a t i n g v a l u e o f 5602 B t u / l b and a mean ash c o n t e n t o f 13.09

p e r c e n t . Tab les 8-19 and 8-20 a r e t a b u l a t i o n s o f t h e measured c o m b u s t i b l e

and non-combust ib le c o n s t i t u e n t s o f t h e bo t tom ash and t h e f l y a s h . An

i n t e r e s t i n g f e a t u r e o f t h i s d a t a i s t h a t t h e f l y a s h and b o t t o m ash m i n e r a l

m a t t e r c o m p o s i t i o n and carbon c o n t e n t a r e s i g n i f i c a n t l y d i f f e r e n t when c o a l

i s t h e o n l y f u e l f i r e d . However, as t h e f u e l m i x t u r e changes f rom 0 t o 20

p e r c e n t RDF, t h e c h a r a c t e r i s t i c s o f . f l y a s h and bot tom ash become n e a r l y

i d e n t i c a l . The m i n e r a l ash c o n t e n t a l s o tended t o become n e a r l y t h e same

a f t e r i n s t a l l a t i o n o f dump g r a t e s . The average r e s u l t s o f t h r e e

independent e m i s s i o n s t e s t s a r e p r e s e n t e d on Table 8-21. U n c o n t r o l l e d

p a r t i c u l a t e emiss ions , as a f u n c t i o n o f RDF h e a t i n p u t and p e r c e n t l oad , i s

p l o t t e d on F i g u r e 8-21. Excep t f o r t h e 100 p e r c e n t l o a d d a t a on c o a l on ly ,

a l l t h e runs show s i g n i f i c a n t i n c r e a s e s i n p a r t i c u l a t e emiss ions as t h e

amount o f RDF c o - f i r i n g i n c r e a s e s . Th i s appears t o b e a r e s u l t o f b o t h

l i g h t e r p a r t i c l e s and i n c r e a s e d f l o w t h r o u g h t h e b o i l e r when b u r n i n g RDF.

F i g u r e s 8-23 and 8-24 show p a r t i c u l a t e s i z e d i s t r i b u t i o n , measured w i t h an

Anderson cascade impac to r , f o r 80 p e r c e n t and 100 p e r c e n t b o i l e r l o a d and

0, 10 and 20 p e r c e n t RDF c o - f i r i n g . From these f i g u r e s i t i s apparen t t h a t

p a r t i c l e s i z e s l i g h t l y i n c r e a s e s w i t h i n c r e a s e d RDF c o - f i r i n g (148).

S t a c k o p a c i t y measurements were n o t r e p o r t e d d u r i n g t h e Ames U n i t 7 t e s t

program.

P r e c i p i t a t o r S i z e S e l e c t i o n

T a b l e 8-22 p r e s e n t s a summary o f t h e Ames U n i t 7 p r e c i p i t a t o r d a t a

measured d u r i n g t h e 1978 t e s t program ( it was e x t r a c t e d f rom Tab le 8-21).

A l s o i n c l u d e d on t h i s t a b l e a r e p r e c i p i t a t o r t e s t r e s u l t s f r o m Meramec

S t a t i o n U n i t 1, Ames S t a t i o n U n i t 8, and Crawford S t a t i o n U n i t 7 . I n

n e a r l y a l l cases, t h e e x i s t i n g p r e c i p i t a t o r s u f f e r e d a decrease i n

c o l l e c t i o n e f f i c i e n c y o f between 0 .2 t o 3 . 5 p e r c e n t when RDF was c o - f i r e d

when compared t o 100 p e r c e n t c o a l f i r i n g . The Ames U n i t 7 p r e c i p i t a t o r

s u f f e r e d e f f i c i e n c y decreases r a n g i n g f r o m 0 . 8 pe rcen t t o 1 .9 p e r c e n t . The

reasan o r reasons f o r these e f f i c i e n c y decreases can be de te rm ined a f t e r

r e v i e w o f c r i t i c a l p r e c i p i t a t o r p rocess parameters , as shown on

Table 8-18

As Fired Coal and RDF

C h a r a c t e r i s t i c s a t Ames F a c i l i t y (MJ)

Coal RDF

w~nber of Samples 1976 1978 1978

fmber of Samples 12

f iear inp Value (HHV) kJ/g 22 .42 0.13 23.6 0.52 13.02 0.83

Ash ( X ) 12.98 2.30 9.74 2.23 13.09 2.72

Carbon ( X ) 53.96 2.81 56.6 1.5 30.66 2.92

Hydrogen ( L ) 3.42 0.65 G.01 0.19 4 .51 0.44

Sulfur ( X ) 3.27 0.85 2.79 0 .81 0.32 0.05

Chlorine ( X ) 0 . 0 3 0.01 0 + 2 1 0.12 0.35 0.15

Analysis of Bottom Ash Before and Af ter I n s t a l l a t i o n

o f Dump Grates a t Ames Boiler Uni t 7 (148)

Parmeter 60% Load ( X ) 0% ROF

Prior to installation o f 0- Grates; 1976,1977

m Load OX ROF

100% Load OX ROF 10X ROF

Carbon 7.51 (4.90)~ 5.46 (1.24) 5.53 (0.95) 35.4 (3.42)

Hydrogen 0.87 (0.56) 0.61 (0.20) 0.49 (0.15) 3.83 (0.55)

Sulfur 2.58 (1.12) 3+59 (1.40) 2.90 (3.95) 0.75 10.06)

Chlorine 0.01 (0.01) 0.00 (0.00) 0.00 (0.011 0.18 (0.04)

Mineral 89.0 (4.33) 90.3 (0.98) 91.1 (4.76) 59.9 (4.06)

After Installation o f OurQ Crates; 1978

BOX Load TOOT Load OX RDF 10X ROF 20% ROF OX ROF 10X RDF MX ROF

Carbon 4.66 (0.88) 2.10 (0.28) 3.11 (0.72) 6.62 * 1.49 (0.27) 1.85 [1.21)

Hydrogen 0.20 (0107) 0.23 (0.02) 0.37 (0.08) 0.38 ( * ) 0.18 (0.04) 0.21 (6.12)

Sulfur 1.07 (0.87) 1.12 (0.99) 0.31 (0.04) 8.98 ( * ) 1.12 (0.71) 0.34 (0.08)

Chlorine 0.01 (0.00) 0.02 (0.01) 0.02 (0.02) 0.03 ( * ) 0.02 (0.0%) 0.02 (0.01)

Mineral 94.8 (0.82) 96.6 (0.82) 96.2 (0.80) 84.0 * 97.2 (0.51) 97.1 (1.411

a~atues i n parentheses are 2 one standard deviation

Table 8-20

Analysis o f Fly Ash Before and After I n s t a l l a t i o n

o f Dump Gates a t Ames Boiler U n i t 7 (148)

Prior to Ins ta l la t ion o f Ounp Grates 1976, 1977

P a r a t e r 60% Load BOX Load 100% Load (X) OX ROF OX ADF OX ROF 1OX ROF

Carban 0.79 (0.19) 0.95 (0.27) 1.87 (1.15) 4.68 (0.43)

Hydrogen 0.27 (0.08) 0.60 (0.25) 0.61 (0.28) 0.07 (0.02)

Sulfur 1.52 (0.25) 1.35 (0.28) 1.35 (0.18) 1.02 (0.12)

Chlorine 0.00 (0.00) 0.00 (0.001 0.01 (0.02) 0.00 (0.00)

Hineral 97.4 (0.47) 97.1 (0.57) 96.2 (1.47) 94.2 (0.57)

After l m t a l l a t i o n o f Ourp Grates 1978

69% toad lMlX Load OX ROF 1OX ROF 20% ROF OX ROF 10% ROF 2OX ROF

Carbon 1.85 (0.55) 2.43 (0.35) 2.54 (0.05) 1.92 (0.78) 2.41 (0.49) 2.40 (0.40)

Hydrogen 0.10 (0.02) 0.11 (0.01) 0.17 (0.05) 0.10 (0.02) 0.11 co.01) 0.11 (0.02)

Sulfur 0.70 (0.34) 0.69 (0.13) 0.86 (0.14) 1.02 (0.511 0.82 (0.21) 0.83 (0.131

Chlorine 0.01 (0.01) 0.01 (0.00) 0.03 (0.01) 0.01 (0.01) 0.02 (0.01) 0.02 (0.01)

Hineral 97.3 (0.55) 96.8 (0.46) 96.4 (0.09) 97.0 (0.39) 96.6 (0.59) 96.6 (0.30)

a~alues i n parentheses are one standard deviation

Table 8 -21

Selected Emissions Before and Af ter I n s t a l l a t i o n

o f Dump Grates a t Ames Boiler U n i t 7 (19)

Pr io r t o I ns ta l l a t i on of O w Grates 1976. 1977

u n i t s MIX Load 0% ROF

BOX Load 100* Load 0% ROF OX ROF 10% RDF

Particulates l b l l 0 ~ 8 ~ ~ ~ 0.23 (0.07)a 0.35 (0.121 0.60 10.09) 0.53 (0.12) (control led)

Part iculates l b/106BlU 9.05 (1.02) 7.49 (1.721 8.26 (0.05) 8.35 (0.30) (uncontrol led)

Oxides of Sulfur SOX I b/ t06BTU 2.61 (0.40) 2.88 (0.70) 3.70 (0.16) 2.88 (1.14) Oxides af Nitrogen Wx lb/106BTU 0.32 10.03) 0.26 (0.09) 0.35 (0.02) 0.27 (0.04) Chlorides lb/lO9BT!J 5.14 (3.75) 13.6 (8.42) 28.14 (6.91) 7.65 (5.05) Formaldehyde I b/lO.BTU 4.56 (5.58) 20.9 (44.0) 5.49 14.58) 60.0 l52.?) Methane I b/lO.BTu 0.00 (0.00,- 0.0 (0.00) 0.00 (0.W) 0.W (0.00)

After I ns ta l l a t i on of Durp Grates 1978

Pardneter Units 80T Load IOOX Load OX RDF 10% RUF 20% ROF 0% RDF 10% RDF 20% RDF

Part icuiates I ~ / I O ~ B T L I 0.21 (0.05) 0.37 (0.09) 0.37 (0.07) 0.42 (0.21) 0.44 (0.07) 0.53 (o.??) (control led)

Part iculates 1b/lO6BTU 6.54 (1.33) 7.63 (0.63) 8.21 0.21) 7.93 13.58) 7.28 (0.53) 7.47 (O.??) (uncontrolled)

Oxides of Sulfur Ib/106BT~ 3.42 (0.14) 2.84 (0.16) 2.33 (0.63) 3.30 (2.07) 2.33 (0.491 1.93 (O.??) SOX

OxidesofWitrogen lb/106BTU 0.39 (0.02) 0.33 (0.02) 0.33 (0.03) 0.31 (0.04) 0.26 (0.01) 0.26 (O.??) WX

Chlorides Ib/lOeBTU 10.7 (1.77) M .9 (35.8) 93.7 (8.96) 7.65 (1.88) 58.4 (31.9) 28.6 (O.??) Formaldehyde Ib/lO*ETu 8.37 114.0) 12. (201.1 0.77 (0.421 0.19 (0.33) 1.44 (0.721 0.42 (O.??) eethane Ib/lO*BTU 5.30 (2.65) 6.07 (1.581 3.77 (0.30) 3.35 (0.93) 4.58 (1.44) 2.47 (0.??1

dvalues i n parentheses are + one standard deviat ion

b to convert frm Ib/106BTU to micrograa/Joule. w l t i p l y values i n the above table by 0.430

- - -

EFFECT OF RDF ON UNCONTROLLED EMISSIONS

0 - 60 PERCENT LOAD a -80 PERCENT LOAD A - 100 PERCENT LOAD

OPEN SYMBOL - 1978 DATA SHADED SYMBOL-1976 OR 1977 DATA

I I i I i 0 4 8 12 16 20

REFUSE DERIVED FUEL INPUT, PERCENT

F igu re 8-22. Uncontrolled Par t i cu la te Emissions versus RDF Heat I n p u t

a t Ames Boi ler U n i t 7 (148)

PARTICLE SIZING 80% LOAD UNIT 7 ANDERSEN 1978

2 5 10 1 5 2 0 30 40 50 60 70 8085 90 95 98

CUMULATlVE PCT LESS THAN DS0

Figure 8-23. P a r t i c u l a t e S ize D i s t r i b u t j o n f o r 80 Percent Load a t Ames Boiler U n i t (148)

PARTICLE SIZING 100% LOAD UNIT 7 ANDERSEN 1978

CUMULATIVE PERCENT LESS THAN DS0

Figure 8-24. P a r t i c u l a t e S ize D i s t r i bu t ion for 100 Percent Load a t

Ames Boi le r U n i t 7(148)

Table 8-22

Location Uni t

(E lec t r i c u t i l i t y tes ts ) S t . Louis Wramec 1

Average ESP E f f i c i e n c y f o r Coa l and

Coal/RDF f i r i n g a s Repor ted a t Var ious F a c i l i t i e s (111)

(EPA tests) s t . Louis wramec I

knes 8

Chicago Crauford 7

Bo i le r Test Date

1913-15

1973-75

1978b

1982

1919

N a i n a l Bci l e r Load (1X)

Averaqe ESP Ef f ic iency Coal Only Coal 6 RDF

0 0

ast. Louis percentage bo i l e r load based on 1 2 5 W rated f u l l load

Average RDF Heat Input

( X )

12 1 I 10

9 18 27 9

18 9

10 20 10 20

22

HA^

ESP Ef f ic iency Reduction Due

t o Cof i r ing jpercentaqe po in ts1

bBefore disc screen i n s t a l l a t i o n c w l e t e d i n Docerrber 1978. Experience since 1979 may be di f ferent.

C~epo r ted average o f 30 tests. Percentage ROF not reported.

Table 8-23. When s i z i n g the p r e c i p i t a t o r ( i f indeed t h e r e i s t h e opportuni ty

t o do so a s most RDF co - f i r i ng i n s t a l l a t i o n s a r e r e t r o f i t t e d i n t o e x i s t i n g

s t a t i o n s with ope ra t ing p r e c i p i t a t o r s ) i t i s suggested t h a t a conserva t ive

approach be t aken , a s fol lows:

S ize t h e p r e c i p i t a t o r f o r t he coal ash r e s i s t i v i t y leve l (do not take c r e d i t f o r reduced coal/RDF ash r e s i s t i v i t y l e v e l s ) a t t he new f l u e gas temperature.

Do not take c r e d i t f o r increased coal/RDF ash p a r t i c l e s i z e .

Take i n t o account increased ash loading when c a l c u l a t i n g ESP emissions.

Account f o r t he increase i n f l u e gas flow r a t e ( a t a c tua l cond i t i ons ) .

Due t o t h e increased amount of carbon p a r t i c u l a t e i n t h e coal/RDF ash , i t i s

a l s o necessary t o maintain low p r e c i p i t a t o r v e l o c i t i e s (p re fe rab ly below 6

f p s ) and moderate a spec t r a t i o s (p re fe rab ly above 0 .8 ) t o minimize carbon

pene t r a t i on through t h e p r e c i p i t a t o r chamber

S p e c i f i c a t i o n of Mechanical and E l e c t r i c a l Features

A t t h i s t ime, i t does not appear t h a t spec i a l cons idera t ions need be

p r e c i p i t a t o r adapt ian t o RDF co-f i r i n g . However, i f high p r e c i p i t a t

v e l o c i t i e s cannot be avoided, then v a r i a b l e i n t e n s i t y e l ec t rode rapp

increased rapping s e c t i o n a l i z a t i o n would be helpful towards reducing

p a r t i c l e reent ra inment .

made f o r

ion

ing and

carbon

COAL-WATER SLURRY (CWS)

Ca lcu l a t i on of Process Parameters

A coal-water s l u r r y was formed using coal from P i t t s t o n , West Vi rg in ia and

burned wi th acceptable r e s u l t s in t he A t l a n t i c Research Corpora t ion ' s

one mi l l i on Btu/hr experimental furnace . Combustion behavior was e s s e n t i a l l y

s i m i l a r t o s l u r r i e s previously t e s t e d i n t h e furnace except t h a t t he P i t t son

CWS was much more d i f f i c u l t t o atomize. Atomization p re s su re s of 30 t o 40

ps ig (3.1 x l o 5 t o 3.8 x lDSPa) were requi red with t h i s s l u r r y .

Three combustion t e s t s a t d i f f e r e n t a i r / f u e l r a t i o s were conducted, each

approximately one hour long. As excess a i r increased from approximately 5 t o

39 pe rcen t , combustion e f f i c i ency improved from about 84 t o 92 percent .

T a b l e 8-23

Review o f Changes in C r i t i c a l ESP Process Parameters During RDF

Go-Firing a t Ames Bo i l e r Unit 7 (Adapted f r o m (148)

Change i n P a r a m e t e r During RDF C o - F i r i n g E f f e c t On

P r o c e s s Pa ramete r (Compared t o Cozl F i r i n g ) ESP Performance

F lyash R e s i s t i v i t y Decreased Improves Performance

Ash Carbon Content I n c r e a s e d Can Have a D e t r i m e n t a l E f f e c t

Flue Gas Flow Rate a t Insignificant Change No E f f e c t S tandard C o n d i t i o n s

Ash P a r t i c l e S i z e

I n l e t Ash Loading

Flue Gas Temperature

S l i g h t I n c r e a s e

I n c r e a s e d

I n c r e a s e d

S l i g h t B e n e f i c i a l E f f e c t

I n c r e a s e d ESP O u t l e t Emiss ions

D e t r i m e n t a l E f f e c t

Combustion e f f i c i ency can be expressed e i t h e r a s t he percent combustible

mat te r of t he coal consumed (sometimes r e f e r r ed t o a s carbon burnout) o r a s

t he percent of the energy of t he coal re leased . There i s only a s l i g h t

d i f f e r e n c e in t he numerical values of t he two. The energy r e l ea se b a s i s was

used i n t h i s study and i s computed from measured s l u r r y flow r a t e , bottom ash

c o l l e c t i o n , f l y ash c o l l e c t i o n , and the respec t ive heat ing values of t h e s e

m a t e r i a l s obtained from proximate ana lys i s . In add i t i on , a small co r r ec t ion

i s app l i ed f o r the presence of CO i n t he s tack gas . The combustion

e f f i c i e n c i e s a r e unique t o t h e experimental furnace used in t h i s study and,

while very respec tab le f o r t h i s small u n i t , a r e not r ep re sen ta t i ve of what i s

expected i n a la rge u t i l i t y b o i l e r (where conversion of 99 percent i s t h e

r u l e ) .

Another f i g u r e of meri t t o eva lua te combustion performance of s l u r r y i s

volumetr ic hea t r e l ea se r a t e . This i s computed a s t he product of the f i r i n g

r a t e and combustion e f f i c i e n c y d iv ided by t h e furnace volume. The heat

r e l e a s e r a t e s varied from 54,100 t o 62,900 B t u / f t 3 / h r . Values f o r o i l

burning a t near 100 percent e f f i c i e n c y a r e approximately 72 ,000 B tu / f t 3 /h r

in t h e same equipment.

COAL-OIL MIXTURE (COM)

Flor ida Power and L i g h t Company has conducted a comprehensive t e s t program of

coa l -o i l mixture a t i t s 400 megawatt Sanford U n i t 4 (154), Mixtures

c o n s i s t i n g of up t o 50 percent coal were burned. The purpose of t he t e s t s

were t o demonstrate the f e a s i b i l i t y of preparing, t r a n s p o r t i n g , s t o r i n g , and

burning coal-oi 1 mixtures.

Because Sanford Unit 4 i s con t ro l l ed by a mechanical dus t c o l l e c t o r , i t was

recognized t h a t an e l e c t r o s t a t i c p r e c i p i t a t o r , o r o ther high e f f i c i ency ash

c o l l e c t i o n device , would need t o be i n s t a l l e d t o reduce atmospheric emissions

of f l y ash t o acceptable l e v e l s . There was concern regarding the a b i l i t y t o

p r e d i c t p r e c i p i t a t o r performance and s i z e a f u l l s c a l e p r e c i p i t a t o r with an

accep tab l e leve l of confidence f o r t he coal-oi l mixture. P r e c i p i t a t o r

performance problems have occurred when unburned o i l , during s t a r t -up , coated

coal f l y a s h . Florida Power and Light Company thus cont rac ted the s e rv i ce s of

F l ak t , I n c . t o operate a p i l o t p r e c i p i t a t o r during the coal-oi l burn t e s t s .

This s e c t i o n wi l l d i scuss t h e r e s u l t s of t he Flakt p i l o t p r e c i p i t a t o r t e s t

program.

Plan t Descript ion

Coal i s brought i n t o t h e p l a n t by r a i l c a r s from Virgina mines. The coal has

a t y p i c a l hea t content of over 13,000 B t u per pound, a s u l f u r content under 1

percent and an ash content under 10 percent . The coal i s e i t h e r s t o r e d on the

ground o r in one of fou r coal s i l o s . As needed, i t flows t o p u l v e r i z e r s where

i t i s reduced i n size t o 80 percent through a 200 mesh screen. The coal i s

then mixed with o i l i n a 15,000 gal lon m i x tank. Production of a 50 percent

by weight bar re l of coa l -o i l mixture r equ i r e s approximately 2013 pounds of coal

and 0 .6 bar re l of o i l . In add i t i on t o t he coal and o i l , an a d d i t i v e and water

a r e a l s o provided t o increase t h e mixture ' s s t a b i l i t y . Coal has a tendency t o

s e t t l e when mixed with o i l , and an a d d i t i v e helps t o reduce t h i s tendency.

The mixture i s pumped t o a 55,000 bar re l s torage tank containing fou r paddle

mixers which help maintain coal i n suspension. The mixture i s pumped t o t h e

b o i l e r burners and atomized w i t h steam. The b o i l e r has t h r e e burner l e v e l s

with s i x burners i n each l e v e l . During t e s t i n g , several d i f f e r e n t t ypes of

burner t i p s were t r i e d . Sometimes d i f f e r e n t t i p s were t e s t e d s imultaneously.

This probably led t o some of t he va r i a t i on i n p r e c i p i t a t o r t e s t r e s u l t s which

w i l l be discussed l a t e r .

P i l o t P r e c i p i t a t o r Descript ion

Flue gas f o r t he F lak t p i l o t p r e c i p i t a t o r was ex t r ac t ed from t h e no r th main

duc t between the a i r p rehea ter o u t l e t and t h e mechanical dus t c o l l e c t o r i n l e t

d u c t . An o f f - take system cons i s t ed of f i v e nozzle banks. Each nozzle bank

had t h r e e nozzles , each with a diameter of four inches . Nozzle banks were

shu t o f f a s required t o g ive i s o k i n e t i c sampling r a t e s over t h e range of

p r e c i p i t a t o r SCAs t e s t e d ; SCA ( s p e c i f i c c o l l e c t i o n a r ea ) i s t h e square f e e t o f

p r e c i p i t a t o r c o l l e c t i o n su r f ace per thousand ac tua l cubic f e e t per minute of

gas flow r a t e .

An e l e c t r i c hea ter was i n s t a l l e d in the i n l e t duct of t he p i l o t p r e c i p i t a t o r

t o cont ro l gas temperature.

The p r e c i p i t a t o r cons is ted of 826.7 square f e e t of c o l l e c t i o n su r f ace with t en

inch c o l l e c t i n g p l a t e spacing. The p r e c i p i t a t o r was d iv ided i n t o t h r e e

e l e c t r i c a l s ec t ions o r f i e l d s , each w i t h i t s own e l e c t r i c a l energ iza t ion and

cont ro l system. The d ischarge e l e c t r o d e s were F l a k t ' s s tandard h e l i c a l wi res

with a wire diameter of 0 .10 inch.

Each p r e c i p i t a t o r f i e l d was equipped with a rapping system. Discharge

e l ec t rodes were rapped a t s i x minute i n t e r v a l s . Co l l ec t i on p l a t e s were rapped

each s i x minutes in t he f i r s t f i e l d , each twelve minutes i n t he second f i e l d ,

and each t h i r t y minutes in t he t h i r d f i e l d .

Gas flow r a t e s and emissions were measured downstream of t h e p r e c i p i t a t o r .

The EPA method 5 (without t h e wet impinger ca tch) was used t o measure t he d u s t

emission. Gelman type A / E g l a s s f i b e r f i l t e r s were u t i l i z e d . I n l e t d u s t

burden was determined by weighing t h e dus t c o l l e c t e d in t h e p r e c i p i t a t o r s

hoppers.

Performance t e s t s were conducted over a range from 150 SCA t o 300 SCA; t h i s

corresponds t o a gas v e l o c i t y of 4 . 3 f e e t per second t o 2.15 f e e t per second,

r e spec t ive ly . The p r e c i p i t a t o r c u r r e n t dens i ty was maintained a t

approximately 21.5 microamps per square f o o t of c o l l e c t i n g p l a t e , which Flak t

an t i c ipa t ed would be s u i t a b l e f o r a f u l l - s i z e p r e c i p i t a t o r . Some t e s t s were

run a t ha l f and a t twice t h i s level t o determine t h e e f f e c t of corona c u r r e n t

v a r i a t i o n s .

Performance Resul ts

A t o t a l of ninety-three p r e c i p i t a t o r performance t e s t s were run between May 5

and October 10 , 1980. These t e s t s were conducted over a wide range o f b o i l e r

opera t ing condit ions. Percent coal i n t he coal-oi l mixture ranged from 20 t o

50 percent . Bo i l e r load ranged from 200 t o 400 megawatts. Boi le r

oxygen level ranged from l e s s than one percent t o f i v e pe rcen t . Various

burner t i p designs were used, hence varying the q u a l i t y of atomizat ion.

Figure 9-25 summarizes t he performance r e s u l t s . Considerable s c a t t e r i s

ev ident . I t w i l l be t h e ob j ec t ive of t h e remainder of t h i s chapter t o expla in

t h i s s c a t t e r and t o p red i c t what s i z e of p r e c i p i t a t o r would be appropr ia te f o r

t h e condi t ions encountered.

N o r m a l l y as t h e SCA o f a p r e c i p i t a t o r i s i nc reased , i t s p e r c e n t c o l l e c t i o n

e f f i c i e n c y i n c r e a s e s . The m o d i f i e d Deutsch-Anderson e q u a t i o n used t o

d e s c r i b e t h e performance i s as f o l l o w s :

k 100 - EFF - -

100 '-

Where :

EFF = c o i l e c t i o n e

SCA = s p e c i f i c c o l

f f i c i e n c y , p e r c e n t

l e c t i o n a rea , f t 2 / 1 0 0 0 acfm

W = p a r t i c u l a t e e f f e c t i v e m i g r a t i o n v e l o c i t y , cm/sec

I n t h e above f o r m u l a , t h e f a c t o r "k" depends on t h e s i z e d i s t r i b u t i o n o f

t h e p a r t i c l e s and on o t h e r p a r t i c l e c h a r a c t e r i s t i c s wh ich make each

p a r t i c l e more o r l e s s easy t o c o l l e c t . I f a l l t h e p a r t i c l e s a r e t h e same

s i z e , k would approx imate u n i t y , wh ich i s v i r t u a l l y never t h e case. A "kl'

o f 0 .5 has been found t o be a p p r o p r i a t e f o r t h e c o n d i t i o n s n o r m a l l y

encountered.

The p r e c i p i t a t o r performance shown on F i g u r e s 8-25, 8-27 and 8-28 e v i d e n t l y

does n o t f o l l o w t h e Deutsch-Anderson e q u a t i o n . T h i s i s p r o b a b l y due t o

many v a r i a b l e s a s s o c i a t e d w i t h t h e p l a n t o p e r a t i o n .

A n a l y s i s o f ash samples i n d i c a t e d r e l a t i v e l y h i g h l e v e l s o f unburned f u e l

( l o s s on i g n i t i o n o r LOI). T h i s v a r i e d f r o m f i v e p e r c e n t t o a lmos t t h i r t y

p e r c e n t . H i g h l e v e l s o f unburned carbon were t h o u g h t t o be d e l e t e r i o u s t o

p r e c i p i t a t o r performance. F i g u r e 8-25 d i s t i n g u i s h e s between h i g h and l o w

LO1 va lues. No c o n s i s t e n t p a t t e r n i s e v i d e n t . I f f a c t , some o f t h e

h i g h e s t c o l l e c t i o n e f f i c i e n c i e s o c c u r r e d w i t h v e r y h i g h LO1 va lues .

G e n e r a l l y , i n c r e a s i n g t h e b o i l e r oxygen l e v e l decreased t h e LO1 l e v e l , as

shown i n F i g u r e 8-26.

NOTE

A LO1 OVER 15% LO1 UNDER 1%

x LO1 10-15%

Figure 8-25. P i l o t P r ec ip i t a t o r Test Results

BOILER OXYGEN LEVEL (%)

Figure 8-26. Boiler Oxygen Effect on Ash Loss on Ignition (FOl)

The LO1 l e v e l i s a l s o a f f e c t e d by t h e q u a l i t y o f a t o m i z a t i o n w h i c h i n t u r n

may a f f e c t t h e p a r t i c l e s i z e ; p r e c i p i t a t o r per formance i s dependent on

p a r t i c l e s i z e . The b u r n e r t i p geometry v a r i e d f r o m t i p t o t i p due t o

e r o s i o n , s e r v i c e c o n d i t i o n s and o p e r a t i n g t i m e . D u r i n g t h e e a r l y

o p e r a t i o n , i t became e v i d e n t t h a t e x c e s s i v e wear was o c c u r r i n g on t h e f r o n t

n o z z l e o f t h e b u r n e r t i p . T h i s caused p o o r a t o m i z a t i o n and r e q u i r e d

f r e q u e n t t i p rep lacement . Through a s e r i e s o f d e s i g n m o d i f i c a t i o n s , t h i s

e r o s i o n was reduced. A s o l i d coa l l i k e d e p o s i t a l s o formed i n some o f t h e

b u r n e r s , and t h i s may have a l s o a f f e c t e d q u a l i t y o f a t o m i z a t i o n .

Because t h e r e were e i g h t e e n bu rne rs , each w i t h i t s own o p e r a t i n g h i s t o r y ,

degree o f e r o s i o n , and a t o m i z a t i o n q u a l i t y , i t was n o t t h o u g h t p o s s i b l e t o

c o r r e l a t e bu rne r per formance t o p a r t i c l e s i z e , LO1 l e v e l o r p r e c i p i t a t o r

performance. Thus, some o f t h e s c a t t e r o f F i g u r e 8-25 can be expec ted t o

l i k e w i s e occur w i t h a f u l l - s i z e p r e c i p i t a t o r , as p e r f e c t a t o m i z a t i o n , and

combust ion cannot be expected t o occu r on a day-to-day b a s i s . *

A l i n e a r m u l t i p l e r e g r e s s i o n a n a l y s i s , i n c l u d i n g LOI , was conduc ted i n an

a t t e m p t t o e x p l a i n some o f t h e spread i n t h e t e s t r e s u l t s . T h i s d i d n o t

p r o v i d e s i g n i f i c a n t r e d u c t i o n t o t h e degree o f d a t a s c a t t e r . Thus, t h e

p r e c i p i t a t o r must be s e n s i t i v e t o o t h e r parameters n o t i n c l u d e d i n t h e

r e g r e s s i o n a n a l y s i s , such as t h e b o i l e r o p e r a t i o n . When such f a c t o r s a r e

exc luded from t h e r e g r e s s i o n a n a l y s i s , c o r r e l a t i o n s f r o m t h e i n c l u d e d

v a r i a b l e s cannot b e assured.

I n l e t p a r t i c u l a t e c o n c e n t r a t i o n v a r i e d f r o m under 0 .5 g r a i n s / d s c f t o 1.6

g r a i n s / d s c f . No c o r r e l a t i o n was e v i d e n t between p a r t i c u l a t e c o n c e n t r a t i o n

and c a l c u l a t e d m i g r a t i o n v e l o c i t y o r p r e c i p i t a t o r c o l l e c t i o n e f f i c i e n c y .

* P a r t i c l e s i z e d i s t r i b u t i o n t e s t s were n o t conducted on c o l l e c t e d ash

because agg lomera t ion c o u l d have o c c u r r e d .

Gas temperature v a r i e d between 280 and 380°F. No s t a t i s t i c a l l y s i g n i f i c a n t

e f f e c t o f t empera tu re was noted. E l e c t r i c a l r e s i s t i v i t y t e s t s on ash

samples i n d i c a t e d dec reas ing r e s i s t i v i t i e s w i t h i n c r e a s i n g tempera tu res

above 300°F.

The p r e c i p i t a t o r secondary v o l t a g e v a r i e d between a p p r o x i m a t e l y 32 and 42

kV. It i s most unusual t h a t t h i s had no apparent i n f l u e n c e on per formance,

as u s u a l l y secondary v o l t a g e has a s t r o n g e r i n f l u e n c e t h a n secondary

c u r r e n t l e v e l . Severa l t e s t s were conducted a t much h i g h e r and much lower

c u r r e n t d e n s i t i e s than a r e expec ted t o occu r d u r i n g normal o p e r a t i o n .

These t e s t s showed lower i n f l u e n c e o f corona c u r r e n t on performance than i s

n o r m a l l y found.

F i g u r e 8-27 shows c a l c u l a t e d m i g r a t i o n v e l o c i t y ve rsus p r e c i p i t a t o r SCA

d u r i n g t h e t e s t s . The m i g r a t i o n v e l o c i t y i s based on a u n i t y exponent i n

t h e Deutsch-Anderson equa t ion . N o r m a l l y , as SCA and c o l l e c t i o n e f f i c i e n c y

inc rease , t h e m i g r a t i o n v e l o c i t y ( w i t h a u n i t y exponent ) wou ld be expec ted

t o decrease. F i g u r e 8-28 shows m i g r a t i o n v e l o c i t y ve rsus SCA f o r a k v a l u e

equal t o 0 . 5 . T h i s forms a more h o r i z o n t a l form and t h u s i s more u s e f u l i n

p r e c i p i t a t o r s i z i n g .

F i g u r e 8-28 does, however, appear t o have a s l i g h t l y downward s lope w i t h

i n c r e a s i n g SCA.** Based on p a s t e x p e r i

c o u l d be due t o a h i g h e r pe rcen tage o f

p r e c i p i t a t o r a t l o w sampl ing ( l o w SCA)

l o w p r e c i p i t a t o r v e l o c i t y a t h i g h SCA 1

ence, t h i s i s most unusual . I t

f i n e p a r t i c u l a t e e n t e r i n g t h e

r a t e s . It a l s o c o u l d be due t o t h e

e v e l s a t 300 SEA, t h e v e l o c i t y

th rough t h e p r e c i p i t a t o r was o n l y 2 .15 f e e t p e r second. T h i s low v e l o c i t y

may decrease t u r b u l e n c e t o l e v e l s where in t h e f i n e p a r t i c u l a t e i s n o t

b r o u g h t c l o s e enough t o t h e c o l l e c t i o n p l a t e s f o r c a p t u r e . T h i s phenomenon

has been observed by o t h e r s .

- ** A h o r i z o n t a l c o n f i g u r a t i o n wou ld be expected.

SCA, ft2/k ACFM

F i g u r e 8-27 . SCA vs. Fligration Velocity, K = 1 .0

f i ~ u r e 8-28. SCA vs. Migration Veloci ty , K = 3.5

In view of the high number of v a r i a b l e s assoc ia ted with t he coa l -o i l

mixture burn t e s t s , some p r e c i p i t a t o r t e s t s c a t t e r can be expected. One

could design a f u l l s i z e p r e c i p i t a t o r based on t h e average performance of

t he p i l o t , which would probably n o t be adequate were performance measured,

on a day-by-day bas is . Designing f o r t he worst p i l o t performance would be

too conserva t ive because s i g n i f i c a n t t e s t e r r o r may be involved.

S t a t i s t i c a l p robab i l i t y can be used t o evaluate t h e leve l o f r i s k

a s soc i a t ed with var ious p r e c i p i t a t o r s i z e s e l e c t i o n s . Assuming a normal

da ta d i s t r i b u t i o n forming the f a m i l i a r bel l curve d i s t r i b u t i o n , and using a

"k" exponent of 0 . 5 , t h e average t e s t migration v e l o c i t y was 23.96 cm/s and

t h e s tandard devia t ion was 6.53 cm/s. The modified Deutsch-Anderson

equat ion and s t a t i s t i c a l p robab i l i t y ana lys i s determined the es t imated

requi red p r e c i p i t a t o r s i z e s shown in Figure 8-29. This f i g u r e i n d i c a t e s

t h a t t o increase t h e confidence leve l t o 90 pe rcen t , a p r e c i p i t a t o r should

be increased i n s i z e by about 50 percent aver t h a t i nd i ca t ed by t h e average

of t h e t e s t da t a . Costs a r e not d i r e c t l y propor t iona l t o p r e c i p i t a t o r

s i z e ; a 50 percent increase in s i z e would c o s t on the order of 30 pe rcen t

more.

The ac tua l s i z e of a p r e c i p i t a t o r w i l l a l so depend on t h e requi red

c o l l e c t i o n e f f i c i e n c y . This can only be determined a f t e r review of the

range o f ash content expected from t h e coa ls which a r e u l t ima te ly purchased

and on a co r r e l a t i on of emissions t o opac i ty . The emission opac i ty l i m i t

may d i c t a t e a lower p a r t i c u l a t e emission level than mass emission l i m i t

r egu la t i ons ,

Other items regarding these t e s t s should be noted:

No back corona was encountered during any of t he t e s t s .

Often a s c a t t e r of p r e c i p i t a t o r performance da ta was noted when the unburned carbon content was high, e s p e c i a l l y with coa r se coke p a r t i c l e s . The unburned content exceeded 1 0 percent f o r more than 75 percent of t he se t e s t s . This unburned content d i d not vary with t he percent coal in the coa l -o i l mixture. P r e c i p i t a t o r migration ve loc i ty a l s o d id not vary in a p r ed i c t ab l e way with percent coal i n t he mixture.

200 300 400 500 600 700

ESTIMATED REQUIRED PRECIPITATOR SIZE (SCA), ~ ~ ' J ~ A C F M

F i g u r e 8-29. E s t i m a t e d Precipitator S i z e

Tes ts were a l s o conduc ted w i t h pure o i l f i r i n g and w i t h c o a l - o i l m i x t u r e s a f t e r p e r i o d s o f o i l f i r i n g . No p r e c i p i t a t o r f o u l i n g was observed.

The p r e c i p i t a t o r t e s t s a t San fo rd were u s e f u l because t h e y p r o v i d e d i n s i g h t t o w a r d t h e v a r i a b i l i t y o f per formance w h i c h can be expected. They demonst ra ted t h a t t h e COM ash can be s u c c e s s f u l l y c o l l e c t e d i n an e l e c t r o s t a t i c p r e c i p i t a t o r . The t e s t s i n d i c a t e d a need f o r f u r t h e r c h a r a c t e r i z a t i o n o f t h e e f f e c t s o f COM p r o d u c t i o n and combust ion v a r i a b l e s on t h e p r e c i p i t a t o r per formance. However, i f a f a i r l y l a r g e p r e c i p i t a t o r i s s e l e c t e d , these v a r i a b l e s would n o t impa i r t h e goa l o f s u c c e s s f u ? l y c o l l e c t i n g t h e ash.

LIMESTONE INJECTION MULTISTAGED BURNERS (LIMB) MODIFIED BOILERS

Limeszone I n j e c t i o n M u l t i s t a g e Burner techno logy a l l o w s f o r t h e r e t r o f i t

f o SO2 c o n t r o l s on to e x i s t i n g b o i l e r s . The b o i l e r i s m o d i f i e d t o a d j u s t

t h e l o c a t i o n where combust ion a i r i s i n t r o d u c e d , t h e r e b y r e d u c i n g n i t r o g e n

ox ides ; and t o a l l o w l i m e s t o n e t o be i n j e c t e d , t h e r e b y r e d u c i n g s u l f u r

d i o x i d e .

S t e i n m u l l e r , an e n g i n e e r i n g f i r m i n West Germany has been p e r f o r m i n g

research w o r k i n t h e area o f LIMB techno logy . LIMB i n i t i a l development was

c a r r i e d o u t w i t h a 2 .3 MW p i l o t s c a l e bu rne r , as an e x t e n s i o n o f t h e low

NOx b u r n e r development. I n t h e f i r s t phase t h e f u e l used was n a t u r a l gas

dosed w i t h SO, o r H,S; l a t e r s e v e r a l b i tum inous c o a l s were burned

i n a p i l o t b u r n e r . Pa ramete r i c s t u d i e s were done w i t h l i m e , l i m e s t o n e and

a c t i v a t e d l i m e a t m o l a r r a t i o s r a n g i n g f rom 1 t o 4 . Three a d d i t i v e

i n j e c t i o n l o c a t i o n s were t r i e d : w i t h f u e l , w i t h s t a g i n g a i r , and i n t h e

e x t e r n a l r e c i r c u l a t i o n zone. O the r v a r i a b l e pa ramete rs exper imented w i t h

were tempera tu re (900 t o l l O O ° C ) , b o i T e r l o a d (60 t o 150 p e r c e n t ) , a i r f low

r a t e s t o b u r n e r , combust ion a i r s w i r l and v e l o c i t y o f s t a g i n g a i r .

R e s u l t s o f t h e p i l o t b u r n e r work showed t h a t t h e r e a r e t h r e e m a j o r

p r e - r e q u i s i t e s f o r a c c o m p l i s h i n g SO, removal i n t h e b o i l e r w i t h a

reasonable r a t e o f success: optimum temperature , good m i x i n g , and adequate

res idence t i m e . The concept o f l ow NOx burne rs p r o v i d e s t h e optimum

tempera tu re and good m i x i n g . A d d i t i v e i n j e c t i o n i n t h e e x t e r n a l

r e c i r c u l a t i o n zone improves b o t h tempera tu re and m i x i n g c o n d i t i o n s .

Residence t i m e i s b a s i c a l l y a f u n c t i o n o f t h e b o i l e r s i z i n g c r i t e r i a .

SO, removal e f f i c i e n c i e s ranged from 0 t o 75 pe rcen t , depending on Ca/S

molar r a t i o (75% removal a t Ca/S=4), s u l f u r con ten t in the coal (h igher

e f f i c i e n c y occured a t h igher s u ? f u r content ) and type o f add i t i ve

( a c t i v a t e d lime provides b e s t e f f i c i ency and l imestone the lowest) . A

r e a l i s t i c e f f i c i e n c y f o r t h e process i s 45% t o 50% SO, removal a t a

Ca/S molar r a t i o of about 2.

A number of e x i s t i n g u t i l i t y f l y ash p r e c i p i t a t o r s may be a f f ec t ed by

b o i l e r r e t r o f i t s o r process changes, such a s iIMB modif ica t ions , undertaken

t o cont ro l s u l f u r oxide emissions. The LIMB modif icat ion may a f f e c t t h e

opera t ion of e x i s t i n g p r e c i p i t a t o r s and t h e design of new p r e c i p i t a t o r s f o r

fou r reasons: - An i nc rease in t h e s t i c k i n e s s of d u s t depos i t s on the ESP e l e c t r o d e s and in the hoppers

An i nc rease in t h e t o t a l p a r t i c u l a t e mass loading en ter ing the ESP, by a f a c t o r of two o r more

An inc rease in t h e mass loading of submicron p a r t i c l e s , by a f a c t o r of two o r more

* A n i nc rease in t he r e s i s t i v i t y of t h e co l l ec t ed p a r t i c u l a t e mat te r by two o r d e r s of magnitude o r more.

In conclusion, the LIMB process i s qu i t e promising f o r special a p p l i c a t i o n s

where high SO, removal i s not requi red . Since t he economics of t h e

LIMB i n d i c a t e low c a p i t a l investment/high opera t ing c o s t (due t o t he high

s to ich iorne t r ic r a t i o of reagent ) , i t appears t h a t t he most economic

advantages of LIMB can be achieved in r e t r o f i t s i t u a t i o n s where low SO,

removal i s acceptable combined with a low capac i ty f a c t o r . These

cond i t i ons may apply t o a l a rge number of u n i t s which would be sub jec t t o

pending ac id r a i n l e g i s l a t i o n . The U.S. Environmental Protect ion Agency

and the E l e c t r i c Power Research I n s t i t u t e a r e involved in labora tory t e s t s

and f u l l - s c a l e demonstrat ions of LIMB. However, t h e r e a r e not y e t enough

da t a t o make c e r t a i n p ro j ec t ions of t he impact of LIMB on ESP design and

ope ra t ion .

9 THE EFFECTS OF DRY SCRUBBERS 0 PRECIPITATORS

Section 9

THE EFFECTS O F DRY SCRUBBERS ON PRECIPITATORS

LIME SPRAY D R Y E R PROCESS

The lime spray dryer process i s a r e l a t i v e l y simple process used t o remove

s u l f u r oxides from the f l u e gas s tream. Most f l u e gas from a b o i l e r passes

unt rea ted t o a spray d r y e r where i t con tac t s an atomized s l u r r y of lime and

recyc led waste. The s u l f u r oxides a r e absorbed and r e a c t with t he lime and

recyc led f l y ash t o form calcium s u l f i t e and calcium s u l f a t e . Water i n j e c t e d

i n t o the spray dryer i s i n s u f f i c i e n t t o s a t u r a t e t h e f l u e gas , and the

r e s u l t i n g waste mater ia l leaves a s en t r a ined , dry p a r t i c u l a t e mat te r . The

f l u e gas next passes i n t o p a r t i c u l a t e c o l l e c t i o n equipment, e i t h e r a baghouse

o r a p r e c i p i t a t o r , where f l ya sh and r eac t ion products a r e removed from the gas

s tream. This r e s u l t s i n higher c o l l e c t i o n e f f i c i e n c i e s , and empir ical t e s t

d a t a bears t h i s ou t . An increase from 98.5 t o 9 9 . 4 percent co l l ec t i on

e f f i c i e n c y was observed f o r dry FGD in p i l o t p l a n t opera t ions obtained by Joy

Manufacturing Company a t t h e Riverside P l an t i n Minneapolis, Minnesota, a s

shown in Table 9-1. The cleaned f l u e gas then flows through induced d r a f t

f ans and ou t t he s t ack .

PROCESS PARAMETERS

I n v e s t i g a t i o n s i n t o dry

t h a t e l e c t r o s t a t i c prec

s eve ra l reasons f o r t h e

One i s t h a t t h e tempera

opera t ion s u b s t a n t i a l l y

c o l l e c t e d f o r a typ

t h a t spray-dried ma

l o 7 t o l o 9 ohm-cm.

problem and the co1

f l u e gas d e s u l f u r i z a t i o n ( F G D ) opera t ions i n d i c a t e

i p i t a t o r s work well with such systems. There a r e

success of dry FGD with e l e c t r o s t a t i c p r e c i p i t a t o r s .

t u r e decrease a s soc i a t ed with a spray drying absorpt ion

reduces the r e s i s t i v i t y of f l ya sh . Empirical d a t a

ca l range of dry FGD opera t ion from 140 t o 180°F shows

e r i a l has r e l a t i v e l y low r e s i s t i v i t y , in t he range o f

In t h i s r e s i s t i v i t y range back corona would not be a

e c t i o n c h a r a c t e r i s t i c s of f l ya sh would be enhanced.

Because t h e spray d r y e r p rocess i s d r y , v i r t u a l l y a l l o f t h e w a t e r d r o p l e t s

a r e evapora ted i n t h e f l u e gas stream, and these w a t e r d r o p l e t s a r e n o t

c a r r i e d i n t o t h e p a r t i c u l a t e removal equipment. Ano the r reason t h a t

e l e c t r o s t a t i c p r e c i p i t a t o r s work w e l l w i t h t h e d r y FGD p rocess i s t h a t t h e

tempera tu re decrease a s s o c i a t e d w i t h o p e r a t i n g t h e sp ray d r y i n g a b s o r b e r

causes a decrease i n f l u e g a s volume f l o w r a t e and a c o r r e s p o n d i n g i n c r e a s e i n

t h e s p e c i f i c c o l l e c t i o n area o f t h e p r e c i p i t a t o r .

T h e r e f o r e , an e l e c t r o s t a t i c p r e c i p i t a t o r appears t o o f f e r a good c h o i c e f o r

p a r t i c u l a t e c o l l e c t i o n w i t h a spray d r y e r system.

A comparison o f t h e range o f o p e r a t i n g v a r i a b l e s f o r t h e d r y p r o d u c t

p r e c i p i t a t o r versus t h e f l y a s h p r e c i p i t a t o r i s shown i n Tab le 9-2.

PRECIPITATOR SIZING

There a r e t w o approaches t o s i z i n g p r e c i p i t a t o r s f o r u t i l i t y use w i t h d r y FGD

systems. One i s t o s i z e t h e u n i t o n l y f o r d r y FGD o p e r a t i o n ; t h e second i s t o

s i z e f o r a w o r s t case s i t u a t i o n whe the r t h a t be f l y a s h o n l y , d r y FGD o n l y , o r

a c o m b i n a t i o n o f d r y FGD w i t h u n t r e a t e d f l u e gas bypass.

Case 1 i s a system where an o p e r a t o r m i g h t b u r n a Wyoming c o a l w i t h a

p r e c i p i t a t o r s i z e d f o r d r y FGD o p e r a t i o n . The u s e r r e q u e s t e d a p r e c i p i t a t o r

s i z e t h a t was approx ima te l y 550 SCA a t 120 p e r c e n t Maximum Cont inuous Rated

(MCR) gas f l o w f rom t h e spray d r y e r absorbers . Tab le 9-3 shows t h e t y p i c a l

c o a l a n a l y s i s t h a t was g i ven t o t h e d r y FGU c o n t r a c t o r on t h i s p r o j e c t . T a b l e

9-4 shows t h e p r e c i p i t a t o r per formance requ i remen ts as a r e s u l t o f p a s s i n g

t h r o u g h t h e sp ray d r y e r v e s s e l s . Due t o s i z i n g a t 120 p e r c e n t o f d e s i g n gas

f l o w , a p r e c i p i t a t o r f o r t h e most p r o b a b l e o p e r a t i n g p o i n t o f 100 p e r c e n t

b o i l e r l o a d i s s i z e d ex t reme ly l a r g e . The requ i remen ts show t h a t a d e s i g n

e f f i c i e n c y

Tab le 9-1

R i v e r s i d e ESP R e s u l t s

Fly Ash W i t h Hz0 C o n d i t i o n i n g

I n 1 e t Loading (GR/ACF) 2.2 ( e s t )

O u t l e t Loading (GWACF) .032

Volume Flow (ACFM) 228,000

SCA ( f t 2 / 1 0 0 0 ACFM) 182

E f f i c i e n c y (%) 98.5 ( e s t )

M i g r a t i o n V e l o c i t y ( c d s e c ) 11.72

Average O p a c i t y % 18

Temperature (OF) 311

D r y FGD

6.79

Tab le 9-2

Comparison o f Range o f O p e r a t i n g V a r i a b l e s Dry P r o d u c t C o l l e c t i o n vs . Fly Ash C o l l e c t i o n Range

Dust Loading

Temperature

Gas V e l o c i t y

M o i s t u r e

Average Secondary V o l t a g e

Average C u r r e n t D e n s i t y

R e s i s t i v i t y

P a r t i c l e S ize Mass Mean D iamete r

D r y FGD P r o d u c t Range

6 - 12 GR/ACF

140 - 180°F

3.5 - 4.5 f t / s e c

10 - 15% b y volume

40 - 50 kV

20 - 50 ma/1000 f t2

l o 7 - lo9 ohm-cm

8 - 20 pm

Fly Ash P r e c i p i t a t o r (Cold-S ide) Range

1 - 5 GR/ACF

250 - 4OO0F

2 .5 - 4 .5 f t / s e c

4 - 12% by volume

5 - 40 rna/1000 f t2

IO9 - 10'' ohm-cm

Tab le 9-3

Case I

Steam Generator Fue l Da ta

P rox ima te A n a l y s i s , W t . P e r c e n t

M o i s t u r e Ash S u l f u r B t u p e r Pound

Mineral A n a l y s i s o f Ash, W t . Percent

T i 0 2

CaO

Wyoming Coal

Tab le 9-4

Case I

FGD Requirements

Gas Flow, acfm

Temperature, OF

SCA ( T o t a l ) , f t 2 / 1 0 0 0 ac fm

SCA ( 5 Percen t Out ) , f t 2 / 1 0 0 0 acfm

I n l e t Loading, GR/ACF

Guarantee O u t l e t , Ib/MBtu

Des ign E f f i c i e n c y , P e r c e n t

of 99.91 percent i s required f o r the d u s t loadings shown, which a r e maximum

dus t loadings t o the e l e c t r o s t a t i c p r e c i p i t a t o r without f a l l o u t from t h e

spray d rye r . Table 9-5 shows computer pred ic ted performance f o r a system

using the expected average vol tages and average c u r r e n t d e n s i t i e s . A t 120

percent l oad , t he p r e c i p i t a t o r i s p red ic ted t o have an e f f i c i e n c y of 99.92

percent . Based on a 20 f t diameter s t ack and 0.03 Ibs/MBtu ou tpu t , t h e

s tack opac i ty i s projected t o be 13 percent . For computer pred ic ted o u t l e t

emissions, which a r e l e s s than 0.03 ?b/MBtu, the predic ted opac i ty i s 12

percent a t 120 percent load and 4 percent a t 100 percent load.

In Case 2 , t h e vendor was requested t o s i z e a p r e c i p i t a t o r f o r opera t ion on

e i t h e r dry FGD bypass condit ion o r f o r t h e dry FGD system, whichever was

dominant. Based on a l l t e s t i n g (and t h e coal da ta shown in Table 9-6), t h e

bypass condi t ion with the worst case coal f lyash determined t h e

p r e c i p i t a t o r s i z e . For t he most d i f f i c u l t case c o a l , a p r e c i p i t a t o r of 550

SCA was s e l e c t e d t o achieve the design e f f i c i e n c y of 99.51 percent requi red

t o meet t he New Source Performance Standards. Table 9-7 shows t h e expected

f l yash performance a s predic ted by the SRI p r e c i p i t a t o r model. I t shows

t h a t t h e p r e c i p i t a t o r should achieve approximately 99.6 percent e f f i c i e n c y

with t he app l i ed vol tages and cu r r en t s an t i c ipa t ed on t h i s r a t h e r d i f f i c u l t

f l ya sh a p p l i c a t i o n . Opacity was predic ted a t approximately 12 percent f o r

0.03 lb/MBtu p r e c i p i t a t o r o u t l e t .

Using t h i s s e l e c t i o n , and applying i t t o t h e dry FGD opera t ing mode, t h e

p r e c i p i t a t o r requirements and s i z e a r e shown i n Table 9-8, i t shows two

opera t ing modes o r temperature opera t ions on t h i s s i z e of p r e c i p i t a t o r .

The p r e c i p i t a t o r spec i f i c co l l ec t i on a r ea i s l a r g e r i n t h i s case due t o

reduced gas temperature and correspondly reduced gas volume. The design

e f f i c i e n c y requirements in e i t h e r opera t ing mode i s 99.9 percent . Table

9-9 i n d i c a t e s t h a t the predicted p r e c i p i t a t o r performance f o r dry FGD

se rv i ce i s i n excess of t he requirement due t o s i z?ng t h i s u n

worst coal ca se . Because of t he moisture condi t ion ing in dry

ope ra t ions , t h i s w i l l be t h e usual ca se . The predic ted o u t l e

o p a c i t i e s i s l e s s than 4 percent f o r t he FGD mode.

i t f o r t h e

FG D

t , t h e s t a c k

Table 9-5

Case I

Dry FGD Expected Performance

100%

Predicted Efficiency, Percent 99.98

Average AppJ ied Voltage, kV 40

Average Current Density, ma/1000 ft2 46

Opacity, Percent a t Stack (= 20 ft)

Calculated for 13.03 Ib/MMBtu 13.2

Calculated for Predicted Outlet Emission 3.69

Gas Flow, acfm

S u l f u r i n Coal , Percent

M o i s t u r e

Fe203, Percen t

Na 0 , Pe rcen t 2

Temperature O F

I n l e t Load ing GR/ACF a t 6.12 lb /MBtu I n p u t

Guarantee O u t l e t a t 0.03 lb /MBtu I n p u t

Design E f f i c i e n c y , P e r c e n t

SCA, f t z / l O O O acfm (10% Bus s e c t i o n s o u t )

T a b l e 9-6

Case I1

F l y a s h Requirement

T a b l e 9-7

Case I1

Expected F l y a s h Performance

P r e d i c t e d E f f i c i e n c y , P e r c e n t

Average A p p l i e d V o l t a g e , kV

Average C u r r e n t D e n s i t y , rna/1000 f t z

O p a c i t y , Pe rcen t a t S tack (= 30 f t )

C a l c u l a t e d f o r 0.0088 GR/ACF

C a l c u l a t e d f o r P r e d i c t e d O u t l e t

Gas Flow, acfm

Temperature O F

SCA, f t2 /1000 acfm (10 pe rcen t bus sect ions ou t )

I n l e t Loading, Maximum GR/ACF

Guarantee o u t l e t , Ib/MBtu

Design E f f i c i e n c y , Percent

Table 9-8

Case I1

FGD Requirement

T a b l e 9-9

Case I1

FGD Expected Performance

P red i c ted E f f i c i e n c y Percent 99.99

Average Appl i ed Vo l tage , kV 49

Average Cur ren t Densi ty ma/lO00 ft2 44

Opaci ty , Percent a t Stack Diameter (= 30 f t )

O u t l e t Opaci ty 13.9

P red i c ted O u t l e t 3 . 5

DESIGN CONSIDERATIONS

Severa l des ign c o n s i d e r a t i o n s shou ld be taken i n t o account when choos ing

p r e c i p i t a t o r s f o r d r y FGD s e r v i c e .

ENERGY MANAGEMENT SYSTEM

Based on t h e o p e r a t i n g mode o f b o i l e r g e n e r a t i n g u n i t s today and t h e h i g h

c o s t o f e l e c t r i c i t y , i t i s i m p o r t a n t t o v iew a c t u a l , l i f e l o n g o p e r a t i o n o f

equipment a t t h e v a r i o u s p l a n t s i t e s . A l though equipment i s u s u a l l y

des igned f o r 100 p e r c e n t MCR c o n d i t i o n s o r g r e a t e r , t h e equipment t y p i c a l l y

o p e r a t e s a t a somewhat l o w e r l o a d f a c t o r . T h e r e f o r e , w i t h t h e

e l e c t r o s t a t i c p r e c i p i t a t o r , i t i s i m p o r t a n t t o examine t h e e l e c t r i c a l power

i n p u t t o t h e t r a n s f o r m e r - r e c t i f i e r s e t s on each p r o j e c t . W i t h o u t an energy

management system, power consumption f rom 100 p e r c e n t d e s i g n volume t o

l o w e r volumes remains f o r p r a c t i c a l purposes c o n s t a n t f o r b o t h f l y a s h and

FGD cases. By u s i n g an energy management system c o n t r o l l e d b y i n - s t a c k

o p a c i t y o r o t h e r pa ramete rs , power consumpt ion can be reduced i n t h e manner

shown w h i l e s t i l l m a i n t a i n i n g o u t l e t em iss ions and o p a c i t y be low f i x e d s e t

p o i n t s . C a l c u l a t i o n s show t h a t f o r a 10 p e r c e n t r e d u c t i o n o f gas f l o w ,

power consumption can be reduced by lOOkW and s t i l l m a i n t a i n p r e c i p i t a t o r

e f f i c i e n c y . Us ing a $5,000 p e r kW e v a l u a t i o n f a c t o r ove r t h e l i f e o f a

p l a n t , t h e decrease i n power consumpt ion cor responds t o a o p e r a t i o n c o s t

r e d u c t i o n o f a p p r o x i m a t e l y $500,000 d u r i n g t h e l i f e o f t h e p l a n t . I n

comparison, t h e c o s t o f an energy management system i s v e r y l o w and shou ld

be cons ide red when s p e c i f y i n g t h i s t y p e o f equipment.

Rapping Systems

The r a p p i n g system i s a n o t h e r s i g n i f i c a n t d e s i g n aspec t t o c o n s i d e r when

choos ing p r e c i p i t a t o r s f o r use w i t h d r y FGD systems. Rapping f r e q u e n c i e s

and i n t e n s i t i e s r e q u

l e s s t h a n f o r a s t r a

p a r t i c l e s a r e l o w e r

e a s i e r t o rap .

i r e d f o r o p e r a t i o n w i t h a spray d r y i n g a b s o r b e r a r e

i g h t f l y ash c o n d i t i o n . The reason i s t h a t t h e

i n r e s i s t i v i t y and, t h e r e f o r e , t h e d u s t cake b u i l d u p i s

In su l a t i on Desiqn and Hopper Heater Design

Based on the t yp i ca l operat ing range of 140 t o 180°F, i n su l a t i on design

and hopper heat ing a r e important t o t h e l i f e l o n g success and r e l i a b i l i t y of

equipment f o r FGD app l i ca t i ons . In su l a t i on design i s important t o conta in

heat and t o prevent corrosion of t he equipment. Much c a r e should be given

t o design and appl ica t ion such a s double lapping of i n s u l a t i o n on housing

s i d e panels and insu la t ion d e t a i l s around t h e doors of t h e equipment t o

minimize problems. Thicknesses must be c a r e f u l l y s e l e c t e d . The lower

temperatures encountered with a p r e c i p i t a t o r w i l l r e s u l t in a c l o s e r

approach t o s a t u r a t i o n temperature. Recommended i n s u l a t i o n f o r a

p a r t i c u l a t e c o l l e c t o r would be t h a t which w i l l hold t h e temperature l o s s t o

a maximum of 1OaF. A l a r g e r temperature drop can y i e l d operat ion below the

water dewpoint and w e t dus t cake wi l l r e s u l t .

( I n p repara t ion of t h i s d i s cus s ion , ex tens ive use was made of t he paper

"The Current S t a t u s o f ESP on Dry FGC Systems,' ' by R . J . T r i s co r i and

H. V . Kr igmont , )

APPENDIXES

Appendix 4A

FLOW MODELING

Exact geomet r i c s i m i l i t u d e e x i s t s when a model i s a sca led down copy o f t h e

i o n i n every l i n e a r d imens ion. For e x a c t dynamic f u l l - s c a l e i n s t a l l a t

s i m i l i t u d e , t h e Mach

t h e model and t h e f u

f o l l o w s :

, Reynolds, Froude and Weber numbers must be t h e same i n

31-sca le system. These f o r c e r a t i o s a r e d e f i n e d as

Mach Number (M=V/C) : The Mach Number i s t h e r a t i o o f f l u i d v e l o c i t y t o t h e l o c a l speed o f sound. I t i s a measure o f t h e r a t i o o f i n e r t i a l f o r c e s t o e l a s t i c f o r c e s . T h i s r a t i o i s an i m p o r t a n t c o r r e l a t i n g parameter o n l y when t h e f l u i d v e l o c i t y i s near o r above t h e s o n i c v e l o c i t y .

Reynolds Number (Re=VD/ ) : The Reynolds Number i s t h e r a t i o o f i n e r t i a l t o v i s c o u s f o r c e s . A c r i t i c a l Reynolds Number d i f f e r e n t i a t e s between l a m i n a r o r t u b u l e n t f l o w i n f l u e s , i n boundary l a y e r s near f l u e su r faces , and around t o t a l l y immersed o b j e c t s such as p i p e t r u s s e s s i t u a t e d i n t h e f l u e gas s t ream.

Froude Number (Fr=VZ/gL): The Froude Number i s t h e r a t i o o f i n e r t i a l f o r c e s t o g r a v i t y f o r c e s . The na tu re o f open channel f l o w depends upon whether t h e Froude Number i s g r e a t e r o r l e s s t h a n u n i t y . I t i s u s e f u l i n c a l c u l a t i o n s o f h y d r a u l i c jump, i n t h e des ign o f h y d r a u l i c s t r u c t u r e s and i n s h i p des ign . - Weber Number (We=VZL / ) : The Weber Number i s t h e r a t i o o f i n e r t i a l f o r c e s t o su r face t e n s i o n f o r c e s . I t becomes an i m p o r t a n t f a c t o r o n l y when a g a s - l i q u i d o r l i q u i d - l i q u i d i n t e r f a c e i s p r e s e n t w i t h i n t h e f l o w system.

For t h e s p e c i a l case o f steady, i n c o m p r e s s i b l e , f u l l y t u r b u l e n t gas f l o w i n a

f l u e system, o n l y v i s c o u s and i n e r t i a l f o r c e s a r e o f impor tance. When

geomet r i c s i m i l i t u d e i s observed, dynamic s i m i l i t u d e i s ach ieved when model

and f u l l - s c a l e b o t h have Reynolds Numbers above t h e c r i t i c a l v a l u e o f 3,200.

A c r i t i c a l Reynolds Number o f 3,200 i s cons ide red the t r a n s i t i o n p o i n t between

l a m i n a r and t u r b u l e n t f l o w f o r duc ted gas. However, a Reynolds Number

mismatch prob lem a r i s e s when a p r e c i p i t a t o r system i s sca led down t o an e x a c t

1 / 1 6 t h s c a l e model, as was t h e p r a c t i c e p r i o r t o t h e m id -seven t ies . I n s i d e a

p r e c i p i t a t i o n chamber, t h e h y d r a u l i c d iamete r ( D ) i s equal t o t w i c e t h e

spac ing between a d j a c e n t c o l l e c t i n g e l e c t r o d e p l a t e s . I n a f u l l - s c a l e

p r e c i p i t a t o r , c o l l e c t i n g p l a t e s t y p i c a l l y f o r m passages r a n g i n g f r o m 9 inches

t o 12 inches wide. C o n s i d e r i n g t h e d i f f e r e n c e i n v i s c o s i t y between a i r a t

70°F and f l u e gas a t 300 t o 900°F, and a l s o a c c o u n t i n g f o r a range i n

p r e c i p i t a t i o n v e l o c i t i e s f r o m 3 f p s up t o 6 f p s , t h e Reynolds Number i n t h e

f u l l - s c a l e p r e c i p i t a t i o n chamber ranges f rom 5,500 t o 39,300, w h i l e i n t h e

model i t ranges o n l y f r o m 1,730 t o 4,600. Hence, t h e s c a l e e f f e c t can (and

n e a r l y a lways does) reduce t h e l o c a l Reynolds Number i n t h e chamber t o a va lue

be low t h e c r i t i c a l v a l u e o f 3,200.

When t h i s prob lem was r e a l i z e d i n t h e 19701s , model d e s i g n e r s sought o u t

techn iques t o assure t h a t a i r f l o w t h r o u g h modeled p r e c i p i t a t i o n chambers would

remain i n t h e t u r b u l e n t f l o w regime. An average Reynolds Number o f a b o u t

4,000 would be m i n i m a l l y s u f f i c i e n t , as t h i s a l l o w s f o r v a l i d mode l ing o f

f l o w - s t a r v e d gas passages c h a n n e l i n g o n l y 75 p e r c e n t o f t h e average

p r e c i p i t a t o r v e l o c i t y . To a c h i e v e t h i s , t h r e e t e c h n i q u e s were deve loped :

I n c r e a s i n g t h e s c a l e o f t h e model, t y p i c a l l y up t o 1 /8 th s c a l e

A r t i f i c i a l l y w i d e n i n g t h e d i s t a n c e s between c o l l e c t i n g e l e c t r o d e p l a t e s w i t h i n t h e modeled chamber, t h u s s a c r i f i c i n g some degree o f geomet r i c s i m i l i t u d e f o r ach ievement o f dynamic s i m i l i t u d e .

I n comb ina t ion w i t h t h e above t e c h n i q u e , i n c r e a s i n g f l o w v e l o c i t y t h r o u g h t h e p r e c i p i t a t o r model.

A l l a r e accep tab le , f i e l d - p r o v

p r e c i p i t a t o r i n d u s t r y .

It i s suggested t h a t t h e p r e c i

t u r b u l e n t f l o w i n t h e modeled

en t e c h n i q u e s c u r r e n t l y i n w idespread use

p i t a t o r s p e c i f i c a t i o n r e q u i r e " f u l l y deve

p r e c i p i t a t i o n chamber," and t h a t t h e mode

i n t h e

1 oped

1

d e s i g n e r ' s method f o r a c h i e v i n g dynamic s i m i l i t u d e be rev iewed and approved by

t h e u t i l i t y p r i o r t o t h e c o n s t r u c t i o n o f a g e o m e t r i c model.

When s p e c i f y i n g model t e s t p rocedures , an a p p r o p r i a t e s t a r t i n g p o i n t i s t h e

I n d u s t r i a l Gas C lean ing I n s t i t u t e s ' s P u b l i c a t i o n No. EP-7, R e v i s i o n 4,

e n t i t l e d "Gas F low Model S t u d i e s " (57) . The American S o c i e t y o f Mechanica l

Engineers c o v e r s t h i s t o p i c i n a manual p u b l i s h e d i n 1980 (61); however, t h e

m a t e r i a l i s n o t t r e a t e d i n a comprehensive manner, and i t s use as a supplement

t o a p r e c i p i t a t o r s p e c i f i c a t i o n i s n o t recommended.

There are several key aspects of flow modeling which should be addressed in

the precipitator specification:

Techniques for ensuring fully developed turbulent flow in the precipitation chamber (as previously discussed)

Velocity measurement, instrumentation and procedures

Procedures for investigation of hopper fly ash reentrainment potential

Pressure loss measurement, instrunentation and procedures

Dust dropout evaluations

Thermal modeling (if applicable)

Extent of model

The following gas flow uniformity criteria are set forth in IGCI Publication

No. EP-7, Revision 4 (38): Within the treatment zone near the inlet and outlet face; of a precipitator collection chamber, the velocity pattern shall have a minimum of 85 percent of the velocities not more than 1.15 times the average velocity, and 99 percent of the velocities not more than 1.40 times the average velocity.

Consideration is often given to having lower than average gas velocity at the upper and lower extremities of the collection plate to minimize fiow over and under the treatment zone. Lower velocity near the bottom of the minimize re-entrainment

For large precipitators serving a single source be considered as a combi single unit.

ollection plate i s par and hopper losses.

ticularly important to

subdivided into severa the uniformity criter

nation of all chambers

1 chambers but i a given above should and evaluated as a

The individual chamber average velocities should be compared with the overall average velocity to ensure that they do not deviate from it by more than 10 percent.

Baffles, large structural members, and rapping mechanisms can cause dead zones immediately downstream. It is meaningless to include velocity measurements made in these dead zones with other velocity data; therefore, these test points may be excluded from the above determinations, provided that all the excluded velocities are less than the average velocity.

These criteria are, for the most part, adequately researched and well

presented. There is a significant difference between this revised set of

c r i t e r i a and f l o w u n i f o r m i t y c r i t e r i a p r e v i o u s l y i ssued by t h e I G C I (40): t h e

f o r m e r c r i t e r i a l i m i t e d b o t h h i g h and low v e l o c i t y r e g i o n s , y e t t h e r e v i s e d

c r i t e r i a l i m i t s o n l y h i g h v e l o c i t i e s . T h i s makes more sense, as h i g h v e l o c i t y

gas f l o w promotes f l y ash r e e n t r a i n m e n t w h i l e l ow v e l o c i t y gas f l o w a t t h e t o p

and b o t t o m o f t h e c o l l e c t i n g p l a t e s i s d e s i r a b l e s i n c e i t h e l p s p r e v e n t gas

sneakage and hopper r e e n t r a i n m e n t .

There a r e , none the less , s e v e r a l m i n o r comments on t h e r e v i s e d c r i t e r i a w h i c h

a r e w o r t h n o t i n g :

I f a u t i l i t y i s concerned about t h e p r a c t i t e o f l ower v e l o c i t i e s a t t h e bo t tom o f t h e c o l l e c t i n g p l a t e s , q u a n t i t a t i v e c r i t e r i a s h o u l d be e s t a b l i s h e d . T h i s can be done i n t h e f o l l o w i n g manner: "The average v e l o c i t y o v e r t h e lower 25 p e r c e n t o f t h e c o l l e c t i n g p l a t e must be 10 p e r c e n t l o w e r t h a n t h e upper 75 p e r c e n t o f t h e c o l l e c t i n g p l a t e s , " o r a l t e r n a t i v e l y , "There s h a l l be no v e l o c i t y r e a d i n g s i n excess o f 1.15 t i m e s t h e average v e l o c i t y o v e r t h e lower 25 p e r c e n t o f t h e c o l l e c t i n g p l a t e s . "

It i s suggested t h a t t h e t e r m " s i n g l e source" be d e f i n e d . T h i s can be m i s i n t e r p r e t e d t o be one s i d e o f a s p l i t a i r - h e a t e r . S i n g l e source should a lways be i n t e r p r e t e d as a t l e a s t one b o i l e r .

The c r i t e r i a o f 10 p e r c e n t d e v i a t i o n on i n d i v i d u a l chamber ave rage v e l o c i t i e s i s l i b e r a l b y p r e s e n t day i n d u s t r y p r a c t i c e ; some u t i l i t i e s s p e c i f y t h i s a l l o w a b l e d e v i a t i o n t o be 5 p e r c e n t .

It i s suggested t h a t v e l o c i t y t e s t p o i n t s o n l y be exc luded by mutua l agreement between t h e purchaser and t h e equipment s u p p l i e r .

I t i s suggested t h a t t h e degree o f v e l o c i t y u n i f o r m i t y a l s o be expressed i n te rms o f an RMS index. T h i s i ndex i s c o n v e n i e n t f o r q u i c k comparisons o f d i f f e r e n t t e s t r e s u l t s :

where:

n = number o f gas passages t r a v e r s e d a t a t e s t p l a n e

rn = number o f v e l o c i t y r e a d i n g s p e r gas passage

V . . = i n d i v i d u a l v e l o c i t y d a t a p o i n t s (fpm) 1 J

V = average v e l o c i t y a t a t e s t p l a n e (fpm)

TABLE 4A-I:

VELOCITY MEASUREMENT INSIDE MODELED P R E C I P I T A T I O N CHAMBER: INSTRUMENTATION AND TEST PROCEDURES (38)

I T E M - REQUIREMENTS

Veloc i ty Measuring Eiec t ronic (ho t wire) anemometer (measures Instrumentat ion magnitude of t he pr inc ipa l ve loc i ty component

and not t he d i r e c t i o n , o r magnitude, of t h e t r u e ve loc i ty vec tor ) wi th :

Veloc i ty Measuring Instrumentat ion Cali b r a t i on

Output s i g n a l s t r eng th adequate t o provide r e l i a b l e r e s u l t s

Overall system response of under one second

Reasonable accuracy, and be repea tab le within 2 percent of t he reading o r 0 . 5 percent of f u l l meter s c a l e .

The system ( s e n s o r , s ignal cond i t i one r s , read- ou t /p r in tou t cond i t i one r ) should be r e c a l i - b ra ted a s f requent ly a s requi red .

Veloc i ty Tes t Points

Veloc i ty Test Locations The da ta should preferab ly be taken wi th in t h r e e f e e t downstrean of t h e leading edges of t he f i r s t f i e l d of c o l l e c t i n g p l a t e s and within t h r ee f e e t upstream o f t he t r a i l i n g edges of t h e l a s t f i e l d of c o l l e c t i n g p l a t e s .

A minimum number of t e s t po in ts equal t o one-ninth t he c ros s s ec t iona l area of t h e ac tua l p r e c i p i t a t o r face ( i n square f e e t ) . To ensure proper eva lua t ion of t he ve loc i ty p a t t e r n , a minimum of every t h i r d gas passage should be t e s t e d . Each passage can then be subdivided i n t o equal po in t s required t o meet minimum requirements . However, t he v e r t i c a l t e s t po in ts should not be f u r t h e r a p a r t than 1 0 percent of t he c o l l e c t i n g p l a t e he igh t .

I n s t r u m e n t a t i o n and t e s t procedures f o r v e l o c i t y measurement i s adequa te l y

covered i n Reference 6 (Tab le 4 . 1 ) , however, i t i s a l s o suggested t h a t :

E l e c t r o n i c ( " h o t w i re " ) anemometers be used f o r a11 v e l o c i t y measurements i n s i d e t h e p r e c i p i t a t i o n chamber. P i t o t t ubes a r e n o t s u i t a b l e f o r a c c u r a t e measurement o f v e l o c i t i e s be low 600 fpm.

C a l i b r a t i o n cu rves f o r a l l t e s t i n s t r u m e n t a t i o n shou ld be i n c l u d e d i n the model s tudy r e p o r t .

I t i s o f u t m o s t impor tance t h a t v e l o c i t y measurements i n t h e p r e c i p i t a t i o n chamber be t a k e n as c l o s e as p o s s i b l e t o t h e l e a d i n g edges o f t h e f i r s t f i e l d o f c o l l e c t i n g p l a t e s a t t h e p r e c i p i t a t o r i n l e t t e s t p l a n e , and as c l o s e as p o s s i b l e t o t h e t r a i l i n g edges o f t h e f i n a l f i e l d o f c o l l e c t i n g p l a t e s a t t h e p r e c i p i t a t o r o u t l e t t e s t p lane . Fur thermore, i t i s e s s e n t i a l t h a t t h e s e l e c t e d t e s t p l a n e s can be p r o p e r l y t r a v e r s e d i n t h e f u l l - s c a l e p r e c i p i t a t o r , f o r v e r i f i c a t i o n o f t h e mode? s t u d y r e s u l t s . The e x a c t l o c a t i o n o f these t e s t p lanes shou ld be de te rm ined by mutua l agreement between t h e u t i l i t y and t h e p r e c i p i t a t o r s u p p l i e r . The b e n e f i c i a l e f f e c t o f many p a s t model s t u d i e s has been negated by use o f t e s t p lanes s i t u a t e d t o o f a r i nward t o w a r d s t h e c e n t e r o f t h e p r e c i p i t a t i o n chamber, where g e n e r a l l y more u n i f o r m gas f l o w e x i s t s r e g a r d l e s s o f t h e presence o f i n l e t and o u t 1 e t f l o w m a l d i s t r i b u t i o n s .

For measur ing a i r v e l o c i t i e s i n t r a n s p o r t d u c t w o r k , t h e S tausche ibe ("S-Type") p i t o t tube i s n o t a d e s i r a b l e measurement d e v i c e . T h i s p i t o t t u b e ' s poor o r i e n t a t i o n s e n s i t i v i t y c h a r a c t e r i s t i c s make i t i m p o s s i b l e t o d e t e c t when t h e probe i s p r o p e r l y a l i g n e d w i t h t h e oncoming a i r stream. The P r a n d t l ("L-Head" o r "S tandard " ) p i t o t t ube i s a f a r more d e s i r a b l e measurement d e v i c e f rom t h i s s t a n d p o i n t .

IGCI p u b l i c a t i o n No. EP-7, R e v i s i o n 4 acknowledges t h e impor tance o f t h e

p r e v e n t i o n o f hopper f l y ash r e e n t r a i n m e n t , s t a t i n g t h a t (9):

Another q u a l i t a t i v e t e s t which s h o u l d be pe r fo rmed d u r i n g t h e geomet r i c

model s tudy i s t h e i n j e c t i o n o f n e u t r a l buoyancy smoke i n t o t h e r o o f and

hopper r e g i o n s o f t h e c o l l e c t i o n chamber, p a r t i c u l a r l y near t h e o u t l e t ,

t o check t h a t s i g n i f i c a n t amounts o f gas a r e n o t e x i t i n g t h e p r e c i p i t a t o r

w i t h o u t pass ing t h r o u g h t h e c o l l e c t i n g p l a t e s ( "sneakage") , and t h a t

t h e r e a r e n o t s t r o n g f l o w s i n t h e hopper r e g i o n s (hopper sweepage), w h i c h

c o u l d cause e x c e s s i v e r e e n t r a i n m e n t . I f t h e smoke t e s t s i n d i c a t e t h a t

e x t e n s i v e sneakage o r hopper sweepage i s o c c u r r i n g , t h e n s t e p s shou ld be

taken t o m i n i m i z e t h e e f f e c t , s i n c e t h i s has a d i r e c t h a r m f u l impact upon

t h e o p e r a t i n g e f f i c i e n c y o f t h e p r e c i p i t a t o r .

Simi l a r smoke t e s t s should be performed on t h e f u l l - s c a l e p r e c i p i t a t o r p r i o r

t o s t a r t u p . I t i s suggested t h a t t he importance of t h i s t e s t be emphasized in

t he p r e c i p i t a t o r s p e c i f i c a t i o n . Three f a c t o r s a r e necessary f o r t he success

of t h e t e s t :

The geometric model must be f ab r i ca t ed wi th p l ex ig l a s s hoppers so t n a t smoKe ~ e s z i n g ca' De p r o ~ e r i y cbserved by the t e s t o r a s well a s by wi tnesses .

A n appropr ia te smoke gene ra to r must be used. Due t o t he low ve loc i ty of hopper flow c u r r e n t s , r e s u l t a n t smoke t r a c e s would not be r ep re sen ta t i ve i f smoke i s i n j ec t ed i n t o t he hopper with even t h e s l i g h t e s t d r iv ing v e l o c i t y .

The i n t e r p r e t a t i o n of an acceptable degree of hopper flow a c t i v i t y should be by mutual agreement between a u t i l i t y and the p r e c i p i t a t o r suppl i e r .

Measurement of system pressure drop i s not addressed i n d e t a i l in IGCI

Publ ica t ion No. EP-7, Revision 4 . I t i s important t o use s i m i l a r techniques

f o r both model and f u l l - s c a l e p re s su re drop measurements. Hence, i t i s

suggested t h a t t h e f i e l d performance t e s t procedure f o r press.Jre drop

measurement be a l s o employed f o r model t e s t i n g . Miniature Prandtl ("L-Head"

o r "Standard") p i t o t tubes or Kiel probes, a s desc r ibed in Reference 6 , should

be u t i l i z e d f o r a l l t o t a l p ressure measurements performed in t he model.

The var ious t e s t s devised over t h e yea r s f o r eva lua t ing dus t dropout p o t e n t i a l

a r e t he l e a s t dependable of the t e s t s t h a t a r e routine?^ ca r r i ed out dur ing

the course of a p r e c i p i t a t o r model s tudy program. Sca l e e f f e c t and p r a c t i c a l

cons idera t ions preclude an app rop r i a t e match of app l i cab l e modeling fo rce

r a t i o s ; however, i f d i l i g e n t l y performed, s u f f i c i e n t l y accura te i n d i c a t i o n s of

d u s t dropout po t en t i a l can be i n t e r p r e t e d from t h e t e s t observat ions. There

a r e two methods f o r conducting d u s t dropout eva lua t ions :

Layering a f i n e l y ground d u s t ma te r i a l , t y p i c a l l y sawdust o r ground cork, on a17 hor izonta l su r f aces . The model a i r f l ow r a t e i s then gradual ly increased t o 2 5 , 50, 75, 100, and (sometimes) 125 pe rcen t of design flow r a t e , and v i sua l observa t ions o r photographs of d u s t p a t t e r n s a r e made a t each flow increment.

Introducing sawdust o r ground cork i n t o t h e i n l e t of the model a t 25 percent of design flow r a t e , and g radua l ly increasing model a i r f l ow t o 50 , 75 , 100 and 125 percent of design flow r a t e while continuously i n j e c t i n g the d u s t material i n t o t he model 's i n l e t i n a con t ro l l ed manner. Visual observa t ions o r photographs of d u s t p a t t e r n s a r e made a t each flow increment.

Ei the r of t he above methods i s adequate ; t h e s e l ec t ion of one procedure over

t h e o t h e r i s u sua l ly a matter of convenience. However, the use of m a t e r i a l s

such a s sawdust and ground cork has r e c e n t l y been i d e n t i f i e d a s a s i g n i f i c a n t

source of e r r o r . I nves t iga to r s have found t h a t t he most s i g n i f i c a n t

c h a r a c t e r i s t i c s of d u s t s f o r t h e i r s e l e c t i o n as a dropout material a r e (45). S p e c i f i c g r a v i t y , which determines depos i t ion r a t e (and inf luences compactabi l i ty )

Compactabi l i t y and/or hygroscopity, which determine removal r a t e s . Thfs proper ty i s be s t cha rac t e r i zed by the d u s t ' s natural angle of repose.

P a r t i c l e s i z e d i s t r i b u t i o n i s of secondary importance. However, s imula t ion should be made wi th p a r t i c l e diameters within 2 50 percent of t he Cull s c a l e d u s t .

I d e a l l y , f u l l - s c a l e dus t material ( f l y a sh ) should be used; however, i f a

s u b s t i t u t e i s necessary, s p e c i f i c g r a v i t i e s should be matched. The l e s s

hygroscopic t he mater ia l used, t h e l e s s l i k e l y i s severe compaction, which

tends t o exaggerate t e s t r e s u l t s , e s p e c i a l l y a t room temperature where f l y ash

hygroscopy i s l i k e l y t o be more severe than a t opera t ing temperature. Based

on experience, model t e s t s conducted a t about 50 t o 70 percent of design flow

r a t e seem t o be s t r ep re sen t normai, f u l l load, f u l l - s c a l e operat ion ( 4 5 ) .

Thermally modeled p r e c i p i t a t o r systems should be considered when a cold-side

p r e c i p i t a t o r i s c l o s e l y coupled t o t h e a i r hea t e r , o r when t h e r e a r e mul t ip le

b o i l e r e n t r i e s i n t o a common duct l ead ing t o the p r e c i p i t a t o r . Thermal

modeling can p r e d i c t temperature d i s t r i b u t i o n s t h a t w i l l e x i s t in t h e

fu l ' l - sca le gas s tream and allows t h e des igner t o optimize mixing devices t o

reduce temperature g rad i en t s while maintaining reasonable pressure l o s s .

Thermal modeling i s achieved by hea t ing t h e model 's gas s tream(s) i n order t o

s imulate f u l l - s c a l e temperature d i s t r i b u t i o n s , An important fo rce r a t i o f o r

thermal modeling i s t h e density-modified Froude Number, the r a t i o of i n e r t i a l

f o rces t o buoyancy fo rces (43).

where:

3 pavg = average density (lbm/ft )

3 PC

= density of cold gas stream (lbm/ft )

3 pH = density of hot gas stream (lbm/ft )

V = gas velocity (ft/sec)

g 2 = acceleration of gravity (ft/sec )

D = duct diameter (ft)

The fluid dynamic modeling of gas mix

will be correctly modeled when the fo

maintained between the full-scale sys

The model is constructed to system.

ing and temperature profiles in a duct

llowing dimensionless parameters are

tem and model (43):

be a geometric scale of the full-size

The momentum ratio of the flows joining in the mixing plenum or duct will be set equal to the full-scale system values for each operating condition to be simulated.

The model density-modified Froude number will be set equal to the full-scale system value for each operating condition to be simulated.

The Reynolds number may not be matched in the model but will be maintained well within the turbulent flow range so that flow patterns will be similar.

A s a result of fluid dynamic modeling, the model stream temperatures will be

proportional to the full-scale values everywhere outside the thin thermal

boundary layers along the flue walls. The accuracy of model gas stream

temperature distributions near flue walls can be improved by applications of

appropriate thermal insulation to the outside surface of the model flue walls.

If there is a need for thermal modeling, the following should be included i n

the precipitator specification:

Temperature distribution data for the air heater outlet, or each of the multiple boiler entries, for full-load and part-load operation and/or various anticipated operating modes.

A request that the precipitator supplier submit a written procedure for thermal modeling, for review and approval by the utility.

Temperature distribution criteria after mixing, and allowable overall system pressure loss (inci uding thermal mixing devices). Typical temperature distribution criteria are: "A maximum variation

i n i n d i v i d u a l measurements o f + 10°F abou t t h e mean gas tempera tu re i n t h e f u l l - s c a l e d u c t a t a p o i n t f i v e f e e t ups t ream o f t h e p r e c i p i t a t o r i n l e t nozz le . " I t i s i m p o r t a n t t o s e l e c t reasonab le tempera tu re d i s t r i b u t i o n c r i t e r i a , as t h e degree o f the rma l m i x i n g i s d i r e c t l y r e l a t e d t o i n c r e a s e d system p r e s s u r e l o s s .

The e x t e n t o f t h e model i s an i m p o r t a n t i s s u e w h i c h s h o u l d be c l e a r l y

i n d i c a t e d i n t h e p r e c i p i t a t o r s p e c i f i c a t i o n . Many p a s t s t u d i e s have had t h e i r

p r e d i c t i v e v a l u e d i m i n i s h e d because t h e g e o m e t r i c model d i d n o t i n c l u d e

f l o w - i n f l u e n c i n g system components such as a i r h e a t e r s and p i p e t r u s s e s . I n

g e n e r a l , i t i s suggested t h a t

Model s t u d i e s o f c o l d - s i d e p r e c i p i t a t o r s s h o u l d a lways i n c l u d e s i m u l a t e d a i r h e a t e r s . The a i r h e a t e r shou ld be modeled as e x a c t l y as p o s s i b l e , complete w i t h t r a n s i t i o n s between t h e round a r c o f t h e wheel and t h e r e c t a n g u l a r o u t l e t f l a n g e s , as w e l l as t h e wash-out hopper underneath t h e a i r h e a t e r o u t l e t d u c t .

Models o f h o t - s i d e p r e c i p i t a t o r s shou ld a lways i n c l u d e s i m u l a t i o n s o f t h e o u t l e t bend o f t h e b o i l e r economizer, comp le te w i t h t h e drop-out hopper underneath t h e economizer o u t l e t d u c t .

P r e c i p i t a t o r o u t l e t t r a n s p o r t duc twork shou ld a l w a y s be i n c l u d e d up t o t h e i n l e t o f t h e I D fans o r chimney f o r a c o l d - s i d e p r e c i p i t a t o r , and up t o t h e i n l e t o f t h e a i r h e a t e r o f a h o t - s i d e p r e c i p i t a t o r .

The geomet r i c model shou ld always i n c l u d e a l l c o l l e c t i n g e l e c t r o d e p l a t e banks. W i t h o u t channeled f l o w i n s i d e t h e p r e c i p i t a t i o n chamber, l a r g e s c a l e , t u r b u l e n t edd ies can a c t t o smooth o u t v e l o c i t y n o n - u n i f o r m i t i e s . Removing s e c t i o n s o f c o l l e c t i n g p l a t e s a c t u a l l y p reven ts , r a t h e r t h a n promotes, gas f l o w r n a l d i s t r i b u t i o n a t t h e chamber o u t l e t .

A17 vane s t i f f e n e r s and i n t e r n a l f l u e s u p p o r t t r u s s e s shou ld be a c c u r a t e l y modeled when p o s i t i o n e d i n c l o s e p r o x i m i t y t o t h e p r e c i p i t a t o r . Vane s t i f f e n e r s p o s i t i o n e d on vanes l o c a t e d w i t h i n p r e c i p i t a t o r b reech ings have a s u b s t a n t i a l e f f e c t on f l o w f i e l d s .

Appendix 4B

RAF9iNG TESTS

Rapping Acceleration

The purpose of rapper acceleration testing is to compare various

rapper/electrode designs based on measurement of accelerations normal to the

collecting electrode surface. The acceleration profile of the plate is

measured on a representative grid of test points using miniature piezoelectric

pick-ups. The voltage output of each pick-up is amplified and recorded on a

suitable instrument. Accelerations are measured i n multiples of " g , " with one 2 g equal to 32.2 ft/sec . Accelerations are usually reported as zero to peak

values measured over a preselected frequency band. Occasionally, a frequency

spectrum analyzer is used to record an entire frequency spectrum plot

(typically 5 to 10,000 Hz) for the shock wave. This specialized analysis is

conducted for investigative purposes only.

Two problems arise with non-standardized test procedures for measurement of

rapping acceleration:

The measurement o f acceleration is sensitive to the type of accelerometer used. It has been demonstrated that a lower weight accelerometer will give higher readings, all other conditions being the same.

Rapping response varies with frequency band

It might seem surprising that a 25 gram accelerometer pick-up could affect the

vibrational response of a collecting plate weighing over 1OOQ kg.

Experimental interference does occur, however, and the degree of this

interference depends on plate thickness, plate construction, and the weight of

the accelerometer pick-up. Only an accelerometer with zero mass could measure

the true acceleration level. The most accurate acceleration measurements are

made with miniature, adhesive-mounted pick-ups that weigh on the order of

0.40 grams.

The frequency responses of the different suppliers' collection plate designs

vary significantly. Frequency composition is also inconsistent over the

surface of each collection plate. Although the optimum frequency for

effective plate cleaning is a topic of debate among the suppliers, it may be

safely said that the most desirable frequencies for electrode cleaning are

below 3,000 Hz (49).

Hence, it is suggested that the precipitator specification address the

following items:

Minimum acceptable rapping acceleration (normal to the collecting plate, measured zero to peak) for the application at hand.

Maximum allowable accelerometer pick-up weight (0.4 grams maximum).

Frequency band (0 to 3000 Hz).

In addition, it is suggested that the test tower apparatus be reviewed by the

utility to ensure that the collecting plate design, the collecting plate

supports, rapper anvils and rapper are all representative of the proposed

full-scale components. Test specimens should be fabricated during normal

. production runs.

For discharge electrodes, rapping intensity is not as critical as with

collecting electrode plates; nevertheless, it must be sufficient to keep the

electrode reasonably clean. It should be noted that the vibration of the

discharge electrode must not result in a significant reduction in discharge electrode to collecting plate spacing. Most precipitator specifications

require 35 to 50 g accelerations on the surface of the discharge electrode

element. The cleaning characteristic of rigid, mast-style electrodes is

interesting; after excitation, the vibration can be sustained for as long as 2

to 4 seconds. This action enhances electrode cleaning. A utility must be

mindful that when requiring a specific minimum acceleration, each supplier

must be evaluated on the merits and experiences of its design on fuels similar

to that to be used for the proposed project.

Accelerated Life Test

Accelerated l i f e t e s t s a r e condensed time eva lua t ions of t he expected l i f e of

rappers , rapper a n v i l s , e l e c t r o d e s and e l e c t r o d e supports . The importance of

these t e s t s has come t o l i g h t in r ecen t y e a r s wi th an increased incidence of

f a t i g u e f a i l u r e s in p r e c i p i t a t o r s t h a t employ high i n t e n s i t y e l ec t rode

rapping.

Typica l ly , p r e c i p i t a t o r s p e c i f i c a t i o n s r equ i r e t h e performance of a c c e l e r a t e d

rapping t e s t s t o demonstrate t h a t rappers and e l ec t rodes wi l l have a 30 year

l i f e . This t e s t i s conducted in the fol lowing manner:

A l imi ted quan t i t y of f u l l - s c a l e components a r e mounted i n a t e s t tower i n much t h e same manner a s f o r t h e rapping acce l e r a t i on t e s t . Usually, a cce l e r a t ed l i f e t e s t i n g immediately fol lows the successful completion of rapping acce l e r a t i on t e s t i n g , and the same t e s t setup i s u t i l i z e d .

Electrodes a r e rapped a t t h e i r maximum design rapping i n t e n s i t y on a continuous, acce l e r a t ed frequency b a s i s u n t i l component f a i l u r e occurs .

By use of a rapping equivalency r a t i o , the t o t a l number of raps t o f a i l u r e i s used t o p r o j e c t t h e number of yea r s the f u l l - s c a l e i n s t a l l a t i o n w i l l ope ra t e before a f a i l u r e occurs . Fatigue f a i l u r e s such a s weld c racks and f a s t e n e r deformations a r e of major concern.

The rapping equivalency r a t i o (Rr) i s t h e r a t i o of the frequency of t e s t

rapping t o f u l l - s c a l e rapping. I f i t i s p ro j ec t ed t h a t t he f u l l - s c a l e

p r e c i p i t a t o r wil l be rapped a t a maximum r a t e of f i v e t imes an hour (based on

the performance of an i n l e t f i e l d a t maximum b o i l e r load, f l y ash loading , and

f l y ash r e s i s t i v i t y ) , and t h e acce l e r a t ed frequency of rapping in t he t e s t

tower i s four times per minute, then ( 5 4 ) :

- No. of t e s t r aps per hour R r - No. of f u l l - s c a l e raps per hour

Hence, i f t h e t e s t i s r u n f o r 1825 hours , i t would be equiva len t of t en yea r s

of continuous, f u l l s ca l e e l e c t r o d e rapping . Note t h a t i t i s not customary t o

take c r e d i t f o r un i t outages in t h i s c a l c u l a t i o n .

Proper s p e c i f i c a t i o n of acce l e r a t ed l i f e

requirements:

A17 l i f e - t e s t e d components sha product ion runs.

ing should include t h e fol lowing t e s t

1 7 be fabr ica ted during normal

Tes t ing s h a l l be c a r r i e d ou t a t t h e maximum design rapper i n t e n s i t y .

The t e s t r e p o r t sha l l inc lude photographs and descr ipt ions o f a l l f a i l e d components. Component design improvements made subsequent t o r e t e s t i n g during the course o f t h e t e s t program sha l l a l s o be descr ibed i n t h e r epo r t .

Although a c c e l e r a t e d rapping t e s t s ignore t h e combined e f f e c t o f corros ion and

f a t i g u e , c a r e f u l execution of them w i l l ensure higher overa l l r e l i a b i l i t y of

key p r e c i p i t a t o r components.

Appendix 4 C

FIELD V E L O C I T Y D I S T R I B U T I O N TESTS

Ear ly f i e l d ve loc i ty d i s t r i b u t i o n t e s t s lacked s u f f i c i e n t accuracy due t o use

of inadequate instrumentat ion and t e s t procedures. The v a l i d i t y of f i e l d t e s t

d a t a improved with technica l improvements, most s i g n i f i c a n t l y in t h e a r ea of

v e l o c i t y measuring ins t rumenta t ion . I t was soon recognized t h a t hot-wire

anemometers should (57) : be rugged; i . e . , shock r e s i s t a n t and dust-proof

be r e l a t i v e l y d r i f t - f r e e ; any c a l i b r a t i o n f a i l u r e s should be sudden

have l i nea r i zed meter ou tput ; logari thmic meter s c a l e s and d i g i t a l ou tpu t s a r e d i f f i c u l t t o read accu ra t e ly under d i f f i c u l t f i e l d t e s t condi t ions

have a ho r i zon ta l l y o r i e n t a t e d wire with a f l a t p i t ch and yaw response and a cosine curve ro t a t i ona l response

have c a p a b i l i t y f o r v a r i a b l e response t ime; e . g . , a t h r ee p o s i t i o n s e l e c t o r switch f o r 10 ms, 1 sec and 2 response t ime, allowing a t e s t o r t o t a i l o r h i s ins t rumenta t ion response time t o t he degree of a i r flow turbulence experienced.

Appropriate ve loc i ty measuring instrumentat ion coupled with the development of

procedures f o r on-s i te anemometer c a l i b r a t i o n s el iminated most of t he

experimental e r r o r found i n e a r l i e r f ie7d v e l o c i t y d i s t r i b u t i o n t e s t s .

Some guidance f o r t h e proper conduct of f i e l d ve loc i ty d i s t r i b u t i o n t e s t i n g

may be found in IGCI Publ ica t ion No. EP-7, Revision 4 ( 5 7 ) . - The fol lowing

procedures, which a r e rou t ine ly prac t iced by the majori ty of the p r e c i p i t a t o r

s u p p l i e r s , a r e suggested a s a supplement t o Reference 57:

I t i s important f o r model v e r i f i c a t i o n t h a t f i e l d t e s t i n g be performed a t the exac t measurement l oca t ions t h a t correspond t o flow model t e s t i n g . This i s e s p e c i a l l y c r i t i c a l f o r ve loc i ty surveys a t t h e i n l e t and o u t l e t of a p r e c i p i t a t i o n chamber.

= When a severe flow rna ld is t r ibu t ion i s discovered a t the i n l e t o r o u t l e t of a p r e c i p i t a t o r chamber, addi t iona l ve loc i ty surveys should be performed t o determine t h e ex ten t of mald is t r ibu ted flow penet ra t ion in to t he c e n t e r of t he p r e c i p i t a t o r chamber. This i s

needed t o e v a l u a t e t h e e f f e c t s of f low m a l d i s t r i b u t i o n on p r e c i p i t a t o r performance.

P i t o t t u b e t r a v e r s e s should be conducted i n t h e duc twork , s p e c i f i c a l l y a t t h e i n l e t t o a p r e c i p i t a t o r . T h i s d a t a can be used t o v e r i f y ductwork v e l o c i t y d i s t r i b u t i o n s measured d u r i n g t h e model s t u d y .

V e r i f i c a t i o n of an a c c e p t a b l e d e g r e e of hopper f low a c t i v i t y should be made by s e ~ t i n g o f f smoke bombs i n t h e o u t : e t row o f p r e c i p i t a t o r hoppers and c o s e r v i n g t h e r e s u l t i n g smoke t r a c e s . Th i s a l s o s e r v e s a s f u l l - s c a l e v e r i f i c a t i o n of smoke t e s t i n g conducted d u r i n g t h e model s t u d y . The i n t e r p r e t a t i o n of an a c c e p t a b l e d e g r e e o f hopper f low a c t i v i t y s h o u l d be by mutual agreement of t h e t h e u t i l i t y and suppl i e r .

I t i s f u r t h e r sugges ted t h a t :

A s u p p l i e r be r e q u i r e d by p r e c i p i t a t o r s p e c i f i c a t i o n s t o submit h i s f i e l d v e l o c i t y d i s t r i b u t i o n t e s t p rocedure t o t h e u t i l i t y f o r review and comment. I f t h e u t i l i t y deems t h e s u p p l i e r ' s p rocedures u n a c c e p t a b l e , t h e u t i l i t y t h e n has an o p t i o n t o make use of a s u i t a b l e t h i r d p a r t y independen t t e s t o r .

A u t i l i t y r e c e i v e s c o p i e s of a l l raw t e s t d a t a and c a l i b r a t i o n d a t a workshee t s b e f o r e a t e s t o r l e a v e s t h e j o b s i t e . The u t i l i t y may then c a r r y o u t i t s own a n a l y s i s of t h e t e s t r e s u l t s .

F i e l d d a t a a n a l y s i s should be s i m i l a r t o model s t u d y d a t a a n a l y s i s i n a l l r e s p e c t s .

S u f f i c i e n t t ime be scheduled f o r t h e performance of t h e s e tes ts . I t should be k e p t in mind t h a t t h e t e s t o r s a r e r e q u i r e d t o r ead and record s e v e r a l hundreds o f r e a d i n g s under cramped, sometimes d i r t y c o n d i t i o n s , and human e r r o r can be h igh when a s c h e d u l e i s unreasonab ly t i g h t .

Appendix 4D

PERFORMANCE TESTS

P a r t i c u l a t e Emiss ions T e s t i n g

P a r t i c u l a t e emiss ions t e s t i n g i s n e a r l y always c a r r i e d o u t i n s t r i c t a c c o r d

w i t h t h e f o l l o w i n g methods s e t f o r t h b y t h e Env i ronmenta l P r o t e c t i o n Agency i n

t h e Code o f Federa l Regu la t i ons CFR40, P a r t 60, Appendix A ( 4 6 ) : Method 1: Sample and v e l o c i t y t r a v e r s e s f o r s t a t i o n a r y sources

Method 2: D e t e r m i n a t i o n o f s t a c k gas v e l o c i t y and v o l u m e t r i c f l o w r a t e (S-type P i t o t Tube)

Method 3: Gas a n a l y s i s f o r carbon d i o x i d e , oxygen, excess a i r , and d r y m o l e c u l a r w e i g h t .

Method 4: D e t e r m i n a t i o n o f m o i s t u r e c o n t e n t i n s t a c k gases

Method 5 : D e t e r m i n a t i o n o f p a r t i c u l a t e emiss ions f rom s t a t i o n a r y sources

Method 17: D e t e r m i n a t i o n o f p a r t i c u l a t e emiss ions f rom s t a t i o n a r y sources ( I n - s t a c k F i l t r a t i o n Method)

Methods 1 and 2 cover t h e use o f S-type p i t o t t ubes f o r d e t e r m i n a t i o n o f f l u e

gas v e l o c i t y and volume f l o w r a t e s . A l t h o u g h n o t as d e s i r a b l e as s t a n d a r d

p i t o t t ubes , t h e S t y p e p i t o t t ube must be used f o r f i e l d t e s t i n g because:

The s t a t i c and impact p r e s s u r e h o l e s o f t h e s t a n d a r d p i t o t t ubes a re s u s c e p t i b l e t o p l u g g i n g i n p a r t i c u l a t e l aden gas streams

The p robe head o f t h e S t y p e t u b e i s compact, a l l o w i n g i t t o e a s i l y f i t th rough s t a n d a r d f i e l d t e s t p o r t s .

Method 1 covers s e l e c t i o n o f duc twork t e s t l o c a t i o n s , t h e number o f t e s t

p o i n t s , and c r o s s - s e c t i o n a l l a y o u t s o f t e s t p o i n t s f o r a c h i e v i n g

r e p r e s e n t a t i v e v e l o c i t y measurement and p a r t i c u l a t e emiss ions sampl ing.

Method 2 covers t h e f a b r i c a t i o n and c a l i b r a t i o n o f S t y p e p i t o t tubes,

requ i remen ts o f o t h e r i n s t r u m e n t a t i o n and appara tus needed f o r v e l o c i t y

measurement, and t h e procedure f o r d e t e r m i n i n g f l u e gas v e l o c i t y and volume

f l o w r a t e s .

Method 3 covers v a r i o u s methods t h a t a r e a v a i l a b l e f o r f l u e gas compos i t i on

a n a l y s i s . I t i s suggested t h a t d r y gas a n a l y s e s be per formed by t h e

m u l t i - p o i n t sampl ing method u s i n g an O r s a t a n a l y z e r . Gas compos i t i on

s t r a t i f i c a t i o n l e v e l s a r e t o o h i g h f o r s i n g l e p o i n t sampl ings t o be a c c e p t a b l y

a c c u r a t e (60).

Two p rocedures a r e g i v e n i n Method 4 f o r d e t e r m i n i n g t h e m o i s t u r e c o n t e n t o f

s t a c k gas:

An a c c u r a t e method f o r use d u r i n g p a r t i c u l a t e c o n c e n t r a t i o n measurement r u n s c a r r i e d o u t i n accordance w i t h Method 5 o r 17

An approx ima te method f o r e s t i m a t i n g m o i s t u r e i n a f l u e gas stream t o a i d i n s e t t i n g i s o k i n e t i c sampl ing r a t e s p r i o r t o a p a r t i c u l a t e c o n c e n t r a t i o n measurement r u n .

Method 5 i s a p rocedure f o r measurement o f p a r t i c u l a t e c o n c e n t r a t i o n . A

schemat ic o f t h e sampl ing t r a i n used i n t h i s method i s shown i n Manual 111,

F i g u r e 5A-1. I n p r i n c i p l e , p a r t i c u l a t e m a t t e r i s w i thdrawn i s o k i n e t i c a l l y

f r o m t h e f l u e gas s t ream and c o l l e c t e d on a g l a s s f i b e r f i l t e r wh ich i s

m a i n t a i n e d a t a tempera tu re i n t h e range o f 248 - + 25'F ( u n l e s s o t h e r w i s e

s p e c i f i e d by t h e £PA A d m i n i s t r a t o r o r g o v e r n i n g env i ronmenta l r e g u l a t o r y

agency). The p a r t i c u l a t e mass i s t h e n de te rm ined g r a v i m e t r i c a l l y a f t e r

uncombined w a t e r i s removed. The p r o p e r conduc t o f Method 5 r e q u i r e s d a t a

i n p u t s f rom Methods 1 and 4. The d a t a o u t p u t f r o m Method 5 t e s t i n g i s

p a r t i c u l a t e c o n c e n t r a t i o n , expressed as e i t h e r u n i t s (gra ins /SCF) a t s tandard

c o n d i t i o n s o r u n i t s (gra ins /ACF) a t s t a c k c o n d i t i o n s . A l t e r n a t i v e l y , a

p a r t i c u l a t e emiss ions r a t e i n u n i t s ( I b / h r ) may be c a l c u l a t e d .

Method 17 may sometimes be used i n p l a c e o f Method 5. A schematic o f t h e

samp l ing t r a i n used i n t h i s method i s shown i n Manual 111, F i g u r e 5A-5.

Method 17 employs an i n - s t a c k f i l t e r i n p l a c e o f t h e cumbersome g l a s s - l i n e d

probe and h e a t e r f i l t e r h o l d e r assembly and i s i n t e n d e d t o be used i n p l a c e o f

Method 5 when p a r t i c u l a t e m a t t e r c o n c e n t r a t i o n s ( o v e r t h e normal range o f f l u e

gas tempera tu res a s s o c i a t e d w i t h a s p e c i f i c a p p l i c a t i o n ) a r e e s t a b l i s h e d t o be

independent o f t empera tu re . The f o r m a t i o n o f p s e u d o - p a r t i c u l a t e s i n t h e

samp l ing t r a i n , w h i c h p r e d o m i n a n t l y o c c u r s a t l o w f i l t e r tempera tu res when

SO2 d i s s o l v e s i n w a t e r and i s o x i d i z e d t o n o n v o l a t i l e s u l f a t e s i s o f concern.

These s u l f a t e s can f u r t h e r u n i t e w i t h i n g r e d i e n t s i n t h e f l y ash t o fo rm meta l

s u l f a t e s . F o r example, one Method 5 t e s t i n v e s t i g a t i o n de te rm ined t h a t when

tie f i l t e r was o p e r a t e d a t 400°F, t h e f i l t e r t r a p p e d 8 t o 24 p e r c e n t

of the total sulfur caught in the sampling train (the combined probe wash

catch, filter catch and impinger catch); however, when the filter was operated

at 250°F, over 41 percent of the total sampling train sulfur catch was

retained by the filter (63). Filter temperature, therefore, can have a

significant effect on measured particulate concentration, especially with the

medium to high sulfur coal applications. In accordance with Section 60.48a of

the EPA Code of Federal Regulations CFR40 entitled "Compliance Determination

Procedures and Method," Method 17 may be used in place of Method 5 when flue

gas temperatures are less than 320°F. The decision on whether to use Method 5

or 17, however, is usually left to the discretion of the EPA administrator or

the governing environmental regulatory agency.

Data inputs and outputs of Method 17 are identical to those previously

described for Method 5 tests. Most emission regulations limit pollutants on

the basis of boiler heat input. Hence, instead of regulating direct

measurements of particulate concentration or emission rate, particulate

pollutants are restricted in terms of pounds of particulate matter emitted per

million Btu of boiler heat input (lb/rnBtu). In order to calculate this, the

applicable sections of EPA Method 19, entitled "Determination of Sulfur

Dioxide Removal Efficiency and Particulate, Sulfur Dioxide and Nitrogen Oxides

Emissions Rates From Electric Utility Steam Generators" must be followed

(59). An essential step in this calculation is the determination of an F-factor. F-factors are ratios o f gas volume released dur

fuel divided by the heat content of that fuel. Within the

framework of Method 19, this F-factor can be determined by

procedures:

ing combustion of a

procedural

one of two optima

A generic F-factor can be selected from a table which lists average F-factors for anthracite, bituminous, and lignite coals.

An F-factor can be calculated from equations which are based on an ultimate analysis of the coal supply (determined in accordance with ASTM O 2015).

The more accurate method i s to calculate the F-factor using the equations set

forth i n Paragraph 5.2.2 of Method 19. In this case, the sampling and

analysis procedures followed in obtaining fuel data from these equations would

be subject to approval of the EPA Administrator.

A second o p t i o n a l s tep i n t h e Method 19 p rocedure a l l o w s t h e c a l c u l a t i o n o f

e m i s s i o n r a t e s t o be based on e i t h e r measurement o f carbon d i o x i d e i n t h e f l u e

gas s t ream o r measurement o f oxygen i n t h e f l u e gas stream. W h i l e t h e r e a r e

p r o s and cons a s s o c i a t e d w i t h t h e s e l e c t i o n o f each, i t i s sugges ted t h a t : - The p r e c i p i t a t o r s p e c i f i c a t i o n e l e c t one o f t h e p rocedures

The measurement be made by m u l t i p o i n t samp l ing w i t h an O r s a t ana lyze r .

I n a d d i t i o n t o EPA Method 17, t h e r e a r e o t h e r s t a n d a r d methods f o r i n - s t a c k

p a r t i c u l a t e emiss ions sampl ing. The most n o t a b l e o f t h e s e was t h e American

S o c i e t y o f Mechanical E n g i n e e r ' s Performance T e s t Code 21 ( p u b l i s h e d i n 1941)

supplemented by ASME Performance T e s t Code 27 ( p u b l i s h e d i n 1957) (2, 2). These t e s t procedures were v e r y genera l i n n a t u r e and have become inadequa te

f o r t e s t i n g modern, h i g h - e f f i c i e n c y p r e c i p i t a t o r s . A new code e n t i t l e d "ASME

Performance Tes t Code f o r De te rm in ing C o n c e n t r a t i o n o f P a r t i c u l a t e M a t t e r i n a

Gas Stream" was completed and approved by t h e ASME and ANSI i n 1980 (35). The

i n t e n t o f t h i s new code i s t o p r o v i d e v i a b l e t e s t p rocedures t o meet p r e s e n t

day needs and t o p r o v i d e r e q u i r e d gu idance i n t h e c h o i c e o f an imp lementa t ion

o f t h e s e procedures. Schematics o f f o u r d i f f e r e n t sampl ing t r a i n

c o n f i g u r a t i o n s used i n t h e new ASME code a r e shown i n Manual 111, F i g . 5A-3.

No te t h a t t h e t y p e 1 and 2 sampl ing t r a i n s a r e comparab le t o EPA Method 17 ,

w h i l e t h e t y p e 3 and 4 sampl ing t r a i n s a r e comparable t o EPA Method 5.

A l t h o u g h use o f ASME t e s t procedures f o r per formance t e s t i n g i s u s u a l l y

d i s a l l o w e d by r e g u l a t o r y agenc ies , these p rocedures a r e n e v e r t h e l e s s w e l l

researched and c o n s t i t u t e a v a l u a b l e r e f e r e n c e gu ide .

There i s an ASTM s tandard on t h e measurement o f p a r t i c u l a t e c o n c e n t r a t i o n ;

however, t h i s t e s t procedure has n o t g a i n e d i n d u s t r y - w i d e acceptance and i s

n o t suggested as a supplement t o a p r e c i p i t a t o r s p e c i f i c a t i o n .

S tack V i s i b l e Emissions

S t a c k v i s u a l emiss ions can be q u a n t i f i e d by one o f two s t a n d a r d methods:

V i s u a l d e t e r m i n a t i o n by human o b s e r v e r s , i n accordance w i t h EPA Method 9 e n t i t l e d " V i s u a l D e t e r m i n a t i o n o f O p a c i t y o f Emiss ions from S t a t i o n a r y Sources," i n t h e Code o f Federa l R e g u l a t i o n s CFR40, P a r t 60, Appendix A (46).

O p t i c a l t ransmissometer measurement i n accordance w i t h EPA Performance S p e c i f i c a t i o n 1 e n t i t l e d "Performance S p e c i f i c a t i o n s and S p e c i f i c a t i o n T e s t Procedures f o r Transmissometer System f o r Cont inuous Measurement o f t h e O p a c i t y o f S tack Emiss ion , " i n t h e Code of Federa l Regu la t i ons CFR40, P a r t 60, Appendix B (3) .

€PA Methoa 9 covers t n e d e t e r m i r z i t i o n o f plume o p a c i t y by human o b s e r v e r s .

The method i n c l u d e s procedures f o r t h e t r a i n j n g and c e r t i f i c a t i o n o f

observe rs , and procedures t o be used i n t h e f i e l d f o r d e t e r m i n a t i o n o f s tack

p l ume o p a c i t y .

€PA Performance S p e c i f i c a t i o n 1 encompasses i n s t r u m e n t a t i o n o p t i c a l des ign and

c a l i b r a t i o n requ i remen ts , i n s t a l l a t i o n requ i remen ts , o p e r a t i o n a l t e s t

p rocedures , and d a t a computat ion procedures f o r o p a c i t y measurement by o p t i c a l

t rans rn i ss iomete r . The o p t i c a l t ransmissomete r i s a p r e c i s i o n e l e c t r o - o p t i c a l

i n s t r u m e n t wh ich measures t h e a t t e n u a t i o n o f a l i g h t beam t r a n s m i t t e d t h r o u g h

a s t a c k o r d u c t . The i n s t r u m e n t c o n s i s t s o f a combined o p t i c a l t r a n s m i t t e r /

r e c e i v e r ( t r a n s c e i v e r ) u n i t a t t a c h e d t o one s i d e o f t h e s t a c k , and a r e f l e c t o r

u n i t oro t h e o t h e r s i d e . B o t h a r e a i r - ,>urged and l o c a t e d i n p r o t e c t i v e

hous ings . B a s i c a l l y , l i g h t f rom a s i n g l e source i n t h e t r a n s c e i v e r i s d i v i d e d

i n t o a measur ing beam and a r e f e r e n c e beam. The measur ing beam i s t r a n s m i t t e d

a c r o s s t h e s t a c k t o t h e r e f l e c t o r which t h e n d i r e c t s t h e a t t e n u a t e d beam back

i n t o t h e t r a n s c e i v e r . The r e f e r e n c e beam and t h e measur ing beam a r e p r o j e c t e d

i n t o t h e same pho to d i o d e where t h e i r measured s i g n a l s a r e compared. A s i g n a l

p r o c e s s o r then c o n v e r t s these t o s t a c k o p a c i t y .

When t h e o p t i c a l t ransmissometer i s c o r r e c t l y c a l i b r a t e d and w e l l - m a i n t a i n e d ,

i t measures s t a c k o p a c i t y more a c c u r a t e l y t h a n can be ach ieved b y a human

o b s e r v e r . The problems o f j u d g i n g s t a c k v i s u a l emiss ions by human observe rs

a r e w e l l known. The r e s u l t s a r e dependent on t h e p o s i t i o n o f t h e sun r e l a t i v e

t o t h e observe r ; e r r o r s a r e sometimes made on o v e r c a s t days, and o b s e r v a t i o n s

c a n n o t be made a t n i g h t t i m e . O p t i c a l t r a n s m i s s i o m e t e r measurements a r e n o t by

any means e r r o r - f r e e , b u t i n comparison w i t h human o b s e r v a t i o n s , t h e y a r e

d e c i d e d l y more a c c u r a t e . Sources o f e r r o r f o r o p t i c a l t ransmissorneters a r e

v o l t a g e changes, tempera tu re changes, l i g h t source and d e t e c t o r a g i n g , e f f e c t s

o f ambient l i g h t , t r a n s c e i v e r u n i t / r e f l e c t o r u n i t a l i g n m e n t d r i f t , and o p t i c s

s o i l i n g d r i f t . W i t h p roper c a l i b r a t i o n and main tenance, however, a

modern-design op t i ca l t ransmissometer can achieve an

percent of span o r 4 1 . 5 percent opac i ty , whichever

opera t iona l period of a t l e a s t t h r e e months ( 4 6 ) .

Although s t ack opac i ty measurement by op t i ca l transm

opera t iona l accuracy 2 3

s g r e a t e r , over an

ssometer i s a continuous

monitoring process , i t i s usua l ly requi red t h a t an average of s t ack opac i ty

measurements be taken during t h e performance t e s t per iod f o r determinat ion of

p a r t i c u l a t e concent ra t ion . This i s done f o r two reasons:

To determine i f t h e equipment s u p p l i e r ' s performance guarantees have been s a t i s f i e d .

To c o r r e l a t e opac i ty with p a r t i c u l a t e concen t r a t i on , f o r f u t u r e use during p r e c i p i t a t o r opera t ions and t rouble-shoot ing .

With regard t o t he l a t t e r , t h e r e a r e numerous f a c t o r s i n addi t ion t o

p a r t i c u l a t e concent ra t ion t h a t in f luence s tack opac i ty . The most no tab le a r e

p a r t i c u l a t e s i z e d i s t r i b u t i o n , p a r t i c l e dens i ty , t h e co lo r of the p a r t i c u l a t e

mat te r ( index of r e f r a c t i o n ) , t h e presence of water vapor, s t ack gas

tempera ture , and s t ack geometry. Because of t he se f a c t o r s , accura te

c o r r e l a t i o n s of s t ack opac i ty t o p a r t i c u l a t e concent ra t ion l e v e l s a r e only

poss ib l e f o r a s p e c i f i c i n s t a l l a t i o n f i r i n g a fuel t h a t does not vary

s i g n i f i c a n t l y i n composition.

A p r e c i p i t a t o r s p e c i f i c a t i o n should i n d i c a t e how opac i ty da t a w i l l be reported

during t h e performance t e s t pe r iod ; e . g . , "opaci ty s h a l l be reported a s

consecut ive s ix minute averages during the e n t i r e du ra t ion of each p a r t i c u l a t e

concent ra t ion t e s t . "

Pressure Drop

Fie ld performance t e s t s t h a t determine f l u e system pressure drop do not have

industry-wide s tandard ized procedures. I n f a c t , t h e r e has been a g r e a t deal

of confusion in r ecen t yea r s concerning such fundamentals a s t h e c o r r e c t

i n t e r p r e t a t i o n of t he term p re s su re drop. Appropriate t e s t ins t rumenta t ion ,

s p e c i f i c a l l y , t he c o r r e c t type of pressure measurement probe, has always been

an item of deba te .

There i s an ASME Performance Power Tes t Code on p re s su re measurement (37);

however, t h i s document gene ra l ly covers measurement instrumentat ion and

appara tus and does not s p e c i f i c a l l y address procedures f o r ductwork pressure

measurements. I t can be u s e f u l , neve r the l e s s , f o r a s s i s t i n g in spec i fy ing

s u i t a b l e probe and l i q u i d leve l gages. The balance of t he t e s t procedure must

be covered in a p r e c i p i t a t o r ' s s p e c i f i c a t i o n .

When d iscuss ing f l u i d f low pressure measurements, i t i s bes t t o begin with an

examination of B e r n o u l l i ' s equat ion. Along a s t reaml ine i n s t eady ,

f r i c t i o n l e s s , incompressible flow, t he following r e l a t i onsh ip app l i e s :

2 pV + + 223 = Bernou l l i ' s Constant 2gc 9,

where:

2 p = f l u i d d e n s i t y ( l b m / f t )

V = f l u i d v e l o c i t y ( f t / s e c )

2 gc = dimensional cons tan t (32 .2 lbm/lbf . f t / s e c )

2 p = s t a t i c p re s su re ( l b f / f t )

z = f l u i d e l e v a t i o n ( f t )

g = a c c e l e r a t i o n due t o g rav i ty ( ~ 3 2 . 2 f t / s e c L )

For t he spec ia l case of gas flowing in ductwork, we can ignore the secondary

e f f e c t of changes i n f l u i d e l eva t ion ; however, t he assumption of f r i c t i o n l e s s

flow introduces a s i g n i f i c a n t e r r o r . Hence, a long a ductwork s t reaml ine from

t e s t s t a t i o n 1 t o t e s t s t a t i o n 2 (assuming a n e g l i g i b l e change in gas d e n s i t y

due t o temperature l o s s ) :

where t he term "Losses" r ep re sen t s the f l u i d flow f r i c t i o n a l and i n e r t i a l ( o r

shock) l o s s e s .

We a r e now prepared t o d e f i n e what i s meant by t h e terms " s t a t i c p re s su re

l o s s " and " t o t a l p r e s su re loss" f o r t h i s spec i a l case of gas flowing in a

ductwork, a s fol lows:

S t a t i c 2 2 Pressure = (pl - p2) = (*)2- (91)1 + I Losses Loss 29c 2gc

Total

Loss

Note t h a t when the gas ve loc i ty a t t e s t s t a t i o n 1 equa l s t he gas v e l o c i t y a t

t e s t s t a t i o n 2 , the s t a t i c pressure l o s s becomes equal t o t he t o t a l p ressure

l o s s (again assuming a neg l ig ib l e change in gas d e n s i t y ) .

Most p r e c i p i t a t o r s p e c i f i c a t i o n s now spec i fy pressure drop guarantees i n terms

of t o t a l p ressure l o s s f o r two primary reasons:

Total pressure can be accu ra t e ly measured by use of a Kiel probe o r a simple impact probe.

S t a t i c pressure measurement i s made by use of s t a t i c p re s su re t a p s , which a r e prone t o plugging and r equ i r e p rec i se pos i t i on ing when making measurement in h igh ve loc i ty , h ighly t u r b u l e n t flow.

- I t i s customary t o c a l c u l a t e t heo re t i ca l p r e s su re drop in terms of t o t a l pressure l o s s during t h e design of ductwork.

The t e s t se tup f o r measuring t o t a l p ressure drop c o n s i s t s of an impact o r Kiel

probe connected by s u i t a b l e tubing t o one tap of a manometer; t h e o the r

manometer t a p i s l e f t open t o atmospheric pressure . Tota l duc t pressure a t a

t e s t s t a t i o n i s measured by conducting a multi-point t o t a l p ressure t r a v e r s e ,

with t he number of t r a v e r s e poin ts s e l ec t ed i n accordance with €PA Method 1

(59) . Total pressure a t a t e s t s t a t i o n i s then the a r i t h m e t i c average of a l l

t h e s t a t i o n ' s t r a v e r s e readings. Concurrent with t o t a l p ressure l o s s

measurements, gas volume flow r a t e i s measured using a type S p i t o t tube in

accordance wi th EPA Methods 1 and 2 ( 4 6 ) . Total p r e s su re l o s s between two

t e s t s t a t i o n s i s by sub t r ac t ion , and i s reported a s a t o t a l p r e s su re l o s s ( i n

W . C . ) , a t ga s volume flow r a t e (acfm) and gas temperature ( O F ) . The flow r a t e

and temperature da ta i s needed t o c o r r e c t the measured t o t a l p ressure l o s s t o

a s e t of pre-selected re ference condi t ions by use of r e l a t i o n s h i p s such as :

where :

PC = Corrected pressure drop (in W.C.)

Pm = Measured pressure drop (in W.C.)

Tm = Measured flue gas temperature (OR)

Tr = Reference flue gas temperature (OR)

Fm = Measured flue gas volume flow rate (acfm)

Fr = Reference flue gas volume flow rate (acfm)

Power Consumption

Power consumption is typically measured at the precipitator system's load

centers by use of calibrated instrumentation and transcribed by recorders

provided by the precipitator supplier. Power consumption measurement usually

takes place simultaneously with particulate concentration measurement.

Various types of power consumption measurements can be made, including:

total system average power consumption

total system maximum instantaneous power consumption

the average power consumption of the transformer-rectifier sets

The average power consumption of the system with selected equipment deactivated.

Total system average power consumption and total system maximum instantaneous

power consumption are measured at the 480V tap of the 13.8 kV/480V

transformer. Some precipitator specifications require that power be measured

at point A with preselected equipment deactivated during testing (usually

hopper heaters and sometimes insulator bushing heaters). This, of course, can

o n l y be done d u r i n g warm weather and f a v o r a b l e c o n d i t i o n s . Ano the r way t o

conduc t t h i s p a r t i a l power measurement i s t o measure power a t p o i n t s A, B and

C o r D, and then s u b t r a c t t h e h e a t e r l o a d s f r o m t h e t o t a l system power

measurement. It i s a d v i s a b l e , however, t o keep t h e number o f i n d i v i d u a l power

measurements on a s i n g l e bus t o a minimum f rom t h e s t a n d p o i n t o f c o s t ,

p r a c t i c a l i t y , and measurement accu racy .

Where power measurements a r e t o be made i n t h e f i e l d , a p r e c i p i t a t o r s u p p l i e r

now t y p i c a l l y p r o v i d e s permanent c u r r e n t t r a n s f o r m e r s and p o t e n t i a l

t r a n s f o r m e r s . Wat tmeter c a l i b r a t i o n and power measurement procedures should

b e i n genera l a c c o r d w i t h ASME Performance T e s t Code PTC 19.6 e n t i t l e d "Master

T e s t Code f o r E l e c t r i c a l Measurements i n Power C i r c u i t s " (74). A p r e c i p i t a t o r

s u p p l i e r ' s s e l e c t i o n o f s p e c i f i c model i n s t r u m e n t s ( w a t t m e t e r s , s i g n a l

p rocessors and r e c o r d e r s ) shou ld be s u b m i t t e d t o t h e u t i l i t y f o r r e v i e w and

a p p r o v a l . C e r t i f i c a t e s o f c a l i b r a t i o n f o r a l l i n s t r u m e n t a t i o n a r e u s u a l l y

submi t ted t o t h e u t i l i t y f o r r e v i e w and approva l p r i o r t o f i e l d t e s t i n g .

A r e p r e s e n t a t i v e average power measurement f o r t h e t e s t p e r i o d may be

de te rm ined i n s e v e r a l ways, depending on t h e d e s i r e d l e v e l o f s o p h i s t i c a t i o n .

D i s c r e t e r e a d i n g s can be r e c o r d e d m a n u a l l y a t t i m e i n t e r v a l s , and an

a r i t h m e t i c mean c a l c u l a t e d f o r t h e t e s t p e r i o d . A l t e r n a t e l y , r e c o r d e r s can be

used t o o b t a i n con t inuous , permanent r e c o r d s o f i n s t a n t a n e o u s power

measurements d u r i n g t h e t e s t p e r i o d .

F l u e Gas Temperature Drop

The d e t e r m i n a t i o n o f f l u e gas t e m p e r a t u r e d rop i s o c c a s i o n a l l y conducted

d u r i n g t h e per formance t e s t i n g program t o e v a l u a t e t h e per formance o f a

d u c t w o r k ' s the rma l i n s u l a t i o n , e s p e c i a l l y f o r h o t - s i d e p r e c i p i t a t o r

a p p l i c a t i o n s . EPA Methods 1 and 2 , w h i c h t o g e t h e r d e t e r m i n e gas v e l o c i t y and

volume f l o w r a t e , i n c l u d e p rocedures f o r f l u e gas t e m p e r a t u r e measurement.

These t e s t methods r e q u i r e t h a t (2): The tempera tu re gauge be c a p a b l e o f measur ing tempera tu re t o w i t h i n 1.5 p e r c e n t o f t h e minimum a b s o l u t e s t a c k tempera tu re .

A tempera tu re measurement be made a l o n g w i t h each v e l o c i t y measurement d u r i n g t h e p i t o t t u b e t r a v e r s e o f t h e d u c t .

The tempera tu re gauge be a t t a c h e d t o t h e p i t o t t u b e such t h a t i n t e r f e r e n c e s a r e avo ided.

Provided t h a t n o t more than a one percent d i f f e r e n c e in ve loc i ty measurement i s introduced, t h e temperature gauge need not be a t tached t o the p i t o t tube .

For f i u e gas temperature drop de termina t ion , i t i s suggested t h a t EPA Methods

1 and 2 be s l i g h t l y modified a s fol lows:

The temperature gauge must be of t he thermocouple thermometer type with an accuracy of + Z°F o r b e t t e r , i n accordance with Chapter 3 o f ASME Performance Test Code PTC 19.3 (2).

The thermocouple thermometer i s t o Se c a l i b r a t e d in accordance with procedures s e t f o r t h i n Chapter 9 of Reference 76.

The temperature gauge can be a t t ached t o t he p i t o t tube during a ve loc i ty t r a v e r s e , o r a mult i -point t r a v e r s e may be performed with the thermocouple device a lone . Under no circumstances, however, a r e t he procedures of EPA Method I t o be waived.

The temperature drop i s then determined t o be t he d i f f e r e n c e of t he a r i t hme t i c

averages of temperature t r ave r se s a t two t e s t s t a t i o n s . Flue gas temperature

drop i s t y p i c a l l y recorded t o t he nea re s t degree . Care should be taken when

using t h i s r e s u l t t h a t i t s l i m i t of accuracy ( i n t h e order of + 4OF) i s not

exceeded.

Appendix 7A

EXAMPLE SCOPE OF SUPPLY STATEMENT

Seller shall furnish complete set(s) of electrostatic precipitators and accessories in accordance with the requirements set forth herein.

7.1.1 If Seller does not specifically list any technical deviations or exceptions to the specification, then it shall be understood by Purchaser that the offering is in complete agreement with this Specification.

7.1.2 The equipment shall be located downstream of the air preheaters. Space limitations and the general layout established are shown on Purchaser's drawings listed i n Appendix A of the contract.

7.1.3 Equipment as detailed herein shall consist of the following components to be furnished by the Purchaser or Seller as noted. Reference is made to attached Figure 7A-1 for power supply and wiring schematics.

Furnished By Purchaser Seller

7.1.3.1 Electrostatic precipitator(s) including Sell er collecting electrodes, discharge electrodes, collecting and discharge electrode rappers and control panels, access doors, key interlock system, transformer - rectifier sets with control panels, and ash hoppers.

7.1.3.2 Supporting structures for precipitator(s) Seller and accessories listed i n Paragraph 7.1.3.

7.1.3.3 Ductwork including flue gas distribution devices, dust collection hoppers, access manholes, instrument and test connections, expansion joints and dampers.

. I - From air preheater outlet flange Sell er which is located - feet beyond column 1 ine - to precipitator inlet flange, including expansion joints.

. 2 - From precipitator(s) outlet flange to Seller induced draft fans, including expansion joints.

.3 - Induced draft fans inlet and outlet Seller transition ductwork.

6 CELL h 1

6-1 ELECTRICAL BUS SECTION

ol] ELECTRICAL F IELD

I , , L

I

Figure 7A-1. Bus Section and Transformer-Rectifier Arrange~ents for Any S i n g l e Electrical Field as Used with Precipitators Hav ing Various Groups o f Cell s and Numbers o f F ie1 ds

Furnished By Purchaser S e l l e r

7 .1 .3 .4 Supporting s t r u c t u r e s f o r S e l l e r suppl ied Se l l e r ductwork and acces so r i e s .

7 .1 .3 .5 Platforms l a d d e r s and handrai 1 s s t r u c t u r e s f o r :

. l - Prec

, wal kways, access s t a i rways , and t h e i r required support ing

i p i t a t o r ( s ) S e l l e r

2 - S e l l e r supplied ductwork ( i nc lud ing platforms t o a l l i n l e t and o u t l e t t e s t s t a t i o n s ) Se l l e r

3 - Fly ash hoppers and hopper acces so r i e s Sel l e r

. 4 - Walkways from steam genera tor t o Se l l e r p r e c i p i t a t o r (roof a r ea )

.5 - Maintenance monorail(s) and t r o l l e y - Se l l e r h o i s t ( s ) f o r t ransformer- rec t i f i e r s e t s

7 . 1 . 3 . 6 P r e c i p i t a t o r dampers and f l u e gas d i s t r i b u t i o n dev ices :

. 1 - Out le t balancing dampers (one per nozzle)* S e l l e r

. 2 - I n l e t and o u t l e t i s o l a t i o n dampers S e l l e r ( i f required)

. 3 - Flue gas d i s t r i b u t i o n devices S e l l e r

. 4 - Rappers f o r gas d i s t r i b u t i o n dev ices S e l l e r

* Optional - Provides f o r a g ros s co r r ec t ion in f l u e gas quan t i t y t o each chamber on an emergency and temporary b a s i s u n t i l t he S e l l e r can r e a d j u s t t h e gas d i s t r i b u t i o n devices .

7 . 1 . 3 . 7 P r e c i p i t a t o r ash hopper acces so r i e s :

1 - Hopper v i b r a t o r s Purchaser*

Purchaser* .2 - Hopper a e r a t o r s

Furnished By Purchaser Se l l e r

3 - Hopper a e r a t o r so lenoid valves Purchaser*

4 - Hopper h e a t e r s S e l l e r

.5 - Hopper leve l d e t e c t o r Se l l e r

. 6 - Hopper o u t l e t va lves Purchaser

* Normally purchased a s p a r t of the f l y ash handling system, but t h e p r e c i p i t a t o r manufacturer can provide them i f so d e s i r e d .

7 .1 .3 .8 P r e c i p i t a t o r ash hopper mounting provis ions :

1 - Hopper v i b r a t o r s S e l l e r

.2 - Hopper a e r a t o r s Sef 1 e r

3 - Hopper a e r a t o r so lenoid valves S e l l e r

4 - Hopper hea t e r s Se1 l e r

. 5 - Hopper leve l d e t e c t o r s S e l l e r

6 - Hopper o u t l e t va lves Se l l e r

7 - Hopper ash handling vent valves Se l l e r

7 . 1 . 3 . 9 P r e c i p i t a t o r i n l e t / o u t l e t connections and f langed ductwork terminal p o i n t s . S e l l e r

7 . 1 . 3 . 1 0 Weather enc losure f o r p r e c i p i t a t o r roof covering t r a n s f o r m e r - r e c t i f i e r r r appe r s and rapper cont ro l c a b i n e t s :

1 - Framing S e l l e r

. 2 - Sid ing , roo f ing , doo r s , louvers and Se l l e r w i ndows

. 3 - Heating* Se l l e r

. 4 - Vent i l a t i on Se l l e r

5 - Lighting S e l l e r

* Dependent upon c l i m a t i c condit ions ( i . e . , extreme hea t o r co ld)


7 .1 .3 .11 Enclosure f o r t h e ash hopper a rea

.l - Framing S e l l e r

.2 - Sid ing , roof ing , doors , louvers and S e l l e r windows

. 3 - Heating S e l l e r

. 4 - Vent i l a t i on Sel l e r

. 5 - Lighting S e l l e r

* Dependent upon c l ima t i c condi t ions ( i . e . , extreme cold) i n order t o reduce cooling e f f e c t s on f l y ash hoppers and provide a pro tec ted environment f o r maintenance personnel during outages.

7 .1 .3 .12 Weather enc losure f o r cont ro l room (conta in ing r e c t i f i e r cont ro l u n i t s , power d i s t r i b u t i o n c e n t e r s , and ash hopper accessory c o n t r o l s )

.l - Framing Sel l e r

. 2 - Siding roo f ing , doors , louvers and S e l l e r windows

. 3 - Heating S e l l e r

.5 - Air condi t ion ing

. 6 - Lighting

Sel i e r

S e l l e r

7 . 1 . 3 . 1 3 I n s u l a t o r compartment hea t e r s and blowers. S e l l e r

7 .1 .3 .14 H i g h vo l tage dc wir ing between r e c t i f i e r s Se l l e r and d ischarge e l ec t rodes .

7 .1 .3 .15 R e c t i f i e r low vol tage alarm c i r c u i t . S e l l e r

7 . 1 . 3 . 1 6 Power supply inc luding:

1 - S t a t i o n se rv i ce t ransformers A , B , C Sel l e r and D (Raceway only)


. 2 - 480 Volt Load Centers Sell er

. 3 - 480 Volt Power Distribution Centers Sell er

7.1.3.17 Grounding

.1 - Underground Purchaser

.2 - Above-ground for Seller supplied Sell er equipment

7.1.3.18 Controls, panels and cabinets for the following:

.1 - Transformer-rectifiers Sell er

. 2 - Collecting electrode rappers Sel l er

.3 - Discharge electrode rappers Seller

.4 - Insulator compartment heater and/or Seller blower system

. 5 - Precipitator inlet flue gas Seller distribution d e v i c e rappers (if required)

. 6 - Precipitator outlet flue gas Sel ier balancing dampers

7 - Precipitator inlet and outlet Sel ler isolation dampers

.8 - Fly ash hopper heaters Sei 1 er

. 9 - Fly ash hopper vibrators* Purchaser

.10 - Fly ash hopper aerators* Purchaser

.11 - Fly ash hopper level detectors Sel l er

12 - Heating, air conditioning, ventilation and l i g h t i n g for weather enclosures:

a - Precipitator roof

b - Ash hopper area

c - Control room

Seller

Sell er

Seller


.13 - Flue gas opacity meters for precipitator control system Seller

14 - Flue gas analyzers for NOx, CO, 02,

SO2 or C02 ** Seller

* May be provided by Seller ** May be provided by Purchaser for steam generator control

information

7.1.3.19 Low voltage power and control wiring between:

. 1 - Power transformers and load centers Seller

. 2 - toad centers and power distribution Seller

. 3 - Power distribution centers and control Sell er cabinets

. 4 - Control cabinets and terminal boxes Seller

. 5 - Control, instrumentation and annunciation between control

Sell er

cabinets or device to retransmitting terminal cabinets

7.1.3.20 Low voltage power and control wiring between terminal boxes and:

1 - Transformer-rectifiers Sell er

2 - Collecting and discharge Sell er electrode rac.+rs

. 3 - Insulator compartment heaters Sell er and blowers

. 4 - Inlet gas distribution device rappers Sell er

. 5 - Outlet flue gas balancing dampers Sell er

.6 - Inlet and outlet isolation dampers Sell er

. 7 - Hopper auxiliaries Seller


7.1.3.21 For low vol tage power and cont ro l wir ing spec i f i ed in Paragraph 7.1.3.19:

.1 - Engineering and design Se l l e r

. 2 - Terminal boxes S e l l e r

.3 - Cables and raceways Sel l e r

.4 - Fie ld i n s t a l l a t i o n Se l l e r

7 .1.3.22 For low vol tage power and cont ro l wir ing spec i f i ed i n Paragraph 7.1.3.20:

.1 - Engineering ahd design Se l l e r

.2 - Cables and raceways S e l l e r

. 3 - Fie ld i n s t a l l a t i o n S e l l e r

7 .1 .3 .23 Thermal i n su l a t i on ( i nc lud ing c l i p s ) f o r the fol lowing:

.1 - P r e c i p i t a t o r ca s ing Se7 l e r

- 2 - P r e c i p i t a t o r hot roof Se: 1 e r

. 3 - S e l l e r supplied ductwork and S e l l e r expansion j o i n t s

.4 - Fly ash hoppers S e l l e r

. 5 - I n s u l a t o r c o ~ r a r t r n e n t s Se l l e r

. 6 - I n l e t and o u t l e t i s o l a t i o n dampers Se l l e r ( i f requi red)

.7 - O u t l e t balancing dampers ( i f requi red) S e l l e r

.8 - Control room Sel l e r

7 . 1 . 3 . 2 4 Lagging f o r t he fol lowing:

. I - P r e c i p i t a t o r cas ing Sel l e r

.2 - P r e c i p i t a t o r ho t roof ( spec i a l walking Se l l e r and maintenance s u r f a c e )

. 3 - Ductwork

. 4 - Fly ash hoppers

S e l l e r

S e l l e r

.5 - i n s u l a t o r compartments

. 6 - P r e c i p i t a t o r weather enc losure

. 7 - Hopper area enc losure

.8 - Control room

7 .1 .3 .Z5 Foundations and a r ea dra inage

7 .1 .3 .26 Area l i gh t ing

7.1.3.27 Motors:

. 1 - Motors ( i f r equ i r ed ) w i t h horsepower r a t i ng above 300 hp


Sel 'i e r

Se l l e r

Se l l e r

Se l7e r

Purchaser

Se l l e r

Not Required

. 2 - Motor s t a r t e r s f o r motors spec i f i ed in Not Required Paragraph 7.1.3.27.1

. 3 - Motors ( i f r equ i r ed ) with horsepower Sel l e r r a t i n g s up t o and inc luding 300 hp

. 4 - Motor s t a r t e r s f o r motors spec i f i ed in Paragraph 7 .1 .3 .27 .3

. 5 - Motors and s t a r t e r s f o r damper a c t u a t o r s

7 .1 .3 .28 F i r e Protect ion System

7 . 1 . 3 . 2 9 P r e c i p i t a t o r Water Washing System ( i f requi red)

7.1.3.30 Erect ion of equipment:

.1 - Precipi t a t o r ( s )

. 2 - P r e c i p i t a t o r support ing s t e e l

. 3 - Ductwork, expansion j o i n t s and dampers

.4 - Ductwork support ing s t e e l

. 5 - Platforms, s t a i rways , walkways and i t s supporting s t e e l

. 6 - P r e c i p i t a t o r a c c e s s o r i e s

. 7 - Unloading, handling and s to rage a t s i t e

Se l l e r

Sel I e r

S e l l e r

Se l l e r

Sel l e r

Se l l e r

Sel l e r

Se1 l e r

Sel l e r

S e l l e r

S e l l e r

. 8 - Control panels and cabinets

.9 - Powered control wiring

.10 - Insulation and lagging

.I1 - Field touch-up painting

. 1 2 - Field finish painting

.13 - Fire Protection System . I 4 - Precipitator Water Washing System

(i f required)

7.1.3.31 Special tools

7.1.3.32 All gaskets, bo:ts, nuts, rivets and welding rods with an excess of 5 percent over actual requirement f o r field installation. In addition, all bolts, nuts and gaskets for ductwork interfaces with Purchaser's equipment f 1 anges.

7.1.3.33 Induced draft fan material and erection

7.1.3.34 Chimney


Sell er

Seller

Seller

Sel 1 er

Sell er

Sell er

Sell er

Sell er

Seller

Purchaser

Purchaser

.6 - O t h e r ou tdoor abnormal c o n d i t i o n s

Appendix 75

EXAMPLE OF PURCHASER PROVIDED TECHNICAL DATA

7.2.1 S i t e Requirements

7 .2 .1 .1 S i t e C o n d i t i o n s

. I - Grade e l e v a t i o n above mean sea l e v e l ft

. 2 - E l e v a t i o n a t t o p o f grade s l a b ( H i g h P o i n t ) f t

. 3 - Outdoor des ign d r y b u l b tempera tu re Range - O F t o -OF

. 4 - Outdoor r e l a t i v e h u m i d i t y Range % t o -%

.5 - Outdoor a i r c o n d i t i o n s : T r o p i c a l (Yes, No) S a l t Laden (Yes, No) A r c t i c (Yes, No)

7 - I n d o o r tempera tu re r e q u i r e d i n heated and v e n t i l a t e d spaces a r e O F minimum i n w i n t e r and O F maximum i n summer.

.8 - I n d o o r tempera tu re r e q u i r e d i n a i r c o n d i t i o n e d spaces a r e O F maximum i n summer and -OF minimum i n w i n t e r .

7 .2 .1 .2 Equipment Des ign L i f e y e a r s

7.2.1.3 Des ign f o r Se ismic Loads (yes , no)

1 - Se ismic r i s k zone (ANSI A58.1) one / two / th ree / fou r

2 - Z (zone c o e f f i c i e n t va lue)

7 .2 .1 .4 Des ign Loads

The equipment s h a l l b e des igned f o r t h e f o l l o w i n g e x t e r n a l c o n d i t i o n s :

.1 - Wind l o a d i n g i n accordance w i t h B u i l d i n g Code :

Bas ic w i n d speed, mph

. 2 - L ive load, psf (walkways, p la t fo rms, s t a i r s , penthouse f l o o r , c o n t r o l room f 1 oor)

.3 - Baseplates s h a l l be designed f o r a maximum a l l owab le bear ing pressure o f - p s i

The above loads a r e i n a d d i t i o n t o se ismic f o r ces , where a p p l i c a b l e . However, wind and earthquake need n o t occur s imu l taneous ly .

7.2.2 Basic P lan t Data

Nominal FRJ

T r i a l Operat ion Date

7.2.3 P r e c i p i t a t o r Data

7.2.3.1 S e l l e r s h a l l des ign and f u r n i s h t h e equipment d e t a i l e d h e r e i n i n accordance w i t h the f o l l o w i n g des ign requi rements:

.1 - I n l e t f l u e gas temperature, O F range

.2 - Maximum f l u e gas f l o w acfm B

gas temp. - O F

. 3 - Maximum i n l e t f l y ash r a t e (does no t i nc l ude p r o v i s i o n f o r soo tb l owi ng), I b/hr

. 4 - Steam generator maximum gross hea t 6 i npu t , 10 Btu

.5 - Maximum p a r t i c u l a t e emiss ion,

l b / f o 6 B tu

.6 - Minimum ope ra t i ng S p e c i f i c C o l l e c t i n g Area (SCA) w i t h 10 pe rcen t o f bus sec t ions o u t o f se rv i ce , sq. f t /1000 8 nominal ac tua l cub i c f e e t - i nch spacing

.7 - Maximum i n l e t f l u e gas v e l o c i t y , f t / s e c

.8 - Ove ra l l c o l l e c t i n g e f f i c i e n c y , percen t

.9 - Locat ion, r e l a t i v e t o t h e a i r hea ters upstream/downstream

.10 - Maximum combust ib les i n p a r t i c u l a t e mat te r , percen t

.ll - Induced d r a f t f an i n l e t c rossover acfm 8 ductwork design gas f l o w gas temp. - O F

7.2.3 .2 The p r e c i p i t a t o r c a s i n g , f l y ash hoppers, duc twork and a l l o t h e r equipment o r components t h e r e o f , s u b j e c t t o f l u e gas -exposure s h a l l be des igned f o r t h e f o l l o w i n g i n t e r n a l p r e s s u r e s :

1 - Maximum o p e r a t i n g posi t ive/maxirnum o p e r a t i n g n e g a t i v e , i n . wg. /

. 2 - Design p o s i t i v e / d e s i g n n e g a t i v e , i n . wg /

7 . 2 . 3 . 3 The equipment s h a l l b e des igned t o w i t h s t a n d a f l u e gas h i g h tempera tu re e x c u r s i o n o f - O F f o r a minimum p e r i o d o f 30 m i n u t e s w i t h o u t s u s t a i n i n g any damage whatsoever .

7 .2 .3 .4 P r e c i p i t a t o r a s p e c t r a t i o s h a l l b e equal t o o r g r e a t e r t h a n - . Aspect r a t i o i s d e f i n e d as t h e r a t i o o f e f f e c t i v e l e n g t h e x c l u s i v e o f i n t e r f i e l d walkways, o f p r e c i p i t a t o r i n t h e d i r e c t i o n o f gas f l o w t o t h e e f f e c t i v e h e i g h t o f p r e c i p i t a t o r .

7 .2 .3 .5 Each p r e c i p i t a t o r s h a l l have a minimum o f e l e c t r i c a l and mechanical f i e l d s i n t h e d i r e c t i o n o f gas f l o w .

7.2.3.6 Performance Warranty

Equipment per formance w a r r a n t y s h a l l be based upon any comb ina t ion o f t h e f o l l o w i n g ranges o f Des ign O p e r a t i n g C o n d i t i o n s f o r t h e equipment i n l e t :

- 1 - I n l e t f l y ash r a t e f r o m z e r o t o and i n c l u d i n g 1 T h i s f l y ash r a t e i s c a l c u l a t e d t o be e q u i v a l e n t t o a p a r t i c u l a t e m a t t e r i n l e t l o a d i n g f rom z e r o t o and i n c l u d i n g pounds p e r m i l l i o n B t u p e r h o u r . However, S e l l e r s h a l l e x t e n d ( i f necessary) t h e p a r t i c u l a t e m a t t e r i n l e t l o a d i n g w a r r a n t y range t o account f o r f l y ash s t r a t i f i c a t i o n and uneven f l u e gas d i s t r i b u t i o n .

.2 - f l u e gas i n l e t v o l u m e t r i c f l o w p e r steam g e n e r a t o r , f r o m z e r o up t o and i n c l u d i n g acfm.

.3 - F l u e gas i n l e t t e m p e r a t u r e o f - O F ( t r a v e r s e average), w i t h v a r i a t i o n s f rom average ac ross t h e f a c e o f d u c t ( s ) up t o 2 O F .

. 4 - F l u e gas i n l e t p r e s s u r e f r o m - t o - i n wg.

.5 - Combus t ib les i n p a r t i c u l a t e m a t t e r f rom - t o - p e r c e n t by w e i g h t .

.6 - Fuel c h a r a c t e r i s t i c s as s p e c i f i e d h e r e i n i n Paragraph 7.2.8.1.

. 7 - Normal u n i t opera t ion inc luding , but no t l im i t ed t o , s t a r t -up , shutdown, 1 oad f l u c t u a t i o n , s imultaneously f i r i n g of coal and fue l o i l and/or r e f u s e der ived s o l i d f u e l , sootblowing, operat ion of p r e c i p i t a t o r f l y ash hopper a e r a t o r s and v i b r a t o r s and f l y ash removal equipment w i t h vent ing of s torage s i l o s t o p r e c i p i t a t o r i n l e t ( i f a p p l i c a b l e ) .

.8 - S e l l e r ' s p a r t i c u l a t e matter co r r ec t ion curves s h a l l , a s a minimum cover the ranges spec i f i ed i n Paragraphs 7.2.3.6.1, 7.2.3.6.2, 7 .2 .3 .6 .3 and 7.2.8.1.5h .

9 - The p a r t i c u l a t e mat te r co r r ec t ion curves sha l l have a value of 1 . O D a t t h e following r e f e rence condi t ions :

a - Flue gas flow r a t e per steam gene ra to r acfm

b - I n l e t p a r t i c u l a t e loading pounds per mill ion Btu per hour

c - Flue gas temperature (Traverse Average) - F

d - Fuel s u l f u r content - percent by weight

. I0 - For p re s su re drop co r r ec t ion , t h e fol lowing re ference cond i t i ons sha l l be used:

a - Flue gas flow r a t e per genera tor acfm

b - Flue gas temperature ( t r a v e r s e average) - a F

7 .2 .4 Ash Hopper Data

7 .2 .4 .1 S e l l e r sha l l des ign and fu rn i sh t h e equipment d e t a i l e d here in i n accordance with t h e fol lowing design requirements:

.1 - A f l y ash d e n s i t y of -lb/cu f t sha l l be used f o r t h e s t r u c t u r a l design of t h e f l y ash hoppers.

- 2 - A f l y ash d e n s i t y of - lb/cu f t sha l l be used t o e s t a b l i s h f l y ash hopper s torage capac i ty .

.3 - The minimum f l y ash hopper va l l ey angle sha l l be - degrees.

. 4 - The terminal po in t of t he f l y ash hopper w i l l be g - i n c h diameter f l a n g e d r i l l e d t o match a s tandard ANSI 150 16 , round 12-inch f lange .

.5 - Each hopper s h a l l be designed t o support approximately pounds o f ash handling equipment.

.6 - Each hopper s h a l l b e des igned t o w i t h s t a n d a r e v e r s i b l e h o r i z o n t a l f o r c e o f a p p r o x i m a t e l y - I b s imposed by f r i c t i o n i n t h e ash h a n d l i n g p i p e expans ion c o u p l i n g s .

.7 - Minimum c l e a r a n c e between t h e hopper o u t l e t f l a n g e and grade s h a l l be f e e t .

.8 - I n l e t duc twork s h a l l be des igned t o s u p p o r t a d e p o s i t e d f l y ash l o a d o f I b s / s q f t .

.9 - O u t l e t d u c t w o r k s h a l l be des igned t o s u p p o r t a d e p o s i t e d f l y ash l o a d o f - Ibs/sq . f t .

7.2 .5 E l e c t r i c a l Grounding

7 . 2 . 5 . 1 Purchaser w i l l p r o v i d e a medium r e s i s t a n c e grounded - kV system f o r t h e - kV f e e d e r s t o S e l : e r l s system.

7 .2 .6 M a t e r i a l o f C o n s t r u c t i o n

7 .2 .6 .1 P r e c i p i t a t o r c a s i n g ( s ) s h a l l be c o n s t r u c t e d o f ASTM A- Type m a t e r i a l , - - i n c h minimum t h i c k n e s s .

7 . 2 . 6 . 2 Ash hoppers s h a l l be c o n s t r u c t e d o f ASTM A- Type - i n c h minimum t h i c k n e s s . m a t e r i a l ,

7 . 2 . 6 . 3 A l l duc twork , s u b j e c t t o exposure t o f l u e gas, s h a l l be - inch minimum t h i c k n e s s . c o n s t r u c t e d o f ASTM A- Type m a t e r i a l , -

7.2.6.4 C o l l e c t i n g e l e c t r o d e s s h a l l be c o n s t r u c t e d o f ASTM A- Type m a t e r i a l , gage minimum t h i c k n e s s .

7.2.7 Appl i c a t i o n

The e l e c t r o s t a t i c p r e c i p i t a t o r t o g e t h e r w i t h appurtenances and accessor ies s p e c i f i e d h e r e i n s h a l l be s u i t a b l e f o r s e r v i c e i n c o n j u n c t i o n w i t h a

steam g e n e r a t o r and a c c e s s o r i e s d e s c r i b e d below: M a n u f a c t u r e r

.1 - Furnace c o n d i t i o n s Pressur i zed . Balance D r a f t

. 2 - Burners , no. and t y p e P u l v . Coal ; Cyclone; Gas; Mechanica l , Steam, o r A i r Atomized O i l

3 - Warm-up t o r c h e s , no. and t y p e Gas; Mechanica l , Steam o r A i r Atomized O i l

. 4 - I g n i t i o n torches, no. and t ype Gas; Mechanical, Steam o r A i r Atomized O i l

.5 - Atomiz ing steam o r a i r f l o w f o r burners/warrn-up to rches / i g n i t i o n torches, l b / h r / /

-6 - Soot b lowers maximum f l o w lb/hr,/Steam o r A i r

-7 - A i r hea te r

a - No. and type, pr imary: secondary:

Ho r i zon ta l o r V e r t i c a l Sbaf t , Tubular o r Ljungstrom

b - Soot blowers/water washing I b / h r , A i r Heater f l o w gpm, A i r Heater

.8 - Est imated number o f c o l d s t a r t s per yea r

.9 - Est imated number o f h o t s t a r t s per yea r

.lo - Forced d r a f t fans number

.11 - Induced d r a f t fans number

12 - Primary a i r fans number

.13 - Gas tempering fans number

.14 - f u e l ( s ) w i l l be cond i t ioned by Purchaser Primary-Secondary- T e r t i a r y

Fuel a d d i t i v e s :

7.2.8 Fuel Data

The steam generat ing u n i t w i t h which t h i s e l e c t r o s t a t i c p r e c i p i t a t o r ( s ) i s assoc ia ted w i l l be f i r e d w i t h the f o l l o w i n g f ue l ($ ) :

D e s c r i p t i o n : P r i m a r y Secondary T e r t i a r y O the r

( A n t h r a c i t e , Bi tuminous,Sub- Ref use B i turninous, L i g n i t e , Bunker B i tuminous D e r i v e d " C " , e t c . ) Coa 1 S o l i d Fuel No. 6 O i l Na t . Gas

Percen t o f t i m e f i r e d ( i f f o r f u t u r e des ign , i n d i c a t e ' 'Future" )

Fue l used f o r l i g h t o f f / warm-up/flame s t a b i l i z a t i o n

Load below w h i c h f lame s t a b i l i z a t i o n may be used, p e r c e n t

S imul taneous f u e l f i r i n g , Yes, No

I f y e s , d e s c r i b e f u l l y :

-

7 .2 .8 .1 Coal C h a r a c t e r i s t i c s

E l e c t r o s t a t i c p r e c i p i t a t o r per formance and performance w a r r a n t y s h a l l be based upon t h e f o l l o w i n g range o f coa l c h a r a c t e r i s t i c s on an a s - r e c e i v e d b a s i s :

. I - Fuel source

a - D i s t r i c t o r f i e l d

b - Mines

c - Seam

.2 - Fuel p r o d u c t i o n

a - Method o f m i n i n g

b - S i z e d e s i g n a t i o n

c - P r e p a r a t i o n

Minimum Maximum

. 3 - Hardgrove g r i n d a b i l i t y Index

. 4 - Prox ima te a n a l y s i s , p e r c e n t by w e i g h t

a - F i x e d carbon

b - V o l a t i l e m a t t e r

c - M o i s t u r e

d - Ash

e - S u l f u r

f - H e a t i n g v a l u e , B t u / l b (as r e c e i v e d )

.5 - U l t i m a t e a n a l y s i s , p e r c e n t b y w e i g h t ( a s r e c e i v e d )

a - Carbon

b - M o i s t u r e

c - Hydrogen

d - Oxygen ( b y d i f f e r e n c e )

e - N i t r o g e n

f - C h l o r i n e

g - F l u o r i n e

h - S u l f u r

i - Ash

-6 - Forms o f s u l f u r , p e r c e n t by w e i g h t :

a - P y r i t i c

b - S u l f a t e

c - Organic

.7 - Ash mine ra l a n a l y s i s , p e r c e n t b y w e i g h t on an i g n i t e d b a s i s :

a - Phosphorus p e n t o x i d e , P205

b - S i l i c a , S i O p

c - F e r r i c o x i d e , Fep03

d - Alumina, A1203

e - T i t a n i a , T i 0 2

f - Lime, CaO

g - Magnesia, MgO

h - S u l f u r t r i o x i d e , SO3

i - Potass ium ox ide , K20

j - Sodium o x i d e , NaeO

k - L i t h i u m , L i 2 0

? - Undetermined

.8 - Ash f u s i o n tempera tu re , O F

a - I n i t i a l d e f o r m a t i o n :

( 1 ) - Reducing

( 2 ) - O x i d i z i n g

b - S o f t e n i n g (H = W ) :

(:) - Reducing

(2) - O x i d i z i n g

c - S o f t e n i n g (H = ? / 2 W ) :

(1 ) - Reducing

( 2 ) - O x i d i z i n g

d - F l u i d :

(1 ) - Reducing

(2 ) - O x i d i z i n g

Minimum Maxi mum

Minimum Maxi mum

.9 - Water s o l u b l e a l k a l i e s

i - Sodium ox ide , NaEO

ii - Potass ium ox ide , '$0

S e l l e r s h a l l n o t e t h a t none o f t h e a fo rement ioned c o a l c h a r a c t e r i s t i c s a r e a d d i t i v e n o r r e p r e s e n t any s i n g l e c o a l sample.

7.2.8.2 O i 1 C h a r a c t e r i s t i c s

E l e c t r o s t a t i c p r e c i p i t a t o r per formance and performance w a r r a n t y s h a l l b e based upon t h e f o l l o w i n g range o f - and - o i 1 c h a r a c t e r i s t i c s :

.1 A S T M c l a s s i f i c a t i o n ASTM f o r No. 2 O i l .

. 2 Percent by w e i g h t ( e x c e p t where pprn i s i n d i c a t e d )

Base

a - Carbon

b - Hydrogen

c - S u l f u r

d - N i t r o g e n

e - Sodium, pprn

f - Ash

g - M o i s t u r e

h - Vanadium, ppm

i - Oxygen

.3 - V i s c o c i t y - SSF a t 12Z°F

. 4 - H e a t i n g Value, B t u / l b

.5 - Maximum s u l f u r , p e r c e n t

.6 - F lash p o i n t , O F

.7 - F i r e p o i n t , O F

Base

.8 - Pour point, O F

.9 - Density, ?b/gal

.10 - Type Base, Asphalt or Paraffin

Seller shall note that none of the aforementioned oil characteristics are additive nor represent any single oil sample.

7.2.8.3 Refuse Derived Solid Fuel (RDSF) Characteristics

Electrostatic precipitator performance and performance warranty shall be based upon the following approximate range of RDSF supplemental fuel characteristics on an as-received basis:

.1 - ASTM classification E-38 RDSF-3

.2 - Ultimate analysis, percent by weight (as-received) Minimum Maximum

a - Carbon b - Hydrogen

c - Oxygen

d - Nitrogen e - Ash

f - Sulfur

g - Chlorine

h - Moisture

.3 - Heating value, Btu/lb (as received)

.4 - Bulk density, lb/ft 3

Seller shall note that none of the aforementioned RDSF characteristics are additive nor represent any single RDSF sample.

7.2.9 Particle Size Distribution

The following anticipated fly ash particle size distribution is for information only and may be used as a guide in the design of the electrostatic precipitator(s). However, in no event shall equipment performance warranties be contingent upon particle size distribution entering said equipment:

Particle Size Distribution Microns

1

5

10

20

30

40

SO

100

7.2.10 F1 ue

Flue gas velocit shall not exceed gas flow:

Percent Distribution by Weight, Percent Primary Fuel Secondary Fuel Tertiary Fuel

Gas Velocities

ies at different points throughout the respective circuits the values given below for maximum continuous average flue

Location Velocity, fps

.1 -Flue gas in duct to precipitator(s)

. 2 -Flue gas through electrostatic precipitator(s)

. 3 -Flue gas in duct to induced draft fan(s)

Economic evaluation factors

Fixed charge rate, percent

Interest during construction, percent/year

Levelized capacity factor, percent

Incremental demand charge, $/kW

Capitalized energy charge, $/kW-yr

She pressure drop through the precipitator shall be evaluated at an equivalent-cap? tai ized' ID fan energy consumption, $/in wg

7.2.11.7 Fly ash handling equipment associated with each hopper, $/hopper

7.2.11.8 kV electric power supply cable, $/1 i near f o o t $/terminal /

7.2.11.9 Cost for power feeds, $/cubicle

7.2.11.10 Foundations:

.1 - Excavations, $/cubic yard

.2 - Vibroflotation, $/linear foot

. 3 - Piling, $/linear foot

. 4 - Concrete, $/cubic yard

. 5 - Paving, $/cubic yard

7.2.11.11 Levelized operating labor, $/man-yr

7.2.11.12 Capitalized incremental levelized heat loss, S / O F

7.2.11.13 Replacement power costs, $/MW-hr

Appendix 7C

EXAMPLE OF SELLER PROVIDED TECHNICAL DATA

The Seller furnished data and information is included in this specification to indicate the warrantied performance data, predicted performance, interface characteristics, and construction features of all the Seller furnished equipment. The Seller s h a l l have the sole responsibility for the accuracy o f such information and the compatibility of such information with the Purchaser's specified overall performance requirements.

The Seller shall complete all blank spaces in this paragraph during the proposal stage. Failure to do so will be cause for rejection of the proposal.

7 .3 .1 Precipitator General Features

The electrostatic precipitator(s) general features are as follows (refer to Figures 7C-1 and 7C-2 for terminology):

7 .3 .1 .1 Model Number

7.3.1.2 Number of precipitators per steam generator

7.3.1.3 Precipitator configuration

7.3.1.4 Size of each precipitator, length/height/ depth, feet / /

7.3.1.5 Number of chambers per precipitator/ steam generator

7.3.1.6 Number of cells per precipitator/steam generator /

7.3.1.7 Number/depth of electrical fields per precipitator /

7.3.1.8 Number of bus sections per precipitator/ steam generator /

7.3.1.9 Precipitator casing material (ASTM)/ thickness, inches /

7.3.1.10 Maximum flue gas velocity through the precipitator(s), fps

7.3.1.11 Minimum effective flue gas treatment time, (excluding interfield walkways) seconds

7.3.1.12 Effective migration velocity with 10 percent of bus sections out of service, cm/sec

NOTES:

COLLECTING ELECTRODES: MAXlMUM 59 PER CELL. NUMBER OF CELLS BASED ON SELECTION OF NUMBER OF COLLECTING ELECTRODES PER CELL TOTAL PRECIPITATOR LENGTH DIVIDED I N T 2 CELLS OF EQUAL SIZE. DEPTH OF ELECTRtCAL FIELD CAN VARY. CHAMBERS SHALL BE SEPARATED BY A DIVISION WALL. FOR OTHER TERM!NOLOGY SEE lGCl (INDUSTRIAL GAS CLEANING INSTITUTE. INC.)

Figure 7C-I. E l e c t r o s t a t i c P r e c i p i t a t o r Terminology

J 1 , w I , , @ .v. 1 I * @ TRANSFORMER-RECTI H E R

CI-.( ELECTRICAL BUS SECTlON

ELECTRICAL FIELD

Figure 7C-2. Bus Section and Transformer-Rectifier Arrangements for Any Single Electrical Field as Used with Precipitators Having Various Groups of Cell s and Numbers of Fields

7.3.1.13 Specific collecting area with 10 percent of bus sections out of service, sq ft/1000 acfm

7.3.1.14 Specific collecting area with all bus sections i n service, sq ft/lOOO acfm

7.3.1.15 Aspect ratio (installed)

7.3.1.16 Precipitator casing design pressure, in. wg, positive/negative

7.3.1.17 Precipitator flue connections

.1 - Inlet connection to each cell

b - Welded, Yes or No

c - Flanged and drilled, Yes or No

d - Bolt size/spacing, in . 2 - Outlet connection from each cell

a - Height/width, f t

b - Welded, Yes or No

c - Flanged and drilled, Yes or No

d - Bolt size/spacing, in 7.3.1.18 Gas flow model, material/scale

7.3.2 Fly Ash Hoppers

7.3.2.1 Hopper material, (ASTM)/thickness, in

7.3.2.2 Minimum hopper valley angles, degrees

7.3.2.3 Number of hoppers per precipitator/ steam generator

7.3.2.4 Number of hoppers in direction of flue gas flow

7.3.2.5 Individual hopper storage capacity at full load with all fields in operation, cu ft/hours at design load

.1 - First row hopper

2 - Second row hopper

.3 - Third row hopper

. 4 - Fourth row hopper

5 - F i f t h row hopper

6 - Sixth row hopper

.7 - Seventh row hopper

8 - Eighth row hopper

9 - Ninth row hopper

.10 - Tenth row hopper

.11 - Eleventh row hopper

.12 - Twelfth row hopper

.13 - Thir teenth row hopper

14 - Fourteenth row hopper

7 . 3 . 2 . 6 Hopper su r f ace a r e a , sq f t per p rec ip i t a to r / s t eam genera tor

7 .3 .2 .7 Total hopper capac i ty (cu f t ) ger p rec ip i t a to r / s t eam genera tor

7 . 3 . 2 . 8 Storage time of f i r s t f i e l d hoppers (hours ) a t maximum loading

7 .3 .2 .9 S i z e of hopper d ischarge , i n

7.3.2.10 Hopper v i b r a t o r s

.1 - Number per hopper/precipi t a t o r / steam generator

.2 - Type, indoor o r outdoor

. 4 - Maximum sound leve l a t a d i s t ance of f i v e f e e t , dB(A)

.5 - Total e l e c t r i c a l requirements

. 6 - In t e r rup t ing c a p a c i t y , amps, rms, sym a t r a t ed vol tage

.7 - C o n t r o l s f o r f l y ash hopper v i b r a t o r s s h a l l be a s d e s c r i b e d h e r e i n :

.8 - Type of e n c l o s u r e f o r e l e c t r i c a l a p p a r a t u s ( i n c l u d i n g c o n t r o l s ) , i ndoor o r ou tdoor

Hopper h e a t e r s

.1 - Number pe r h o p p e r / p r e c i p i t a t o r / steam g e n e r a t o r / /

. 2 - Type, indoor o r ou tdoor

. 3 - Makdnodel /

.4 - Heat ing d u t y p e r hopper , kW/Btu p e r hour

a - F i r s t row hopper /

b - Second row hopper

c - Thi rd row hopper

d - Fourth row hopper

e - F i f t h row hopper

f - S i x t h row hopper

g - Seventh row hopper

h - Eighth row hopper

i - Ninth row hopper

j - Tenth row hopper

k - Eleventh row hopper

1 - Twelfth row hopper

m - T h i r t e e n t h row hopper

n - Four teen th row hopper

. 5 - Total simultaneous maximum heating duty, kV/Btu/hr

a - Per precipitator /

b - Per steam generator /

. 6 - Total electrical requirements -kW- V - Hz-pf

.7 - Electrical loads equally divided between phases, Yes or No/load percent per phase /

.8 - Interrupting capacity, amps, rms, sym at rated voltage

. 9 - Controls for fly ash hopper heaters shall be as described herein:

.10 - Type of enclosure for electrical apparatus (including controls), indoor or outdoor

. l I - Thermostat

a - Electrical requirement

b - Range

7 .3 .2 .12 Hopper level detectors

.1 - Number per hopper/precipitator/ steam generator

.2 - Type, indoor or outdoor

.4 - Total electrical reauirements

5 - Level detector application (describe the intended service, i-e., for alarm or contact, if for control, location of control, etc.)

7.3.2.13 Hopper poke holes

.1 - Quantity per hopper

. 2 - Size, inches 7.3.3 Ductwork

7.3.3.1 Number of inlet nozzles per precipitator/ steam generator /

7.3.3.2 Number of outlet nozzles per precipitator/ steam generator /

7.3 .3 .3 Ductwork material (ASTM)/thickness, in. /

7.3.3.4 Inlet flue gas distribution devices

. I - Material (ASTM)/thickness, in. /

- 2 - Type

. 3 - Quantity per precipitator/steam generator /

. 4 - Number of rappers for distribution devices, per precipitator/steam generator /

a - Make/type b - Operation

c - Mounting d - Access during operation e - Minimum acceleration rating "g's" f - Adjustable, describe

g - Lubrication, describe

h - Rapping bar material (ASTM)/size /

i - Total electrical requirements w V H z p f

j - Maximum sound level at a distance of 5 feet, dB peak impact

k - Total maximum continuous/inrush current, amps

1 - I n t e r r u p t i n g c a p a c i t y , amps, rms, sym a t r a t e d v o l t a g e

m - C o n t r o l s h a l l be as d e s c r i b e d h e r e i n ( i n c l u d i n g degree o f au tomat ion , remote manual c o n t r o l and/or s u p e r v i s i o n and l o c a t i o n o f c o n t r o l c a b i n e t s ) :

7 .3 .3 .5 Out1 e t f 1 ue gas d i s t r i b u t i o n d e v i c e s

. I - M a t e r i a l (ASTM)/thickness, i n . /

.3 - Q u a n t i t y p e r p r e c i p i t a t o r / s t e a m genera to r

7 .3 .3 .6 Out1 e t f 1 ue gas b a l a n c i n g dampers

.2 - M a t e r i a l (ASTM)/thickness, i n . /

.3 - Number p e r cell/chamber/precipitator/ steam g e n e r a t o r / / /

.4 - Opera t ion

. 5 - Mount ing

.6 - Access d u r i n g o p e r a t i o n

.7 - A d j u s t a b l e , d e s c r i b e

.8 - L u b r i c a t i o n , d e s c r i b e

.9 - T o t a l e l e c t r i c a l r e q u i r e m e n t s - W-V-Hz-pf

.10 - T o t a l maximum c o n t i n u o u s / i n r u s h c u r r e n t , amps

.11 - I n t e r r u p t i n g c a p a c i t y , amps, rms, sym a t r a t e d v o l t a g e

.12 - Control shall be as described herein (including degree of automation, remote manual control and/or supervision and location of control cabinets):

7 . 3 . 3 . 7 Inlet Flue Gas Isolation Dampers

.2 - Material (ASTM)/thickness, in. /

.3 - Number per cell/chamber/precipitator/ steam generator / / /

. 4 - Operation

.5 - Access

6 - Lubrication, describe

7 - Total electrical requirements w V H z p f

. 8 - Total maximum continuous/inrush current, amps /


. I 0 - Control shall be as described herein (including degree of automation, remote manual control and/or supervision and location of control cabinets):

11 - Purge blower motor, hp -

12 - Purge air heater, kW

7 . 3 . 3 . 8 Outlet flue gas isolation damper

.2 - Material (ASTM)/thickness, in. /

. 3 - Number per cell/chamber/precipitator/ steam generator / / /

.4 - Operation

.5 - Access

.6 - Lubrication, describe

.7 - Total electrical requirements w V H z p f

.8 - Total maximum continuous/inrush current, amps


.10 - Control shall be as described herein (including degree of automation, remote manual control and/or supervision and location of control cabinets):

-11 - Purge blower motor, hp

.12 - Purge air heater, kW

7.3.3.9 Expansion joints

1 - Metal

a - No. per precipitator/steam generator /

b - Make/type /

c - Material/thickness /

2 - Fabric

a - No. per precipitator/steam generator /

b - Make/type /

c - Material/thickness /

7.3.4 Insulation and lagging

7.3.4.1 Total surface area to be insulated

.1 - Precipitator roof (per precipitator/ steam generator) /

. 2 - Casing (per precipitator/steam generator) /

.3 - Hoppers (per precipitator/stearn generator)

.4 - Inlet nozzles (per precipitator/steam generator)

. 5 - Outlet plenums (per precipitator/steam generator)

.6 - Ductwork (per steam generator)

7 - Control room (per steam generator)

.8 - Total area to be insulated ( p e r steam generator)

7 . 3 . 4 . 2 Precipitator roof

1 - Insulation (material/thickness)

.2 - Method of application

3 - Lagging (rnaterial/thickness)

4 - Method of application

7.3.4.3 Casing, hoppers, ductwork, etc

1 - Insulation (materialithickness)

.2 - Method of application

. 3 - Lagging (material/thickness)

4 - Method of application/Material

.5 - Control room (per steam generator)

7.3.5 Coll ecti ng Electrode System

7.3.5 .1 Number of gas passages per precipitator/ steam generator /

7.3.5.2 Spacing between gas passages, in.

7 .3 .5 .3 Collecting electrode material (ASTM)/ thickness, in. /

7.3.5.4 Shape or form

7.3.5.5 Electrode projected size, height/depth, ft /

7 . 3 . 5 . 6 Method of support and guiding (describe, including reference to typical drawings)

7 . 3 . 5 . 7 C o l l e c t i n g e l e c t r o d e s i n each f i e l d p e r s team g e n e r a t o r :

. I - F i e

. 2 - Fie

. 3 - Fie

. 4 - rie

- 5 - Fie

.6 - Fie

. 7 - Fie

.8 - F i e

.9 - Fie

.10 - F i e

. I1 - Fie

.12 - F i e

d No. 1

d No. 2

d No. 3

d No. 4

d No. 5

d No. 6

d No. 7

d No. 8

d No. 9

d No. 10

d No. 11

d No. 12

P r o j e c t e d Depth/

H e i g h t , f t

P r o j e c t e d S u r f a c e Area

sq. f t

.13 - F i e l d No. 13

.14 - F i e l d No. 14

7 . 3 . 5 . 8 T o t a l p r o j e c t e d c o l l e c t i n g e l e c t r o d e s u r f a c e a r e a p e r p r e c i p i t a t o r / s t e a r n g e n e r a t o r , sq f t -

7 . 3 . 5 . 9 T o t a l p r o j e c t e d c o l l e c t i n g e l e c t r o d e s u r f a c e a r e a w i t h t e n p e r c e n t of t h e e l e c t r i c a l bus s e c t i o n s o u t of s e r v i c e per p r e c i p i t a t o r / s t e a m g e n e r a t o r , sq f t -

l l e c t i n g e l e c t r o d e r a p p e r s

- T o t a l number of r a p p e r s p e r p r e c i p i t a t o r / s t e a m g e n e r a t o r /

. 3 - Provision f o r add i t i on of add i t i ona l rappers (Yes o r No)/number per steam genera tor

.4 - Rapper l o c a t i o n

.5 - Rapper opera t ion

.6 - Maximum sound leve l a t a d i s t a n c e of 5 f e e t dB Peak impact

.7 - Total p ro j ec t ed c o l l e c t i n g e l e c t r o d e su r f ace a r e a per rapper

.8 - Maximum pro jec ted c o l l e c t i n g e l e c t r o d e su r f ace a r e a rapped a t any i n s t a n t per steam gene ra to r , sq f t / p e r c e n t o f t o t a l /

- 9 - Minimum acce l e r a t i on r a t i ng " g ' s "

.10 - Mounting

.11 - Access dur ing operat ion

. 1 2 - Adjus t ab l e , de sc r ibe

.13 - Lubr i ca t ion , de sc r ibe

. 1 4 - Rapping b a r mater ia l (ASTM)/size /

.15 - Total e l e c t r i c a l requirements - W - V H z p f

. 16 - Total maximum continuous/ inrush c u r r e n t , Amps

.17 - I n t e r r u p t i n g capac i ty , Amps, Rms, Sym a t r a t e d vol tage

.18 - Control s h a l l be a s described below ( inc lud ing degree of automatic c o n t r o l , remote manual cont ro l and/or superv is ion , and l o c a t i o n of cont ro l cab ine t s ) :

7 .3 .5 .10 Type rapper con t ro l (microprocessor/ so l id-s ta te /mechanica l )

7 . 3 . 5 . 1 1 P l a t e a r ea l o s t i f t ransformer r e c t i f i e r f a i l s (% of t o t a l )

7 .3 .6 D ischarge E l e c t r o d e System

7 .3 .6 .1 Discharge e l e c t r o d e m a t e r i a l (ASTM)/ t h i c k n e s s , i n /

7.3 .6 .2 Shape o r forrn/ type ( r i g i d mast o r r i g i d frame) /

7.3.6.3 T o t a l d i s c h a r g e e l e c t r o d e l e n g t h p e r p r e c i p i t a t o r / s t e a m g e n e r a t o r , f t /

7 . 3 . 6 . 4 Number o f d i s c h a r g e e l e c t r o d e s p e r p r e c i p i t a t o r / s t e a m g e n e r a t o r /

7.3 .6 .5 D ischarge e l e c t r o d e spac ing i n d i r e c t i o n o f f l u e gas f l o w , i n .

7 . 3 . 6 . 6 D ischarge e l e c t r o d e spac ing p e r p e n d i c u l a r t o f l u e gas f l o w , i n .

7 .3 .6 .7 O ischarge e l e c t r o d e p r o j e c t e d h e i g h t , f t

7 . 3 . 6 . 8 T o t a l d i s c h a r g e e l e c t r o d e Tength p e r bus section/transformer-rectifier, f t /

7 . 3 . 6 . 9 Method o f suppor t and g u i d i n g ( d e s c r i b e i n c l u d i n g r e f e r e n c e t o t y p i c a l d raw ings )

7 .3 .6 .10 Number o f bus s e c t i o n s p e r e l e c t r i c a l f i e l d per p r e c i p i t a t o r / s t e a m g e n e r a t o r

.1 - F i e l d No. 1

. 2 - F i e l d No. 2

. 3 - F i e l d No. 3

. 4 - F i e l d No. 4

. 5 - F i e l d No. 5 /

.6 - F i e l d No. 6 /

.7 - F i e l d No. 7 /

.8 - F i e l d No. 8

. 9 - F i e l d No. 9

.10 - F i e l d No. 10 /

.11 - Fie ld No. 11

.12 - Fie ld No. 12

.13 - Field No. 13

.14 - Fie ld No. 14

7.3.6.11 Arrangement of bus sec t ions in each e l e c t r i c a l f i e l d per p r e c i p i t a t o r ( r e f e r t o Figure 7C-2)

.1 - Fie ld No. 1

- 2 - Fie ld No. 2

.3 - Fie ld No. 3

. 4 - Field No. 4

. S - Fie ld No. 5

.6 - Fie ld No. 6

. 7 - Fie ld No. 7

.8 - Fie ld No. 8

.9 - Fie ld No. 9

.10 - Fie ld No. 10

.11 - Field No. 11

.12 - Field No. 12

13 - F i e l d No. 13

.14 - Fie ld No. 14

7 .3 .6 .12 B u s d u c t m a t e r i a l (ASTM) / th ickness , in . /

7.3 .6 .13 B u s d u c t f o r m

7 .3 .6 .14 Bus duc t method o f support (desc r ibe , i nc lud ing r e f e r ence t o t yp i ca l drawings)

7.3.6.15 Bus duc t enclosure (desc r ibe , i nc iud ing r e f e r ence t o t y p i c a l drawi ngs)

7 .3 .5 .16 Number of i n s u l a t o r s p e r c e l l / p r e c i p i t a t o r / s t eam g e n e r a t o r / /

7.3.6 .17 I n s u l a t o r m a t e r i a l

7 . 3 . 6 . 1 8 I n s u l a t o r compartment h e a t e r 2nd blower sys tem

. 1 - Heat ing du ty p e r i n s u l a t o r , kW/Btu/hr / /

. 2 - Toral s i m u l t a n e o u s maximum h e a t i n g d u t y , kW/Etu/hr

a - Per p r e c i p i t a t o r / /

b - P e r steam g e n e r a t o r / /

.3 - T o t a l e l e c t r i c a l r e q u i r e m e n t s w V H z p f

.4 - I n t e r r u p t i n g c a p a c i t y , amps, rms, sym a t r a t e d v o l t a g e

. 5 - Number o f h e a t e r s p e r steam g e n e r a t o r

.6 - Number of b lowers p e r steam g e n e r a t o r

. 7 - C o n t r o l s f o r i n s u l a t o r compartment h e a t e r and/or blower system s h a l l be a s d e s c r i b e d h e r e i n ( i n c l u d i n g d e g r e e o f a u t o m a t i c c o n t r o l , remote manual c o n t r o l and/or s u p e r v i s i o n and l o c a t i o n o f c o n t r o l c a b i n e t s ) , i n d o o r , o u t d o o r :

7 . 3 . 6 . 1 9 Discha rge e l e c t r o d e r a p p e r s

.2 - T o t a l number of r a p p e r s p e r p r e c i p i t a t o r / s t e a m g e n e r a t o r

.3 - P r o v i s i o n f o r a d d i t i o n of a d d i t i o n a l r a p p e r s (Yes o r No)/number p e r s team g e n e r a t o r

. 4 - Rapper l o c a t i o n

5 - Rapper o p e r a t i o n

.€I - Maximum sound leve l a t a d i s t ance of 5 f e e t dB Peak impact

.7 - Number o f d i scha rge e l ec t rodes per rapper

.8 - Total d i scharge e l e c t r o d e length per Rapper, f t

.9 - Maximum d i scha rge e l ec t rode length rapped a t any i n s t a n t per steam gene ra to r , f t / p e r c e n t of t o t a l /

.10 - Minimum a c c e l e r a t i o n r a t i n g "g1s"

.11 - Mounting

.12 - Access dur ing opera t ion

.13 - Adjustable - d e s c r i b e

.14 - Lubricat ion - d e s c r i b e

.15 - Rapping bar ma te r i a l (ASTM)/size

.16 - Total e l e c t r i c a l requirements - W - V H z p f

.17 - Total maximum continuous/ inrush c u r r e n t , amps /

.18 - In t e r rup t ing c a p a c i t y , amps, rms, sym a t r a t e d vol tage

.19 - Control s h a l l be a s descr ibed herein ( i nc lud ing degree of automatic c o n t r o l , remote manual and/or superv is ion , and loca t ion of con t ro l cab ine t s )

20 - Type rapper con t ro l (microprocessor/ so l id-s ta te /mechanica l )

7 . 3 . 7 High Vo7tage E l e c t r i c a l System

7 . 3 . 7 . 1 Number and s i z e o f t ransformer r e c t i f i e r s e t s per steam genera tor by e l e c t r i c a l f i e l d

Power From Each Each No. o f Load Center Transformer R e c t i f i e r

T /R v o l t s kV Sets A 3 C D kVA rms Avg/Peak & - - - - - - -

- 1 - F i e l d No. 1 - - - - /

. 2 - F i e l d No. 2 - - - - /

. 3 - F i e l d No. 3 - - - - /

. 4 - F i e l d No. 4 - - - - /

.5 - F i e l d No. 5 - - - - /

.6 - F i e l d No. 6 - - - - /

. 7 - F i e l d No. 7 - - - - /

.8 - F i e l d No. 8 -- /

. 9 - F i e l d No. 9 - - - - /

. l o - F i e l d No. 10 - - - /

.11- F i e l d No. 11 - - - - /

-12- F i e l d No. 12 - - - - /

.13- F i e l d No. 13 - - - - /

. 1 4 - F i e l d N o . 1 4 - - - - /

.15- T o t a l -- /

T o t a l Connected Load: kVA p f =

T o t a l Normal Opera t i og Load: kVA p f =

Rated / Expected

7.3.7.2 Cur ren t d e n s i t y , rnicroarnperes/sq f t /

.1 - F i e l d No. 1 /

. 2 - F i e l d No. 2 /

. 3 - F i e l d No. 3 /

. 4 - F i e l d No. 4 /

.5 - Fie ld No. 5

.6 - Field No. 6

. 7 - Fie ld No. 7

.8 - Fie ld No. 8

.9 - Fie ld No. 9

. l o - F ie ld No. 10

.11- F ie ld No. 11

.12- F i e l d No. 12

.13- F ie ld No. 13

-14- Fie:d No. 14

7 .3 .7 .3 Corona power d e n s i t y , w a t t s / s q f t

.1 - Field No. 1

.2 - Fie ld No. 2

. 3 - Fie ld No. 3

. 4 - Fie ld No. 4

.5 - Field No. 5

.6 - Fie ld No. 6

.7 - Field No. 7

.8 - Field No. 8

.9 - Field No. 9

. l o - Field No. 10

.11- Field No. 11

.12- F ie ld No. 12

.13- Field No. 13

.14- Field No. 14

Rated / Expected

7.3.7.4 Tranformers

.1 - Number (pe r p rec ip i t a to r / s t eam genera tor ) /

. 2 - Manufacturer

. 3 - Liquid immersed o r dry type

. 4 - Liquid type

.5 - Design temperature r i s e , O C

Maximum design temperature, O C

R e c t i f i e r s

.1 - Number ( p e r precipi tator/s tearn gene ra to r ) /

. 2 - Manufacturer

.3 - Type/wave form

. 4 - Ambient design temperature, O C

.5 - Design temperature r i s e , O C

.6 - R e c t i f i e r t r a n s i e n t pro tec t ion -

7 .3 .7 .6 R e c t i f i e r Control Unit

.1 - Number (pe r prec ip i ta tor / s team gene ra to r )

. 2 - Manufacturer

. 3 - Type

. 4 - Voltage cont ro l

. 5 - Location

.6 - Power supply, each -Volts,- Amps H z , pf

.7 - Ambient design temperature, O C

.8 - Maximum ambient temperature, O C

.9 - Control cab ine t ( s )

a - Number furn ished per p r e c i p i t a t o r / steam genera tor /

b - Enclosure, indoor , outdoor/NEMA /

c - Number space h e a t e r s requi red / hea t ing duty , kW each /

d - Automatic temperature cont ro l ( Y e s , No)

e - Hi-low temperature alarm (Yes, No)

f - Describe o the r design f e a t u r e s

.10 - Arc superv is ion sha l l be by means of

11 - Overload p ro t ec t ion s h a l l be (desc r ibe )

a - H igh vol tage

b - Low vol tage - f u s e s

c - Low vol tage - molded case a i r c i r c u i t breakers

.12 - Control cab ine t i n d i c a t o r s on each cab ine t

No. Function Sca l e / Range -

1 Primary Voltage 1 Primary Amps 1 Secondary KV 1 Secondary MA 1 S p a r k R a t e

.13 - Provision f o r remote superv is ion of cont ro l ( d e s c r i b e )

7 .3 .7 .8 Power D i s t r i b u t i o n

7 .3 .7 .8 .1 Transformers

1 - 6.9-.48 kV Switchgear

a - Manufacturer

b - kVA r a t i n g

c - Catalog No.

d - Technical Bu l l e t i n No.

. 2 - D i s t r i b u t i o n

a - M a n u f a c t u r e r

b - kVA r a t i n g

c - C a t a l o g No.

d - Techn ica l B u l l e t i n No.

7 .3 .7 .8 .2 Cables

7 .3 .7 .8 .3 Panelboards

.1 - Manu fac tu re r

.2 - Type and S i z e

M a n u f a c t u r e r Techn ica l

B u l l e t i n No.

.3 - Techn ica l B u l l e t i n No.

7 .3 .7 .8 .4 L i g h t i n g F i x t u r e s

Manu fac tu re r T e c h n i c a l

B u l l e t i n No.

7.3.7.8.5 Communications

Technical ID!? Manufacturer

7.3.7.8.6 Spare Parts

Major Components Part

Key Inter1 ock System

Quantity Bulletin No.

Manufacturer

Total Number per Steam Generator

.1 - Top housing doors

-2 - Precipitator doors . 3 - Hopper door (including ductwork hoppers) . 4 - High tension selector switches . 5 - H a l f wave-full wave switches

.6 - Grounding switches

.7 - Line circuit breakers

.8 - Discharge electrode rappers

.9 - Collecting electrode rappers

.10 - Number o f f u t u r e p r o v i s i o n door keys f o r a d d i t i o n a l i n t e r l o c k c i r c u i t s when f u t u r e a d d i t i o n a l s e c t i o n ( s ) a r e i n s t a l l e d

.11 - I n l e t and o u t l e t i s o l a t i o n dampers

.12 - Hopper l e v e l d e t e c t o r s

To ta 1

7 .3 .9 Access Doors

7 . 3 . 9 . 1 Weather E n c l o s u r e

. I - Number

.2 - Type /s i ze

7 .3 .9 .2 Roof

. l - Number

. 2 - Type /s i ze

7 .3 .9 .3 Cas ing

. l - Number

. 2 - Type /s i ze

7 .3 .9 .4 Hoppers ( i n c l u d i n g duc twork hoppers)

. l - Number

.2 - Type /s i ze

7 .3 .9 .5 I n s u l a t o r Compartment (penthouse r o o f )

. ? - Number

. 2 - Type /s i ze

7.3.9.6 I n l e t Duc twork

.I - Number

.2 - Type /s i ze

P r e c i p i t a t o r / S t e a m Generator

O u t l e t Ductwork

- 1 - Number

2 - Type/size

I n l e t and Ou t l e t Nozzles

. l - Number

. 2 - Type/size

Control Room

. I - Number /

. 2 - Type/sizc /

Weather Enclosure, Heating and Vent i la t ing /

Trolley-Hoists

.1 - Number per prec ip i ta tor / s tearn genera tor /

.2 - Model

. 3 - Capaci ty, tons

Power Consumption Summary Per Steam Generator

Average Connected LpfLpf

Trans fo rmer - r ec t i f i e r s e t s - - - -

Col lec t ing e l ec t rode rappers - - - - Discharge e l ec t rode rappers - - - -

I n s u l a t o r compartment hea ter - - - - Hopper hea t e r s

a . P r e c i p i t a t o r b. Ductwork

Hopper v i b r a t o r s

Lighting

Other ( I d e n t i f y )

Total

7.3 .11 .10 S e l l e r sha l l provide an e l e c t r i c a l load t a b u l a t i o n in t h e fol lowing format:

Normal Bus T ie Connected Operation Operation

Bus Number (kW/pf) ( kW/pf) _( kW/pf)

To ta l s :

(1) Represents t o t a l of bus - and - with t i e breaker c losed . This w i l l be load t o one (1) t ransformer.

(2) Represents t o t a l of bus and - with t i e breaker c losed . This w i l l be load t o one (1) transformer.

7 .3.12 Performance Warranty

7 .3 .12 .1 The t o t a l f l u e gas pressure drop across t h e equipment ( p r e c i p i t a t o r p lus i n l e t / o u t l e t ductwork and dampers within S e l l e r ' s scope of supply) sha l l no t exceed

7 . 3 . 1 2 . 2 . a The t o t a l power requirement of a l l t r a n s f o r m e r - r e c t i f i e r s e t s sha l l not exceed

7 .3 .12 .2 .b The t o t a l power requirement of a l l t r a n s f o r m e r - r e c t i f i e r s e t s , with 10 percent of t he t r ans fo rmer - r ec t i f i e r s e t s out of se rv ice sha l l not exceed

7 .3 .12 .2 . c The t o t a l maximum power consumption of a l l connected loads , including S e l l e r supplied a c c e s s o r i e s , with 10 percent of t he transformer- r e c t i f i e r s e t s ou t of se rv ice sha l l not exceed

7.3.12.3 The equipment s h a l l , when operated with t e n (10) percent of t h e i n s t a l l e d and i n i t i a l l y energized bus s e c t i o n s out of se rv ice have an overa l l maximum p a r t i c u l a t e mat te r emission r a t e of

7 .3 .12 .4 The equipment sha l l have an average max heat l o s s of

imum

i n . wg

0.030 pounds/mi 11 ion B t u

7.3.12.5 The maximum c u m u l a t i v e u n i t f o r c e d outage and/or f o r c e d gas f l o w r e d u c t i o n f r o m d e s i g n gas f l o w r a t e caused o r i n i t i a t e d by t h e equipment s p e c i f i e d h e r e i n f rom t r i a l O p e r a t i o n Date and t o F i n a l Acceptance

hours s h a l l n o t exceed

7.3.12.6 The f l u e gas average s h a l l n o t exceed

7.3.13 Sound C o n t r o

7 .3 .13.1 - Expected

o p a c i t y on a one (1) hour p e r c e n t

sound p r e s s u r e l e v e l measured a t a d i s t a n c e o f 5 f t f r o m t h e o u t l i n e o f t h e equipment shown as a s i n g l e dB(A) r e a d i n g .

Equipment D e c i b e l s

7 .3 .13.2 - Expected sound p r e s s u r e l e v e l measured under " f r e e f i e l d " c o n d i t i o n s a t a d i s t a n c e o f 5 f t f rom t h e o u t l i n e o f equipment shown i n d e c i b e l s a t the o c t a v e hand c e n t e r f r e q u e n c i e s r a n g i n g f rom 31.5 t o 8,000 Hz.

125 250 500 1 K 2K 4K 8K C e n t e r F r e q u e n c y 31.5 63 - - - Equipment D e c i b e l s

Cente r A

3 - C a l c u l a t e d sound power l e v e l o f t h e equipment shown i n d e c i b e l s a t band c e n t e r f r e q u e n c i e s r a n g i n g f rom 31.5 t o 8,000 Hz and

r e f e r r e d t o a base o f 10- l2 w a t t s .

Frequency 31.5 63 125 250 500 T K 2 K 4K 8K - - - - - - - - p e n t D e c i b e l s

7.3.13.4 Expected peak d i s t a n c e o f 5 f t f r o m t h e an impac t t y p e i n s t r u m e n t

sound p r e s s u r e l e v e l r a p p e r when measured

-

-

a t a w i t h

7.3.13.5 S t a t e whe the r t h e sound l e v e l s l i s t e d above a r e a t t a i n e d w i t h a c o u s t i c a l t r e a t m e n t (Yes, No)

7 .3 .13 .6 I f t h e answer t o 7 .3 .13.5 i s Yes, t h e n d e s c r i b e t h e t y p e o f a c o u s t i c a l t r e a t m e n t , manu fac tu re r and s t a t e i n d e t a i l S e l l e r ' s scope i n c l u d i n g e n g i n e e r i n g , supp ly , i n s t a l l a t i o n , e t c .

7 . 3 . 1 4 E l e c t r i c a l Motors

I t e m Number 1 2 3 4 5 6 7 8 - - - - - - - - .1 - Q u a n t i t y / S e r v i c e

( D r i v e n Equipment

.2 - Horsepower, hp - - - - - - -

. 3 - Vo l tage R a t i n g -------- /Phase

. 4 - Speed, rpm

5 - Location (Outdoor, Indoor) --------

6 - Ambient Greater than 40°C --------

7 - Full-load/Locked Rotor Amperes

.8 - Temperature Rise, O C

9 - Enclosure

.10 - Full Travel Time - Sec*

. l l - Type (Open/Close o r Jogging)* --------

* For damper motors only

7 . 3 . 1 5 Equipment Weights

Precipi tator/Stearn Generator

7.3.15.1 Assembled p r e c i p i t a t o r , 7 b /

7 .3 .15 .2 P r e c i p i t a t o r support s t e e l , 1b /

7 . 3 . 1 5 . 3 Ductwork, l b /

7 . 3 . 1 5 . 4 Ductwork support s t e e l , l b /

7.3 .15 .5 Platforms, s t a i r s and walkways, Ib /

7.3.15.6 P l a t f o r m s , s t a i r s and walkway suppor t s t e e l , l b /

7.3.15.7 Accessor ies /

7.3.15.8 T o t a l /

7.3.15.9 H e a v i e s t p r e f a b r i c a t e d s e c t i o n t o be handled d u r i n g e r e c t i o n /

7.3.15.10 H e a v i e s t p r e f a b r i c a t e d s e c t i o n t o be handled d u r i n g maintenance /

7.3.16

7.3.16.1

7.3.16.2

7.3.16.3

7.3.16.4

7.3.16.5

7.3.16.6 s t e e l

7.3.16.7

7.3.16.8

7.3.16.9

7.3.17

E s t i m a t e d E r e c t i o n Workhours

P r e c i p i t a t o r / S t e a m Genera to r

Assernbl ed p r e c i p i t a t o r /

P r e c i p i t a t o r suppor t s t e e l /

Ductwork /

Ductwork s u p p o r t s t e e l /

P l a t f o r m s , s t a i r s and walkways /

P l a t f o r m s , s t a i r s and walkway suppor t /

H igh and l o w v o l t a g e w i r i n g /

Accessor ies /

T o t a l /

E r e c t i o n Guarantee

The S e l l e r s h a l l w a r r a n t t h a t t h e amount o f shop f a b r i c a t i o n s h a l l n o t be l e s s t h a n s t a t e d h e r e i n . S e l l e r s h a l l a l s o w a r r a n t t h a t t h e amount o f P u r c h a s e r ' s f i e l d w e l d i n g and b o l t i n g ( e x c l u d i n g f o u n d a t i o n b o l t s ) i n e r e c t i n g a l l t h e S e l l e r p r o v i d e d equipment s h a l l n o t exceed t h e q u a n t i t i e s s t a t e d h e r e i n . T h i s w a r r a n t y i s wa ived i f e r e c t i o n i s pe r fo rmed by t h e S e l l e r .

The P u r c h a s e r ' s c o s t o f p e r f o r m i n g t h e e r e c t i o n work, based on t h e f o l l o w i n g i n f o r m a t i o n , w i l l be used i n t h e b i d e v a l u a t i o n i f t h e e r e c t i o n i s t o b e per formed by t h e Purchaser .

A f t e r S e l l e r

e r e c t i o n . ' s f i e l d

i s c o m p l e t e d , t h e f o l l o w i n g s t a t e m e n t s w i l l be compared t o i n s t a l l a t i o n drawings t o d e t e r m i n e i f S e l l e r met h i s

w a r r a n t y .

Number o f p r e f a b r i c a t e d s e c t i o n s -.

7 . 3 . 1 7 . 2 Roof e r e c t i o n

Number of p r e f a b r i c a t e d s e c t i o n s

7 . 3 . 1 7 . 3 Casing e r e c t i o n

Number o f p r e f a b r i c a t e d S e c t i o n s

7 . 3 . 1 7 . 4 Ductwork e r e c t i o n

Number of p r e f a b r i c a t e d s e c t i o n s

S i z e of each s e c t i o n

S i z e of each s e c t i o n

S i z e o f each s e c t i o n

S i z e o f each s e c t i o n

7.3 .17 .5 Col lec t ing p l a t e s e r e c t i o n

Number of p re fab r i ca t ed sec t ions

7.3.17.6 Discharge e l ec t rodes e r e c t i o n


7 .3 .17 .7 Weather enclosure e r e c t i o n


S ize of each sec t ion

S i z e o f each sec t ion

Size of each sec t ion

7.3.17.8 S t r u c t u r a l s t e e l , platform and stairway e r e c t i o n


S i z e of each sec t ion

7.3 .18 S e l l e r ' s Drawings

S e l l e r ' s drawings l i s t e d in p a r t a s fol lows and spec i f i ed by c h a r a c t e r , number and d a t e sha l l be submitted with t h e proposal .

Character of Drawings o r Curves Number

7 .3 .18 .1 E l e c t r o s t a t i c p r e c i p i t a t o r and a s soc i a t ed ductwork o u t l i n e , plan and sec t iona l views

7 .3 .18 .2 E l e c t r o s t a t i c p r e c i p i t a t o r and ductwork support s t e e l plan

7 .3 .18 .3 E l e c t r o s t a t i c p r e c i p i t a t o r and a s soc i a t ed ductwork loading diagrams

7 .3 .18 .5 Platforms and s ta i rways - sec t ions

7 .3 .18 .6 Col lec t ing e l ec t rode supports and guides

7 .3 .18 .7 Anchor b o l t l o c a t i o n s and foundat ion loads

7 .3 .18 .8 Discharge e l e c t r o d e supports and guides

7.3. enc

7 . 3

7 .3

18 .9 High vol tage bus , supports and osu re

18.10 E l e c t r i c a l one-1 ine diagram

18 .11 S t ruc tu ra l s t e e l assembly and e r e c t i o n procedure

7.3.18.12 Engineering cons t ruc t ion and procurement schedules

7 .3 .18 .13 Eff ic iency Correct ion Curves

. I - Correct ion f a c t o r v s Gas Volume C F 7

. 2 - Correct ion Factor vs I n l e t Grain C F 2 Loading

Date

C F 3 . 3 - Correct ion Factor vs Gas Temperature

. 4 - Correction Factor vs Sulfur Content in Fuel

.5 - Correction Factor vs Percentage Bus-Sections Deenergized

7.3.18.14 Power Consumption Curves

.1 - Correction Factor v s T/R Set Guaranteed Power Consumption CF 10

7.3.19 Seller shall fully describe all operating and maintenance procedures and manpower requirements on a precipitator and steam generator basis.

7.3.20 Seller shall fully describe all recommended spare parts on a precipitator and steam generator basis.

Appendix 7D

COMMERCIAL TERMS AND CONDITIONS

CONCEPTS FOR MATERIAL SUPPLY

Since t he mer i t s of d e l i v e r and e r e c t c o n t r a c t s were discussed i n

Sect ion 7 , t he concepts f o r mater ia l supply terms and condi t ions a r e a s

fo l lows . The following a r e t y p i c a l examples of terms and condi t ions of t h e

mater ia l supply port ion of a d e l i v e r and e r e c t e l e c t r o s t a t i c p r e c i p i t a t o r

c o n t r a c t .

De f in i t i ons

This sec t ion de f ines those words and terms which appear throughout a

c o n t r a c t , which i f l e f t undefined could be construed d i f f e r e n t l y by t h e

p a r t i e s involved. Some of t h e more commonly used terms and d e f i n i t i o n s

appearing in material c o n t r a c t s a r e :

Owner - a u t i l i t y o r group of u t i l i t i e s involved in t he p ro j ec t .

Notice t o Proceed - means a n o t i c e duly au thor ized and de l ivered by t h e owner,

au thor iz ing the con t r ac to r t o commence the performance of any Work.

Change Order - means a w r i t t e n order t o t he c o n t r a c t o r signed by t h e owner and

accepted by the con t r ac to r e f f e c t i n g an add i t i on , d e l e t i o n , o r r ev i s ion in t h e

Work, o r an adjustment in t h e c o n t r a c t p r i c e o r t h e con t r ac t time i s sued a f t e r

execution of t h e con t r ac t .

Contract - means the c o n t r a c t documents s p e c i f i c a l l y i d e n t i f i e d and

incorporated i n t o the c o n t r a c t such a s terms and cond i t i ons , s p e c i f i c a t i o n s

and drawings.

Contract Execution - means t h e da t e on which a c o n t r a c t o r executes and e n t e r s

i n t o a con t r ac t t o perform t h e work w i t h t he owner. This da te i s usua l ly not

more than 20 calendar days a f t e r r e c e i p t of t h e c o n t r a c t by t he c o n t r a c t o r .

Contract Pr ice - means the t o t a l monies, ad jus t ed i n accordance with

con t r ac tu ra l p rovis ions , payable t o t h e c o n t r a c t o r under t h e con t r ac t .

Contrac t Time - means the period of time s t a t e d in t he con t r ac t f o r the

completion of t h e Work.

Cont rac tor o r S e l l e r - means the pa r ty o r p a r t i e s con t r ac t ing d i r e c t l y w i t h

t h e owner t o perform the work pursuant t o t h e con t r ac t .

- means c o l l e c t i v e l y , a l l of t he drawings, r e c e i p t of which i s

acknowledged by t h e con t r ac to r , l i s t e d in t he c o n t r a c t , and a l s o such

supplementary drawings a s t h e owner may i s sue from time t o time in order t o

c l w i f y o r expla in such drawings or t o show d e t a i l s which a r e not shown

thereon.

Con t r ac to r ' s Representa t ive - means the individual designated i n wri t ing by

t h e c o n t r a c t o r a s having the a u t h o r i t y t o a c t on behalf of t h e con t r ac to r with

r e spec t t o t h e con t r ac t .

Engineer - means t h a t e n t i t y (Company, Corporat ion, e t c . ) r e t a ined by t h e

owner t o a s s i s t i n t h e des ign , engineer ing , procurement and e r e c t i o n of a

p r o j e c t .

Equipment - means a l l of t he m a t e r i a l s , appara tus , s t r u c t u r e s , supp l i e s ,

equipment, and any o the r t h ings fu rn i shed by the con t r ac to r in t h e performance

of t he c o n t r a c t .

Erect ion Consultant - means an employee of t h e con t r ac to r who s h a l l be a t t h e

j o b s i t e and advise t h e owner and/or i t s agents o r con t r ac to r s a s t o the

s p e c i f i c method of e r ec t ion o f t he Work provided hereunder.

T r i a l Operation - i s t h e d a t e upon which t h e t u rb ine genera tor i s synchronized

wi th the g r i d system.

J o b s i t e - means t h e ' l o c a t i o n a t w h i c h t h e work f u r n i s h e d b y t h e c o n t r a c t o r i s

t o be permanent ly i n s t a l l e d and c o n s t r u c t i o n i s r e q u i r e d .

Owner's P r o j e c t R e p r e s e n t a t i v e - means an employee o f t h e Owner who s h a l l have

t h e a u t h o r i t y t o a c t on b e h a l f o f t h e t h e Owner i n c o n n e c t i o n w i t h t h e day t o

day a c t i v i t i e s o f t h e P r o j e c t .

P a r t y - means t h e c o n t r a c t o r o r t h e owner o r b o t h t h e c o n t r a c t o r and owner, as

app l i c a b l e .

P r o j e c t - means t h e c o a l - f i r e d e l e c t r i c g e n e r a t i n g u n i t ( s ) l o c a t e d a t a s i t e

i n a p a r t i c u l a r s t a t e . I f two g e n e r a t i n g u n i t s a r e b u i l t , t h e f i r s t b u i l t

s h a l l be known a s " U n i t 1," and t h e second b u i l t s h a l l be known as " U n i t 2,"

t h e p r o j e c t c o m p r i s i n g b o t h t o g e t h e r .

Commercial O p e r a t i o n - t h e d a t e upon w h i c h a u n i t i s i n c o r p o r a t e d i n t h e power

g r i d d i s p a t c h system and t h e owners r a t e base.

P r o j e c t Manager - means an employee who s h a l l have t h e a u t h o r i t y t o a c t on

b e h a l f o f Eng ineer w i t h r e s p e c t t o t h e P r o j e c t .

S p e c i f i c a t i o n s - means t h e w r i t t e n t e c h n i c a l p r o v i s i o n s i n c l u d i n g a

appendices t h e r e t o , b o t h genera l and s p e c i f i c , wh ich f o r m a p a r t o f

c o n t r a c t documents.

S u b c o n t r a c t o r - means any person, f i r m , p a r t n e r s h i p , j o i n t v e n t u r e ,

1

t h e

company,

c o r p o r a t i o n , o r e n t i t y hav ing a c o n t r a c t u r a l agreement w i t h t h e c o n t r a c t o r o r

w i t h any o f i t s s u b c o n t r a c t o r s a t any t i e r t o p r o v i d e a p a r t o f t h e work

c a l l e d f o r by t h e c o n t r a c t .

Work - means any and a l l o b l i g a t i o n s , d u t i e s and r e s p o n s i b i l i t i e s , i n c l u d i n g

f u r n i s h i n g equ ipment , e n g i n e e r i n g , d e s i g n , workmanship, l a b o r and any o t h e r

s e r v i c e s o r t h i n g s necessary t o t h e s u c c e s s f u l c o m p l e t i o n o f t h e p r o j e c t

ass igned t o o r under taken by t h e c o n t r a c t o r under t h e c o n t r a c t .

M i s c e l l a n e o u s Terms - Wherever t h e words " o r Owner approved equal1' a r e used i n

a c o n t r a c t i n connec t ion w i t h m a t e r i a l s , p r o d u c t s o r equ ipment d e s i g n a t e d by

m a n u f a c t u r e r s ' o r vendors1 names, t r a d e names, c a t a l o g numbers, e t c . , t h e y a r e

i n t e n d e d t o e s t a b l i s h a s t a n d a r d . O the r m a t e r i a l s , p r o d u c t s o r equ ipment

m e e t i n g t h e e s t a b l i s h e d s t a n d a r d s may be used p r o v i d e d t h a t t h e i r e q u i v a l e n c y

has been demonst ra ted t o t h e s a t i s f a c t i o n o f t h e owner and eng ineer .

C o n t r a c t Documents

T h i s s e c t i o n d e l i n e a t e s component p a r t s o f a c o n t r a c t by name, s t a t i n g t h a t

t h e s e i t e m s a l o n e c o n s t i t u t e wha t s h a l l be known and r e f e r r e d t o as t h e

c o n t r a c t documents. I n a d d i t i o n , t h i s s e c t i o n d e a l s w i t h r e s o l v i n g p o s s i b l e

c o n f l i c t s between t h e component p a r t s o f a c o n t r a c t by l i s t i n g t h e o r d e r o f

precedence f o r each p a r t . The f o l l o w i n g i s an example o f a t y p i c a l o r d e r o f

precedence f o r c o n t r a c t u r a l documents:

1 - Change Orders

2 - Agreement

3 - S p e c i a l C o n d i t i o n s

4 - Supplementary Terms and C o n d i t i o n s and Standard Terms and C o n d i t i o n s

5 - S p e c i f i c a t i o n s

6 - Drawings

A d d i t i o n a l l y , d e t a i l e d d r a w i n g s s h a l l govern ove r g e n e r a l drawings, w i t h

c a l c u l a t e d measurements on d raw ings b e i n g a b s o l u t e . No s c a l e measurements a r e

t o b e shown o r used on d r a w i n g s .

Fu r the rmore , i n t h e e v e n t t h e meaning o f f u l f i l l m e n t o f a p a r t i c u l a r

s p e c i f i c a t i o n o r d raw ing depends upon i n d i v i d u a l judgement, t h e n t h i s s e c t i o n

must l i s t t h e owner o r i t s e n g i n e e r as t h e r e s p o n s i b l e p a r t y t o make t h e

judgement . It should a l s o r e q u i r e t h e eng ineer t o make such judgements i n

w r i t i n g , c o n s i s t e n t w i t h good e n g i n e e r i n g o r c o n s t r u c t i o n p r a c t i c e s .

Contractor's Obligations

This section deals with all the facts necessary for the Contractor to adhere

to in fulfilling its obligations under the Contract:

Plan, schedule, design, fabricate, inspect, deliver and direct the Work in accordance with the Contract requirements.

Meet all delivery dates by development of a detailed schedule for all design, engineering, material procurement and erection to support the agreed contract dates.

Procedures for ensuring that equipment shipped to the jobsite will be protected from the environment until start-up.

Furnishing of all drawings and technical data as called for by the Contract Specifications, including layout, installation, licensing, start-up, operation and maintenance.

Provide instruction manuals containing maintenance and operating instructions for the equipment.

Provide the Owner with a fabrication, inspection and testing schedule, including test reports within a specified time period after completion of the testing. Also, provisions for surveillance and inspection programs for major pieces of equipment must be established, with the Owner having the right of program audit prior to the event.

Supply spare parts as specified, including a recommended tist of additional spare parts to be used during the operating life of the equipment.

Prior to the delivery of the equipment or portion thereof, supply a bill of material identifying the various components, items and pieces comprising the equipment to be delivered.

Provide technical consultation services regarding the installation of the work along with start-up training and services of the Owner's operating personnel in the operation and maintenance of the equipment.

Require all material including that supplied by or through subcontractors, to be free and clear from liens.

Provide a security interest, in the Owners's favor, for all material paid for by the Owner prior to fina: acceptance of equipment.

Owner's Obl iga t ions

This s ec t ion s t a t e s t h a t t he Owner w i l l pay the Cont rac tor f o r s a t i s f a c t o r y

performance of t h e Work i n accordance with t h e payment provis ions s e t f o r t h i n

t he Contract . By using the phrase " s a t i s f a c t o r y performance", t h e Owner can

make t h e determinat ion as t o whether o r n o t t he C o n t r a c t o r ' s performance has

been s a t i s f a c t o r y . Suggested remedies f o r u n s a t i s f a c t o r y performance a r e

presented in Sect ion 7 of t h i s manual.

Delivery, T i t l e and Storage

This por t ion of t h e commercial terms and cond i t i ons d e a l s wi th shipment of

mater ia l t o t h e p r o j e c t s i t e .

Delivery - The f i r s t item of information t o be provided t o t h e Cont rac tor

i s t h e F.O.B. po in t . A determina t ion by the Owner and i t s legal and

insurance s t a f f s should be made on the F . O . B . po in t p r i o r t o developing

t h e terms and conditons. The next item i s t o d e f i n e t h e Owner's meaning

of t h e word "del ivery" - i t should s t a t e whether i t i s d e l i v e r y t o t h e

c a r r i e r o r de l ive ry t o t h e p r o j e c t s i t e .

I t i s a l s o suggested t h a t t h i s sec t ion s t a t e which p a r t y i s respons ib le

f o r making shipping arrangements, paying f r e i g h t charges , f i l i n g and

c o l l e c t i n g damage and l o s s c la ims , e t c . Fur ther , i t should ensure t h a t

t h e Cont rac tor i s respons ib le f o r packing and c r a t i n g , e t c . , of t h e

equipment i n order t o p r o t e c t i t from damage dur ing t r a n s i t . Moreover,

i n s t r u c t i o n s should be inc luded , l i s t i n g the r e s p o n s i b i l i t y f o r unloading

equipment a t t h e s i t e .

Shipp

t o a1

T i t l e

ng papers a r e t o be forwarded t o t he Owner a t t h e time o f shipment

ow time f o r a r r i v a l p r epa ra t ion .

- Concurrent with t h e de termint ion of t h e F . O . B . po in t f o r d e l i v e r y

purposes, i t should a l s o be determined a t what po in t t i t l e passes t o t he

Owner and which par ty has t h e r i s k of l o s s dur ing shipment. Again, t he se

de termina t ions should be made based upon the advice from the Owner's

l ega l and insurance s t a f f s .

Storage - In the event the equipment is going to be stored for some length of time prior to installation, provisions must be included in the

Contract for such circumstances. Included in the instructions should be

the location for such storage, provisions for protection of equipment to

be provided by Contractor (with the Owner responsible for the payment of

incurred storage expenses), inspection requirments and responsibiliy for

risk of loss.

Risk of Loss

This section deals with the loss of equipment during transit and then during

installation at the project site. The following wording is illustrative of

such a risk of loss provisions for a deliver and erect contract:

R I S K O F LOSS

Prior to commencement of shipments of Equipment from the manufacturing facilities to the Jobsite or construction at the Job-site, other than site preparation, whichever is earlier, Owner will obtain, at Owner's ex?ense, (except as hereinafter provided), Builder's Risk Insurance in a minimum amount of $50,000,000 (except $10,000,000 with respect to losses in transit) covering the insurable interest of Owner, Engineer, and their respective contractors and subcontractors of every tier. Coverage is to insure generally against "all risks'' of direct physical loss of, or damage to, the Project, permanent and temporary structures at the Jobsite used in connection with the Project, materials, equipment and supplies to be incorporated into the Project while such property is in transit by land, air and inlet water conveyance from points or places in the continental United States or Canada, to and from, and while in the course of construction at, the Jobsite. Contractor shall, however, at its own expenses pay, subject to a maximum amount of $10,000 per occurrence, any deductible applicable to the Builder's Risk Insurance. Contractor however, may be responsible for more than 510,000 per occurrence should a specific loss be such that the cause of loss i s not insured under the Bidder's Risk policy, or the a mount of loss exceeds the amount of insurance available. Should more than one insured be involved in a single occurrence covered by this insurance, eacb insured shall assume the same portion of the deductible amount that their portion of the loss bears to the total loss. Should owner elect to purchase Builder's Risk Insurance with deductible in excess of $10,000 per occcurrence, to the extent the loss would have been covered but for the selection of a higher deductible by Owner, Owner shall be responsible for that

Taxes

portion of the loss in excess of 510,000 up to the amount of deductible by Owner, Owner shall be responsible for that portion of the loss in excess of 510,000 up to the amount of deductible selected. Except with respect to Owner's responsibility for the excess deductible portion, however, Owner's agreement to provide the Builder's Risk Insurance shall in no way transfer the risk of loss to Owner. The Builder's Risk Insurance shall contain waivers of subrogation in favor of Contractor and its Subcontractors. At Contractor's request, a copy of the Builder's Risk Insurance Policy will be made available by Owner for Contractor's inspection at Owner's office. Contractor shall provide owner with a copy of insurance policies, if any, which Contractor obtains due to the $10,000 deductible included in Owner's Builder's Risk Insurance Policy. Nothing herein shall obligate Owner to obtain Builders Risk Insurance until such time a s actual commencement of shipments of Equipment from the manufacturing facility to the Jobsite or construction at the Jobsite, other than site preparation, whichever is earlier.

Risk of loss or damage for each item of the Equipment shall pass to Owner upon arrival on carrier at the Jobsite or at the storage location specified except when Contractor's Work includes installation or erection of the Equipment, in which case Contractor shall retain risk of loss or damage for each item until trial operation.

After any loss or damage for which Contractor shall have risk of loss or damage, Contractor shall, with due diligence and dispatch, repair or replace the lost or damaged items at its own expense. This provision shall not be construed to prevent Contractor from recovering the proceeds of any applicable insurance covering such a loss or damage.

This section is used by an owner to advise the contractor of its tax status

for the equipment being purchased. Tax exemption certificates etc. should be

included in this area in order to avoid future problems.

Warranties

An electrostatic precipitator is an expensive and complex piece of

equipment. In order to obtain the proper warranty coverage, it is prudent

that a strong warranty provision be included in a Contract. The following

warding i s illustrative of such a warranty provision for a deliver and erect

contract:

WARRANTIES

C o n t r a c t o r w a r r a n t s t o Owner t h a t a l l Equipment f u r n i s h e d under t h i s C o n t r a c t s h a l l be : a) f r e e f rom d e f e c t s i n d e s i g n , m a t e r i a l and workmanship; b ) s u i t a b l e f o r t h e use and purpose s p e c i f i e d o r r e f e r r e d t o i n t h i s C o n t r a c t ; c ) s u i t a b l e f o r any o t h e r use o r purpose as rep resen ted i n w r i t i n g by C o n t r a c t o r ; d) i n conformance w i t h t h e Drawings, S p e c i f i c a t i o n s and d e s i g n c r i t e r i a s u p p l i e d t o C o n t r a c t o r by Owner; and e) new and o f f i r s t - c l a s s q u a l i t y . C o n t r a c t o r s h a l l , a t i t s expense, c o r r e c t any d e f e c t s which may appear i n t h e Work d u r i n g per formance o f t h e Work o r anyt ime p r i o r t o t h e d a t e t h i r t y - t h r e e (33 ) months a f t e r t h e Commercial O p e r a t i o n Date s t a t e d i n t h i s C o n t r a c t ; p r o v i d e d , however, t h a t t h e f o r e g o i n g w a r r a n t y p e r i o d s h a l l be extended by an amount o f t i m e equal t o any downtime r e s u l t i n g f r o m a b reach o f t h i s w a r r a n t y and t h a t shou ld t h e Work be r e p a i r e d o r r e p l a c e d , pu rsuan t t o t h i s A r t i c l e , t h e a f f e c t e d p o r t i o n t h e r e o f s h a l l be s i m i l a r l y war ran ted f o r an a d d i t i o n a l p e r i o d t w e l v e (12) months f rom t h e t i m e o f such r e p a i r o r rep lacement . C o n t r a c t o r ' s l i a b i l i t y under t h i s s e c t i o n f o r c o r r e c t i o n o f d e f e c t s i n t h e Work s h a l l i n no even t exceed t h e c o s t o f r e p a i r o r rep lacement o f such d e f e c t i v e Work, i n ~ l u d i n g c o s t o f removal , supp ly , t r a n s p o r t a t i o n and r e i n s t a l l a t i o n . Where e i t h e r r e p a i r o r rep lacement i s f e a s i b l e and Owner d e s i r e s t h e more c o s t l y a l t e r n a t i v e , C o n t r a c t o r s h a l l p roceed i n accordance w i t h the d e s i r e s o f Owner, and t h e P a r t i e s w i l l m u t u a l l y agree upon t h e a d d i t i o n a l compensat ion t o be p a i d t o C o n t r a c t o r . C o n t r a c t o r s h a l l bear a l l f i e l d c o s t s , i n c l u d i n g a p p l i c a b l e overhead, i n c u r r e d i n c o n n e c t i o n w i t h c o r r e c t i n g d e f e c t s i n t h e Work. W i t h r e g a r d t o premiums f o r o v e r t i m e , m u l t i p l e s h i f t s and o t h e r t i m e p a i d f o r b u t n o t worked: 1) C o n t r a c t o r s h a l l n o t be r e s p o n s i b l e f o r such premiums i f t h e c o r r e c t i v e a c t i o n c o u l d be per formed w i t h o u t premiums d u r i n g a schedu led outage o f t h e Work; and 2) C o n t r a c t o r s h a l l be r e s p o n s i b l e f o r such premiums i f Owner d i r e c t s t h a t c o r r e c t i v e a c t i o n be t a k e n on an o v e r t i m e o r m u l t i p l e s h i f t b a s i s as t h e r e s u l t o f an emergency shutdown o f t h e Work. Emergency shutdown i s d e f i n e d as a f o r c e d outage r e s u l t i n g f rom a w a r r a n t y d e f e c t n e c e s s i t a t i n g immediate shutdown o f t h e Work. I f t h e necessary c o r r e c t i v e a c t i o n cannot be pe r fo rmed immed ia te l y due t o t h e i n a b i l i t y t o shu t down t h e o p e r a t i o n o f t h e Work, C o n t r a c t o r ' s r e s p o n s i b i l i t y t o pe r fo rm t h e c o r r e c t i v e a c t i o n w i l l e x t e n d u n t i l such t i m e when i t can be completed. Owner w i l l , t o t h e e x t e n t p r a c t i c a b l e , g i v e C o n t r a c t o r n o t i c e o f when C o n t r a c t o r may, a t a t i m e conven ien t t o Owner, o e r f o r m such c o r r e c t i v e a c t i o n .

There s h a l l be no b reach o f w a r r a n t y hereunder t o t h e e x t e n t t h a t i t is demonst ra ted t h a t a d e f e c t i s caused by improper i n s t a l l a t i o n o f Equipment f u r n i s h e d , b u t n o t i n s t a l l e d , by C o n t r a c t o r o r i t s s u b c o n t r a c t o r s o r by t h e improper use o r maintenance o f t h e Equipment. Use o r maintenance s h a l l be i n accordance w i t h C o n t r a c t o r ' s O p e r a t i o n and Maintenance I n s t r u c t i o n s whicb have been rev iewed and accepted b y Owner and i n accordance w i t h g e n e r a l l y accep ted u t i l i t y p r a c t i c e s .

i f , i n s t e a d o f r e q u i r i n g c o r r e c t i o n o r removal and rep lacement o f d e f e c t i v e Work, Owner p r e f e r s t o accep t i t , i t may do so. I n such case, i f acceptance occurs p r i o r t o r e m i t t a n c e o f f i n a l payment, a Change Order s h a i l be i s s u e d i n c o r p o r a t i n g t h e necessary r e v i s i o n s i n t h i s C o n t r a c t , i n c l u d i n g a p p r o p r i a t e r e d u c t i o n i n t h e C o n t r a c t P r i c e , o r , i f t h e acceptance occurs a f t e r f i n a l payment, an a p p r o p r i a t e amount s h a l l be p a i d t o Owner by C o n t r a c t o r .

Owner s h a l l have t h e r i g h t t o use t h e Work, o r p a r t t h e r e o f , wh ich may r e q u i r e c o r r e c t i o n , rep lacement o r r e p a i r by C o n t r a c t o r u n t i l such t i m e as Owner may c o n v e n i e n t l y remove f r o m s e r v i c e such Work, o r p a r t t h e r e o f , as may r e q u i r e c o r r e c t i o n , r e p a i r o r rep lacement . C o n t r a c t o r s h a l l n o t be r e s p o n s i b l e f o r any d e f e c t s wh ich may o c c u r d u r i n g and be a t t r i b u t a b l e t o such use b y Owner, u n l e s s o t h e r w i s e agreed t o i n w r i t i n g by C o n t r a c t o r .

I f C o n t r a c t o r f a i l s t o r e p l a c e o r c o r r e c t any d e f e c t i v e Work w i t h i n a reasonab le t i m e p e r i o d f o l l o w i n g r e c e i p t o f w r i t t e n n o t i c e t o C o n t r a c t o r f r o m Owner, Owner may, a t i t s o p t i o n , cause such d e f e c t i v e Work t o be r e p l a c e d o r c o r r e c t e d and a l l d i r e c t and i n d i r e c t c o s t s and expenses, i n c l u d i n g c o s t s f o r a d d i t i o n a l p r o f e s s i o n a l s e r v i c e s , i n c u r r e d i n c o n n e c t i o n t h e r e w i t h s h a l l be borne by C o n t r a c t o r .

CONTRACTOR AND OWNER AGREE THAT, I N CONSIDERATION OF THE WARRANTIES AND GUARANTEES STATED I N THIS CONTRACT, ALL OTHER WARRANTIES AND GUARANTEES, OTHER THAN TITLE, EITHER EXPRESSED OR IMPLIED, WHETHER ARISING UNDER LAW OR EQUITY OR CUSTOM OF THE TRADE, INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE EXCLUDED FRDN THIS CONTRACT.

L i m i t a t i o n Of L i a b i l i t y

T h i s p o r t i o n c f t h e te rms and c o n d i t i o n s i s used t o s e t f o r t h t h o s e areas

where an owner i s l i m i t i n g a c o n t r a c t o r ' s l o s s due t o d e l a y , t e r m i n a t i o n , o r

suspension o f t h e c o n t r a c t . Converse ly , t h i s s e c t i o n a l s o s e t s f o r t h those

a reas where a c o n t r a c t o r l i m i t s an o w n e r ' s l o s s due t o d e l a y s o r poor

per formance on t h e c o n t r a c t o r ' s p a r t . The f o l l o w i n g w o r d i n g i s i l l u s t r a t i v e

o f such a l i m i t a t i o n o f l i a b i l i t y f o r a d e l i v e r and e r e c t c o n t r a c t . I t must

be no ted i n a l l cases, t h a t an owner 's l e g a l and i n s u r a n c e s t a f f s must be

c o n s u l t e d d u r i n g t h e development o f t h i s s e c t i o n .

LIMITATION OF LIABILITY

Except as o t h e r w i s e e x p r e s s l y p r o v i d e d i n t h i s C o n t r a c t , i n no e v e n t s h a l l Owner be l i a b l e ( i n C o n t r a c t o r i n t o r t i n c l u d i n g n e g l i g e n c e ) t o C o n t r a c t o r f o r c o n s e q u e n t i a l damages, i n c l u d i n g , b u t n o t l i m i t e d t o , i n t e r e s t o r c a r r y i n g charges on i t s i nves tmen t , expenses a r i s i n g from c o s t s o f c a p i t a l , l o s s o r p r o f i t s on work n o t performed, o r f o r l o s s o f use o f , o r u n d e r - u t i l i z a t i o n o f l a b o r , equipment o r f a c i 1 i t i e s o f C o n t r a c t o r , r e s u l t i n g f r o m Owner1 s performance, nonperformance, o r d e l a y i n per formance o f i t s o b l i g a t i o n s under t h i s C o n t r a c t , o r f rom Owner's de lay , t e r m i n a t i o n o r suspension o f t h e Work under t h i s C o n t r a c t .

I n no e v e n t s h a l l C o n t r a c t o r , o r i t s s u b c o n t r a c t o r s o f any t i e r , be l i a b l e ( i n C o n t r a c t o r i n t o r t i n c l u d i n g n e g l i g e n c e ) t o Owner f o r consequen t ia l damages i n c l u d i n g b u t n o t l i m i t e d t o i n t e r e s t o r c a r r y i n g charges on i t s i nves tmen t , expenses a r i s i n g f rom c o s t o f c a p i t a l , l o s s o f p r o f i t s o r revenue, l o s s o f a n t i c i p a t e d p r o f i t s , c l a i m s o f customers r e l a t e d t o e l e c t r i c a l s e r v i c e , o r c o s t o f purchased o r rep lacement power r e s u l t i n g f rom C o n t r a c t o r ' s performance, nonperformance o r d e l a y i n per formance o f i t s o b l i g a t i o n s under t h i s C o n t r a c t .

The p r o v i s i o n s o f t h i s pa rag raph s h a l l n o t be a p p l i c a b l e t o d i r e c t p r o p e r t y damage caused b y a b reach o f C o n t r a c t o r ' s w a r r a n t y o r t r a n s p o r t a t i o n c o s t t h e r e under , p e r s o n a l i n j u r y , b o d i l y i n j u r y , death , o r l i q u i d a t e d damages and/or f o r f e i t u r e o f economic assessments f o r f a i l u r e t o meet ~ e r f o r m a n c e w a r r a n t y . o r f i n e s f o r C o n t r a c t o r ' s v i o l a t i o n o f OSHA o r o t h e r laws o r reg;iations.

The p r o v i s i o n s o f t h i s S e c t i o n and any o t h e r p r o v i s i o n o f t h i s C o n t r a c t p r o v i d i n g f o r l i m i t a t i o n o f o r p r o t e c t i o n a g a i n s t l i a b s h a l l a p p l y t o t h e f u l l e x t e n t p e r m i t t e d by law .

The p r o v i s i o n s o f t h i s S e c t i o n and any o t h e r p r o v i s i o n s o f t h i s C o n t r a c t p r o v i d i n g f o r l i m i t a t i o n o f o r p r o t e c t i o n a g a i n s t l i a b i l i t i e s between t h e P a r t i e s h e r e t o s h a l l s u r v i v e t e r m i n a t i o n o f t h i s C o n t r a c t o r c o m p l e t i o n o f t h e Work hereunder .

Repor ts and Schedul i nq

T h i s s e c t i o n e s t a b l i s h e s t h e r e q u i r e m e n t s f o r t h e t y p e o f r e p o r t s t o be

submi t ted by a c o n t r a c t o r t o an owner. The r e p o r t s must i n c l u d e a v a i l a b

and s t a t u s o f m a t e r i a l and equipment and components i n c l u d i n g d e l i v e r y d

The r e p o r t s shou ld a1 so i n c l u d e d r a w i n g s t a t u s and s u b m i t t a l schedules,

i l i t y

a t e s .

e x p e d i t i n g e f f o r t s , f a b r i c a t i o n s t a t u s , and t e s t d a t e s t o a l l o w t h e Owner t o

adequate ly p l a n inhouse work l o a d s and make p l a n s t o w i t n e s s t h e t e s t i n g o f

components.

Patents

This sec t ion of t he terms of condi t ions addresses the p ro t ec t ion t h a t a

c o n t r a c t must a f f o r d t o an owner f o r pa t en t infr ingement , copy r i g h t

infr ingement , e t c . I t o u t l i n e s those a r e a s in which an owner i s t o be

pro tec ted from harm from t h i r d p a r t i e s due t o infringement s o l e l y o r p a r t l y on

a c o n t r a c t o r ' s p a r t . The following wording desc r ibes those t ypes of a r ea s and

circumstances t h a t must be addressed. I t i s t he r e s p o n s i b i l i t y of an owner's

legal and purchasing departments t o develop s p e c i f i c wording which i s i n

conformance wi th an owner's corporate po l i cy

PATENTS

Contrac tor s h a l l a t i t s own expense defend, indemnify, save harmless and pay any and a l l awards of damages assessed a g a i n s t Owner or Engineer, and t h e i r r e spec t ive members, d i r e c t o r s , o f f i c e r s , agents , and employees, o r any of them, from and a g a i n s t l i a b i l i t y o r l o s s , including but not l imi ted t o any c la ims , judgements, c o u r t c o s t s and a t t o r n e y s ' f e e s incurred in any c la ims , o r any p r e t r i a l , t r i a l o r a p p e l l a t e proceedings on account of infr ingements of p a t e n t s , copyrighted o r uncopyrighted works, s e c r e t processeq, t r a d e s e c r e t s , pa ten ted o r unpatented inven t ions , a r t i c l e s o r app l i ances , o r a l l e g a t i o n s t h e r e o f , pe r t a in ing t o the Work, o r any p a r t t h e r e o f , combinations t h e r e o f , processes t h e r e i n or t he use of any t o o l s o r implements used by Cont rac tor . For one d o l l a r ($1.00) acknowledged t o be included and paid f o r in t h e Contract Pr ice and o t h e r good and va luable cons ide ra t i ons , Cont rac tor agrees t o indemnify and hold harmless Owner, Engineer and t h e i r r e spec t ive o f f i c e r s , agen t s and employees, i n accordance with t h e provis ions of t h i s Paragraph.

Contractor s h a l l , a t i t s own expense, procure f o r Owner t h e r i g h t t o continue use of t h e Work, p a r t s o r combinations t h e r e o f , o r processes used t h e r e i n r e s u l t i n g from a s u i t o r judgement on account of pa t en t o r copyright infr ingement t h e r e i n .

i f , i n any such s u i t o r proceeding, a temporary r e s t r a i n i n g order or pre l iminary in junc t ion i s g r an t ed , Contractor sha l l make every reasonable e f f o r t , by g iv ing a s a t i s f a c t o r y bond o r o the rwi se , t o secure t he suspension of such r e s t r a i n i n g o rde r o r temporary i n junc t ion .

I f , i n any such s u i t o r proceeding, t h e Work, any p a r t t h e r e o f , combination t h e r e o f , o r process t h e r e i n i s held t o c o n s t i t u t e an infr ingement and i t s use i s permanently en jo ined , Cont rac tor s h a l l , a t once, make every reasonable e f f o r t t o secure f o r Owner a l i c ense , a t no expense t o Owner, au tho r i z ing the continued use of t h e Work, p a r t t he reo f o r process t h e r e i n . I f Contractor f a i l s t o secure such l i c e n s e f o r Owner, Contractor s h a l l , a t i t s own expense, r ep l ace the Work, p a r t o r combination t h e r e o f , o r process t h e r e i n , wi th non-infr inging Work, o r modify t h e Work, p a r t o r combination

t h e r e o f , or process t h e r e i n , i n a way s a t i s f a c t o r y t o Owner, so t h a t t h e Work i s non-infr inging.

Termination f o r Convenience

This a r e a of t h e terms and condi t ions al lows an owner t o terminate a Contract

a t h i s convenience f o r reasons o t h e r than a c o n t r a c t o r ' s d e f a u l t . An owner

w i l l be ob l iga t ed t o pay t h a t por t ion of a con t r ac t p r i ce corresponding t o t h e

amount of work completed t o the owner's s a t i s f a c t i o n , along with any c o s t s

incurred by a Cont rac tor in terminat ing. a con t r ac t . A con t r ac to r , upon

r e c e i p t of a "Notice of Termination," i s ob l iga ted t o s top work a s speci

under t h e n o t i c e of terminat ion. This no t i ce of terminat ion may be used

te rmina te a l l o r only por t ions of t h e work. A con t r ac to r i s f u r t h e r obl

t o cancel a l l subcont rac tor work and purchase orders and then begin t u r n

i ed

t 0

gated

over equipment, m a t e r i a l , t o o l s , e t c - , f o r which payment has been received t o

an owner.

Termination f o r Defaul t

In t he event a c o n t r a c t o r f a i l s t o perform work in accordance with a con t r ac t

and c o n t r a c t schedules , o r in t he event of a c o n t r a c t o r ' s bankruptcy,

insolvency, e t c . , an owner r e t a i n s t he r i g h t t o terminate a c o n t r a c t f o r

d e f a u l t . The fol lowing i s i l l u s t r a t i v e wording f o r a n owner's remedies and

r i g h t s :

TERMINATION FOR DEFAULT

The Owner may, by wr i t t en no t i ce of d e f a u l t t o t he Cont rac tor , t e rmina te t h e whole o r any p a r t of t h i s Contract in any one of the fol lowing circumstances:

i - i f t he Contractor f a i l s t o perform the Work c a l l e d f o r by t h i s Cont rac t within t h e tirne(s) spec i f i ed herein o r any extension t h e r e o f , o r

i i - i f t he Contractor f a i l s t o perform any of the o t h e r provis ions of t h i s Contract , o r so f a i l s t o make progress a s t o endanger performance of t h i s Cont rac t in accordance with i t s terms, o r

i i i - i f t he Contractor r e f u s e s t o perform the requirements of the Cont rac t o r repudia tes i t s ob l iga t ion t o perform under t h i s Con t r ac t , o r

i v - i n the event of Con t r ac to r ' s bankruptcy, inso lvency , assignment f o r t he b e n e f i t of c r e d i t o r s , o r of a p e t i t i o n o r a p p l i c a t i o n by o r a g a i n s t i t f o r r eo rgan iza t ion , d i s s o l u t i o n o r l i q u i d a t i o n , o r in the event a r ece ive r o r t r u s t e e i s appointed f o r any of i t s p roper ty , o r i f t h e r e i s any at tachment o r levy aga ins t o r upon t h e person o r property of Con t r ac to r , o r i f any judgement i s rendered aga ins t Cont rac tor which i s unbonded, unstayed, and i f i n any of t he se circumstances t h e Cont rac tor does not c o r r e c t such f a i l u r e wi th in a period of t en (10 ) calendar days a f t e r r e c e i p t of n o t i c e from t h e Owner spec i fy ing such f a i l u r e .

Owner reserves t h e r i g h t t o provide f o r immediate t e rmina t ion in t h e event o f ( i v ) above i f the Owner cons ide r s t h i s t o be i n i t s b e s t i n t e r e s t .

I f t he Contractor does n o t c o r r e c t any of t he se circumstances within a period of t en (10) calendar days a f t e r r e c e i p t of n o t i c e from the Owner, the Owner r e se rves t h e r i g h t t o execute an immediate Contract te rmina t ion .

In t he event of any such te rmina t ion , Owner s h a l l immediately serve no t i ce thereof upon Contractor and Sure ty i f e r e c t i o n i s requi red under t h i s Contract and wherein Surety s h a l l have t h e r i g h t t o take over and perform the Contract , provided, however, t h a t Sure ty commences performance thereof within t h i r t y (30) ca lendar days from t h e d a t e of t he mailing t o such Surety of no t ice of t e rmina t ion .

Owner may procure, upon such terms and in such manner a s t h e Owner may deem approp r i a t e , work, suppl ies o r s e rv i ce s s i m i l a r t o those so te rmina ted , and Contractor and i t s Su re ty , i f e r e c t i o n i s r equ i r ed , s h a l l be l i a b l e t o t h e Owner f o r any excess c o s t s occasioned thereby.

The Contractor s h a l l cont inue the performance of t h i s Cont rac t t o t he ex t en t not terminated under t h e p rov j s ions of t h i s Sec t ion .

I f t h i s Contract i s terminated a s provided under t h i s S e c t i o n , t he Owner i n addi t ion t o any o ther r i g h t s provided in t h i s c l a u s e , may r equ i r e the Contractor t o t r a n s f e r t i t l e and d e l i v e r t o t h e Owner, i n t h e manner and t o t h e e x t e n t d i r e c t e d by t h e Owner any completed s u p p l i e s , any p a r t i a l l y completed supp l i e s and m a t e r i a l s , p a r t s , t o o l s , d i e s , j i g s , f i x t u r e s , p l ans , drawings, and informat ion , and Cont rac t r i g h t s ( h e r e i n a f t e r ca l l ed "manufacturing mater ia l s" ) a s t h e Contractor has s p e c i f i c a l l y produced o r s p e c i f i c a l l y acquired f o r t he performance of such p a r t of t h i s Contract a s has been terminated. The Contractor s h a l l , upon d i r e c t i o n of t h e Owner, p r o t e c t and preserve property in t he possession of t h e Cont rac tor i n which the Owner has an i n t e r e s t . Payment f o r completed supp l i e s de l ive red t o and accepted by the Owner s h a l l be a t t h e Cont rac t P r i ce .

Payment f o r m a n u f a c t u r i n g m a t e r i a l s d e l i v e r e d t o and accep ted by t h e Owner and f o r t h e p r o t e c t i o n and p r e s e r v a t i o n o f p r o p e r t y s h a l l be i n an amount agreed upon b y t h e C o n t r a c t o r and Owner. The Owner may w i t h h o l d f r o m amounts o t h e r w i s e due t h e C o n t r a c t o r f o r such completed s u p p l i e s o r m a n u f a c t u r i n g m a t e r i a l s such sum as t h e Owner de te rm ines t o be necessary t o p r o t e c t t h e Owner a g a i n s t l o s s because o f o u t s t a n d i n g l i e n s o r c l a i m s o r fo rmer l i e n h o l d e r s .

- I f , a f t e r n o t i c e o f t e r m i n a t i o n o f t h i s C o n t r a c t under t h e p r o v i s i o n s o f t h i s Sec t ion , i t i s de te rm ined f o r any reason t h a t t h e C o n t r a c t o r was n o t i n d e f a u l t under t h e p r o v i s i o n s o f t h i s c lause , t h e r i g h t s and o b l i g a t i o n s o f t h e p a r t i e s s h a l l be t h e same as i f t h e n o t i c e o f t e r m i n a t i o n had been i s s u e d p u r s u a n t t o t h e s e c t i o n o f t h e C o n t r a c t e n t i t l e d , " T e r m i n a t i o n f o r Convenience".

The r i g h t s and remedies o f t h e Owner p r o v i d e d i n t h i s c l a u s e s h a l l n o t be e x c l u s i v e and a r e i n a d d i t i o n t o any o t h e r r i g h t s and remedies p r o v i d e d by law o r under t h i s C o n t r a c t .

Upon t e r m i n a t i o n o f t h i s C o n t r a c t , a l l o f t h e te rms and p r o v i s i o n s o f t h e C o n t r a c t s h a l l remain i n f u l l f o r c e and e f f e c t as t o a l l m a t e r i a l o r e a u i ~ m e n t d e l i v e r e d h e r e i n t o Owner p r i o r t o , o r i n , 6

connec t ion w i t h , such t e

Suspension o f Work

T h i s s e c t i o n o f t h e te rms and cond

n i n a t i o n .

t i o n s a1 lows t h e Owner t o suspend,

i n t e r r u p t o r d e l a y any p a r t o r o r a l l o f t h e work f o r any reason, upon w r i t t e n

n o t i c e t o t h e C o n t r a c t o r . The n o t i c e s h o u l d i n c l u d e t h e reason f o r t h e

suspension and i t s expec ted d u r a t i o n . The C o n t r a c t o r shou ld t h e n a d v i s e t h e

Owner o f t hose p o r t i o n s o f work which, i n t h e C o n t r a c t o r ' s o p i n i o n , a r e i n

such a s t a t e a s t o r e q u i r e c o m p l e t i o n t o a v o i d a d d i t i o n a l c o s t s . The Owner

w i l l t h e n a d v i s e t h e C o n t r a c t o r o f i t s d e c i s i o n as t o whe the r t o proceed.

The C o n t r a c t o r must resume a l l work when so d i r e c t e d by t h e Owner, and t h e

d e l i v e r y schedule and t i m e f o r per formance i s t o be r e v i s e d f o r a p e r i o d o f

t i m e necessary t o overome t h e e f f e c t o f t h e d e l a y . F u r t h e r , t h e C o n t r a c t o r

shou ld be e n t i t l e d t o reimbursement f o r r e a s o n a b l e a d d i t i o n a l c o s t s i n c u r r e d

due t o t h e d e l a y .

Inspec t ion and T e s t s

This s e c t i o n o u t l i n e s t h e Owner'? r i g h t s r e l a t i v e t o making inspec t ions and

the wi tness ing of t e s t s . I t a l s o o b l i g a t e s t h e Contractor t o provide acccess

f o r Owner's inspec t ion r e p r e s e n t a t i v e s and t o inform t h e Owner p r i o r t o t h e

performance of any t e s t s . A determinat ion by the Owner a s t o what types of

i n spec t ion w i l l be performed and which t e s t s w i l l be witnessed must be made in

conjunct ion with Owner's Q u a l i t y Assurance/Control s t a f f s . Addi t iona l ly , i t

i s i n t h i s s ec t ion t h a t t h e Contractor i s informed t h a t f a i l u r e of t h e Owner

t o w i tnes s any t e s t s does no t r e l i e v e t he Contractor of i t s ob l iga t ion t o

f u l f u l l t h e requirements of t h e Cont rac t , nor i s i t t o be construed a s

acceptance of t he work.

Force Ma j e u r e

Th i s s e c t i o n of the terms and cond i t i ons addresses de l ays o r nonperformance

due t o e v e n t s not reasonably wi th in t h e cont ro l o r not reasonably forseeable

by e i t h e r o r both p a r t i e s . Such events may be f i r e , f l ood , war, r i o t , a c t s of

God, e t c . Neither pa r ty would be considered i n d e f a u l t f o r nonperformance due

t o t h e occurrence of such an event . The fol lowing i l l u s t r a t i v e wording

d e s c r i b e s those events which may be addressed. Again, i t i s t he

r e s p o n s i b i l i t y of t he Owner's Legal and Purchasing Departments t o develop

s p e c i f i c wording.

FORCE MAJEURE

Performance of t h i s Contract by both Owner and Cont rac tor sha l l be pursued with due d i l i g e n c e in a l l requirements hereof ; however, n e i t h e r Owner nor Cont rac tor sha l l be considered in d e f a u l t in t he performance of i t s o b l i g a t i o n s under t h i s Cont rac t t o t h e e x t e n t t h a t such performance i s prevented o r delayed by causes not reasonably w i t h i n i t s cont ro l and not reasonably forseeable o r , i f f o r seeab le , cannot be avoided by t h e exe rc i s e of a l l reasonable e f f o r t s , inc luding but no t l imi ted t o , a c t of c i v i l o r m i l i t a r y a u t h o r i t y (incTuding but no t l imi ted t o c o u r t s o r admnis t ra t ive agencies ) ; a c t s of God; war; r i o t ; i n s u r r e c t i o n ; i n a b i l i t y t o secure approval , v a l i d a t i o n o r s a l e of bonds; i n a b i l i t y t o obta in any required permi ts , l i c e n s e s o r zoning; blockades; embargoes; sabotage; epidemics; f i r e s ; f loods ; s t r i k e s ; lockouts ; o r c o l l e c t i v e bargaining. In t h e event of any delay r e s u l t i n g from such cause the time f o r performance of each of the P a r t i e s hereunder ( inc luding the

payment o f monies i f such e v e n t a c t u a l l y p r e v e n t s payment) s h a l l be extended f o r a p e r i o d o f t i m e r e a s o n a b l y necessary $0 overcome t h e e f f e c t o f such d e l a y s .

I n t h e e v e n t o f any d e l a y o r nonperformance caused by t h e above causes, t h e P a r t y a f f e c t e d s h a l l p r o m p t l y n o t i f y t h e o t h e r i n w r i t i n g o f t h e n a t u r e , cause, d a t e o f commencement and t h e a n t i c i p a t e d e x t e n t o f such d e l a y , and s h a l l i n d i c a t e t h e e x t e n t , i f any, t o w h i c h i t i s a n t i c i p a t e d t h a t any d e l i v e r y o r c o m p l e t i o n d a t e s w i l l be a f f e c t e d t h e r e b y .

L i e n s

T h i s s e c t i o n i s used b y an owner t o i n f o r m a c o n t r a c t o r t h a t a l l m a t e r i a l ,

equipment and l a b o r i s t o be p r o m p t l y p a i d f o r by t h e c o n t r a c t o r i n o r d e r t o

keep i t f r e e and c l e a r f r o m m a t e r i a l m e n ' s and workmen's l i e n s . A c o n t r a c t o r

must h o l d an owner harmless f rom any and a l l c l a i m s a r i s i n g o u t o f any such

c l a i m s . T h i s s e c t i o n f u r t h e r r e q u i r e s t h e C o n t r a c t o r t o p r o v i d e t h e Owner

w i t h a f f i d a v i t s t o t h e e f f e c t t h a t a l l b i l l s have been p a i d .

Compliance w i t h Codes, P e r m i t s , Laws, and L i censes

T h i s s e c t i o n i n s t r u c t s a c o n t r a c t o r as t o h i s r e s p o n s i b i l i t y t o comply w i t h

a l l a p p l i c a b l e l aws , r u l e s , r e g u l a t i o n s , codes, and s tandards o f a l l f e d e r a l ,

s t a t e , l o c a l and m u n i c i p a l agenc ies t h a t c o u l d i n any way a f f e c t t h e work . A

c o n t r a c t o r must a l s o comply w i t h any f u t u r e changes i n laws wh ich c o u l d a f f e c t

t h e work , b u t he s h a l l be compensated f o r any a d d i t i o n a l c o s t s and schedule

changes a r i s i n g t h e r e f r o m .

A d d i t i o n a l l y , a c o n t r a c t o r must h o l d an owner harmless f rom any damages,

l o s s e s , e t c , , o c c u r r i n g f r o m a c o n t r a c t o r ' s noncompl iance w i t h any o f t h e

laws , r u l e s , r e g u l a t i o n s , codes, e t c .

A p p l i c a b l e S t a t e Law

T h i s s e c t i o n s t a t e s t h a t a c o n t r a c t s h a l l be i n t e r p r e t e d and governed i n a l l

r e s p e c t s by t h e laws o f a p a r t i c u l a r S t a t e s p e c i f i e d b y an owner.

Changes and Extra Work

This s ec t ion of t h e commercial terms and condi t ions adv i se s a c o n t r a c t o r t h a t

an owner may, a t any t ime, make changes within t h e general scope of t he

con t r ac t i n t h e form of a wr i t t en change order . When any such change causes

an increase o r decrease in t h e cos t and/or a f f e c t s t h e time requi red f o r a

c o n t r a c t o r ' s performance, an equ i t ab l e adjustment i n the p r i c e and/or d e l i v e r y

schedule must be made. I t i s customary t o give a c o n t r a c t o r 30 ca l enda r days

no t i ce t o respond wi th t he a f f e c t an owner's change may have on a c o n t r a c t .

Assignments and Subcontracts

This s ec t ion prevents t he Contractor from subcontract ing o r ass igning t h e

Contract t o o t h e r p a r t i e s without t he p r i o r wr i t t en approval of t h e Owner.

Unless a s p e c i f i c item i s t o be suppl ied by a so l e subcont rac tor a s s p e c i f i e d

i n t he Con t r ac t , t h e Contractor must provide a l i s t o f p o t e n t i a l

subcont rac tors f o r the Owner's apprc 11 p r i o r t o Cont rac t Award and p re fe rab ly

i n t he C o n t r a c t o r ' s proposal .

In t he even t t he Contract i s assigned by e i t h e r pa r ty , t h e Cont rac t s h a l l be

binding on t h e ass ignee and must be c a r r i e d through t o completion.

P rop r i e t a ry Information

This s ec t ion of t h e terms and cond i t i ons s t a t e s t h a t a l l drawings,

s p e c i f i c a t i o n s , t echnica l d a t a , and any information fu rn i shed t o a c o n t r a c t o r

by an owner a r e and sha l l remain the property of t h e owner. A c o n t r a c t o r i s

no t permit ted t o use t h e drawings, s p e c i f i c a t i o n s , e t c . f o r any purposes o t h e r

than t h a t d i r e c t l y r e l a t e d t o t h e work required by a c o n t r a c t . The drawings,

s p e c i f i c a t i o n s , e t c . , a r e not t o be d i sc lo sed t o t h i r d p a r t i e s o r used i n a

manner which could be de t r imenta l t o an owner, and they a r e t o be r e tu rned

upon r eques t a t t h e completion of work.

A con tac to r i s t o provide f o r t he se same r e s t r i c t i o n s i n any of i t s

subcont rac ts .

Nonwaiver

T h i s s e c t i o n s t a t e s t h a t a f a i l u r e o f e i t h e r p a r t y t o i n s i s t upon s t r i c t

per formance o f any o f t h e p r o v i s i o n s o f a c o n t r a c t , d e l a y i n e x e r c i s i n g any o f

e i t h e r p a r t y ' s r i g h t s o r remedies p r o v i d e d i n a c o n t r a c t o r by law s h a l l n o t

c o n s t i t u t e a w a i v e r o r r e l e a s e by e i t h e r p a r t y o f i t s o b l i g a t i o n s under a

c o n t r a c t .

N o t i c e s and Correspondence

T h i s s e c t i o n i s t o l i s t t h e names o f i n d i v i d u a l s who a r e t o r e c e i v e

cor respondence, t h e i r addresses, and t h e r e s p e c t i v e number o f c o p i e s each i s

t o r e c e i v e .

Equal Employment O p p o r t u n i t y and A f f i r m a t i v e A c t i o n

T h i s s e c t i o n addresses t h e r e q u i r e m e n t f o r a c o n t r a c t o r t o conform t o

a p p l i c a b l e r e q u i r e m e n t s o f a l l f e d e r a l , s t a t e and l o c a l laws, o rd inances ,

r u l e s , and r e g u l a t i o n s r e l a t i n g t o equal employment o p p o r t u n i t y . A

c o n t r a c t o r ' s s u b c o n t r a c t o r s must a l s o conform t o t h i s requ i remen t .

Occupa t iona l S a f e t y and H e a l t h A c t

T h i s s e c t i o n d e a l s w i t h t h e r e q u i r e m e n t t h a t t h e equipment s u p p l i e d by a

c o n t r a c t o r c o m p l i e s w i t h , and i n no way p r e v e n t s an owner f rom comply ing w i t h

OSHA 1970. The f o l l o w i n g i s an example:

OCCUPATIONAL SAFETY AND HEALTH ACT

C o n t r a c t o r ' s Equipment s h a l l comply w i t h , and i n no way p r e v e n t Owner 's comp l iance w i t h t h e OccupationaT S a f e t y and H e a l t h A c t o f 1970 and a l l r e g u l a t i o n s and s tandards p romu lga ted the reunder i n e f f e c t on t h e d a t e o f t h i s C o n t r a c t . C o n t r a c t o r s h a l l n o t be r e s p o n s i b l e f o r f a i l u r e t o comply w i t h t h e A c t , r e g u l a t i o n s and s tandards t o t h e e x t e n t such f a i l u r e r e s u l t s f rom t h e f a i l u r e o f Owner t o p r o p e r l y l o c a t e , opera te , use, o r m a i n t a i n t h e Work, f rom a l t e r a t i o n s o f t h e Work b y persons o t h e r t h a n C o n t r a c t o r , f r o m an o p t i o n o r accessory t o t h e Work wh ich was a v a i l a b l e t o t h e Owner b u t o m i t t e d a t Owner 's d i r e c t i o n , o r f rom des ign o r i n s t r u c t i o n s f u r n i s h e d by Owner and i n c o r p o r a t e d i n t h e Work o v e r C o n t r a c t o r ' s w r i t t e n o b j e c t i o n . C o n t r a c t o r s h a l l be r e s p o n s i b l e f o r a l l c o s t s , i n c l u d i n g c o s t s o f removal , t r a n s p o r t a t i o n and r e i n s t a l l a t i o n o f , m o d i f i c a t i o n o f , o r s u p p l y i n g a rep lacement f o r , t h e Work so t h a t t h e Work conforms t o t h e a p p l i c a b l e r e g u l a t i o n s o r s tandards and, e x c e p t a s o t h e r w i s e p r o v i d e d h e r e i n , s h a l l be r e s p o n s i b l e f o r a l l damages due t o d e l a y r e s u l t i n g f rom nonconformance. I f caused by C o n t r a c t o r ' s a c t s o r omiss ions , C o n t r a c t o r s h a l l i n d e m n i f y Owner f o r any f i n e s and p e n a l i t i e s ,

i n c l u d i n g a t t o r n e y s ' f e e s and o t h e r defense c o s t s and expenses. Fo r one d o l l a r ($1.00) acknowledged t o be i n c l u d e d and p a i d f o r i n t h e C o n t r a c t P r i c e and o t h e r good and v a l u a b l e c o n s i d e r a t i o n s , C o n t r a c t o r ag rees t o i ndemn i f y and h o l d harmless Owner, Eng ineer and t h e i r r e s p e c t i v e o f f i c e r s , agen ts and employees, i n accordance w i t h t h e p r o v i s i o n s o f t h i s S e c t i o n .

R o l e o f Engineer

I n t h e e v e n t an owner has r e t a i n e d an o u t s i d e e n g i n e e r i n g f i r m t o p r o v i d e

des ign , e n g i n e e r i n g , and a s s o c i a t e d s e r v i c e s , t h i s s e c t i o n l i s t s t h e d u t i e s ,

r e s p o n s i b i l i t i e s and a u t h o r i t y o f t h e e n g i n e e r .

C o n t r a c t o r ' s Drawings and I n s t r u c t i o n Manuals

T h i s s e c t i o n i n f o r m s a c o n t r a c t o r t h a t t h e r e v i e w o f any d raw ings , d a t a ,

e t c . , b y an owner i s f o r t h e purpose o f a s c e r t a i n i n g g e n e r a l c o n f o r m i t y w i t h

t h e t e c h n i c a l s p e c i f i c a t i o n s , and f o r i n t e r f a c e i n f o r m a t i o n . It does n o t

i n c l u d e a r e v i e w o f c o n t r a c t o r ' s e f f i c i e n c y o r adequacy o f c o n s t r u c t i o n

methods, n o r does i t i n c l u d e a rev iew o f any d e t a i l e d d e s i g n s o r

s p e c i f i c a t i o n s p repared by a c o n t r a c t o r . A l s o , t h i s r e v i e w does n o t r e l i e v e a

c o n t r a c t o r f rom t h e e n t i r e r e s p o n s i b i l i t y f o r c o r r e c t n e s s o f h i

des ign , workmanship, and a1 1 o t h e r s e r v i c e s r e q u i r e d by him.

A d d i t i o n a l l y , t h i s s e c t i o n may be used t o l i s t an owner ' s d r a w i

(mylar , washof f , e t c . ) and t h e fo rmat f o r i n s t r u c t i o n manuals.

P h y s i c a l Damage t o J o b s i t e

s e n g i n e e r i n g ,

ng requ i remen ts

T h i s s e c t i o n r e q u i r e s a c o n t r a c t o r t o be s o l e l y r e s p o n s i b l e f o r any c o s t s

i n c u r r e d due t o r e p a i r o r rep lacement o f damaged equipment o r s t r u c t u r e s a t a

p r o j e c t s i t e which have been damaged o r d e s t r o y e d as t h e r e s u l t o f a

c o n t r a c t o r ' s o r h i s s u b c o n t r a c t o r ' s n e g l i g e n c e o r b reach o f w a r r a n t y .

However, t h i s r e s p o n s i b i l i t y i s only f o r t h o s e c o s t s w h i c h an owner c o u l d n o t

r e c o v e r t h r o u g h damage insu rance .

P r i c e P o l i c y

Due t o t h e l o n g l e a d t i m e a s s o c i a t e d i n t h e procurement o f an e l e c t r o s t a t i c

p r e c i p i t a t o r and t h e c o n s t a n t f l u c t u a t i o n o f t h e economy, t h i s s e c t i o n o f a

c o n t r a c t d e t a i l s t h e p r i c e ad jus tmen t p o l i c y t o be used t o r e f l e c t t h e changes

i n m a t e r i a l and l a b o r p r i c e s . The customary manner t o t r a c k and account f o r

p r i c e ad jus tments i s t o use t h e U.S. Depar tment o f Labor , Bureau o f Labor

S t a t i s t i c s (BLS) which p u b l i s h e s i n d i c e s f o r m a t e r i a l and shop l a b o r . F i e l d

l a b o r p r i c e ad jus tments may be based upon changes i n t h e h o u r l y r a t e f o r

c o n t r a c t o r s work ing under agreements w i t h t h e B u i l d i n g and C o n s t r u c t i o n Trades

Department (AFL-CIO) hav ing j u r i s d i c t i o n i n t h e a rea . Fo r c o n t r a c t o r s n o t

w o r k i n g under AFL-CIO agreements, a r e p r e s e n t a t i v e crew m ix can be used t o

de te rm ine t h e h o u r l y r a t e and then compared w i t h changes i n t h e B u i l d i n g and

C o n s t r u c t i o n Trades Department h o u r l y r a t e .

F o r purposes o f c a l c u l a t i n g p r i c e a d j u s t m e n t s , o r e s c a l a t i o n , n i n e t y p e r c e n t

(90%) o f a c o n t r a c t p r i c e i s t y p i c a l l y b r o k e n down i n t o t h r e e p a r t s :

m a t e r i a l , shop l a b o r , and f i e l d l a b o r . The r e m a i n i n g t e n p e r c e n t o f t h e p r i c e

i s n o t s u b j e c t t o e s c a l a t i o n . T h i s t e n p e r c e n t p o r t i o n o f t h e p r i c e i s

g e n e r a l l y c o n s i d e r e d t o i n c l u d e a c o n t r a c t o r ' s p r o f i t , overhead and

a d m i n i s t r a t i v e c o s t s , o v e r which i t has c o n t r o l . It i s g e n e r a l l y assumed t h a t

a c o n t r a c t o r has no c o n t r o l o v e r t h e b a l a n c e o f t h e p r i c e and i s t h e n e n t i t l e d

t o be compensated f o r any such i n c r e a s e s . Converse ly , an owner would b e n e f i t

i n t h e event o f decreases i n economic i n d i c e s . O v e r a l l , t h i s concep t o f f e r s

l i t t l e r i s k t o a c o n t r a c t o r w h i l e expos ing an owner t o p o t e n t i a l l y s u b s t a n t i a l

and s i g n i f i c a n t i n c r e a s e s i n a c o n t r a c t p r i c e .

Changes i n c u r r e n t pu rchas ing p r a c t i c e s a r e t e n d i n g toward e s c a l a t i n g

c o n t r a c t s w i t h a "cap" o r maximum percen tage b y w h i c h a c o n t r a c t may be

inc reased . T h i s b e n e f i t s an owner i n two ways: f i r s t , an owner w i l l know a t

a71 t imes what t h e maximum t o t a l c o n t r a c t p r i c e w i l l be ( i n c l u d i n g changes),

and secondly , t h e p o s s i b i l i t y e x i s t s t h a t r e d u c t i o n s i n i n f l a t i o n r a t e s w i l l

r e s u l t i n a c o n t r a c t p r i c e t h a t i s l e s s t h a n t h e maximum amount. Should an

owner e l e c t t o use t h i s t y p e o f arrangement, i t w i l l be necessary t o i n c l u d e

t h a t t h e p r i c e cap i s t o be based on t h e s p e c i f i c schedule c o n t a i n e d i n a

c o n t r a c t . I n t h e even t o f a suspens ion o r d e l a y w h i c h i s beyond a

c o n t r a c t o r ' s c o n t r o l , t h e t o t a l d o l l a r cap amount may be a d j u s t e d b y add ing

t h e a c t u a l d o l l a r amount i n c r e a s e i n c u r r e d (based upon i n c r e a s e s i n t h e BLS

i n d i c e s ) d u r i n g t h e suspension o r d e l a y t o t h e cap amount. The same would

hold t r u e f o r f i e l d l abo r because the percentage inc rease in t he wage r a t e

could be added t o t h e cap amount on f i e l d labor .

Invoic ing and Payment Terms

This s ec t ion of t he commercial terms and condi t ions provides t he invoicing

i n s t r u c t i o n s and terms of payment. Invoicing i n s t r u c t i o n s usua l ly advise a

c o n t r a c t o r where t o mail t h e invoice , number of cop ie s , format , and any o the r

information an owner d e s i r e s t o have included on the invoice . The payment

terms f o r c o n t r a c t s a s s o c i a t e d with p r e c i p i t a t o r s should be based upon the

ac tua l monthly progress made by the con t r ac to r . Progress i s usua l ly measured

i n terms o f t he amount of engineering completed, number of drawings completed,

ma te r i a l received a t a c o n t r a c t o r ' s f a c i l i t i e s , amount of shop f a b r i c a t i o n

completed, material rece ived a t t he j o b s i t e , and payment f o r work in p lace

dur ing e r e c t i o n . The t ime frame f o r each of t h e s e t y p i c a l milestones i s

agreed upon during c o n t r a c t nego t i a t i ons . Any milestone not met by a

c o n t r a c t o r through h i s own f a u l t would r e s u l t i n non-payment by an owner.

This form of payment a l lows an owner t o c l o s e l y monitor a c o n t r a c t o r ' s

p rogress and performance.

Payment terms should a l s o spec i fy t h a t r e t en t ion wi l l be withheld from each

invoice . The t o t a l r e t e n t i o n , expressed a s a percentage of a con t r ac t p r i c e ,

t y p i c a l l y ranging between f i v e and ten percent , i s determined by an owner.

Many c o n t r a c t o r s ba lk a t t h e idea of an owner withholding even f i v e percent of

money due ( 5 percent of $100,000,000 i s $5,000,000), so i t may be necessary

f o r an owner t o pay i n t e r e s t on t h e money. I n t e r e s t can be t i e d , f o r

i n s t a n c e , t o t he d iscounted r a t e f o r U.S. Treasury Notes o r some o ther

published i n t e r e s t amount. Release of r e t en t ion i s then t i e d t o t he

successfu l completion of performance t e s t s .

Esca l a t i on p r i c e ad jus tments a r e normalTy invoiced a t f u l l value of t he ac tua l

amount o f e sca l a t i on on mater ia l and labor invoices with no r e t en t ion withheld

from t h e e s c a l a t i o n invo ices .

In t h e even t o f a d i s p u t e over an i nvo ice , t h e d isputed amount i s not paid

u n t i l t h e r e i s a s a t i s f a c t o r y r e so lu t ion of t he d i spu te by the p a r t i e s .

Owner 's P r e s c r i b e d Forms

T h i s s e c t i o n l i s t s t h e forms p r e s c r

a c o n t r a c t o r . Forms may i n c l u d e an

c e r t i f i c a t e s o f i n s u r a n c e , c o n t r a c t

o t h e r p e r t i n e n t forms r e q u i r e d by a

Complete Agreement

bed by an owner f o r use i n a c o n t r a c t by

owner ' s i n s u r a n c e requ i remen ts and

bond, a p p l i c a t i o n f o r payment, o r any

o w n e r ' s procedures and p r a c t i c e s .

T h i s s e c t i o n s t a t e s t h a t a c o n t r a c t i s t h e e x c l u s i v e s ta tement o f t h e

agreement between owner and c o n t r a c t o r . Verba l o r w r i t t e n ev idence may n o t be

used t o v a r y o r c o n t r a d i c t t h e express te rms o f a c o n t r a c t , and a l l p r i o r

d e a l i n g s , agreements, s u b m i t t a l s , e t c . , s h a l l be n u l l and v o i d . T h i s s e c t i o n

a l s o s t a t e s t h a t a c o n t r a c t cannot be m o d i f i e d o r amended and no w a i v e r o f any

p r o v i s i o n can o c c u r u n l e s s a w r i t t e n change o r d e r i s s igned by b o t h p a r t i e s .

S e c t i o n Headings

T h i s a r t i c l e e x p l a i n s t h a t s e c t i o n headings appear ing i n t h e c o n t r a c t a r e

i n s e r t e d f o r convenience o f r e f e r e n c e o n l y and i n no way a r e t o be cons t rued

as i n t e r p r e t a t i o n s o f t h e t e x t o f t h e c o n t r a c t .

Indernni f i c a t i o n

I n t h e e v e n t o f a i n j u r y , a c c i d e n t , d e a t h , o r damage t o p r o p e r t y due t o o r

i n c i d e n t a l t o t h e work , an owner uses t h i s p r o v i s i o n t o make a c o n t r a c t o r

r e s p o n s i b l e f o r d e f e n d i n g and h o l d i n g t h e owner harmless f rom c l a i m s . An

example f o l l o w s , b u t i t i s a b s o l u t e l y necessary t h a t an owner 's l e g a l and

i n s u r a n c e s t a f f s be i n v o l v e d i n t h e development o f t h i s c l a u s e .

INDEMNIFICATION

C o n t r a c t o r s h a l l h o l d harmless, i n d e m n i f y 'and defend Owner and Eng ineer ( f o r purposes o f t h i s S e c t i o n e n t i t l e d INDEMNIF ICAT ION, t h e words "Owner" and "Eng ineer " s h a l l be deemed t o i n c l u d e d t h e i r r e s p e c t i v e members, d i r e c t o r s , o f f i c e r s , employees, r e p r e s e n t a t i v e s and agents) a g a i n s t any c l a i m , a c t i o n , l o s s , damage, i n j u r y , l i a b i l i t y , c o s t and expense o f whatsoever k i n d o r n a t u r e ( i n c l u d i n g , b u t n o t by way o f l i m i t a t i o n , a t t o r n e y s ' f ees ) a r i s i n g o u t o f i n j u r i e s (whe the r mental o r c o r p o r e a l ) t o persons, i n c l u d i n g dea th , o r damage t o p r o p e r t y a r i s i n g o u t o f o r i n c i d e n t a l t o t h e performance o f t h i s C o n t r a c t o r Work pe r fo rmed t h e r e u n d e r , whe the r o r n o t due t o o r caused by neg l i gence o f Owner o r Engineer , e x c l u d i n g t h e s o l e n e g l i g e n c e o r Owner and Engineer . Owner and Engineer agree t o p r o v i d e C o n t r a c t o r n o t i c e o f any such c l a i m as soon as p r a c t i c a b l e and p r o v i d e a l l reasonable a s s i s t a n c e i n connec t ion t h e r e w i t h as C o n t r a c t o r may r e q u e s t . C o n t r a c t o r ' s s a i d o b l i g a t i o n t o h o l d

harmless , i n d e m n i f y and defend Owner and Eng ineer p u r s u a n t t o t h i s S e c t i o n e n t i t l e d INDEMNIFICATION s h a l l ex tend up t o , b u t s h a l l n o t exceed t h e sum o f $5,000,000.00 f o r i n j u r y , dea th o r damage t o p r o p e r t y a r i s i n g o u t o f a s i n g l e occu r rence .

S u b c o n t r a c t o r s

T h i s s e c t i o n a l l o w s t h e Owner t o r e q u e s t t h e C o n t r a c t o r t o t e r m i n a t e a

s u b c o n t r a c t o r i f , i n t h e Owner's s o l e o p i n i o n , t h e r e s p o n s i b i l i t y o f t h e

s u b c o n t r a c t o r becomes i m p a i r e d such t h a t t h e work pe r fo rmed would b e

q u e s t i o n a b l e as t o q u a l i t y and workmanship.

Schedule

T h i s s e c t i o n p r o v i d e s a c o n t r a c t o r w i t h a s p e c i f i c t i m e frame d u r i n g w h i c h he

i s t o p e r f o r m i t s d u t i e s and r e s p o n s i b i l i t i e s under t h e c o n t r a c t . T h i s t i m e

frame u s u a l l y commences w i t h a d a t e no l a t e r than w h i c h a c o n t r a c t o r can b e g i n

d e l i v e r y o f equipment t o a j o b s i t e . F u r t h e r , a d a t e i s e s t a b l i s h e d w h i c h

n o t e s t h e e a r l i e s t t i m e a c o n t r a c t o r may commence c o n s t r u c t i o n a c t i v i t i e s .

Moreover, i n t e r f a c e d a t e s a r e t o be e s t a b l i s h e d f o r o t h e r p i e c e s o f equipment

and/or systems such as duc twork connec t ions w i t h t h e steam g e n e r a t o r ' s a i r

h e a t e r and induced d r a f t f a n s , i n s t a l l a t i o n o f t h e f l y ash h a n d l i n g system,

and t h e a p p l i c a t i o n o f the rma l i n s u l a t i o n . T h i s s p e c i f i c t i m e frame f o r a

c o n t r a c t o r ' s a c t i v i t i e s r e q u i r e s a comp le t ion d a t e o r s e r i e s o f d a t e s f o r

e s t a b l i s h i n g a gas p a t h t o t h e chimney f o r steam g e n e r a t o r b o i l o u t and t r i a l

o p e r a t i o n .

U n i t ( s ) O p t i o n

T h i s s e c t i o n a l l o w s an owner t o e x e r c i s e an o p t i o n t o have a c o n t r a c t o r

p r o v i d e d u p l i c a t e work f o r a s p e c i f i c number o f a d d i t i o n a l u n i t s a t t h e same

j o b s i t e f o r t h e o p t i o n p r i c e i n c l u d e d i n t h e c o n t r a c t . T h i s s e c t i o n i s t o be

used o n l y i f more t h a n one u n i t i s p lanned f o r c o n s t r u c t i o n w i t h i n a

reasonab le p e r i o d o f t i m e .

C o n t r a c t Bonds

Due t o t h e s i g n i f i c a n t c o s t s i n v o l v e d i n a p r e c i p i t a t o r c o n t r a c t , an owner

must be a f f o r d e d p r o t e c t i o n t h a t a c o n t r a c t o r w i l l p e r f o r m and make payment

f o r a l l o f i t s o b l i g a t i o n s . T h i s p r o t e c t i o n i s i n t h e form o f pe r fo rmance and

payment bonds o b t a i n e d by t h e c o n t r a c t o r i n t h e f o r m and manner p r e s c r i b e d by

an owner and w i t h t h e premiums p a i d f o r by an owner as p a r t o f t h e c o n t r a c t

rice.

C a n c e l l a t i o n Charges

A l t h o u g h i t i s n o t normal t o b e g i n t h e procurement o f an e l e c t r o s t a t i c

p r e c i p i t a t o r w i t h p r o j e c t c a n c e l l a t i o n i n mind b e f o r e c o m p l e t i o n , t h e

p o s s i b i l i t y a lways e x i s t s t h a t c i r cumstances beyond an owner 's c o n t r o l may

f o r c e t h e c a n c e l l a t i o n o f t h e work . Should t h i s occu r , t h e owner must know a t

any t i m e , t h e t o t a l amount o f t h e c a n c e l l a t i o n charges f o r wh ich it would be

l i a b l e . D f course, any payments made t o a c o n t r a c t o r by a owner wou ld be

deduc ted f rom t h e c a n c e l l a t i o n charge. C a n c e l l a t i o n charges a r e expressed i n

c u m u l a t i v e percentages o f t h e c o n t r a c t p r i c e on a mon th l y b a s i s o v e r t h e

d u r a t i o n o f t h e schedule .

CONCEPTS FOR ERECTION

T h i s s e c t i o n p r e s e n t s t h e concepts f

t h e e r e c t i o n p o r t i o n o f d e l i v e r and

t h e te rms and c o n d i t i o n i s commonly

C o n d i t i o n s " . These concepts w i t h il

o r terms and c o n d i t i o n s a s s o c i a t e d w i t h

e r e c t c o n t r a c t s . T h i s e r e c t i o n p o r t i o n o f

r e f e r r e d t o as "Supplementary Terms and

l u s t r a t i v e examples must n o t be

i n c o r p o r a t e d i n t o c o n t r a c t s w i t h o u t a approva l and d i r e c t i o n o f a u t i l i t y ' s

l ega l depar tmen t .

D e f i n i t i o n s

T h i s s e c t i o n d e f i n e s a l l o f t h e s e words and te rms which appear t h r o u g h o u t a

c o n t r a c t , wh ich i f l e f t u n d e f i n e d m igh t be c o n s t r u e d d i f f e r e n t l y by t h e

p a r t i e s i n v o l v e d . Some of t h e more commonly used terms and d e f i n i t i o n s

appear ing i n e r e c t i o n c o n t r a c t s a re :

C o n t r a c t o r ' s Super in tenden t - means a c o n t r a c t o r ' s d u l y a u t h o r i z e d

r e p r e s e n t a t i v e d e s i g n a t e d i n accordance w i t h t h e p r o v i s i o n s of a

c o n t r a c t , who s h a l l have t h e a u t h o r i t y t o manage a c o n t r a c t o r ' s j o b s i t e

a c t i v i t i e s a s s o c i a t e d w i t h a p r o j e c t .

E n g i n e e r ' s S u p e r i n t e n d e n t - means an eng ineer

a u t h o r i t y t o manage an e n g i n e e r ' s j o b s i t e a c t

t h i s P r o j e c t .

employee who

i v i t i e s assoc

s h a l l have t h e

i a t e d w i t h t o

F i e l d Order - means a w r i t t e n o r d e r i ssued by t h e e n g i n e e r and approved

by t h e owner w i t h r e c e i p t acknowledged by the c o n t r a c t o r , wh ich o r d e r s

m ino r changes i n t h e work n o t i n v o l v i n g e x t r a c o s t and c o n s i s t e n t w i t h

t h e o v e r a l l i n t e n t o f t h e c o n t r a c t .

S u b s t a n t i a l Complet ion - means t h e d a t e as c e r t i f i e d by t h e owner when

t h e work pe r fo rmed i n accordance w i t h t h e c o n t r a c t i s s u f f i c i e n t l y

complete so t h a t t h e work can be u t i l i z e d f o r t h e purposes f o r wh ich i t

was in tended ; o r , i f t h e r e be no such c e r t i f i c a t i o n , t h e d a t e when f i n a l

payment i s due.

S u r e t y - means t h e p a r t y who has made secure t h e f u l f i l l m e n t o f t h e

c o n t r a c t b y a bond.

M i s c e l l a n e o u s Terms - wherever f i g u r e s a re g i v e n i n t h i s c o n t r a c t under

t h e w o r d " E l e v a t i o n " o r a b b r e v i a t i o n o f i t , o r where f i g u r e s r e p r e s e n t i n g

e l e v a t i o n s a r e g i v e n , t h e y s h a l l mean t h e e l e v a t i o n r e l a t i v e t o U n i t e d

S t a t e s G e o l o g i c a l Survey Sea Leve l Datum, as r e p r e s e n t e d b y v a r i o u s bench

marks i n t h e v i c i n i t y o f t h e work, o r t h e y s h a l l mean t h e e l e v a t i o n

r e l a t i v e t o t h e a r b i t r a r y datum p l a n e f i x e d by t h e e n g i n e e r f o r t h e

p a r t i c u l a r work .

O b l i g a t i o n s o f C o n t r a c t o r

T h i s s e c t i o n o f t h e supplementary terms and c o n d i t i o n s d e a l s w i t h t h e

c o n t r a c t u a l o b l i g a t i o n s a c o n t r a c t o r must f o l l o w p r i o r t o , d u r i n g , and a f t e r

c o m p l e t i o n o f a l l j o b s i t e r e l a t e d work . The f o l l o w i n g i l l u s t r a t e s s e v e r a l o f

t h e more common requ i remen ts f o r wh ich a c o n t r a c t o r w o u l d be o b l i g a t e d :

OBLIGATIONS OF CONTRACTOR

The C o n t r a c t o r s h a l l f u r n i s h and p r o v i d e a1 1 m a t e r i a l , l a b o r , s u p e r v i s i o n , t o o l s , p l a n t , appara tus , conveyances, equipment, and i n c i d e n t a l s r e q u i r e d f o r accomp l i sh ing t h e Work, e x c e p t t h e m a t e r i a l s and s e r v i c e s s p e c i f i c a l l y ment ioned i n t h i s C o n t r a c t t o be p r o v i d e d by Owner.

The C o n t r a c t o r s h a l l keep one ( I ) r e c o r d copy of a l l S p e c i f i c a t i o n s , Drawings, and o t h e r d rawings a t t h e J o b s i t e i n good o r d e r and a n n o t a t e d ( a s - b u i l t d rawings ) t o show a l l changes made d u r i n g c o n s t r u c t i o n . These s h a l l be a v a i l a b l e t o t h e Owner and Eng inee r and s h a l l be d e l i v e r e d t o t h e Owner upon complet ion of t h e Work.

The C o n t r a c t o r a g r e e s t o meet t h e d e l i v e r y and complet ion d a t e s r e q u i r e d by t h i s C o n t r a c t . The C o n t r a c t o r s h a l l deve lop a d e t a i l e d s c h e d u l e f o r t h e e x e c u t i o n of t h e Work, s a i d s c h e d u l e t o be submi t t ed t o t h e Eng inee r f o r i t s review p r i o r t o s t a r t of C o n t r a c t o r ' s J o b s i t e a c t i v i t i e s . The d e t a i l e d schedu le s h a l l conform t o t h e o v e r a l l s c h e d u l e f o r P r o j e c t c o n s t r u c t i o n . The C o n t r a c t o r s h a l l p r o v i d e a monthly updated s c h e d u l e , i n c o r p o r a t i n g t h e C o n t r a c t o r ' s and S u b c o n t a c t o r s ' d e l i v e r y s c h e d u l e s , f o r a l l Work.

C o n t r a c t o r s h a l l perform a l l a p p l i c a b l e q u a l i t y c o n t r o l a c t i v i t i e s , e x c e p t t h o s e t o be p rov ided by t h e Owner, a t t h e J o b s i t e , i n c l u d i n g rad iography and p r o v i d e a l l equipment a s r e q u i r e d t o perform such q u a l i t y c o n t r o l a c t i v i t i e s .

The C o n t r a c t o r ' s c o r r e s p o n d e n c e , r e c o r d s , vouchers and books of a c c o u n t a t t h e J o b s i t e and C o n t r a c t o r ' s home o f f i c e s h a l l be open t o t h e Owner 's o r i t s d e s i g n a t e d a g e n t ' s , i n s p e c t i o n and s u b j e c t t o i t s a u d i t t o t h e e x t e n t n e c e s s a r y t o v e r i f y r e imbursab le c o s t s i n c u r r e d under t h i s C o n t r a c t . The C o n t r a c t o r a g r e e s t o ma in ta in such books and r e c o r d s f o r a p e r i o d of t h r e e ( 3 ) y e a r s from t h e d a t e of comple t ion of t h e Work and t o make such r e c o r d s a v a i l a b l e t o t h e Owner, o r i t s d e s i g n a t e d a g e n t , d u r i n g normal b u s i n e s s hours w i t h i n t h e t h r e e - y e a r p e r i o d .

The C o n t r a c t o r a l o n e s h a l l be and remain l i a b l e and r e s p o n s i b l e f o r t h e e f f i c i e n c y , adequacy and s a f e t y o f t h e methods and means by which i t pe r fo rms i t s Work, and of i t s m a t e r i a l s , working f o r c e and equ ipment , i r r e s p e c t i v e of whether o r n o t t h e C o n t r a c t o r makes any change a s a r e s u l t of any comments r e c e i v e d from t h e Owner o r Eng inee r .

The C o n t r a c t o r s h a l l submi t resume's o f key c o n s t r u c t i o n pe r sonne l ( P r o j e c t S u p e r i n t e n d e n t , QA/QC p e r s o n n e l , Schedule /Cost Control p e r s o n n e l ) t o the Engineer a t l e a s t s i x ( 6 ) months p r i o r t o s t a r t of e r e c t i o n work.

The C o n t r a c t o r s h a l l comply w i t h t h e Owner ' s J o b s i t e s a f e t y and s e c u r i t y programs and a l l changes and a d d i t i o n s t h e r e t o , c o p i e s o f which s h a l l be f u r n i s h e d t o t h e C o n t r a c t o r p r i o r t o s t a r t of C o n t r a c t o r ' s J o b s i t e a c t i v i t i e s .

P r i o r t o t h e C o n t r a c t o r commencing i t s J o b s i t e a c t i v i t i e s , C o n t r a c t o r shaT1 p r o v i d e t o t h e Owner, f o r review, i t s r e q u i r e m e n t s f o r J o b s i t e t empora ry c o n s t r u c t i o n b u i l d i n g space and laydown a r e a s . The C o n t r a c t o r s h a l l p rov ide a l l o f f i c e equipment and s u p p l i e s r e q u i r e d f o r t h e performance of t h e Work.

Contrac tor may e l e c t t o perform work with labor not working under agreements with t he Building and Construct ion Trades Department (AFL-CIO). However, i f t h e Contractor performs work with l abo r t h a t i s working under agreements with t he Building and Construct ion Trades Department (AFL-CIO), t he Contractor s h a l l provide and adminis te r a labor r e l a t i o n s program which s h a l l be c o n s i s t e n t with t h e P r o j e c t labor r e l a t i o n s program. Any j u r i s d i c t i o n a l d i s p u t e which may a r i s e in connection with t h e Work performed pursuant t o t he terms of t h i s Contract sha l l be s e t t l e d in accordance with t he Plan f o r t h e Set t lement of J u r i s d i c t i o n a l d i s p u t e s in t he Construct ion Industry and any dec is ion by the Impar t ia l J u r i s d i c t i o n a l Disputes Board wi? l be f i n a l and binding.

Obl iga t ions of Owner

This sec t ion addresses t h e ob l iga t ions of an owner. They normally involve

securing a l l permi ts and l i censes required by a l l l e v e l s of government;

supplying a l l requi red s p e c i f i c a t i o n s , drawings, e t c . ; inspec t ion and a u d i t i n g

of t h e work and performance of t he c o n t r a c t o r , and fu rn i sh ing cons t ruc t ion and

drinking water and e l e c t r i c power f o r c o n s t r u c t ~ o n use.

Delivery and Storage

This sec t ion covers t he ob l iga t ions pursuant t o t he de l ive ry and s to rage of

t he ma te r i a l s and equipment a con t r ac to r wi l l e r e c t . Customary procedures t o

be follcwed a r e ou t l i ned below a s an example of such wording

DELIVERY AND STORAGE

Cont rac tor s h a l l rece ive , document the r e c e i p t o f , i n s p e c t , unload, handle, s t o r e and maintain, pursuant t o t h i s Con t r ac t , a11 m a t e r i a l s and equipment furnished under t h i s Contract which i t w i l l e r e c t o r i n s t a l l and t h e Owner furn ished ma te r i a l s and equipment which t h e Cont rac tor w i l l e r e c t o r i n s t a l l . Con t r ac to r ' s documentation of r e c e i p t of ma te r i a l s (Material Receiving Reports) s h a l l be furn ished t o t he Engineer. Spare p a r t s sha l l be turned over t o t h e Owner, i n t h e Owner's s torage f a c i l i t y , upon r ece ip t a t t he J o b s i t e . All ma te r i a l possession changes sha l l be documented by a Material Report, signed by the Contractor and a copy given t o t h e Engineer. The Cont rac tor sha l l have t o t a l r e s p o n s i b i l i t y f o r t h e s a f e t y and p ro t ec t ion o f mate r i a l s and equipment from l o s s o r damage by t h e elements o r from any cause whatsoever while in i t s care and through completion of e rec t ion by t h e Contractor and acceptance by t h e Owner. Material received in damaged condit ion s h a l l be s e t a s i d e f o r inspec t ion by the Engineer and r ep re sen ta t i ves of t he c a r r i e r .

The Owner furnished equipment and ma te r i a l s i n s t a l l e d by t h e Cont rac tor and, i f spec ia l arrangements have been made with t h e Owner, t he Contractor furnished equipment and m a t e r i a l s , a r r i v i n g a t the J o b s i t e p r i o r t o t he Con t r ac to r ' s s t a r t i n g J o b s i t e a c t i v i t i e s , sha l l be received by t h e Contractor on the ground a s they occur , o r from t h e Owner's s t o rage f a c i l i t y on the J o b s i t e o r landed on foundat ions.

The Cont rac tor sha l l develop a formal s torage procedure u t i l i z i n g the a r ea designated by t h e Engineer. The s torage procedure s h a l l be presented t o t he Engineer f o r review and sha l l include a ske tch wi th necessary explanat ion t o expose the Con t r ac to r ' s plan f o r space a l l o tmen t , dunnage, weather p ro t ec t ion , e t c . The s to rage procedures sha l l spec i fy t he methods t o be used t o avoid damage t o o r d e t e r i o r a t i o n of mater ia l during s torage due t o handling, p r e se rva t ion , packaging, o r cleaning. These procedures sha l l be submitted in wr i t ing f o r t he Engineer 's review p r i o r t o imp1ementat;on. I f required by t h i s Contract , t h e foregoing procedure sha l l be developed in accordance with t h e app l i cab l e Owner and ANSI s tandards , including coverings, indoor s to rage , preserva t ion a p p l i c a t i o n s , c lo su re s , heat and humidity c o n t r o l s , and o t h e r measures recommended by the manufacturer, t o e l imina t e damage in handling and from exposure t o the environment.

The Cont rac tor sha l l provide f o r s torage p ro t ec t ion and p e r i o d i c maintenance of r o t a t i n g equipment. In the case t h a t s p e c i f i c manufac turer ' s i n s t r u c t i o n s a r e absent , the Cont rac tor sha l l p r o t e c t t h e equipment from adverse weather , r o t a t e and l u b r i c a t e t h e equipment a t a frequency spec i f i ed by the Engineer.

The Cont rac tor sha l l i n s t a l l t h e f i r s t change of l u b r i c a t i n g o i l in equipment, and in s i t u a t i o n s where temporary o i l i s i n i t i a l l y p laced in equipment, t h e Contractor sha l l d r a in and recharge equipment with permanent 1 ubr ica t ion .

Contractor Responsible f o r Work u n t i l Accepted

T h i s sec t ion r e q u i r e s a con t r ac to r t o be respons ib le f o r t h e risk of l o s s f o r

t he work. Examples follow although the exact nature of t h e wording should be

developed by a u t i l i t y ' s legal department

CONTRACTOR RESPONSIBLE FOR WORK UNTIL ACCEPTED

Subjec t t o t he Risk of Loss Sect ion of the Standard Terms and Condi t ions , a l l Work, including without l i m i t a t i o n any Eauipment furn ished by t h e Contractor under t h i s Contract and any temporary work o r f a c i l i t i e s r equ i r ed , sha l l be a t the C o n t r a c t o r ' s r i s k u n t i l Unit T r a i l Operation and i f t he Work, o r any por t ion t h e r e c f , s h a l l be damaged in any way except by so le negligence of t he Owner o r Engineer , before Unit T r i a l Operat ion, the Contractor s h a l l promptly r e p a i r o r rep lace such damaged work f r e e from a l l expense t o t h e

Owner and Engineer, before Unit T r a i l Operation. T h e Cont rac tor s h a l l be respons ib le f o r any l o s s o r damage t o m a t e r i a l , t o o l s o r o the r a r t i c l e s used o r held f o r use in connection wi th t h e Work. The Work s h a l l be c a r r i e d on t o completion without damage t o any work or proper ty of t h e Owner o r of o the r s and wi thout i n t e r f e r ence w i t h t he opera t ion of e x i s t i n g machinery o r equipment* Any damage t o o the r c o n t r a c t o r ' s equipment o r t o o l s s h a l l be s e t t l e d d i r e c t l y between the c o n t r a c t o r s involved.

The Contractor sha l l not s e l l , a s s i g n , mortgage, hypothecate o r remove Work which has been d e l i v e r e d t o o r i n s t a l l e d a t t h e J o b s i t e without t he p r i o r w r i t t e n consent of the Owner.

Personal At ten t ion of Contractor

This sec t ion r equ i r e s a c o n t r a c t o r t o g ive personal a t t e n t i o n t o t he work

This r e q u i r e s t he use of an on - s i t e duly au thor ized r e p r e s e n t a t i v e . A n

example fo l lows:

PERSONAL ATTENTION OF CONTRACTOR

The Contractor s h a l l cons t an t ly g ive i t s personal a t t e n t i o n t o t h e f a i t h f u l prosecution of t he Work, and sha l l con t inua l ly be p re sen t during progress e i t h e r i n person o r represented by a duly au thor ized r ep re sen ta t i ve on t h e J o b s i t e . Before proceeding with t h e Work, t h e Contractor sha l l provide t he Owner i n wr i t i ng , wi th t he name and t i t l e of i t s duly au thor ized r e p r e s e n t a t i v e , who sha l l be accep tab l e t o t h e Gwner. I f requi red by t h e Owner, t h e Contractor s h a l l maintain an o f f i c e on o r ad jacent t o t he s i t e of t he Work and sha l l a t a l l t imes keep in such o f f i c e a complete copy of t h e Drawings and S p e c i f i c a t i o n s .

Con t r ac to r ' s Representat ions

This sec t ion s t a t e s t h a t upon signing t h e c o n t r a c t , a c o n t r a c t o r makes

c e r t a i n r ep re sen ta t i ons of work t o be performed. The fol lowing provides an

example of t h i s concept .

CONTRACTOR'S REPRESENTATIONS

The Contractor s t a t e s t h a t i t has examined a l l the a v a i l a b l e records pe r t a in ing t o t he Work; t h a t i t has made a f i e l d examination of t he dobs i t e and rights-of-way; and t h a t i t has informed i t s e l f about t he c h a r a c t e r , q u a l i t y and quan t i t y of sur face and subsur face ma te r i a l s and water condi t ions t o be encountered , t h e q u a n t i t i e s i n t h e various s ec t ions of t h e Work, t h e cha rac t e r of equipment and f a c i l i t i e s needed f o r t he prosecut ion of t he Work, t h e loca t ion and s u i t a b i l i t y of a l l cons t ruc t ion m a t e r i a l s , t he loca l l abo r cond i t i ons , t h e app l i cab l e laws and governmental r egu la t i ons and a l l o the r mat te rs which may in any way a f f e c t t h e performance of the Work under t h i s Cont rac t .

Records of su r f ace and subsur face condi t ions , water records o r o ther observa t ions which may have been made by o r f o r t h e Owner o r Engineer s h a l l be made a v a i l a b l e t o t h e Contractor upon reques t f o r i t s in format ion , but t h e r e i s no expressed o r implied warranty a s t o t h e accuracy of t h e records o r any i n t e r p r e t a t i o n of them. The Contractor s t a t e s t h a t i t recognizes t h i s , and t h a t i t has formed i t s own opinion of a l l t he se cond i t i ons from an inspec t ion of t he J o b s i t e and has made i t s own i n t e r p r e t a t i o n of t he records .

The Contractor f u r t h e r s t a t e s t h a t t he Contract P r i ce and d e t a i l e d schedule f o r t he execution of t h e Work a r e based o n i t s own knowledge and judgment of t he condi t ions and hazards involved, and not upon any r ep re sen ta t i on of t h e Owner o r Engineer. The Owner and Engineer assume no r e s p o n s i b i l i t y whatsoever f o r any understanding o r r ep re sen ta t i on made by any of t h e i r r ep re sen ta t i ves during a r p r io r t o t h e execution of t h i s Cont rac t uniess such understandings or r ep re sen ta t i ons a r e exp re s s ly s t a t e d in t h i s Cont rac t and t h i s Contract express ly provides t h a t t h e r e s p o n s i b i l i t y i s assumed by the Owner.

The Cont rac tor s h a l l c a r e f u l l y s tudy and review t h i s Cont rac t . The Contractor sha l l perform work on any por t ion of t h e Work only upon r e c e i p t of drawings and s p e c i f i c a t i o n s issued f o r cons t ruc t ion . P r io r t o commencing any po r t i on of t he Work, t he Cont rac tor sha l l c a r e f u l l y review t h e drawings and spec i f i ca t i ons and sha l l a t once r epu r t t o Engineer any c o n f l i c t with appl icable law, o r any e r r o r , incons is tency o r omission i t may d i scove r . The Contractor s h a l l not be l i a b l e t o Owner f o r a d d i t i o n a l c o s t s incurred by Owner r e s u l t i n g from any such repor ted e r r o r s , i ncons i s t enc i e s o r omissions. Engineer w i l l promptly review t h e a l l eged c o n f l i c t s , e r r o r s , i ncons i s t enc i e s o r omissions and i s sue revised drawings o r s p e c i f i c a t i o n s , o r t h e Owner may i s s u e a Change Order. Any Work done a f t e r such discovery and u n t i l r e c e i p t of rev ised drawings o r s p e c i f i c a t i o n s o r t h e Owner's Change Order sha l l be a t t h e Con t r ac to r ' s so l e r i s k .

Insurance Requirements

This sec t ion s e t s f o r t h t he requirement t h a t a con t r ac to r maintain c e r t a i n

l e v e l s of insurance. The fol lowing i l l u s t r a t e s such insurance requirements.

I t must be noted t h a t each u t i l i t y has i t s own insurance requirement and must

be reviewed before any at tempt i s made in using the following concepts .

INSURANCE REQUIREMENTS

Without l i m i t i n g any of t h e o t h e r ob l iga t ions o r l i a b i l i t i e s of t he Cont rac tor , t h e Cont rac tor s h a l l provide and maintain, from the commencement of t h e C o n t r a c t o r ' s work under t h i s Cont rac t , insurance coverage i n accordance wi th requirements e s t ab l i shed in Form -, insurance Requirements, which i s a t tached hereto and made a p a r t of

t h i s Contract . Except with r e spec t t o coverage f o r Products - Completed Operat ions ( Inc luding Broad Form Property Damage) which must be maintained f o r a minimum per iod of t h r e e (3) y e a r s a f t e r completion of a l l Services/Work by Contractor , a l l coverages must be maintained u n t i l completion and acceptance of a l l ServicedWork by t h e Contractor .

The Contractor s h a l l , before commencing i t s work on t h i s Cont rac t and upon each renewal t h e r e a f t e r , d e l i v e r t o t h e address s p e c i f i e d i n Form - t h r e e (3 ) copies of t h e C e r t i f i c a t e of Insurance, completed by i t s insurance c a r r i e r c e r t i f y i n g t h a t insurance coverages a s requi red a r e i n e f f e c t . Duplicate copies of insurance p o l i c i e s sha l l be furnished t o t h e Owner o r Engineer wi th in t en ( 1 0 ) days when requested. The copies provided sha l l be t r u e and complete i n a l l r e spec t s , except t h a t , t he Cont rac tor may, a t i t s o p t i o n , deface those po r t i ons of the insurance p o l i c i e s t h a t r e l a t e t o r a t e s , premiums and r a t i n g bases and which do n o t , i n any way, modify t he coverages otherwise a f forded by the insurance p o l i c i e s .

As an a l t e r n a t i v e t o inc lus ion of t h e Owner, Engineer and t h e i r respec t ive members, d i r e c t o r s , o f f i c e r s and employees a s Addit ional Insureds under Coverages a s s e t f o r t h i n Insurance Requirements, t he Contractor may provide an Owners' and Cont rac tors ' P ro t ec t ive Policy wi th a combined s i n g l e l i m i t of l i a b i l i t y of 520,000,000 wi th t h e Owner and E n ~ i n e e r a s Named Insureds and with t h e l r r e spec t ive members, d i r e c t o r s , o f f i c e r s , and employees a s Addit ional Insureds . Said pol icy sha? l not l i m i t t he coverage f o r a c t s o r omissions of t h e Owner, Engineer o r t h e i r respec t ive members, d i r e c t o r s , o f f i c e r s and employees, t o only t h a t l i a b i l i t y a r i s i n g out o f general supervision of t h e Work performed by o r on behalf of t h e Contractor . The designated con t r ac to r s h a l l inc lude t h e Cont rac tor and Subcontractor and t h e i r r e spec t ive pa ren t s , s u b s i d i a r i e s , a f f i l i a t e s , o f f i c e r s and employees. The pol icy sha l l r e q u i r e a minimum of t h i r t y (30) days w r i t t e n no t i ce by C e r t i f i e d Mail t o t h e Owner p r io r t o c a n c e l l a t i o n , nonrenewal o r change. Except wi th r e spec t t o t he requirement of inc lus ion of the Owner, Engineer and t h e i r r e spec t ive members, d i r e c t o r s , o f f i c e r s and employees a s Additiona? Insureds and the inc lus ion of a c ross l i a b i l i t y o r s e v e r a b i l i t y of i n t e r e s t provision, the providing of t h e Owner's and Contractors ' P ro t ec t ive Policy by t h e Cont rac tor sha l l i n no way r e l i e v e Cont rac tor of t h e r e s p o n s i b i l i t y t o provide t h e insurance coverages s e t f o r t h i n Insurance Requirements.

With respec t t o t he insurance required by t h i s Sec t ion , notwithstanding the a p p l i c a b i l i t y of any deduc t ib l e o r r e t e n t i o n appl icable t o insurance coverage provided f o r t h e Cont rac tor , t h e r e sha l l be no deduc t ib l e , r e t en t ion o r s i m i l a r provision a p p l i c a b l e with respec t t o t he insurance coverages t o be provided by t h e Contractor f o r t he Owner, Engineer, and t h e i r r e spec t ive members, d i r e c t o r s , o f f i c e r s and employees. Provided f u r t h e r , should any such deduc t ib l e , r e t en t ion o r s i m i l a r provision apply, t h e Contractor s h a l l hold harmless, indemnify and defend t h e Owner,

Engineer and t h e i r r e spec t ive members, d i r e c t o r s , o f f i c e r s and employees a g a i n s t any claim, a c t i o n , l o s s , damage, i n j u r y , l i a b i l i t y , c o s t o r expense of whatsoever kind o r na tu re ( i nc lud ing , but not by way of l i m i t a t i o n , a t t o r n e y ' s f ee s ) t o t h e extent t h e required insurance coverage would have otherwise responded t o such claim, a c t i o n , l o s s , damage, i n j u r y , l i a b i l i t y c o s t o r expense had the insurance not been sub jec t t o any deduct ib le , r e t e n t i o n o r s i m i l a r provis ion . For one d o l l a r ($1.00) acknowledged t o be included and paid f o r in t h e Contract Pr ice and o t h e r good and valuable cons ide ra t i ons , t h e Contractor agrees t o indemnify and hold harmless t h e Owner, Engineer and t h e i r respec t ive members d i r e c t o r s , o f f i c e r s and employees in accordance with the p rov i s ions of t h i s Sect ion.

Contractor agrees t h a t , i f requested by t h e Owner, the Cont rac tor sha l l p a r t i c i p a t e and s h a l l requi re a l l i t s subcont rac tors t o p a r t i c i p a t e in an Owner provided Vorker 's Compensation/Employerst L i a b i l i t y and Comprehensive General L i a b i l i t y insurance program the e s s e n t i a l s of which a r e descr ibed in t h e Owner Provided Insurance Program, which i s a t tached here to and made a p a r t of t h i s Cont rac t . The Cont rac tor c e r t i f i e s t h a t no insurance c o s t s s h a l l be included in t he Cont rac t Pr ice o r i n t h a t of i t s subcont rac ts t o t he e x t e n t t h a t such coverages a r e provided by t h e Owner Provided Insurance Program.

The Cont rac tor s h a l l , upon w r i t t e n r eques t of t h e Owner or Engineer, prepare o r cause t o be prepared and execute f o r p re sen ta t i on t o i n s u r e r s , a l l a p p l i c a t i o n s and documents necessary o r d e s i r a b l e f o r use by the Owner in s o l i c i t a t i o n o f proposals f o r Owner Provided Insurance o r f o r any o the r insurance proposed by t h e Owner with r e spec t t o t h e P ro j ec t .

Planning, Cost, Scheduling and Control

This sec t ion r e q u i r e s a con t r ac to r t o properly s t a f f a job so t h a t work can

be appropr ia te ly planned, scheduled, and c o s t con t ro l l ed . These a c t i v i t i e s

must be ongoing dur ing t h e work. In add i t i on , a con t r ac to r should genera l ly

be required t o maintain t he se a c t i v i t i e s i n accordance with an owners o r

engi neer l s s tandard programs.

Independent Contractor and Key Personnel

This sec t ion def ines t he r e l a t i o n s h i p between a c o n t r a c t o r and owner, and the

assignment of a c o n t r a c t o r ' s personnel t o t h e p r o j e c t . The fo l lowing

i l l u s t r a t e s wording f o r t h e s e concepts:

INDEPENDENT CONTRACTOR AND K E Y PERSONNEL

In t he performance of t h i s Con t r ac t , t he Cont rac tor s h a l l opera te a s an independent c o n t r a c t o r , and not a s a subcon t r ac to r , agen t o r employee of t he Owner, and s h a l l have complete charge of i t s workers engaged in t h e performance of t he Work.

The Owner sha l l have t h e r i g h t t o review the experience record of Con t r ac to r ' s key personnel p r i o r t o t h e i r assignment t o t h e Work. The Contractor and Owner w i l l mutually agree on i n i t i a l assignments of lead personnel and on a l l changes i n such personnel . Cont rac tor w i l l provide a l t e r n a t e personnel a s required u n t i l such agreement can be reached, which agreement s h a l l no t be unreasonably withheld by e i t h e r Party. Owner s h a l l have the r i g h t t o p e r i o d i c a l l y review the q u a l i f i c a t i o n s and performance of personnel assigned t o t h e Work by Contractor and may reques t app rop r i a t e changes, which r eques t s sha l l not be unreasonably made by Owner and sha l l be complied with within a reasonable t ime.

None of t he Con t r ac to r ' s super in tendents , superv isors o r engineers may be withdrawn from the Work without due no t i ce being given t o t h e Owner; however, no such withdrawal s h a l l be made i f i t w i l l jeopardize successfu l completion of t he Work. The Cont rac tor sha l l provide a two ( 2 ) week t r a n s i t i o n period f o r t he Owner approved changes of C o n t r a c t o r ' s supe r in t enden t s , superv isors o r engineers .

Con t r ac to r ' s Employees

Th i s sec t ion d e a l s with t h e d u t i e s and r e s t r i c t i o n s placed upon a

c o n t r a c t o r ' s employees. The following a r e examples of t he se concepts :

CONTRACTOR'S EMPLOYEES

The Contractor s h a l l perform t h e Work in an o rde r ly and workmanlike manner, enforce s t r i c t d i s c i p l i n e and o r d e r among i t s employees, and s h a l l exe rc i s e due d i l i g e n c e so a s not t o employ on t h e Work any u n f i t person o r anyone unsk i l l ed i n t h e work assigned t o such person.

At ten t ion i s c a l l e d t o t h e f a c t t h a t c e r t a i n por t ions of t h e Work c a l l s f o r workers s k i l l e d not only i n t h e i r t r a d e bu t speciaTized in t he p a r t i c u l a r type of work requi red by t h i s Cont rac t . The Contractor s h a l l ensure t h a t such Work sha l l be done by workers who a r e s k i l l e d and spec i a l i zed i n t h e work t o which they a r e ass igned .

The Contractor s h a l l use loca l m a t e r i a l , equipment, subcont rac tors and workers when such use w i l l not r e s u l t i n add i t i ona l expense t o t h e Contractor .

The Contractor sha l l immediately remove from the Work any person considered by t h e Owner t o be incompetent, disposed t o be d i s o r d e r l y , o r unsa t i s f ac to ry or undes i rab le f o r any o t h e r reason , and such person sha l l not again be employed on t h e Work without t he p r i o r w r i t t e n consent of t he Owner.

The Con t r ac to r ' s employees' c a r s and Con t r ac to r ' s c a r s and t r u c k s sha l l be parked in a r e a s express ly s e t a s i d e and des igna ted a s parking a r eas .

The Con t r ac to r ' s employees sha l l be provided with means of i d e n t i f i c a t i o n showing employee's payrol l number and t h e Con t r ac to r ' s name. The employees s h a l l be required t o d i s p l a y t h i s i d e n t i f i c a t i o n where p l a in ly v i s i b l e t o t he Owner's s e c u r i t y personnel and in spec to r s . Employees fa i : ing t o do t h i s s h a l l , upon request of t he Owner, be summarily d ischarged . The C o n t r a c t o r ' s employment records and job records sha l l include any reasonable information a s may be required by Owner and sha l l be made a v a i l a b l e if requested.

The Cont rac tor , i t s employees, a l l of i t s subcont rac tors and t h e i r employees sha l l comply w i t h the requirements of t he J o b s i t e s e c u r i t y program. I t i s t he prime funct ion of the Owner's guard s e r v i c e t o provide a per iphera l pa t ro l and guard s t a t i o n s t o prevent unauthorized removal of t he Owner's p roper ty and prevent unauthorized eo t rance of personnel and v e h i c l e s , This may be accomplished by checking employees lunch boxes o r veh ic l e s leav ing the ga te t o d e t e c t t h e removal of s to l en a r t i c l e s . I t s h a l l remain the Con t r ac to r ' s r e s p o n s i b i l i t y t o po l i ce i t s own employees and p ro t ec t i t s own premises and property a g a i n s t t h e f t o r unauthorized removal of job r e l a t e d property such a s t o o l s , s u p p l i e s , m a t e r i a l s and equipment from t h e J o b s i t e . The Owner and/or Engineer w i l l not be respons ib le f o r any of t he Con t r ac to r ' s l o s s e s .

Tes t s and Inspec t ions ; Access t o t he Work

This s ec t ion d e a l s with con t r ac tu ra l r i g h t of e n t r y f o r t e s t s and in spec t ions

by an owner. The following wording i s i l l u s t r a t i v e of t h i s concept:

TESTS AND INSPECTIONS: ACCESS TO THE WORK

* The Owner o r Engineer, o r t h e i r des ignees , sha l l a t a l l reasonable t imes have access t o t he Work. The Owner reserves t h e r i g h t t o perform such examinations, inspec t ions and t e s t s of equipment, mater ia l and workmanship a s i t may d e s i r e t o a s su re i t s e l f t h a t t h e Work meets a l l s p e c i f i e d requirements.

The Contractor and a l l of i t s subcont rac tors sha l l permit u n r e s t r i c t e d access t o t h e Owner, o r Engineer o r t h e i r des ignees f o r t he purpose of conducting such examinations, i n spec t ions and t e s t s a t a l l reasonable t imes and places where t he Work i s in p roces s , sha l l provide s u f f i c i e n t , s a f e and proper f a c i l i t i e s such a s ladders , s c a f f o l d s , openings, and drop l i g h t s required f o r such acces s , and sha l l make ava i l ab l e any and a l l da t a which i s r e l e v a n t t o the performance of t he Work.

The C o n t r a c t o r s h a l l a ? s o g i v e t h e S e c r e t a r y o f Labor , o r h i s / h e r a u t h o r i z e d r e p r e s e n t a t i v e , a r i g h t o f e n t r y t o any s i t e o f C o n t r a c t per formance f o r t h e purpose o f i n s p e c t i n g , i n v e s t i g a t i n g , o r c a r r y i n g o u t any o f t h e S e c r e t a r y ' s d u t i e s , i n c l u d i n g t h o s e d u t i e s under t h e Occupa t iona l S a f e t y and H e a l t h A c t o f 1970, as amended (OSHA).

I f t h i s C o n t r a c t , laws, o rd inances , r u l e s , r e g u l a t i o n s o r o r d e r s o f any p u b l i c a u t h o r i t y h a v i n g j u r i s d i c t i o n r e q u i r e any Work t o s p e c i f i c a l l y b e i n s p e c t e d , t e s t e d , o r approved by someone o t h e r than t h e C o n t r a c t o r , t h e C o n t r a c t o r s h a l l g i v e t h e E n g i n e e r t i m e l y n o t i c e o f r e a d i n e s s t h e r e f o r . The C o n t r a c t o r s h a l l f u r n i s h t h e Engineer t h e r e q u i r e d c e r t i f i c a t e s o f i n s p e c t i o n , t e s t i n g o r a p p r o v a l . A l l t e s t s , i n s p e c t i o n s and/or a p p r o v a l s w i l 7 be a r r a n g e d and/or pe r fo rmed b y t h e C o n t r a c t o r , u n l e s s o t h e r w i s e s p e c i f i e d i n t h i s C o n t r a c t , i n accordance w i t h t h e methods p r e s c r i b e d by t h e American S o c i e t y f o r T e s t i n g and M a t e r i a l s o r such o t h e r a p p l i c a b l e methods as may b e r e q u i r e d by t h i s C o n t r a c t , laws, o r d i n a n c e s , r u l e s , r e g u l a t i o n o r o r d e r s o f any p u b l i c a u t h o r i t y h a v i n g j u r i s d i c t i o n . I f any Work r e q u i r e d t o be i n s p e c t e d , t e s t e d o r approved i s covered up w i t h o u t w r i t t e n approva l o r consen t o f t h e Owner, i t must, i f d i r e c t e d b y t h e Eng ineer f o r t h e Owner, b e uncovered f o r o b s e r v a t i o n a t C o n t r a c t o r ' s expense. The c o s t o f a l l i n s p e c t i o n s , t e s t s and approva l r e q u i r e d under t h i s s u b s e c t i o n , o t h e r t h a n t h o s e a r ranged f o r o r p e r f o r m e d by t h e Owner o r Eng ineer , s h a l l b e b o r n e by t h e C o n t r a c t o r u n l e s s o t h e r w i s e p r o v i d e d i n t h i s C o n t r a c t .

Any Work w h i c h f a i l s t o meet t h e requ i remen ts o f any t e s t , i n s p e c t i o n o r approva l , and any Work wh ich does meet t h e r e q u i r e m e n t s o f any t e s t , i n s p e c t i o n o r approva l b u t does n o t meet t h e r e q u i r e m e n t s o f t h i s Con t rac t , s h a l l be c o n s i d e r e d d e f e c t i v e .

Observa t ions , i n s p e c t i o n s , t e s t s o r a p p r o v a l s b y pe rsons o t h e r than t h e C o n t r a c t o r s h a l l n a t r e l i e v e t h e C o n t r a c t o r f r o m i t s o b l i g a t i o n s t o p e r f o r m t h e Work i n accordance w i t h t h e r e q u i r e m e n t s o f t h i s C o n t r a c t .

In a d d i t i o n t o t e s t s , i n s p e c t i o n s and a p p r o v a l s s p e c i f i c a l l y r e q u i r e d by t h i s C o n t r a c t , t h e Owner may d i r e c t t h a t t h e C o n t r a c t o r l e a v e Work exposed o r uncovered f o r t i m e l y i n s p e c t i o n o r o b s e r v a t i o n b y t h e Owner o r Eng ineer . I f any Work i s covered c o n t r a r y t o such d i r e c t i o n , i t must , i f r e q u i r e d b y t h e Owner, b e uncovered f o r i n s p e c t i o n or o b s e r v a t i o n and r e p l a c e d a t t h e C o n t r a c t o r ' s expense.

If any Work has been covered w h i c h t h e Owner has n o t s p e c i f i c a l l y r e q u e s t e d t o observe p r i o r t o i t s b e i n g covered, o r i f t h e Engineer c o n s i d e r s i t necessary o r a d v i s a b l e t h a t covered Work be i n s p e c t e d o r t e s t e d b y o t h e r s , t h e C o n t r a c t o r , a t t h e Owner 's r e q u e s t , s h a l l uncover, expose o r o t h e r w i s e make a v a i l a b l e f o r o b s e r v a t i o n , i n s p e c t i o n o r t e s t i n g , as t h e Eng ineer may r e q u i r e , t h a t p o r t i o n of t h e Work i n q u e s t i o n , f u r n i s h i n g a17 necessary l a b o r , m a t e r i a l and equipment. I f i t i s f o u n d t h a t such Work i s d e f e c t i v e o r does n o t meet t h e requ i remen ts o f t h i s C o n t r a c t , t h e C o n t r a c t o r s h a l l bear a l l expenses o f uncover ing , exposure, o b s e r v a t i o n , i n s p e c t i o n ,

t e s t i n g and r e c o v e r i n g o f such Work. I f , however, such Work i s f ound n o t t o be d e f e c t i v e and meets t h e requ i remen ts o f t h i s C o n t r a c t , t h e C o n t r a c t o r may be a l l owed an i n c r e a s e i n t h e C o n t r a c t P r i c e o r e x t e n s i o n o f t h e C o n t r a c t Time d i r e c t l y a t t r i b u t a b l e t o such u n c o v e r i n g , exposure , o b s e r v a t i o n , i n s p e c t i o n , t e s t i n g and r e c o v e r i n g .

N o t h i n g c o n t a i n e d i n t h e above paragraphs s h a l l i n any way v o i d , r e s t r i c t o r l i m i t t h e r i g h t o f t h e Owner o r Engineer t o l a t e r c o n d u c t such pe r fo rmance t e s t s as i t may d e s i r e , o r v o i d , r e s t r i c t o r l i m i t t h e Owner 's r i g h t s under t h i s C o n t r a c t .

Tu rnover

T h i s s e c t i o n d e s c r i b e s t h o s e c i r cumstances when a c o n t r a c t o r t u r n s t h e

equipment o v e r t o an owner. An example f o l l o w s :

TURNOVER

When i n t h e C o n t r a c t o r ' s o p i n i o n , t h e c o n s t r u c t i o n and c o n s t r u c t i o n t e s t i n g o f t h e Work has been completed and i s ready f o r t u r n o v e r t o t h e Owner f o r per formance t e s t i n g , and t h e Work can be t e s t e d o r i n s p e c t e d under r e p r e s e n t a t i v e o p e r a t i n g c o n d i t i o n s , t h e C o n t r a c t o r s h a l l so n o t i f y t h e Owner i n w r i t i n g , i d e n t i f y i n g any m ino r i t e m s o f c l e a n u p wh ich remain t o b e completed. The Owner o r i t s des ignee w i l l i n s p e c t t h e Work and w i l l g i v e t h e C o n t r a c t o r w r i t t e n n o t i c e o f e i t h e r acceptance f o r t u r n o v e r t o t h e Owner o r o f u n f i n i s h e d Work o r d e f i c i e n c i e s . The b a s i s f o r such i n s p e c t i o n and n o t i f i c a t i o n s h a l l be whether each p a r t o f t h e Work conforms w i t h t h e requ i remen ts o f t h i s C o n t r a c t . Upon l a t e r c o m p l e t i o n o f any such u n f i n i s h e d Work o r c o r r e c t i o n o f any such d e f i c i e n c i e s as covered by s a i d Owner's n o t i c e s , t h e f o r e g o i n g p rocedure f o r C o n t r a c t o r n o t i f y i n g t h e Owner i n w r i t i n g w i t h r e s p e c t t o c o m p l e t i o n o f such s p e c i f i e d u n f i n i s h e d Work o r c o r r e c t i o n o f such d e f i c i e n c i e s s h a l l b e repea ted .

C o n t r a c t o r ' s Records

T h i s s e c t i o n r e q u i r e s t h e C o n t r a c t o r t o m a i n t a i n a p p r o p r i a t e r e c o r d s f o r a l l r e i m b u r s a b l e c o s t s a s s o c i a t e d w i t h t h e work, and t h e f o l l o w i n g word ing i s r e p r e s e n t a t i v e o f t h e concep t .

CONTRACTOR'S RECORDS

The C o n t r a c t o r s h a l l m a i n t a i n a p p r o p r i a t e books and r e c o r d s w i t h r e s p e c t t o wages, s a l a r i e s , re imbursab les , c o s t s , charges, f e e s and expenses r e l a t i n g t o t h e Work, compensated f o r on a r e i m b u r s a b l e c o s t b a s i s , and such r e c o r d s s h a l l be s u p p o r t e d by p a y r o l l s , i n v o i c e s , vouchers , cor respondence and o t h e r documents e v i d e n c i n g i n p r o p e r d e t a i l t h e n a t u r e and p r o p r i e t y o f cha rges . A l l checks, p a y r o l l s , i n v o i c e s and o t h e r documents p e r t a i n i n g i n whole o r i n p a r t t o t h e Work, compensated f o r on a r e i m b u r s a b l e c o s t b a s i s s h a l l be c l e a r l y i d e n t i f i e d , r e a d i l y a c c e s s i b l e and, t o t h e e x t e n t f e a s i b l e , k e p t s e p a r a t e and a p a r t f rom a l l o t h e r such documents n o t

r e l a t e d t o t h e Work. Contractor sha l l provide f r e e access t o such books and records t o the Owner during reasonable bus iness hours and t h e r i g h t t o examine and a u d i t t he same and t o make o r have made copies of t r a n s c r i p t s therefrom a s necessary t o allow inspec t ion of a l l d a t a , documents, proceedings and a c t i v i t i e s r e l a t i n g t o t h e Work performed under t h i s Contract . The Contractor s h a l l l ikewise s p e c i f i c a l l y r equ i r e a1 1 subcont rac tors t o conform t o t h e requirements of t h i s Sect ion.

Copies of t h e Con t r ac to r ' s cons t ruc t ion books of account and copies of o t h e r o r i g i n a l records of account a t t h e J o b s i t e , inc luding any dup l i ca t e f i e l d payroll records r e l a t i n g t o Work performed on a reimbursable c o s t b a s i s , sha l l be de l ive red t o t he Owner upon completion of t h e Work.

Suspension of' Work. This sec t ion addresses t he se i n s t ances when t h e owner may

wish t o suspend work f o r e i t h e r cause o r convenience. The fol lowing wording

is i l l u s t r a t i v e of t h e concept .

SUSPENSION FOR CAUSE

The Owner may temporari ly suspend the Work under t h i s Cont rac t o r any por t ion t h e r e o f , when the performance thereof by t he Cont rac tor i s unr .a t i s fac tory t o obta in t he r e s u l t s required by t h e Drawings and S p e c i f i c a t i o n s .

a The methods by which the Cont rac tor performs i t s work a r e e n t i r e l y t h e r e s p o n s i b i l i t y of the Contractor . The Owner's r i g h t t o suspend Work under t h i s sec t ion i s intended so l e ly t o see t h a t t h e Work being performed by t h e Contractor w i l l r e s u l t in t h a t requi red by the Drawings and Spec i f i ca t i ons and s h a l l not o b l i g a t e t h e Owner t o review t h e e f f i c i e n c y , adequacy o r s a f e ty of t he C o n t r a c t o r ' s methods o r means of cons t ruc t ion .

I f t h e u n s a t i s f a c t o r y condit ion i s promptly co r r ec t ed by t h e Cont rac tor , t h e Owner w i l l au tho r i ze resumption of t h e Work. I f t h e Cont rac tor does not promptly c o r r e c t the u n s a t i s f a c t o r y cond i t i ons , Owner may proceed under t he provis ions of t h e Sec t ion e n t i t l e d "TERMINATION FOR DEFAULTN of t h e Standard Terms and Condit ions. The Cont rac tor s h a l l not be e n t i t l e d t o add i t i ona l compensation a s a r e s u l t of suspension of Work under t h i s s ec t ion .

SUSPENSION FOR CONVENIENCE

The Owner has t he absolu te r i g h t t o temporari ly suspend, o r extend t h e time f o r performance of t h e Work, o r any por t ion t h e r e o f , of t h i s Contract a t anytime by wr i t t en n o t i c e t o t he Cont rac tor . The rea f t e r , t h e Cont rac tor s h a l l resume the f u l l performance of t h e Work when d i r e c t e d t o do so by the Owner.

T h i s r i g h t t o t e m p o r a r i l y suspend, o r ex tend t h e t i m e f o r per formance o f , t h e Work i s i n t e n d e d o n l y t o f a c i l i t a t e , t h e Dwner 's convenience and s h a l l n o t be cons t rued as imposing upon t h e Owner o r Eng ineer any d u t y t o i n s p e c t t h e Work o r t o i n s p e c t , r e v i e w o r approve t h e methods by w h i c h t h e C o n t r a c t o r pe r fo rms i t s Work.

I n t h e e v e n t o f suspension o r e x t e n s i o n o f t h e per formance o f t h e Work, t h e C o n t r a c t o r s h a l l be e n t i t l e d t o re imbursement f o r a d d i t i o n a l c o s t s reasonab ly and n e c e s s a r i l y i n c u r r e d by t h e t h e C o n t r a c t o r i n suspending o r ex tend ing t h e Work and d u r i n g t h e p e r i o d o f suspens ion o r e x t e n s i o n t o t h e e x t e n t t h a t such a d d i t i o n a l c o s t s a r e i n c u r r e d , which c o s t s s h a l l be determined i n accordance w i t h t h e S e c t i o n e n t i t l e d "CHANGES I N THE WORK". The C o n t r a c t o r s h a l l use i t s b e s t e f f o r t s t o m in im ize such c o s t s . The schedules f o r per formance o f t h e Work s h a l l be amended by mutua l agreement t o r e f l e c t any such suspens ion o r e x t e n s i o n .

Force Majeure

T h i s s e c t i o n addresses these c i r cumstances which a re beyond t h e reasonab le

c o n t r o l o f t h e C o n t r a c t o r and Owner. The f o l l o w i n g w o r d i n g i s i l l u s t r a t i v e of

g e n e r a l l y accep ted concepts :

FORCE MAJEURE

N o t w i t h s t a n d i n g a n y t h i n g t o t h e c o n t r a r y , n e i t h e r P a r t y s h a l l be i n any way r e l i e v e d o f o r excused i n i t s per formance under t h i s C o n t r a c t f o r d e l a y s due t o normal weather c o n d i t i o n s , i n c l u d i n g b u t n o t l i m i t e d t o seasonal r a i n f a l l and seasonal f l o o d i n g .

N o t w i t h s t a n d i n g a n y t h i n g t o t h e c o n t r a r y , n e i t h e r P a r t y s h a l l be i n any way r e l i e v e d o f o r excused i n i t s per formance under t h i s C o n t r a c t f o r d e l a y s due t o reasonab ly f o r s e e a b l e a c t s o r f a i l u r e t o a c t b y f e d e r a l , s t a t e o r l o c a l a d m i n i s t r a t i v e agenc ies .

P a r t i a l U t i l i z a t i o n of Work. T h i s s e c t i o n addresses t h e Owner 's r i g h t and

r e s p o n s i b i l i t y t o u t i l i z e a p o r t i o n o f t h e work. The f o l l o w i n g example

i l l u s t r a t e s t h e concep t :

PARTIAL UTILIZATIDN OF WORK

P r i o r t o f i n a l payment, t h e Owner may r e q u e s t t h e C o n t r a c t o r i n w r i t i n g t o p e r m i t t h e Owner t h e use o f a s p e c i f i e d p a r t o f t h e Work t h a t may be used w i t h o u t s i g n i f i c a n t i n t e r f e r e n c e t o t h e c o n s t r u c t i o n o f t h e o t h e r p a r t s o f t h e Work. I f t h e C o n t r a c t o r ag rees , i t w i l l c e r t i f y t o t h e Owner and Engineer t h a t s a i d p a r t o f t h e Work i s s u b s t a n t i a l l y comp le te and r e q u e s t t h e Owner t o i s s u e a c e r t i f i c a t e o f S u b s t a n t i a l Complet ion f o r t h a t p a r t . Tu rnover o r use o f p o r t i o n s o f t h e Work as necessary t o p e r m i t o t h e r

c o n t r a c t o r s t o p e r f o r m t h e i r work i s n o t s u b j e c t t o t h e p rocedure d e s c r i b e d i n t h i s s e c t i o n .

Changes For Work. T h i s s e c t i o n d e s c r i b e s t h e r e s p o n s i b i l i t i e s of b o t h t h e

C o n t r a c t o r and Owner t o w a r d s changes i n t h e work t o be per formed. The

f o l l o w i n g word ing i s i l l u s t r a t i v e o f t h e c o n c e p t s i n v o l v e d .

CHANGES IK THE UORK

The Owner, t h r o u g h t h e Owner 's a u t h o r i z e d r e p r e s e n t a t i v e , may, a t any t i m e o r f rom t i m e t o t ime, make changes i n t h e Work by an o r d e r i n w r i t i n g t o t h e C o n t r a c t o r . Un less o t h e r w i s e i n d i c a t e d by t h e Owner, t h e C o n t r a c t o r s h a l l p roceed w i t h t h e Work i n v o l v e d upon r e c e i p t o f such o r d e r . A l l such Work s h a l l be execu ted under t h e a p p l i c a b l e c o n d i t i o n s o f t h i s C o n t r a c t . I f any change causes an i n c r e a s e o r decrease i n t h e C o n t r a c t P r i c e o r an e x t e n s i o n o r s h o r t e n i n g o f t h e C o n t r a c t Time, an e q u i t a b l e a d j u s t m e n t w i l l be made and such ad jus tment w i l l be a u t h o r i z e d by a Change Order . I n o r d e r t o comply w i t h t h e p r o v i s i o n s o f t h i s S e c t i o n , t h e C o n t r a c t o r s h a l l f u r n i s h , i n a t i m e l y manner, whatever i n f o r m a t i o n may be reasonab ly r e q u i r e d by t h e Owner t o make a d e c i s i o n a s t o t h e d e s i r a b i l i t y o f such changes.

The Engineer may, w i t h approva l o f t h e Owner 's P r o j e c t R e p r e s e n t a t i v e , i s s u e F i e l d Orders a u t h o r i z i n g minor changes o r a l t e r a t i o n s i n t h e Work n o t i n v o l v i n g e x t r a c o s t and c o n s f s t e n t w i t h t h e o v e r a l l i n t e n t o f t h i s C o n t r a c t .

Except i n an emergency endanger ing l i f e o r p r o p e r t y , no change shall be made by C o n t r a c t o r w i t h o u t an o r d e r i n w r i t i n g a u t h o r i z i n g t h e change and no c l a i m by C o n t r a c t o r f o r a d d i t i o n a l compensat ion s h a l l be v a l i d u n l e s s so ordered.

CHANGES I N SCHEDULE

The C o n t r a c t Time and C o n t r a c t d e l i v e r y and comp le t ion d a t e s may be a d j u s t e d o n l y by a Change Order . I f t h e C o n t r a c t o r i s e n t i t l e d by t h i s C o n t r a c t t o make a c l a i m f o r an ad jus tmen t i n t h e C o n t r a c t Time o r C o n t r a c t d e i i v e r y and co rnp ie t i on d a t e s , t h e C o n t r a c t o r s h a l l g i v e w r i t t e n n o t i f i c a t i o n o f i t s i n t e n t t o submi t a c l a i m d e l i v e r e d t o t h e Owner and Engineer w i t h i n t e n (10) w o r k i n g days o f t h e occur rence o f t h e even t g i v i n g r i s e t o t h e c l a i m .

C la ims f o r e x t e n s i o n s o f t i m e t o t h e p a t h o f c r i t i c a l e v e n t s w i l l be approved o n l y i f t h e Work o r t h e e v e n t t h a t causes t h e d e l a y a f f e c t s t h e p a t h o f c r i t i c a l even ts of t h e P r o j e c t . I n such case, an e x t e n s i o n o f t i m e w i l l be a l l o w e d o n l y equal t o t h e number o f days by which t h i s p a t h o f even ts i s l e n g t h e n e d wh ich i n c l u d e s such a d d i t i o n a l t i m e as i s r e a s o n a b l y necessary t o enable t h e C o n t r a c t o r t o resume per fo rmance of i t s o b l i g a t i o n s . I f r e q u i r e d b y t h e

Engineer, t h e C o n t r a c t o r s h a l l i n d i c a t e t h i s p a t h o f c r i t i c a l even ts , by d iagram o r n a r r a t i v e , i n such d e t a i l as may be necessary t o j u s t i f y i t s c l a i m and e s t a b l i s h t h e number o f days d e l a y . The p a t h o f c r i t i c a l event; men t ioned h e r e i n i s d e f i n e d a s t h a t s e r i e s o f i n t e r d e p e n d e n t c o n s t r u c t i o n e v e n t s t h a t must be s e q u e n t i a l l y per formed and t h a t r e q u i r e a l o n g e r t o t a l t ime t o p e r f o r m t h a n any o t h e r such s e r i e s .

CHANGES I N CONTRACT PRICE

The C o n t r a c t P r i c e c o n s t i t u t e s t h e t o t a l compensation payab le t o t h e C o n t r a c t o r f o r p e r f o r m i n g t h e Work. A l l d u t i e s , r e s p o n s i b i l i t i e s and o b l i g a t i o n s ass igned t o o r under taken by t h e C o n t r a c t o r i n p e r f o r m i n g t h e Work d e s c r i b e d i n t h i s C o n t r a c t s h a l l be a t i t s expense w i t h o u t change i n t h e C o n t r a c t P r i c e .

The C o n t r a c t P r i c e may be a d j u s t e d o n l y by a Change Order . I f t h e C o n t r a c t o r i s e n t i t l e d b y t h i s C o n t r a c t t o make a c l a i m f o r an ad jus tmen t i n t h e C o n t r a c t P r i c e , t h e C o n t r a c t o r s h a l l g i v e w r i t t e n n o t i f i c a t i o n o f i t s i n t e n t t o submi t a c l a i m d e l i v e r e d t o t h e Owner and Eng ineer w i t h i n t e n ( 1 0 ) w o r k i n g days o f t h e occurence o f t h e event g i v i n g r i s e t o t h e c l a i m .

The v a l u e o f any Work covered by a Change Order o r o f any c l a i m f o r an a d j u s t m e n t i n t h e C o n t r a c t P r i c e s h a l l be de te rm ined i n one o f t h e f o l l o w i n g ways:

i - By a p p l i c a t i o n o f u n i t p r i c e s t o t h e q u a n t i t i e s o f t h e i t ems i n v o l v e d , where t h e Work i n v o l v e d i s covered by u n i t p r i c e s c o n t a i n e d i n t h i s C o n t r a c t o r i n t h e Change Order .

ii - By mutua l acceptance o f a lump sum.

iii - On t h e b a s i s o f a c t u a l d i r e c t c o s t o f l a b o r , m a t e r i a l , i n c i d e n t a l expenses and s u b c o n t r a c t e d s e r v i c e s pe r fo rmed on a r e i m b u r s a b l e c o s t b a s i s n e c e s s a r i l y i n c u r r e d i n good f a i t h and pa id d i r e c t l y by t h e C o n t r a c t o r and approved b y t h e Owner as d e s c r i b e d h e r e i n , p l u s a pe rcen tage t h e r e o f f o r t h e C o n t r a c t o r ' s f e e as s p e c i f i e d i n t h i s C o n t r a c t . Work per formed on t h i s b a s i s must b e accompanied b y a guaran teed maximum n o t t o exceed amount which amount s h a l l be d e t e r m i n e d by t h e C o n t r a c t o r . I n t h e e v e n t t h e a c t u a l d i r e c t c o s t o f l a b o r , m a t e r i a l , i n c i d e n t a l expenses and s u b c o n t r a c t e d s e r v i c e s p l u s t h e C o n t r a c t o r ' s f e e exceeds t h e e s t a b l i s h e d guaran teed maximum n o t t a exceed amount, payment t o t h e C o n t r a c t o r by t h e Owner f o r such expenses and s e r v i c e s p l u s f e e w i l l be l i m i t e d t o s a i d guaran teed maximum n o t t o exceed amount.

The d i r e c t c o s t o f l a b o r s h a l l i n c l u d e a l l l a b o r d i r e c t l y on t h e C o n t r a c t o r ' s j o b p a y r o l l . i n c l u d i n q c o n t r i b u t i o n s t o funds and o t h e r f r i n g e b e n e f i t s r e q u i r e d under t h e terms o f c o l l e c t i v e

b a r g a i n i n g agreements, s a l a r i e s and wages o f t h e C o n t r a c t o r ' s employees ( o t h e r t h a n super in tendence) s t a t i o n e d a t t h e J o b s i t e , and S o c i a l S e c u r i t y , Unemployment I n s u r a n c e and Worke r ' s Compensation app l i cab1 e t o t h e f o r e g o i n g .

The d i r e c t c o s t o f m a t e r i a l s s h a l l i n c l u d e m a t e r i a l s , t o o l s ( o t h e r than "sma l l t o o l s " as d e f i n e d h e r e i n ) and suppl i e s purchased and d e l i v e r e d t o t h e J o b s i t e by t h e C o n t r a c t o r ; a p p l i c a b l e sa les and use t a x e s , l o a d i n g and u n l o a d i n g , demurrage, express, f r e i g h t and c a r t a g e charges.

The d i r e c t i n c i d e n t a l expense s h a l l i n c l u d e a p r o r a t a p o r t i o n o f preniium f o r t h e C o n t r a c t o r ' s bond, i f any, and f o r such i n s u r a n c e as may be r e q u i r e d by t h e Owner, i n a d d i t i o n t o i n s u r a n c e r e q u i r e d i n c o n n e c t i o n w i t h l a b o r , and s p e c i f i c t e l e g r a p h i c and t e l e p h o n e charges i n c u r r e d s o l e l y on account o f such Work.

F o r Work i n v o l v i n g t h e use o f t r a n s p o r t a t i o n equipment and heavy equipment such as t r u c k s , t r a c t o r s , d e r r i c k s , c ranes, excava to rs , e t c . , t h e C o n t r a c t o r s h a l l be re imbursed f o r t h e i r use a t r e n t a l p r i c e s s p e c i f i e d i n t h i s C o n t r a c t . Such r e n t a l p r i c e s s h a l l i n c l u d e t h e f u r n i s h i n g o f a l l necessary power o r f u e l , and l a b o r and m a t e r i a l s t o l u b r i c a t e , grease, r i g , m a i n t a i n and r e p a i r equ iament , b u t , u n l e s s o t h e r w i s e s p e c i f i c a l l y agreed t o , s h a l l n o t i n c l u d e l a b o r f o r o p e r a t i n g purposes. For heavy equipment n o t s e l f - p r o p e l l e d o r r e a d i l y movable, e x t r a expense f o r t r a n s p o r t a t i o n t o and from t h e J o b s i t e w i l l be p a i d f o r a t agreed p r i c e s i n a d d i t i o n t o r e n t a l r a t e s . Such r e n t a l r a t e s and t r a n s p o r t a t i o n p r i c e s s h a l l c o n s t i t u t e t h e complete payment f o r equipment f u r n i s h e d , i n c l u d i n g p r o f i t , super in tendence , genera? overhead and o t h e r i n d i r e c t expenses, and s h a l l be exc luded f rom t h e amount t o w h i c h a percentage f e e i s a p p l i e d .

I n r e s p e c t t o any Work f u r n i s h e d under t h e p r o v i s i o n s o f t h i s Subsec t ion iii, t h e C o n t r a c t o r s h a l l , p r i o r t o 10:OO A . M . on t h e f o l l o w i n g day, f u r n i s h t o t h e Eng ineer d a i l y t i m e s l i p s showing t h e name and number o f each worker and p i e c e o f equipment employed the reon , w i t h t h e t i m e worked, t h e c h a r a c t e r o f Work i n v o l v e d , t h e wages o r r e n t a l p r i c e s p a i d o r t o be p a i d , and a d a i l y memorandum o f t h e m a t e r i a l , used on such Work showing t h e amount and c h a r a c t e r o f such m a t e r i a l f r o m whom purchased, and t h e amount p a i d o r t o be p a i d t h e r e f o r .

Fo r subcon t rac ted s e r v i c e s , t h e C o n t r a c t o r s h a l l be re imbursed f o r each o f i t s r e s p e c t i v e s u b c o n t r a c t o r ' s a c t u a l d i r e c t c o s t of l a b o r , m a t e r i a l and i n c i d e n t a l expense de te rm ined on t h e same b a s i s as s e t f o r t h i n Subsec t ion iii.

The pe rcen tage f e e s h a l l cove r t h e C o n t r a c t o r ' s p r o f i t ; supe r in tendence ; p e r s o n a l s e r v i c e s and expense o f t h e C o n t r a c t o r ' s pe rsonne l ass igned t o main o r b ranch o f f i c e s ; main and b r a n c h o f f i c e overhead and genera l expense o f any k i n d ; and t h e c o s t , t r a n s p o r t a t i o n , use, d e p r e c i a t i o n , wear and t e a r o r l o s s o f " s m a l l t o o l s " . "Smal l t o o l s i i s h a l l be d e f i n e d as t o o l s and equipment o t h e r t h a n ma jo r equipment where t h e i n i t i a l c o s t p e r i t e m does n o t exceed 5500.00. The amount o f l a b o r bonus payments and premium payments made by t h e C o n t r a c t o r t o l a b o r , on accoun t o f premium t i m e worked and a l l o w e d f o r payment t o t h e C o n t r a c t o r as d i r e c t c o s t o f l a b o r s h a l l be e x c l u d e d f r o m t h e amount t o wh ich a pe rcen tage f e e i s a p p l i e d . I n t h e e v e n t a d d i t i o n a l s u p e r v i s o r s o r t e c h n i c a l s p e c i a l i s t s a r e r e q u i r e d t o p e r f o r m t h e e x t r a scope o f work , the C o n t r a c t o r s h a l l p r o v i d e such p e r s o n n e l , s u b j e c t t o t h e Owner 's p r i o r w r i t t e n a p p r o v a l , n o t as p a r t o f t h e pe rcen tage f e e b u t a t a r a t e m u t u a l l y ag reed upon between t h e Owner and t h e C o n t r a c t o r .

The maximum percen tage t h a t s h a l l be a l l o w e d f o r t h e C o n t r a c t o r ' s pe rcen tage fee s h a l l be as f o l l o w s :

( a ) F o r a l l such Work done by i t s own o r g a n i z a t i o n , t h e C o n t r a c t o r mzy add up t o p e r c e n t ( ) o f i t s a c t u a l d i r e c t c o s t o f l a b o r , m a t e r i a l and i n c i d e n t a l expense.

( b ) F o r a l l Work done b y s u b c o n t r a c t o r s , each r e s p e c t i v e s u b c o n t r a c t o r may add up t o t w e n t y p e r c e n t (20%) o f i t s a c t u a l d i r e c t c o s t o f l a b o r , m a t e r i a l and i n c i d e n t a l expense f o r t h e S u b c o n t r a c t o r l s pe rcen tage fee ; and C o n t r a c t o r may add up t o

p e r c e n t ( %) o f S u b c o n t r a c t o r ' s t o t a l c o s t s .

S u b c o n t r a c t s . T h i s s e c t i o n d e s c r i b e s t h e r e l a t i o n s h i p between t h e C o n t r a c t o r

and i t s s u b c o n t r a c t o r s . The f o l l o w i n g word ing i s i l l u s t r a t i v e o f t h e concep t .

SUBCONTRACTS

I f t h e C o n t r a c t o r s h a l l cause any p a r t o f i t s J o b s i t e a c t i v i t i e s t o be p e r f o r m e d b y a s u b c o n t r a c t o r , t h e p r o v i s i o n s o f t h i s C o n t r a c t s h a l l a p p l y t o such s u b c o n t r a c t o r and i t s o f f i c e r s , a g e n t s o r employees i n a l l r e s p e c t s as i f t h e y were employees o f t h e C o n t r a c t o r , and t h e C o n t r a c t o r s h a l l n o t t h e r e b y be d i s c h a r g e d f r o m any o f i t s o b l i g a t i o n s and l i a b i l i t y hereunder , b u t s h a l l be l i a b l e hereunder f o r a l l a c t s and omiss ions o f t h e s u b c o n t r a c t o r , i t s o f f i c e r s , agen ts and employees, as i f t h e y were employees o f t h e C o n t r a c t o r . No s u b c o n t r a c t s h a l l be made w i t h o u t w r i t t e n n o t i c e t o t h e Owner o f t h e s u b c o n t r a c t and w r i t t e n r e p l y t h a t t h e Owner has no o b j e c t i o n s b u t no such r e p l y s h a l l a f f e c t t h e p r o v i s i o n s h e r e o f . Copies o f a l l s u b c o n t r a c t s s h a l l be f u r n i s h e d t o t h e Eng inee r .

The C o n t r a c t o r s h a l l n o t s u b l e t i t s J o b s i t e a c t i v i t i e s t o any one s u b c o n t r a c t o r i n a g r e a t e r monetary pe rcen tage o f t h e C o n t r a c t P r i c e t h a n w i l l be pe r fo rmed by i t s own o r g a n i z a t i o n w i t h o u t p r i o r approva l o f t h e Owner, i n w r i t i n g . I n a d d i t i o n , t h e C o n t r a c t o r s h a l l n o t s u b l e t i t s J o b s i t e a c t i v i t i e s i n an amount more t h a n - p e r c e n t () o f t h e C o n t r a c t P r i c e . I n t h e e v e n t t h e Owner approves t h e C o n t r a c t o r ' s s u b l e t t i n g i t s J o b s i t e a c t i v i t i e s t o a degree g r e a t e r t h a n t h e percentages s t a t e d above, t h e above percentage l i m i t a t i o n s s h a l l a p p l y w i t h r e s p e c t t o s a i d S u b c o n t r a c t o r and i t s sub -subcon t rac to rs .

Labor Requirements and F r i n g e B e n e f i t s - J o b s i t e A c t i v i t i e s On ly . T h i s

s e c t i o n d e s c r i b e s t h e p rocedures t h e C o n t r a c t o r i s r e q u i r e d t o use i n

compensat ing i t s employees. The f o l l o w i n g word ing i s i l l u s t r a t i v e o f t h e

concep ts .

LABOR REQUIREMENTS AND FRINGE BENEFITS - JOBSITE ACTIVITIES ONLY

I t s h a l l be mandatory upon a l l c o n t r a c t o r s and s u b c o n t r a c t o r s t o pay t h e i r s k i l l e d and u n s k i l l e d employees employed d i r e c t l y on t h e s i t e o f such Work, a t i n t e r v a l s n o t t o exceed one (1) week, and w o r k e r s s h a l l n o t be r e q u i r e d t o work more than t e n (10) hours i n any t w e n t y - f o u r (24) hour p e r i o d , excep t i n cases o f emergency o r a u t h o r i z e d ove r t ime ; t h e C o n t r a c t o r and i u b c o n t r a c t o r s s h a l l keep, o r cause t o be k e p t , an a c c u r a t e r e c o r d showing names and o c c u p a t i o n s o f a l l l a b o r e r s , journeymen, and a p p r e n t i c e s employed by them and showing t h e a c t u a l r a t e o f wages p e r d iem o r p e r hour o f each s a i d worker , t h e c o r r e c t n e s s o f wh ich s h a l l be sworn t o by t h e C o n t r a c t o r and/or Subcon t rac to rs and s a i d r e c o r d s h a l l be open t o i n s p e c t i o n a t t h e J o b s i t e by t h e Owner o r by an a u t h o r i z e d agen t o f t h e Owner n o t o t h e r w i s e i n t e r e s t e d i n t h e P r o j e c t .

C o n t r a c t o r unders tands t h a t i t w i l l be r e s p o n s i b l e f o r i t s own l a b o r r e l a t i o n s w i t h any u n i o n r e p r e s e n t i n g i t s employees, and t h e C o n t r a c t o r agrees t o n e g o t i a t e and seek t o a d j u s t any d i s p u t e s between t h e C o n t r a c t o r and i t s employees o r anyone r e p r e s e n t i n g such employees. Whenever t h e C o n t r a c t o r has knowledge o f any a c t u a l o r p o t e n t i a l l a b o r d i s p u t e w h i c h may a f f e c t t h e Work, C o n t r a c t o r s h a l l immed ia te l y g i v e n o t i c e t h e r e o f , i n c l u d i n g a l l r e l e v a n t i n f o r m a t i o n r e g a r d i n g any a c t i o n s o r proposed s t e p s t h e C o n t r a c t o r i s t a k i n g o r w i l l t a k e t o r e s o l v e t h e d i s p u t e , t o Owner. The C o n t r a c t o r s h a l l i n c l u d e t h e substance o f t h i s S e c t i o n i n a l l c o n t r a c t s w i t h Subcon t rac to rs and r e q u i r e t h a t a l l such s u b c o n t r a c t o r s i m m e d i a t e l y i n f o r m t h e C o n t r a c t o r o f any knowledge t h e S u b c o n t r a c t o r may have o f any a c t u a l o r p o t e n t i a l l a b o r d i s p u t e w h i c h may a f f e c t t h e Work.

Waiver of Claims. This s ec t ion desc r ibes t he Cont rac tor ' s ob l iga t ion t o

complete t h e work a s s e t f o r t h i n t he Cont rac t . The following example i s

r ep re sen t s t h e concept.

WAIVER O F CLAIMS

The Con t r ac to r ' s ob l iga t ion t o perform and complete t he Work i n accordance with t h i s Contract sha l l be abso lu t e . Approval of any progress o r f i n a l payment by the Engineer, issuance of a c e r t i f i c a t e of Subs t an t i a l Completion, any payment by the Owner t o t he Contractor under t h i s Cont rac t , any use o r occupancy of t he Work o r any p a r t t he reo f by the Owner, any a c t of acceptance by the Owner o r any f a i l u r e t o do so , o r any co r r ec t ion of f a u l t y o r d e f e c t i v e work by t h e Owner sha l l not c o n s t i t u t e waiver of any of t he Owner's r i g h t s under t h i s Contract nor c o n s t i t u t e an acceptance of t he Work not in accordance with t h i s Contract .

Temporary F a c i l i t i e s . This s ec t ion desc r ibes t he nature of those temporary

cons t ruc t ion f a c i l i t i e s which w i l l be made a v a i l a b l e t o the Cont rac tor . The

fol lowing wording i l l u s t r a t e s of t he concepts .

TEMPORARY FACILITIES

The bui ld ings o r s t r u c t u r e s f o r housing workers, and the e r e c t i o n of o t h e r forms of s h e l t e r s a t t h e J o b s i t e w i l l be permitted only a t such p laces and times a s des igna ted by Engineer. Contractor s h a l l a t a l l t imes maintain, in a manner s a t i s f a c t o r y t o Engineer, s a n i t a r y condi t ions in and about such bu i ld ing , s t r u c t u r e s and s h e l t e r s .

* Except a s otherwise provided in t h i s Cont rac t , necessary s a n i t a r y f a c i l i t i e s f o r use by t he C o n t r a c t o r ' s employees a t the J o b s i t e s h a l l be furnished and maintained by the Cont rac tor in such manner and a t such poin ts a s s h a l l be approved by t h e Engineer. The Cont rac tor sha l l s t r i c t l y enforce t he use of such f a c i l i t i e s .

All of t h e C o n t r a c t o r ' s support a r e a s on the J o b s i t e s h a l l be assigned by the Engineer. The Cont rac tor sha l l confine i t s o f f i c e , shops, s t o rage , assembly and equipment and vehic le parking t o t h e a r e a s so ass igned . Should t he Cont rac tor f i nd i t necessary o r advantageous t o use any add i t i ona l land outs ide the J o b s i t e f o r any purpose whatever, t he Cont rac tor s h a l l , a t i t s own expense, provide and make i t s own arrangements f o r t h e use of such add i t i ona l land .

Temporary s t r u c t u r e s such a s f a b r i c a t i o n shops, s torage bu i ld ings and o f f i c e s w i l l not be permit ted wi th in t he p l an t s t r u c t u r e s . Such temporary s t r u c t u r e s w i l l be permit ted ou t s ide and ad j acen t t o t h e p l an t s t r u c t u r e s wi th in an a r e a des igna ted by the Engineer. All such bu i ld ings sha l l be cons t ruc ted o f f i r e r e t a r d e n t m a t e r i a l s .

- The Contractor sha l l perform e l e c t r i c and water hook-ups t o t he Owner suppl ied sources and provide necessary d i s t r i b u t i o n of same.

Overnight s torage of mobile yard equipment such a s hydraul ic c r anes , l o a d e r s , e t c . , wi l l not be permit ted within t he p l a n t s t r u c t u r e s .

Permi ts , Fees, Notices. This s ec t ion desc r ibes the Con t r ac to r ' s ob l iga t ion

r e l a t i v e t o t h e securing of necessary permits . The fol lowing wording i s

i l l u s t r a t i v e of t he concepts .

PERMITS, FEES, NOTICES

The Cont rac tor sha l l secure and pay f o r a l l permits , governmental fees and l i c e n s e s necessary f o r i t t o c a r r y on i t s business and f o r proper execut ion and completion of t h e Work unless otherwise spec i f i ed i n t h i s Cont rac t .

Health and Sa fe ty . This s ec t ion desc r ibe t he hea l th and sa fe ty precaut ions

t h e Cont rac tor i s t o implement a t t h e J o b s i t e . The fol lowing wording i s

i l l u s t r a t i v e of t he concepts .

HEALTH AND SAFETY

The importance of t h e s a f e t y of a l l personnel on the P ro j ec t shaTl be recognized by the Cont rac tor , and acc ident prevention sha l l be an i n t e g r a l p a r t of the Con t r ac to r ' s opera t ions . The Contractor sha l l t a k e a l l p recaut ions necessary and sha l l bear s o l e r e s p o n s i b i l i t y f o r t h e s a f e ty of t he Work and the s a f e ty and adequacy of t h e methods and means i t employs in performing the Work.

The Cont rac tor sha l l t a k e a l l precaut ions f o r t h e s a f e ty and hea l th o f , and sha l l provide a l l p ro t ec t ion necessary t o prevent damage, i n j u r y o r l o s s t o :

( i ) All employees on t h e Work and a l l o t h e r persons w h o may be a f f e c t e d thereby;

( i i ) All Work and a l l m a t e r i a l s and equipment t o be incorporated t h e r e i n , whether in s to rage on o r o f f t he J o b s i t e , under t h e ca re , custody o r con t ro l of t he Contractor or i t s Subcontractors

* The Contractor sha l l comply with a l l app l i cab l e f e d e r a l , s t a t e and loca l laws, ordinances, r u l e s and r egu la t i ons pe r t a in ing t o t h e h e a l t h and s a f e t y of persons o r proper ty , inc luding those promulgated pursuant t o OSHA. The Cont rac tor sha l l e r e c t and maintain a s requi red by e x i s t i n g cond i t i ons and progress of t he Work a l l sa feguards f o r s a f e ty and p ro t ec t ion inc luding , without l i m i t a t i o n , pos t ing danger s igns and o t h e r warnings aga ins t hazards, enforcing

a p p l i c a b l e s a f e t y and h e a l t h and f i r e r e g u l a t i o n s and n o t i f y i n g owners and use rs o f a d j a c e n t u t i l i t i e s .

The C o n t r a c t o r s h a l l m a i n t a i n a s a f e t y program, i n c l u d i n g a w e e k l y c r a f t s a f e t y meet ing, on t h e J o b s i t e . The purpose o f such s a f e t y program s h a l l be t o m a i n t a i n a s a f e work p l a c e and t o ensure compl iance w i t h t h e s a f e t y r e g u l a t i o n s and s tandards adopted p u r s u a n t t o OSHA t o g e t h e r w i t h a l l o t h e r a p p l i c a b l e r u l e s and r e g u l a t i o n s .

The C o n t r a c t o r s h a l l c o o p e r a t e w i t h t h e Owner, Eng ineer and a l l o t h e r c o n t r a c t o r s i n t h e i r r e s p e c t i v e s a f e t y programs. The C o n t r a c t o r ' s s a f e t y program s h a l l con fo rm t o t h e P r o j e c t s a f e t y program and s h a l l be s u b j e c t t o c o o r d i n a t i o n and m o n i t o r i n g by t h e Engineer . The C o n t r a c t o r ' s r e p r e s e n t a t i v e s h a l l a t t e n d t h e week ly P r o j e c t S a f e t y Committee meet ings.

Any c i v i i o r c r i m i n a l p e n a l t i e s imposed upon t h e C o n t r a c t o r p u r s u a n t t o OSHA by governmental agenc ies hav ing j u r i s d i c t i o n s h a l l n o t c o n s t i t u t e r e i m b u r s a b i e c o s t s o f t h e C o n t r a c t o r . I n a d d i t i o n , t h e C o n t r a c t o r s h a l l re imburse t h e Owner and Engineer f o r c o s t s o f compl iance and, t o t h e e x t e n t p e r m i t t e d by law, any p e n a l t i e s r e l a t i n g t o OSHA c i t a t i o n s i n c u r r e d by Owner o r Eng ineer a r i s i n g f r o m t h e C o n t r a c t o r l s OSHA v i o l a t i o n s . The C o n t r a c t o r s h a l l remedy a t i t s expense t h e s i t u a t i o n wh ich produced t h e c i t a t i o n w i t h i n t h e t i m e s e t f o r t h i n such c i t a t i o n . A copy o f a l l OSHA c i t a t i o n r e p o r t s , as w e l l as any S t a t e s a f e t y i n s p e c t i o n r e p o r t s , sha l ; be s u b m i t t e d t o t h e Eng ineer immed ia te l y upon r e c e i p t i n each i n s t a n c e b y C o n t r a c t o r . A copy o f each s e r i o u s a c c i d e n t and f a t a l i t y r e p o r t s h a l l a l s o be s u b m i t t e d t o t h e Eng ineer .

The C o n t r a c t o r s h a l l t a k e a l l necessary p r e c a u t i o n s t o assure t h a t i t s employees and t h o s e o f i t s Subcon t rac to rs d u r i n g t h e t i m e t h e y a r e w o r k i n g a t t h e J o b s i t e comp7y w i t h a i l a p p l i c a b l e s a f e t y , h e a l t h and pe rsonne l r u l e s and r e g u l a t i o n s i n e f f e c t . Owner may r e q u i r e t h e C o n t r a c t o r t o remove f r o m t h e P r o j e c t employees who f a i l t o obey such r u l e s and r e g u l a t i o n s a t no i n c r e a s e d c o s t t o Owner. The Owner's s a f e t y i n s p e c t o r s w i l l have access t o t h e J o b s i t e a t a l l t i m e s .

The C o n t r a c t o r s h a l l f u r n i s h a l l reasonable i n f o r m a t i o n concern ing t h e s a f e t y o f i t s o p e r a t i o n s on t h e P r o j e c t as may be r e q u i r e d b y Eng ineer , i n c l u d i n g r e c o r d s o f a c c i d e n t s t o employees, exposure h o u r s o f employees and l o s t t i m e due t o acc iden ts , when so reques ted b y t h e Eng ineer .

Excep t as o t h e r w i s e p r o v i d e d f o r i n t h i s Con t rac t , t h e C o n t r a c t o r s h a l l be s o l e l y r e s p o n s i b l e f o r t h e des ign , c o n s t r u c t i o n , i n s t a l l a t i o n , use, and adequacy o f a l l temporary suppor ts , s h o r i n g , b r a c i n g , s c a f f o l d i n g , machinery o r equipment, s a f e t y p r e c a u t i o n s o r d e v i c e s and s i m i l a r i t e m s used by t h e C o n t r a c t o r and S u b c o n t r a c t o r s d u r i n g performance o f t h e Work.

Owner sha l l provide P ro j ec t f i r s t - a i d f a c i l i t i e s ( i nc lud ing ambulance s e r v i c e and the s e rv i ce s of a q u a l i f i e d f i r s t - a i d a t t e n d a n t during normal working hours) which s h a l l be a v a i l a b l e a t t h e main cons t ruc t ion a r ea f o r the C o n t r a c t o r ' s use. Use of t h e Owner's f a c i l i t i e s by t h e Contractor i s cont ingent upon Con t r ac to r s execution of t h e F i r s t Aid F a c i l i t i e s Hold Harmless Agreement, which i s a t tached he re to and made a p a r t o f t h i s Cont rac t . Should t h e Contractor f a i l t o execute such hold harmless agreement, t h e Contractor sha l l provide and main ta in i t s own adequate f i r s t a i d f a c i l i t i e s f o r t h e dura t ion of t h i s Cont rac t .

When t h e use o r s torage of explos ives o r o the r hazardous ma te r i a l s o r equipment i s necessary f o r execution of t h e Work, t h e Cont rac tor sha l l exe rc i s e t h e utmost ca re and s h a l l c a r r y on such a c t i v i t i e s under t he supervision of proper ly q u a l i f i e d personnel .

The Contractor s h a l l not permit o r s u f f e r t h e i n t roduc t ion o r use of i n tox ica t ing 1 iquor o r n a r c o t i c s o r con t ro l l ed subs tances on t h e J o b s i t e o r upon any of t h e grounds occupied o r c o n t r o l l e d by t h e Cont rac tor .

A11 m a t e r i a l s and products conta in ing a sbes tos a r e express ly p roh ib i t ed from being brought i n t o o r used a t t h e J o b s i t e , e i t h e r a s a temporary means of cons t ruc t ion o r a s a p a r t of t h e permanent i n s t a l l a t i o n .

Pub l i ca t i ons , Photoqraphs and Commerciai A c t i v i t i e s . This s ec t ion r e s t r i c t s

t he commercial purposes f o r which the Cont rac tor may wish t o use t h e

Contract . The fol lowing example i l l u s t r a t e s t he concept .

PUBLICATIONS, PHOTOGRAPHS AND COMMEKIAL ACTIVITIES

The Contractor s h a l l not take any photographs, make any announcement o r r e l ea se any information concerning t h i s Cont rac t o r t h e Pro jec t o r any p a r t thereof t o any member of t h e pub l i c , p r e s s o r o f f i c i a l body, f o r adve r t i s ing o r o the r commercial purposes, un l e s s p r i o r w r i t t e n consent i s obtained from the Owner.

The Contractor s h a l l not e s t a b l i s h any commercial a c t i v i t y o r i s s u e concessions o r permits of any kind t o t h i r d p a r t i e s f o r e s t a b l i s h i n g commercial a c t i v i t i e s on lands owned o r c o n t r o l l e d by t h e Owner . The Contractor s h a l l not al low i t s employees t o engage in any commercial a c t i v i t i e s on t h e Jobsi t e .

T i t l e t o Mater ia l s Found

This s ec t ion informs the Contractor t h a t any m a t e r i a l s found dur ing t h e

cons t ruc t ion a c t i v i t i e s a r e t he proper ty of t he Owner. The fol lowing wording

i s i l l u s t r a t i v e of t he concept .

TITLE TO MATERIALS FOUND

The t i t l e t o water , s o i l , rock, g r a v e l , sand, mine ra l s , t imber and any o the r ma te r i a l s developed o r obtained in t he excavat ion o r o ther opera t ions of t h e Contractor o r any of i t s subcont rac tors and the r i g h t t o use sa id item o r t o dispose of same i s hereby exp res s ly reserved by t h e Owner. Neither t h e Cont rac tor , Subcontractors nor any of t h e i r r ep re sen ta t i ves o r employees s h a l l have any r i g h t , t i t l e o r i n t e r e s t i n s a id ma te r i a l s . The Contractor s h a l l use o r d i spose of such m a t e r i a l s i n accordance with t h i s Contract o r , a s determined by t h e Owner and s u b j e c t t o t he app rop r i a t e Change Order , a f f o r d the Owner t h e r i g h t t o use o r consume these ma te r i a l s .

Pro tec t ion of Property of Others

The sec t ion desc r ibes t he requirements f o r t h e Cont rac tor in pro tec t ing t h e

property of o t h e r s during the execution of t he Cont rac t . The fojlowing

wording i s i 7 l u s t r a t i v e of t he concept .

PROTECTION OF PROPERTY OF OTHERS

The Cont rac tor s h a l l , un l e s s otherwise s p e c i f i c a l l y provided f o r , make s u i t a b l e arrangements wi th and obta in a l l necessary permits from governmental a u t h o r i t i e s and r a i 1 roads f o r t h e c o n s t w c t i o n of a1 1 s t r u c t u r e s underneath o r w i th in road and r a i l r o a d rights-of-way and f o r p ro t ec t ing and safeguard ing t h e pub l i c using t h e roads and t h e movement of t r a i n s from acc iden t and d e l a y , a l l in accordance w i t h t he requirements of t h e owners t he reo f .

The Cont rac tor sha l l not damage, c l o s e , o r o b s t r u c t any u t i l i t y i n s t a l l a t i o n , highway, road o r o the r property u n t i l permits t h e r e f o r have been obtained. I f f a c i l i t i e s a r e c lo sed , obs t ruc t ed , damaged o r rendered unsafe by the Con t r ac to r ' s ope ra t ions , t h e Contractor s h a l l , a t i t s own expense, make such r e p a i r s and provide such temporary guards, l i g h t s and o t h e r s i g n a l s a s necessary o r requi red f o r s a f e t y and a s w i l l be acceptable t o t h e Owner, governmental a u t h o r i t i e s o r the owners of such i n s t a l l a t i o n , highway, road o r o t h e r property.

Unless otherwise s p e c i f i c a l l y provided in t h i s Cont rac t , t he Cont rac tor sha l l not do any Work t h a t would d i s r u p t o r otherwise i n t e r f e r e with the opera t ion of any p i p e l i n e , te lephone o r e l e c t r i c t ransmission l i n e , d i t c h o r o the r s t r u c t u r e , nor e n t e r upon lands i n t h e i r na tura l s t a t e u n t i l approved by t h e Owner.

Pro tec t ion of Environment

This sec t ion desc r ibes those a c t i v i t i e s t he Cont rac tor i s t o undertake i n

order t o p ro t ec t t h e environment.

Pro tec t ion of t h e environment s h a l l be an i n t e g r a l p a r t of t he Con t r ac to r ' s ope ra t ions hereunder. Unless otherwise provided f o r in t h i s Cont rac t , t h e Contractor s h a l l , a t no add i t i ona l c o s t t o the Owner, f u r n i s h a l l such f a c i l i t i e s and measures a s may be necessary t o prevent contamination of t he atmosphere and bodies of water .

No substance o r mater ia l sha l l be permit ted t o e n t e r any stream, r i v e r , l ake o r o t h e r body of water which may p o l l u t e t h e water o r c o n s t i t u t e subs tances o r m a t e r i a l s harmful t o f i s h o r w i l d l i f e . In t he event a substance or mater ia l e n t e r s a s t ream, r i v e r , lake o r o t h e r body of water , t he Contractor s h a l l immediately n o t i f y t h e Engineer of such happening.

Dust, smoke o r o t h e r a i r contaminants from any source whatsoever s h a l l not be discharged i n t o t h e atmosphere in v io l a t i on of laws, r u l e s and r e g u l a t i o n s of governmental a u t h o r i t i e s having j u r i s d i c t i o n .

The Cont rac tor s h a l l use reasonable e f f o r t s t o minimize d u s t cond i t i ons i n a l l a r ea s within t h e s i t e of t he Con t r ac to r ' s ope ra t ions . The Contractor may use methods s u i t a b l e t o t h e a rea involved inc luding sp r ink l ing , chemical t reatment o r o the r s tandard methods of d u s t c o n t r o l .

The Cont rac tor s h a l l no t i fy t he Engineer a t l e a s t twenty-four ( 2 4 ) hours p r i o r t o t h e need t o use explos ives in t he Con t r ac to r ' s performance of t h e Work. The use of explos ives in a manner which might d i s t u r b o r endanger t h e s t a b i l i t y , s a f e ty o r q u a l i t y of t he Work o r t he opera t ion of ad jacent p l a n t s and f a c i l i t i e s sha l l not be al lowed. Explosives sha l l be s t o r e d , handled and used a s prescr ibed by t h e app l i cab l e f e d e r a l , s t a t e and loca l laws and r egu la t i ons . The Cont rac tor s h a l l g ive spec ia l a t t e n t i o n t o t he immediate d isposa l of paper wrappings from explosives which wrappings may be de t r imenta l t o t he environment.

A17 add i t i ona l c o s t s t o t h e Owner, due t o t he Con t r ac to r ' s noncompliance wi th t he above, s h a l l be f o r t he account of t h e Cont rac tor .

Cleaning Up

The sec t ion desc r ibes t h e e f f e c t s requi red of t h e Contractor in keeping a

c l ean work p l ace . The fol lowing wording i s i l l u s t r a t i v e of t he concept

CLEANING UP

As p a r t of t he Work included i n t h i s Con t r ac t , t he Contractor sha l l remove d a i l y a l l d e b r i s r e s u l t i n g from i t s performance of t he Work and dispose of same a t a l oca t ion wi th in t he J o b s i t e a s des igna ted by the Engineer. All d e b r i s r e s u l t i n g from the r e p a i r o r removal of de fec t ive Work s h a l l be

disposed of o f f - s i t e by the Cont rac tor . As required by Owner, Cont rac tor sha l l completely remove and s a t i s f a c t o r i l y d ispose of a17 temporary works, sha l l t e a r down and d ispose of a l l temporary bui ld ings ; sha l l remove o r grade a l l embankments o r cofferdams made f o r i t s cons t ruc t ion purposes; sha l l s a t i s f a c t o r i l y f i l l excavat ions ; s h a l l remove a l l i t s p l a n t and equipment; sha l l s a t i s f a c t o r i l y d i spose of a l l rubbish r e s u l t i n g from t h e opera t ions under t h i s Cont rac t ; and sha l l do a l l work necessary t o r e s t o r e t h e t e r r i t o r y embraced within t h e s i t e of i t s opera t ions t o a t l e a s t a s good order and cond i t i on a s a t t h e beginning of t he Work under t h i s Contract . Fa i lure on the p a r t of t h e Cont rac tor t o abide by t h e s e condi t ions wi l l cause t he Owner t o perform, o r cause t o have performed, t h e necessary clean-up work. All c o s t s t o t h e Owner a s soc i a t ed wi th same sha l l be charged t o t h e C o n t r a c t o r ' s account .

Con t r ac to r ' s P lan t and Equipment

This sec t ion desc r ibes t h e requirements f o r the Con t r ac to r ' s cons t ruc t ion

p l a n t .

CONTRACTOR1 S PLANT AND EQUIPMENT

The Contractor sha l l provide and use on t h e Work only such cons t ruc t ion p l a n t and equipment capable of producing the q u a l i t y and quan t i t y of Work required by t h i s Contract and within t h e time o r t imes spec i f i ed i n t h i s Con t r ac t .

The Contractor s h a l l not remove i t s cons t ruc t ion p l an t o r equipment from the J o b s i t e before t h e Work i s f i n a l l y accepted without t h e Owner's w r i t t e n approval . Such approval s h a l l not be unreasonably withheld.

Emergency I n s t r u c t i o n s

This sec t ion desc r ibes t h e requirements of t he Contractor during emergency

s i t u a t i o n s . The fol lowing wording i s i T l u s t r a t i v e of t he concept .

EMERGENCY INSTRUCTIONS

When the Contractor o r i t s au thor ized r ep re sen ta t i ve i s no t p r e sen t on any p a r t of the Work where i t may be des i r ed t o g ive d i r e c t i o n s in t h e event of emergencies, i n s t r u c t i o n s may be given by t h e Owner o r Engineer and sha l l be received and c a r r i e d out by the superintendent o r foreman who may have charge of t h e p a r t i c u l a r p a r t of t he Work i n re fe rence t o which i n s t r u c t i o n s a r e g iven . I f reques ted , the Owner o r Engineer w i l l confirm such i n s t r u c t i o n s in w r i t i n g .

Lines and Grades

This sec t ion desc r ibes t h a t t he Owner w i l l e s t a b l i s h and maintain base l ines

and bench marks ad j acen t t o t he Work. The fol lowing wording i s i l l u s t r a t i v e

of t h e concept.

LINES AND GRADES

The Owner w i l l e s t a b l i s h and m a i n t a i n base l i n e s and bench marks a d j a c e n t t o t h e var i .ous s e c t i o n s o f Work. A l l such marks and s t a k e s mus t be c a r e f u l l y p r e s e r v e d b y t h e C o n t r a c t o r , and i n case o f t h e i r d e s t r u c t i o n by t h e C o n t r a c t o r o r any o f i t s employees, t h e y w i l l be r e p l a c e d by t h e Owner a t t h e C o n t r a c t o r ' s expense.

The C o n t r a c t o r s h a l l l a y o u t i t s work and be r e s p o n s i b l e f o r a l l l i n e s and e l e v a t i o n s , and s h a l l be r e s p o n s i b l e f o r t h e accuracy o f a l l d imens ions w i t h i n t h e v a r i o u s s e c t i o n s o f t h e Work a c c o r d i n g t o t h e f i g u r e d d imens ions on t h e Drawings.

* The C o n t r a c t o r s h a l l , as and t o t h e e x t e n t necessary f o r p roper accu racy and accompl ishment o f t h e Work, v e r i f y a l l measurements i n t h e f i e l d . E x i s t i n g d imens ions and c l e a r a n c e s s h a l ? be v e r i f i e d by t h e C o n t r a c t o r b e f o r e l a y i n g o u t t h e Work and any d imens ions o r c l e a r a n c e s found t o be i n e r r o r s h a l l be r e p o r t e d t o t h e Engineer immed ia te l y .

Time and O r d e r o f Complet ion and Cooperat ion. T h i s s e c t i o n d e s c r i b e s t h e

r e q u i r e m e n t t h a t t h e C o n t r a c t o r complete i t s work i n accordance w i t h t h e

schedule . The f o l l o w i n g word ing i s i l l u s t r a t i v e o f t h e concep t .

T IME AND ORDER OF COMPLETION AND COOPERATION

The C o n t r a c t o r agrees t h a t t h e Work s h a l l be commenced and c a r r i e d on a t such l o c a t i o n s , and i n t h e sequence, as may be r e q u i r e d t o meet t h e C o n t r a c t o r ' s d e t a i l e d schedule. Un less o t h e r w i s e s t a t e d i n t h i s C o n t r a c t , t h i s schedule has been e s t a b l i s h e d on t h e b a s i s o f w o r k i n g f i v e (5) days p e r week, s i n g l e s h i f t , e i g h t (8) hours p e r day o r f o u r (4 ) days p e r week, t e n (10) h o u r s p e r day . A d d i t i o n a l c o s t i n c u r r e d due t o t h e imp lementa t ion o f f o u r days p e r week t e n (10) hours p e r day work ing c o n d i t i o n s s h a l l be re imbursed i n accordance w i t h S e c t i o n h e r e o f e n t i t l e d "Changes i n C o n t r a c t P r i c e " .

i f t h e C o n t r a c t o r f a i l s t o p r o s e c u t e t h e Work w i t h necessary means and d i l i g e n c e t o ensure i t s c o m p l e t i o n w i t h i n t h e t i m e l i m i t o f t h e C o n t r a c t o r ' s d e t a i l e d schedule , then t h e Owner may g i v e t h e C o n t r a c t o r w r i t t e n n o t i c e t o t h a t e f f e c t and t h e C o n t r a c t o r s h a l l , i f so d i r e c t e d and a t i t s own expense, i n c r e a s e o r supplement t h e w o r k i n g f o r c e and equipment and pe r fo rm t h e Work on an o v e r t i m e o r m u l t i p l e s h i f t b a s i s t o such an e x t e n t as t o g i v e reasonable assurance o f compl iance w i t h t h e schedule and t h e r e q u i r e d q u a l i t y o f t h e Work. When so d i r e c t e d by t h e Owner, t h e C o n t r a c t o r s h a l l submi t f o r r e v i e w b y t h e Owner such supplementary c o n s t r u c t i o n schedules as may b e necessary t o demonst ra te t h e manner i n wh ich such compl iance w i l l be e s t a b l i s h e d . I f t h e C o n t r a c t o r does n o t p r o m p t l y comply w i t h such d i r e c t i o n s , t h e Owner may proceed under t h e p r o v i s i o n s o f t h e S e c t i o n h e r e o f e n t i t l e d "TERMINATION FOR DEFAULT". The f a i l u r e o f t h e Owner t o make such demands s h a l l n o t

r e l i e v e t h e C o n t r a c t o r o f i t s o b l i g a t i o n t o secure t h e q u a l i t y and t h e r a t e o f p r o g r e s s r e q u i r e d by t h i s C o n t r a c t o r i t s r e s p o n s i b i l i t y f o r l i q u i d a t e d damages.

The C o n t r a c t o r s h a l l n o t be p e r m i t t e d t o p e r f o r m Work o u t s i d e o f t h e normal w o r k i n g h o u r s w i t h o u t p r i o r approva l o f t h e Owner, u n l e s s o t h e r w i s e d i r e c t e d .

Should t h e Owner r e q u i r e , e i t h e r f o r t h e Owner's convenience o r f o r a c c e l e r a t i o n o f t h e schedule f o r c o m p l e t i o n o f t h e Work, t h a t t h e C o n t r a c t o r p e r f o r m Work o u t s i d e o f t h e normal work ing hours , t h e C o n t r a c t o r s h a l l do so, i n which case t h e C o n t r a c t o r s h a l l be re imbursed f o r t h e a c t u a l premium payments made f o r l a b o r o v e r t i m e worked. For an a u t h o r i z e d e x t e n s i o n o f t h e work week, t h e i n e f f i c i e n c y f a c t o r s s h a l l app ly i n accordance w i t h the p r o v i s i o n s o f t h e S e c t i o n e n t i t l e d "Over t ime and S h i f t Work'' o f t h e S p e c i a l C o n d i t i o n s . I n t h e e v e n t t h a t such o v e r t i m e work i s r e q u i r e d b y t h e Owner, t h e C o n t r a c t o r s h a l j , a t t h e end o f each day on w h i c h t h e o v e r t i m e i s worked, f u r n i s h t o t h e Engineer d a i l y t i m e s l i p s showing t h e employee 's p a y r o l l number o f each worker employed t h e r e o n w i t h t h e t i m e worked, t h e c h a r a c t e r o f work done and t h e wages t o b e p a i d .

The C o n t r a c t o r s h a l l coopera te w i t h t h e Owner i n schedu l ing t h e o r d e r o f per formance o f , and s h a l l pursue, t h e Work i n o r d e r t o m in im ize i n t e r f e r e n c e w i t h o t h e r work b e i n g per formed a t t h e J o b s i t e .

The Owner r e s e r v e s t h e r i g h t t o have o t h e r s as i t may e l e c t , e n t e r upon t h e p r o p e r t y o r l o c a t i o n upon which t h e Work h e r e i n contemplated i s b e i n g c o n s t r u c t e d , f o r t h e purpose o f i n s t a l l i n g o r e r e c t i n g such c o l l a t e r a l work as t h e Owner may r e q u i r e . Such c o l l a t e r a l work w i l l be i n s t a l l e d o r e r e c t e d w i t h as l i t t l e h i n d r a n c e o r i n t e r f e r e n c e as p o s s i b l e w i t h t h e C o n t r a c t o r . The C o n t r a c t o r s h a l l work i n harmony w i t h o t h e r c o n t r a c t o r s employed by t h e Owner, and any d i f f e r e n c e s o f o p i n i o n between c o n t r a c t o r s s h a l l be a r b i t r a t e d by t h e Owner b u t s h a l l n o t r e s u l t i n a d d i t i o n a l c o s t t o t h e Owner.

I n v o i c i n g and Payment Terms. T h i s s e c t i o n d e s c r i b e s t h e i n v o i c i n g and payment

p rocedures wh ich t h e C o n t r a c t o r i s r e q u i r e d t o f o l l o w . The f o l l o w i n g w o r d i n g

i s i l l u s t r a t i v e o f t h e concepts .

INVOICING AND PAYMENT TERMS

W i t h i n t e n (10 ) days a f t e r C o n t r a c t Execu t ion , t h e C o n t r a c t o r s h a l l submi t a breakdown o f t h e C o n t r a c t P r i c e (Schedule o f Values), i n c l u d i n g q u a n t i t i e s and u n i t p r i c e s , r e p r e s e n t i n g t h e C o n t r a c t o r ' s pay i t e m s . T h i s Schedule o f Values s h a l l be s a t i s f a c t o r y t o t h e Owner and Eng ineer i n fo rm and substance and s h a l l s u b d i v i d e t h e Work i n t o component p a r t s i n accordance w i t h t h e Owner's c o s t m o n i t o r i n g and s c h e d u l i n g requ i remen ts . Upon recommendation o f t h e Engineer and a p p r o v a l by t h e Owner, t h e Schedule o f Va lues w i l l be i n c o r p o r a t e d i n t o t h e A p p l i c a t i o n f o r Payment form.

When prosecuting Work, f o r which u n i t p r i c e s have been e s t ab l i shed i n t h i s Cont rac t , t he b a s i s of payment f o r such Work s h a l l be the ac tua l amount of Work completed in each case . The Cont rac tor agrees t h a t i t wi l l make no claim f o r l o s s of a n t i c i p a t e d p r o f i t s o r f o r any o t h e r damages because no Work i s ordered under c e r t a i n items o r because of a d i f f e r ence between t h e q u a n t i t i e s of Work a c t u a l l y completed and any est imated q u a n t i t i e s t h a t have been o r may be furnished t o t he Contractor by t h e Owner o r Engineer. The f i n a l q u a n t i t i e s incorporated i n t o t h e Work under items f o r which u n i t p r i c e s a r e e s t ab l i shed in t h i s Cont rac t w i l l be determined by the Engineer e i t h e r by measurement o r approximation. Items f o r which u n i t p r i c e s have been e s t ab l i shed a s t h e b a s i s of payment s h a l l be included a s Tine items in t he Schedule of Values r e f e r r e d t o above.

Applicat ion For Proqress Payments

i - As s e t f o r t h in t h i s Cont rac t o r a s otherwise agreed by the Owner and Cont rac tor , t h e Con t r ac to r s h a l l submit , b u t not more o f t en than once a month, t o the Engineer f o r review the Applicat ion of Payment f i l l e d ou t and signed by the Contractor covering a l l Work completed up t o t he da te of t h e Applicat ion f o r Payment and supported by such d a t a a s Owner r e q u i r e s . The Con t r ac to r ' s Application f o r Payment s h a l l inc lude a l l Change Orders. I f payment i s reques ted on the b a s i s of Equipment not incorporated in t he Work bu t de l ive red and s u i t a b l y s to red a t t h e J o b s i t e o r a t another l oca t ion agreed t o i n w r i t i n g , t he Applicat ion f o r Payment s h a l l a l s o be accompanied by such support ing da t a s a t i s f a c t o r y t o t h e Owner, inc luding evidence of appTicab1e insurance, a s w i l l e s t a b l i s h t h e Owner's t i t l e t o t h e Equipment and p ro t ec t t h e Owner's i n t e r e s t t h e r e i n .

ii - The Engineer w i l l , not l a t e r than f i f t e e n (15) working days a f t e r r e c e i p t of each Appl ica t ion of Payment, e i t h e r t ransmi t t o t h e Owner i t s wr i t t en recommendation f o r payment o r i nd i ca t e t o t h e Contractor the Engineer ' s r e j e c t i o n of t he Applicat ion f o r Payment advising the Cont rac tor of t he b a s i s f o r t he Engineer 's r e j e c t i o n . I n p a r t i c u l a r , t h e Con t r ac to r ' s r ep re sen ta t i ons of quan t i t y and q u a l i t y of Work completed o r otherwise e l i g i b l e f o r payment w i l l be reviewed by t h e Engineer. Disagreement by t h e Engineer with t h e q u a n t i t i e s and q u a l i t y of Work covered by an Applicat ion f o r Payment o r t he Con t r ac to r ' s unsa t i s f ac to ry prosecut ion of t h e Work may form a b a s i s f o r t he Engineer 's r e j e c t i o n of t he Appl ica t ion f o r Payment. With respec t t o any Applicat ion f o r Payment r e j ec t ed by t h e Engineer, t he Con t r ac to r may make necessary co r r ec t ions o r otherwise e f f e c t r e s o l u t i o n of t h e mat te r g iv ing r i s e t o such r e j e c t i o n . The Con t r ac to r may then resubmit t h e Application f o r Payment.

i i i - The Owner w i l l , not l a t e r than t h i r t y (30) days a f t e r r e c e i p t from the Engineer of a recommended Appl ica t ion f o r Payment, pay the Contractor t he amount recammended by t h e Engineer o r , not l a t e r than ten (10) working days a f t e r r e c e i p t , r e tu rn t h e Applicat ion f o r Payment t o the Cont rac tor , through t h e

Engineer, s t a t i n g in wr i t i ng the Owner's reasons f o r re fus ing payment.

i v - In t he event e i t h e r t h e Engineer o r Owner d i s ag ree with an Application f o r Payment, the Engineer o r Owner w i l l approve such por t ion of t h e app l i ca t i on which i s no t in d i spu te and t h e Owner w i l l make payment f o r such por t ion . The Engineer o r Owner w i l l , a t t he same t ime, n o t i f y t h e Cont rac tor regarding t h a t por t ion of t h e Applicat ion f o r Payment in d i spu te .

Unless otherwise provided o r agreed upon, from t h e amount s t i p u l a t e d in the Applicat ion fo r Payment and accepted by Owner a s e l i g i b l e f o r payment, a ten percent (10%) r e t en t ion wi l l be deducted, and from the remainder t he re w i l l f u r t h e r be deducted a l l previous payments. In add i t i on , Owner may deduct from sa id amount any amounts due Owner from Contractor under t h e terms of t h i s Cont rac t including c o s t s per ta in ing t o r e t e s t i n g of Equipment due t o Equipment f a i l u r e t o meet performance c r i t e r i a , i f app l i cab l e . In c a s e Contractor i s i n v io l a t i on of any condi t ion o r term of t h i s Con t r ac t , Owner may withhold any payment which may be due Cont rac tor on account of any Applicat ion of Payment.

Applicat ion f o r Payment s h a l l be made on the forms and in t he format prescribed by Owner.

Final Appl ica t ion For Payment

i - Upon wr i t t en no t i ce from t h e Contractor t h a t t he Work i s complete, the Owner, Engineer and Cont rac tor w i l l make a f i n a l inspec t ion of the Work. The Engineer w i l l n o t i f y t he Contractor in w r i t i n g of any p a r t i c u l a r s i n which t h i s inspec t ion revea ls t h a t t he Work i s incomplete o r de fec t ive . The Contractor sha l l immediately take such measures as a r e necessary t o complete o r remedy such incomplete o r de fec t ive Work.

i i - Af te r t he Contractor has completed the Work t o t he s a t i s f a c t i o n of t he Owner and Engineer including the d e l i v e r y of a l l maintenance and opera t ing i n s t r u c t i o n s , a s b u i l t drawings, schedules, guarantees , bonds, c e r t i f i c a t e s of i n spec t ion , and o the r documents, a l l a s required by t h i s Cont rac t , t h e Contractor may make, and the Owner w i l l pay, t h e C o n t r a c t o r ' s f i n a l Application of Payment following t h e same procedure a s s e t f o r t h above in Applicat ion f o r Progress Payments. The f i n a l Application f o r Payment sha l l be accompanied by complete and l e g a l l y e f f e c t i v e r e l e a s e s o r waivers , s a t i s f a c t o r y t o t h e Owner, of a l l l i e n s , c l a ims , s e c u r i t y i n t e r e s t s and encumbrances a r i s i n g ou t o f the performance of t h i s Cont rac t . In l i e u thereof and i f approved by the Owner, t h e Contractor may fu rn i sh ( a ) r e c e i p t s o r r e l e a s e s in f u l l ; ( b ) an a f f i d a v i t of Contractor t h a t t h e r e l e a s e s and r e c e i p t s include a l l l a b o r , s e r v i c e s , material and equipment f o r w h i c h a l i e n , c la im,

s e c u r i t y i n t e r e s t o r encumbrance c o u l d be f i l e d , and t h a t a l l p a y r o l l s , m a t e r i a l and equipment b i l l s , and o t h e r indebtedness connected w i t h t h e Work f o r which t h e Owner o r i t s p r o p e r t y m i g h t i n any way be r e s p o n s i b l e , have been p a i d o r o t h e r w i s e s a t i s f i e d ; and, ( c ) c o n s e n t o f t h e S u r e t y , i f any, t o f i n a l Appl i c a t i o n f o r Payment.

iii - I f , a f t e r S u b s t a n t i a l Corcp le t ion o f t h e Work, f i n a l comp le t ion t h e r e o f i s m a t e r i a l l y d e l a y e d t h r o u g h no f a u l t o f t h e C o n t r a c t o r , and such d e l a y i s c o n f i r m e d by t h e Owner and Engineer , t h e Owner may, w i t h o u t t e r m i n a t i n g t h i s C o n t r a c t , make payment o f t h e b a l a n c e due f o r t h a t p o r t i o n o f t h e Work completed. I f t h e v a l u e , on t h e b a s i s o f t h e C o n t r a c t P r i c e , o f t h e incomp le te Work i s l e s s t h a t t h e r e t e n t i o n , and i f a bond has been f u r n i s h e d , t h e C o n t r a c t o r s h a l l submi t t o t h e Owner t h e w r i t t e n consen t o f t h e S u r e t y t o t h e payment o f t h e ba lance due f o r t h a t p o r t i o n o f t h e Work completed p r i o r t o such payment. Such payment s h a l l be made under t h e terms and c o n d i t i o n s govern ing f i n a l A p p l i c a t i o n f o r Payment.

i v - I n a d d i t i o n t o t h e f o r e g o i n g requ i remen ts , t h e C o n t r a c t o r s h a l l , p r i o r t o t h e Owner 's payment o f t h e f i n a l A p p l i c a t i o n f o r Payment, execute and submi t t h e a f f a d a v i t e n t i t l e d " C e r t i f i c a t e o f C o n t r a c t Comp le t ion " .

v - Payment o f t h e r e t e n t i o n w i l l be made by t h e Owner n o t l a t e r than t h i r t y ( 30 ) days a f t e r t h e Owner 's payment o f t h e f i n a l A p p l i c a t i o n f o r Payment o r t h i r t y (30) days a f t e r a l l per formance w a r r a n t i e s o f t h e Equipment a r e met, wh ichever occu rs l a s t . I n t h e even t s t a r t o f per formance t e s t s a r e d e l a y e d due t o reasons beyond t h e C o n t r o l o f t h e C o n t r a c t o r f o r a p e r i o d i n excess o f one hundred and e i g h t y (180) days f rom n o t i f i c a t i o n by t h e C o n t r a c t o r t h a t t h e Equipment i s ready f o r such per formance t e s t s , payment o f t h e r e t e n t i o n w i l l be made by t h e Owner n o t l a t e r t h a n t h i r t y (30 ) days t h e r e a f t e r upon r e c e i p t o f a performance bond o r o t h e r m u t u a l l y agreed upon s e c u r i t y f rom t h e C o n t r a c t o r , i n an amount equa? t o t h e r e t e n t i o n .

C o n t r a c t Bonds. T h i s s e c t i o n d e s c r i b e s t h e requ i remen ts f o r bonding o f t h e

C o n t r a c t o r . The f o l l o w i n g word ing i s i l l u s t r a t i v e o f t h e concep t .

CONTRACT BONDS

The C o n t r a c t o r s h a l l f u r n i s h per formance and payment bonds as s e c u r i t y f o r t h e f a i t h f u l pe r fo rmance and payment o f a l l i t s o b l i g a t i o n s under t h i s C o n t r a c t w i t h r e s p e c t t o t he e r e c t i o n p o r t i o n o f t h e Work. These bonds s h a l l be i n amounts equal t o t h e p o r t i o n o f t h e C o n t r a c t P r i c e a p p l i c a b l e t o Work t o be per formed a t t h e J o b s i t e f o r b o t h U n i t 1 and U n i t 2 and i n such form and w i t h such

s u r e t y as a r e a c c e p t a b l e t o t h e Owner. Premiums f o r such per formance and payment bonds s h a l l be i n c l u d e d i n t h e C o n t r a c t P r i c e f o r t h e complete e r e c t i o n o f t h e Equipment f o r U n i t 1 and f o r U n i t 2 as a p p l i c a b l e . The Owner may r e q u i r e t h e C o n t r a c t o r t o f u r n i s h o t h e r bonds, i n such form and w i t h such s u r e t i e s as t h e Owner may r e q u i r e , t h e premiums t h e r e f o r t o be p a i d by t h e Owner. Such o t h e r bond fo rms and s u r e t i e s a r e s u b j e c t t o t h e C o n t r a c t o r ' s r e v i e w and approva l . The C o n t r a c t o r s h a l l f u r n i s h separate bonds f o r each U n i t . A l l bonds s h a l l be executed i n t h e fo rm p r o v i d e d b y t h e Owner and s h a l l accompany t h e executed C o n t r a c t when i t i s r e t u r n e d by t h e C o n t r a c t o r t o t h e Owner.

The s u r e t i e s on a l l bonds s h a l l be d u l y l i c e n s e d and a u t h o r i z e d t o do b u s i n e s s i n t h e s t a t e i n wh ich t h e P r o j e c t i s l o c a t e d . Each s u r e t y s h a l l be one w h i c h i s l i s t e d by t h e U n i t e d S t a t e s T reasury Depar tment as h o l d i n g a C e r t i f i c a t e o f A u t h o r i t y f rom t h e S e c u r i t y o f t h e T reasury as b e i n g a c c e p t a b l e as a s u r e t y on f e d e r a l bonds. No s u r e t y s h a l l be p a r t y t o a bond where in such s u r e t y ' s l i a b i l i t y exceeds t h e u n d e r w r i t i n g l i m i t a t i o n s s p e c i f i e d by t h e Treasury Department f o r t h e r e s p e c t i v e s u r e t y .

Bomb T h r e a t Procedure. T h i s s e c t i o n d e s c r i b e s t h e procedures f o r bomb t h r e a t s

t h a t t h e C o n t r a c t o r would f o l l o w d u r i n g such an even t . The f o l l o w i n g word ing

i s i l l u s t r a t i v e o f t h e concept

BOMB THREAT PROCEDURE

I n t h e e v e n t t h a t a bomb t h r e a t i s r e c e i v e d a t t h e J o b s i t e by t h e Owner o r Eng ineer , t h e C o n t r a c t o r s h a l l be adv ised o f t h e t h r e a t w i t h o u t d e l a y and g i v e n a l l a v a i l a b l e d e t a i l s . I f war ran ted , a bomb search w i l l be conducted b y a search team d e s i g n a t e d by t h e Engineer . I f de te rm ined necessary b y the Engineer , an emergency warn ing s i g n a l w i l l be g i v e n s i g n i f y i n g t h a t t h e E n g i n e e r ' s employees w i l l evacuate t h e a f f e c t e d a r e a . The w a r n i n g w i l l be f o l l o w e d by a second s i g n a l s i g n i f y i n g t h a t t h e E n g i n e e r ' s employees a r e t o r e t u r n t o work . The C o n t r a c t o r s h a l l be r e s p o n s i b l e f o r d e t e r m i n i n g t h e course o f a c t i o n i t s employees a r e t o f o l l o w when i t i s adv ised o f a bomb t h r e a t , i n c l u d i n g a d e c i s i o n , e i t h e r b e f o r e o r a f t e r t h e E n g i n e e r ' s warn ing s i g n a l , as t o whether t o evacuate t h e a f f e c t e d area o r c o n t i n u e w o r k i n g . The C o n t r a c t o r w i l l n o t be re imbursed f o r t i m e l o s t w h i l e i t s employees a r e absent f rom t h e i r p l a c e o f work as a r e s u l t o f a c t i o n s t a k e n i n response t o n o t i f i c a t i o n o f a bomb t h r e a t .

Appendix 7E

EXAMPLE OF SELLER PROVIDED MICROPROCESSOR BASED CONTROL SYSTEM DATA

7 . 4 . 1 Operating Experience on Similar Installation

.1 - Utility users list (name and telephone number)

. 2 - Non-utility users list (name and telephone number)

. 3 - Last major design change (describe and date)

. 4 - Component suppliers (list name and equipment)

7.4.2. Maintenance

. I - Test equipment required

. 2 - Training schools available (on-si te)

. 3 - Training schools available (off-si te)

. 4 - Spare parts required (on-si te)

. 5 - Spare parts available from manufacturer (on-shelf)

. 6 - Location of manufacturer's spare parts (city, state)

. 7 - Maintenance services available (describe)

.8 - Equipment warranty (describe)

M i c r o p r o c e s s o r

.1 - M a n u f a c t u r e r

. 2 - Model

. 3 - Processor c y c l e t i m e

.4 - R e g i s t e r s i z e ( b i t s )

.5 - A p p l i c a t i o n program response t i m e

1 - d i g i t a l

.2 - a n a l o g

. 6 - R e c o g n i t i o n t i m e o f manual i n p u t (maximum t i m e i n p u t c o n t a c t must be ma in ta ined)

.7 - I n c r e m e n t a l memory s i z e

.8 - Maximum i n t e g r a l memory s i z e

.9 - Type o f memory ( a p p l i c a t i o n program s t o r a g e )

. I 0 - Type o f programming

.11 - Method o f program backup

.12 - Type o f d i a g n o s t i c s

.13 - Maximum number o f d i g i t a l 1/0

.14 - Maximum number o f ana log I / O

.15 - Number and t y p e o f s t a n d a r d c o n t r o l a l g o r i t h m s

.16 - Type o f s t a n d a r d c o n t r o l a l g o r i t h m s

.17 - E f f e c t of power f a i l u r e on memory

.1 - AC - maximum t i m e o f b a t t e r y backup

. 2 - DC - maximum t i m e o f b a t t e r y backup

3 - Both - maximum t i m e o f b a t t e r y backup

7 .4 .4 A d d i t i o n a l Memory

.1 - R e s i d e n t

1 - Type o f memory

. 2 - Access speed

. 3 - E f f e c t o f power f a i l u r e

. 2 - Non-Resident

1 - Type o f memory

. 2 - Access speed

. 3 - E f f e c t o f power f a i l u r e

7.4.5 I n p u t / O u t p u t (I/O)

.1 - D i g i t a l Inputs

. I - V o l t a g e range AC

2 - Vo l tage range DC

. 3 - C u r r e n t range AC

4 - C u r r e n t range DC

5 - I s o l a t i o n v a l u e

.6 - Response t i m e

7 - I n t e r r o g a t i o n v o l t a g e s u p e r v i s i o n

.8 - O n - l i n e d i a g n o s t i c s ( d e s c r i b e )

. 9 - Surge w i t h s t a n d c a p a b i l i t y

. I D - LED s u p e r v i s i o n

.11- Number p e r c a r d

.2 - D i g i t a l Ou tpu ts

1 - Vo l tage range AC

.2 - Vo l tage range DC

. 3 - C u r r e n t maximum AC

. 4 - C u r r e n t maximum DC

.5 - S w i t c h i n g t i m e

.6 - F a i l u r e mode o p t i o n s (on l o s s o f m ic rop rocessor )

.7 - I s o l a t i o n v a l u e

.8 - Surge w i t hs tand

.9 - Number p e r c a r d

. lo- LED s u p e r v i s i o n

. 3 - Analog I n p u t s (4-20 ma) and thermocouple

.1 - Loop r e s i s t a n c e

. 2 - Accuracy (number o f b i t s per c o n v e r s i o n )

.3 - R e p e a t a b i l i t y i s o l a t i o n

.4 - On- l i ne d i a g n o s t i c ( d e s c r i b e )

. 5 - O n - l i n e c a l i b r a t i o n ( d e s c r i b e )

. 6 - Loss o f i n p u t sens ing

.7 - Number p e r c a r d

.8 - Loop power supp ly

. 4 - Analog o u t p u t s 4-20 ma

.1 - Maximum l o o p r e s i s t a n c e

.2 .- Accuracy

.3 - Number of bits per conversion

.4 - Repeatability . 5 - On-line diagnostic

. 6 - Open loop alarm

.7 - On-line calibration (describe)

.8 - Failure mode options (on loss of microprocessor)

Power Supply

. I - 125 VDC input

.1 - Maximum input voltage

. 2 - Minimum input voltage

.3 - Maximum input current (on-1 i ne)

.4 - Minimum input current ( standby)

.5 - Maximum ripple voltage

. 6 - Output voltages

- 7 - Monitoring and alarming (describe)

.1 - 120 VAC input

-1 - Maximum input voltages

- 2 - Minimum input voltage

.3 - Maximum input current (on-1 ine)

4 - Minmum input current ( standby)

- 5 - Maximum harmonic content

.6 - Output voltages

.7 - Monitoring and alarming (describe)

.3 - Distribution .1 - Redundancy

.2 - Fuse or breaker coordination (describe)

3 - Distribution diagram (attach)

. 4 - Coordination with mechanical and electrical systems (describe)

7.4.7 Internal Data Bus

.1 - Redundancy (describe)

. 2 - Speed

.3 - Security (describe)

7.4.8 External Data Bus

.1 - Redundancy (describe)

.2 - Speed

. 3 - Cable type

.4 - Maximum cable length

.5 - Configuration (radial, party line, combination]

.6 - Security (describe)

.7 - Operation (describe)

7.4.9 System Diagnostics

Seller shall completely explain system diagnostics, how they relate to 1/0 diagnostics, individual microprocessor diagnostics, and the operator/maintenance interface system.

Programming

Seller shall completely explain programming techniques including the following:

.1 - Type of language for interlock sequencing

. 2 - Type o f language for analog control

. 3 - Method of entering field programs by Purchaser

.4 - Standard Seller supplied programs including flow charts, analog control schematics, etc. (Seller shall supply complete information including written description o f each program and options available)

. 5 - Method of scaling inputs and outputs and modifying scales and ranges of each analog 1/0 device

. 6 - Method of calibrating control algorithms Support of Computer Type Peripheral

.1 - Operating experience on similar instal lation .1 - Utility users list (name and

telephone number)

. 2 - Non-utility users list (name and telephone number)

.3 - Last major design change (describe and date)

. 4 - Last major design change (date)

. 5 - Component suppliers (list name and equipment)

.1 - Maintenance

1 - Test equipment required

. 2 - Training schools available (on-si te)

. 3 - Training schools available (off-site)

.4 - Spare p a r t s required (on-si te )

. 5 - Spare parts a v a i l a b l e from manufacturer (on-shelf)

-6 - Location of manufacturer 's spare p a r t s ( c i t y , s t a t e )

.7 - Maintenance se rv i ce s ava i 1 able (desc r ibe )

.8 - Equipment warranty (desc r ibe )

REFERENCES

REFERENCES

Whi te , H . J . I n d u s t r i a l E l e c t r o s t a t i c P r e c i p i t a t i o n . Addison-Wesley P u b l i s h i n g Co. Reading, MA, 1963.

G a l l a e r , C. A. E l e c t r o s t a t i c P r e c i p i t a t o r Reference Manual. EPRI Repor t CS-2809. E l e c t r i c Power Research I n s t i t u t e , Pa lo A l t o , CA, January 1983*

Ka tz , J . The A r t o f E l e c t r o s t a t i c P r e c i p i t a t i o n . P r e c i p i t a t o r Technology, I n c . M u n h a l l , PA, 1979.

Standards o f Per formance f o r F o s s i l - F u e l - F i r e d Steam Generators . Federa l R e g i s t e r 2 No. 177, September 11, 1974.

D a h l i n , R . S . , and R . F. Al tman. " P r e d i c t i o n o f Mass Loading and P a r t i c l e S i z e D i s t r i b u t i o n f o r Use i n a P r e c i p i t a t o r S i z i n g Procedure. " EPRI R e p o r t CS-2908, E l e c t r i c Power Research I n s t i t u t e , Pa lo A l t o , CA, A p r i l 1983.

Smi th , W . B . , K. M. Cush ing, and J. D. McCain. Procedures Manual f o r E l e c t r o s t a t i c P r e c i p i t a t o r Eva lua t ion . EPA-600/7-77-059. U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park , NC, 1977.

Wi lson, R. R., and W . B. Smi th . "Procedures f o r Cascade Impac to r C a l i b r a t i o n and O p e r a t i o n i n Process Streams." EPA C o n t r a c t No. 68-02-3118, T .D. No. 114, U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park, NC, November, 1979.

Johnson, J . W . , G. I. C l i n a r d , L . G . F e l i x , and J . D. McCain. "A Computer-Based Cascade Impac to r Data Reduct ion System." EPA-600/7-78-042. U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park , NC, 1978.

Campbel l , K. S . , e t a l . "Economic E v a l u a t i o n o f F a b r i c F i l t r a t i o n ve rsus E l e c t r o s t a t i c P r e c i p i t a t i o n f o r U l t r a h i g h P a r t i c u l a t e C o l l e c t i o n E f f i c i e n c y . " EPRI Repor t FP-775, E l e c t r i c Power Research I n s t i t u t e , P a l o A l t o , CA, June 1978.

DuBard, J . L. , and R . S. D a h i i n . "A Performance E s t i m a t i o n Procedure f o r U t i 1 i t y F l y Ash P r e c i p i t a t o r s .It EPRI C o n t r a c t RP629-5. E l e c t r i c Power Research I n s t i t u t e , P a l o A l t o , CA, Repor t t o be p u b l i s h e d .

B i c k e l haup t , R . E. "Measurement o f F l y Ash R e s i s t i v i t y Using' S imu la ted F l u e Gas Env i ronments . " EPA-600/7-78-035, Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park , NC, 1978.

American S o c i e t y Mechanica l Engineers, Power T e s t Code 28, De te rm in ing t h e P r o p e r t i e s o f F i n e P a r t i c u l a t e M a t t e r . S e c t i o n 4.05, Method f o r D e t e r m i n a t i o n o f Bu'ik E T e c t r i c a l R e s i s t i v i t y , 1965.

Bickelhaupt, R. E. "A Technique for Predicting Fly Ash Resistivity." EPA-600/7-79-204. U.S. Environmental Protection Agency, Research Triangle Park, NC, 1979. NTIS PS80-102379.

Dubard, J. L., and R. F. Altman. "Prediction of Electrical Operating Points for Use in a Precipitator Sizing Procedure." EPRI Report CS-2908, Electric Power Research Institute, Palo Alto, CA, April 1983

Matts, S. and P. 0. Ohnfeldt. "Efficient Gas Cleaning with SF Electrostatic Precipitators." AB Svenska Flatfabriken Technical Bulletin, 1973.

Faulkner, M. G., and J. L. DuBard. "A Mathematical Model of Electrostatic Precipitation (Revision 3) . " Volume I: Modeling and Programming, NTIS PB84-212-679. Volume 11: User Manual, NTIS PB84-212-687. Source Code Magnetic Tape, NTIS PB84-232-990. U.S. Environmental Protection Agency, Research Triangle Park, NC, 1984.

Gooch, J. P., and G. H. Marchant, Jr. "Electrostatic Precipitator Rapping Reentrainment and Computer Model Studies." EPRI FP-792 Volume 3. Electric Power Research Institute, Palo Alto, CA, 1978.

DuBard, J. L., and R. F. Altman. "Analysis of Error in Precipitator Performance Estimates." EPMEPRI Fifth Symposium on the Transfer and Utilization of Particulate Control Technology, Kansas City, MO, 1984.

Faulkner, M . G., J. L. DuBard, R. S . Dahlin, and L. E. Sparks. "Microcomputer Programs for Precipitator Performance Estimates." EPA/EPRI Fifth Symposium on the Transfer and Utilization of Particulate Control Technology, Kansas City, MO, 1984.

Mie, G. "Beitrage zur Optik truber Medien." Speziell Kolloidaler Metallosunge. Ann. Physik. 25:377-455, 1908.

Van der Hulst, H. C. Light Scattering by Small Particles. John Wiley and Sons, New York, 1957.

Bickelhaupt, R. E. "Surface Resistivity and the Chemical Composition of Fly Ash." JAPCA, 25:148-152, 1975.

Gooch, J. P. "A Manual for the Use of Flue Gas Conditioning for Reduction of Fly Ash Resistivity." EPRI Contract RP 724-2. Electric Power Research Institute, Pa10 Alto, CA. Report to be published.

White, H. J. "Precipitator Design." JAPCA 27: 206-217, 1977.

N. W . Frisch. "Electrostatic Precipitator Sizing Methodologies - A Review." Second International Conference on Electrostatic Precipitators, Kyoto, Japan, November 1984.

Puttick, D. A Reconciliation: Wide Versus Narrow Spaced Collectinq Plates for Precipitators. Peabody-Sturtevant, October 1982.

Petersen, H. "New Trends i n Electrostatic Precipitation, Wide Duct Spacing, Precharging, Pulse Energization." IEEE Cement Industry Conf., Toronto, 1980.

Juricic, D and G. Herrmann. "Response of Collecting Plates in Electrostatic Precipitators Due to Shear Rapping." Journal of Mechanical Design, Vol. 100, January 1978.

Green, G. "Opera t ing Exper ience w i t h P a r t i c u l a t e C o n t r o l Dev ices . " P u b l i c S e r v i c e o f Colorado, A p r i l 1973.

Bump, R. E l e c t r o s t a t i c P r e c i p i t a t o r i n I n d u s t r y . Research -Co t t re l 1

McGraw, M. " F l y Ash Emi s s i o n Problems Resolved." E l e c t r i c a l Wor ld , November 1980.

" E n g i n e e r i n g A n a l y s i s o f t h e Neal S t a t i o n U n i t No. 3 Cold-S ide E l e c t r o s t a t i c P r e c i p i t a t o r s , " Me teo ro logy Research, I n c . August 1977.

"ASME Performance T e s t Code f o r Dus t S e p a r a t i n g Apparatus,' ' ASME PTC-21, The American S o c i e t y o f Mechanical Eng ineers , New York , NY 1941

"ASME Performance T e s t Code f o r De te rm in ing t h e Dus t C o n c e n t r a t i o n i n a Gas Stream." ASME PTC-27, The American S o c i e t y o f Mechanica l Eng ineers , New York , NY 1957

"ASME Performance T e s t Code f o r De te rm in ing C o n c e n t r a t i o n o f P a r t i c u l a t e M a t t e r i n Gas Stream." ASME PTC-38, The American S o c i e t y o f Mechanica l Engineers , New Y o r k , NY 1980

"ASME Power Tes t Code Codes, Supplement on I n s t r u m e n t s and Appara tus , P a r t 6 , Mas te r T e s t Code f o r E l e c t r i c a l Measurements i n Power C i r c u i t s . ' ' ASME PTC 19.6 , The American S o c i e t y o f Mechanica l Enqineers , New York , NY 1955

"ASME Power Tes t Codes, Supplement on I n s t r u m e n t s and Apparatus, P a r t 2, P ressure Measurement." ASME PTC 19.2, The American S o c i e t y o f Mechanica l Eng ineers , New York, NY, 1964

"ASME Power Tes t Codes, Supplement on I n s t r u m e n t s and Appara tus , P a r t 3 , Temperature Measurement." ASME PTC 19.3, The American S o c i e t y o f Mechanica l Eng ineers , New York, NY 1974

B a l a s i c , P . J., "Mechanical R e l i a b i l i t y C o n f i r m a t i o n o f C o l l e c t i n g and D ischarge E l e c t r o d e s , " R e s e a r c h - C o t t r e l l , August 1983.

Beu tne r , ti. P. "Measurement o f O p a c i t y and P a r t i c u l a t e Emiss ions w i t h an On-Stack i ransmissomete r . " JAPCA, Volume 24, No. 9, September, 1974

B i c k e l h a u p t , R . , "Corona E l e c t r o d e F a i l u r e S tudy . " EPRI FP-792, E l e c t r i c Power Research I n s t i t u t e , Pa lo A l t o , CA, Volume 1, June, 1978.

Brooks, E. F. e t a l , "Cont inuous Measurement o f T o t a l Gas F l o w r a t e f r o m S t a t i o n a r y Sources." EPA-650/2-75-020, U.S. Environments? P r o t e c t i o n Agency, Research T r i a n g l e Park, NC, February , 1975.

B rooks , E. F. e t a l . "Cont inuous Measurement o f Gas Composi t ion f r o m S t a t i o n a r y Sources. " EPA-600/2-75-012, U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park, NC, J u l y , 1975.

Brown, D. M. and S h i l l i n g , N. Z . , "Aspects o f Gas Flow D i s t r i b u t i o n and The Impac t on P r e c i p i t a t o r Des ign and Performance." Proceedings o f t h e I n t e r n a t i o n a l Conference on E l e c t r o s t a t i c P r e c i p i t a t i o n , October 1981.

B y l i n , 3. "Keep F l y Ash From P l u g g i n g I n Your Hoppers." Paper p r e s e n t e d a t t h e APCA Annual Mee t ing , June 1983.

''Code of Federal Regulations - Protection of the Environment. " CFR40, Parts 53 to 80, published by the Office of the Federal Register, National Archives and Records Service, General Services Administration, as a Special Edition of the Federal Register, July, 1982.

Cook, D. R., J. M. Ernbrey and D. Novogoratz. "Gas Flow Distribution Model Testing." Paper presented at the Fourth Symposium on the Transfer and Utilization of Particulate Control Technology, October 1982.

Coors Porcelain Company Bulletin No. 3500, Undated

Dumbauld, J. E., "Electrostatic Precipitator Hopper Evacuation Problems and Their Sotution ." Proceedings of the APCA Specialty Conference on the Operation and Maintenance of Electrostatic Precipitators, April, 1978

C. A . Gallaer, Electrostatic Precipitator Reference Manual. EPRI CS-2809 RP1402-4, Electric Power Research Institute, Palo Alto, CA, January 1983.

"Electrical Power Measurement Handbook." Yokogawa Corporation of America, 1982.

"Endevco Short Form Catalog," Endevco, 1982.

Engelbrecht, H. L . , "Air Flow Model Studies for Electrostatic Precipitators." Paper presented at the First Symposium on the Transfer and Utilization of Particulate Control Technology, February 1979.

Engelbrecht, H. L. "Measurement of Collecting Plate Acceleration in an Electrostatic Precipitator." Wheelabrator-Frye, Inc., August, 1982.

Engelbrecht, H. L. "Rapping Systems for Collecting Surfaces in an Electrostatic Precipitator.'' Paper presented at the Second Symposium on the Transfer and Utilization of Particulate Control Technology, 1979.

56. "Gas Flow Model Studies." Industrial Gas Cleaning Institute, Inc., Publ ication EP-7, August, 1969

57. "Gas Flow Model Studies." Industrial Gas Cleaning Institute, Inc., Publication No. EP-7, Revision 4, October 1981.

58. Gilbert, G. B., "Experimental Flow Modeling for Power Plant Equipment." Power Enqi neering, May 1974.

59. Grieco, G., and 0. Fortune. "Flow Modeling: Key to More-Effective Precipitation," Research-Cottrell Technical Bulletin TB202, 1977.

60. Gruber, J . C. "Flow Modeling of Electrostatic Precipitators." Paper presented at the 75the Annual Meeting of the Air Pollution Control Association, June, 1982.

61. "Guidance Manual for Model Testing," ANSI/ASME PTC 19.23-1980, Part 23, Instruments and Apparatus, April 15, 1980.

62. Hemeon, W. C. L. and A . W, Black. "Stack Dust Sampling: In-stack Filter or E.P.A. Train," JAPCA, Volume 22, No. 7, July 1972.

63. Hiilebrand, L. J., R. B. Engdahl, and R . E. Barrett. "Chemical Composition of Particulate Air Pollutants from Fossil-Fuel Combustion Sources." Battelle Memorial Institute, U.S. Environmental Protection Agency, Research Triangle Park, NC, March 1973.

64. "Informati on Required for the Selection and Application of Electrostatic Precipitators for the Collection of Dry Particulate Material," APCA TC-1 Particulate Committee Informative Report No. 6, m, Volume 25, No. 4, April 1975.

65. Janicke, J. M., "Power Measurement Handbook," RFL Industries, Inc. 1980.

66. Lodge-Cottrell/Dresser Industries, Inc. Precipitator Brochure, Undated.

67. McCandless, J . B. "Improved Precipitator Internals, Rigid C. E. Panel to Anvil Bean Attachments, Project 5200, Test I11 Final Report." Combustion Engineering Power Systems, 1981.

68. Dglesby, 5. and G. Nichols. "A Manual of Electrostatic Precipitator Techno1 ogy, Part I - Fundamentals." Nationai Air Pol 1 ution Control Administration, PB 196-380/381, August 1970.

69. "Operating Instructions for Ourag D-R281AV Visible Emission Monitoring System." Electronic Developments & Service, Pty. Ltd, Undated.

70. Pilat, M . J. and 0. S. Ensor. "Plume Opacity and Particulate Mass Concentration," Atmospheric Environment, Vol. 4, 1970.

71. Private communication with American Air Filter Company, Inc.

72. Private communication with Combustion Engineering, Inc

73. Private communication with Environmental Elements Corporation

74. Ramsdell, R. G. "Practical Design Parameters for Hot and Cold Electrostatic Precipitators." Paper presented at the American Power Conference, Chicago, Illinois, May 1973.

75. Russel ]-Jones, A . and A. P . Bayli s. "Lo1 lecting Electrode Rapping Designed for High Efficiency Electric Utility Boiler Electrostatic Precipitators." Paper presented at the Fourth Symposium on the Transfer and Utilization of Particulate Control Technology, October 1982.

76. Schlichting, H . Boundary-Layer Theory. McGraw-Hill Book Company, Sixth Edition. 1968.

77. Singer, J . G . "Design and Operation of Reliable Central Station Fly Ash Hopper Evacuation Systems." Paper presented at the American Power Conference, April, 1980.

78. Singer, J. G . "Design for Better ESP/Fabric Filter Hopper Operation and Maintenance." Paper presented at the APCA Annual Meeting, June, 1983.

79. "Standard Method for Sampiing Stacks for Particulate Matter." ASTM Designation D2928-71, Book of ASTM Standards, Part 23, 1971.

80. Stern, A. C. Air Pollution. Volume 11: "Analysis, Monitoring and Surveying," Academic Press, 1968.

Streeter, V. L. and E . B. Wylie. Fluid Mechanics, Sixth Edition McGraw-Hill Book Company, 1975.

"Survey of Precipitator Manufacturers' Experience." Ebasco Services Incorporated, 1984.

"Survey of Recent Precipitator Experience in the United States, Canada and Australia." Ebasco Services Incorporated, 1980.

Szabo, M. and R. Gerstle. "Electrostatic Precipitator Malfunctions in the Electric Utility Industry." €PA-600/2-77-006, U.S. Environmental Protection Agency, Research Triangle Park, NC, January, 1977.

"Technical Instruction Manual, Precision Optical Smoke and Dust Density Measuring Instrument Model RM4 Optical Transmissometer." Lear Siegler, Inc., November, 1973.

"Terminology for Electrostatic Precipitators." Industrial Gas Cleaning Institute Publication No. EP-1, last revised January 1973.

"Terminology for Electrostatic Precipitators." Industrial Gas Cleaning Institute. Publication No. EP-1, Revised January 1984.

Theodore, i. and A. J . Buonicore, editors. Air Pollution Control Equipment: Section, Design, Operation and Maintenance. Chapter 10 entitled "Electrostatic Precipitators," Prentice-Hall, Inc., 1982.

Theodore, L. and A. J. Buonicore, editors. Air Pollution Control Equipment: Selection, Design, Operation and Maintenance, Chapter 10 entitled "Electrostatic Precipitators," Prentice-Hall , Inc., 1982.

Walsh, M. A . , "Test Report: Acceleration Response of the Collecting Plate Assembly for the E Precipitator." General Electric Company, August, 1979.

White, H. J. and W. A . Baxter. "A Superior Collecting Plate for Electrostatic Precipitators." Mechanical Engineering, 82:84, 1960.

White, H. J. ltElectrostatic Precipitation of Fly Ash - Precipitator Equipment." JAPCA, Volume 27, No. 4, April 1977.

White, Harry J., "Electrostatic Precipitation of Fly Ash - Precipitator Design." JAPCA, Volume 27, No. 3, March 1977.

Wolf, E. F., H. L. Von Hohenleiten, and M. 6. Gordon. "The Use of Transparent Scale Models i n the Design of Dust-Collector and Gas Duct Systems for Coal Burning Electric Generating Stations." ASME Paper NO 59-A-305, The American Society of Mechanical Engineers, New York, NY, 1959.

Wybenga, F. A . , and R. J . Gray. "Electrostatic Precipitators-Design and Operational Considerations for Startup and Low Load Operation." Paper presented at the Joint Power Generation Conference, October, 1979.

Zarfoss, J. R . "New Precipitator Technology for Particulate Control." Paper presented at the Third Symposium on the Transfer and Utilization of Particulate Control Technology, March, 1981.

J. J. Smortchevsky. "Electrostatic Precipitator Rate Rapping; An Approach to Theoretical Analysis." Combustion, March 1975.

98. Bradburn, K . M . and K. Darby. " E l e c t r o s t a t i c P r e c i p i t a t o r E n e r g i z a t i o n and C o n t r o l Systems." L o d g e / C o t t r e l l D resse r I n d u s t r i e s , I n c . , Undated.

F r i e d l a n d e r , G. D. "Corona Power A f f e c t s ESP Per formance. " E l e c t r i c a l World, F e b r u a r y 1983.

H a l l , H . J., "Summary O v e r a l l Concepts Fbr Design, E n e r g i z a t i o n and C o n t r o l o f E l e c t r o s t a t i c P r e c i p i t a t o r s 1 ' . J- 83-57.6, June 1983.

Langan, W . Upgrad ing E l e c t r o s t a t i c P r e c i p i t a t o r Per formance. B u e l l , January 1980.

B ibbo, P . " D e f i n i n g P r e v e n t a t i v e Main tenance Tasks f o r E l e c t r o s t a t i c P r e c i p i t a t o r s . " Research C o t t r e l l , I n c . , August 1975.

M a t t s , S. " E f f i c i e n t Gas C l e a n i n g w i t h SF E l e c t r o s t a t i c P r e c i p i t a t o r s . " F l a k t , I n c . , Undated.

Ne ldner , J. "Exper ience w i t h C o l d P r e c i p i t a t o r on Western Coal a t P l e a s a n t P r a i r i e Power P l a n t . " W iscons in E l e c t r i c Power Co , , A p r i l 1983.

Heacock, F. "Exper iences i n t h e S u c c e s s f u l Upgrad ing o f A Hot -S ide P r e c i p i t a t 0 r . I ' Co lorado-Ute E l e c t r i c , A p r i l 1983.

Sorsheim, R. "Chemical C o n d i t i o n i n g o f Low-Sul fur Western Coa l . " Montana Power Co., A p r i l 1977.

Gooch, J. " Improvement o f Ho t -S ide P r e c i p i t a t o r Per formance w i t h Sodium C o n d i t i o n i n g - An I n t e r i m R e p o r t . " Southern Research I n s t i t u t e , Birmingham, AL, March 1981.

Greco, J . "Main tenance o f E l e c t r o s t a t i c P r e c i p i t a t o r s . " Tennessee Val l e y A u t h o r i t y , September 1973.

" E l e c t r i c Power Supply & Demand 1983-1992." N o r t h American E l e c t r i c R e l i a b i l i t y C o u n c i l , P r i n c e t o n , NJ, 1983.

Dean, A. H. "Study o f E l e c t r o s t a t i c P r e c i p i t a t o r s I n s t a l l e d on O i l - F i r e d B o i l e r s . " EPRI FP-792, E l e c t r i c Power Research I n s t i t u t e , Pa lo A l t o , CA, Volume 2 , June , 1978.

F iscus, D . E. e t a l . "RDF C o f i r i n g i n t h e E l e c t r i c U t i l i t y I n d u s t r y . " Paper p r e s e n t e d a t t h e ASME S o l i d Waste P rocess ing Conference, June 1983.

Smock, R . W . "Success E l u s i v e i n Garbage Power." E l e c t r i c L i g h t and Power, J u l y 1981.

L i c c a r d i , A. L . "Keynote Speech f o r T h i r d I n t e r n a t i o n a l Symposium on Coa l -O i l M i x t u r e Combust ion." P roceed ings o f t h e T h i r d I n t e r n a t i o n a l Symposium on C o a l - O i l M i x t u r e Combust ion, CONF-810498 ( V o l . I ) , A p r i l , 1981.

114. F a r t h i n g , G. A. Jr . , S. A. Johnson, and S. J. Vecc i . "Combust ion T e s t s o f Coal-Water S l u r r y . " EPRI CS-2286, E l e c t r i c Power Research I n s t i t u t e , P a l o A l t o , CA, March 1982.

R- 7

R i t t enhouse , R . C . "Hand1 i n g and F i r i n g Nonconvent iona i F u e l s .I1 Power E n g i n e e r i n g , December 1983.

Bav ing ton , A . F. and E. A. K imel . "P lann ing f o r COM Convers ion . " Proceedings o f t h e T h i r d I n t e r n a t i o n a l Symposium on Coa l -O i l M i x t u r e Combustion, CONF-810498 (Vo l 2 ) , A p r i l , 1981.

Slepow, L. 0. and A. S. Mendelssohn. "FPL1s San fo rd COM Demons t ra t i on P r o j e c t . " Proceedings o f t h e T h i r d I n t e r n a t i o n a l Symposium on Coa l -O i l M i x t u r e Combustion, CONF-810498 ( V o l . I ) , A p r i l , 1981.

O f f e n , G. R. e t a l . " C o n t r o l o f P a r t i c u l a t e M a t t e r f rom O i l B u r n e r s and B o i l e r s . " EPA-450/3-76-005, U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park , NC, A p r i l , 1976.

Sahagian, J., R . Dennis , and N. Surp renan t . " P a r t i c u l a t e Emiss ion C o n t r o l Systems f o r O i l - F i r e d B o i l e r s . " EPA Repor t No. EPA-450/3-74-063, U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park, NC, December, 1974.

Walker , A. B. " S t a t u s o f Technology f o r C o n t r o l o f P o l l u t a n t s f rom F o s s i l Fuel F i r e d Power P l a n t , " A ta7 k p resen ted a t t h e M e t r o p o l i t a n S e c t i o n ASME D i n n e r Mee t ing , January 1972.

H a r t s h o r n , W . T. " E l e c t r o s t a t i c Dus t C o l l e c t i o n From O i l - F i r e d B o i l e r s . " w, Volume 56, No. 6, June 1973.

P i n h e i r o , G. " P r e c i p i t a t o r s f o r O i 1 - F i r e d B o i l e r s . " Power E n g i n e e r i n g , A p r i l 1971.

P r i v a t e communicat ion w i t h L o d g e - C o t t r e l l / D r e s s e r I n d u s t r i e s , I n c . .

S team/ I t s Genera t ion and Use. The Babcock and Wi l cax Company, 1975.

" C o m p i l a t i o n o f A i r P o l l u t a n t Emiss ion F a c t o r s . " U . S . Env i ronmenta l P r o t e c t i o n Agency AP-42, Second E d i t i o n , U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park , NC, March, 1975.

M o r t e l , G. and T. V e r a t t i , "Reduce Impac t o f A c i d Emiss ions f rom Your 0 i 1-F i r e d B o i l e r .I1 Power, October , 1983

D a n i e i s o n , J . A. A i r P o l l u t i o n E n g i n e e r i n g Manual. U.S. Env i ronmenta l P r o t e c t i o n Agency AP-40, Second E d i t i o n , U . S . Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park , NC, May 1973.

W i l l i a m s , H. R . and C . J. Meyers. O i l and Gas Terms. Matthew Bender & Company, T h i r d E d i t i o n , 1971.

G i l l s , B. G. " P r o d u c t i o n and Emiss ions o f S o l i d s , SO2 and NOX f r o m L i q u i d Fuel Flames." J o u r n a l o f t h e I n s t i t u t e o f Fue l , Volume 46, February , 1973.

B a r s i n , J. A. "Foss i 1 Steam Genera to r NO x C o n t r o l Update." Paper p r e s e n t e d a t t h e EPRI/EPA J o i n t Symposium on S t a t i o n a r y Combust ion NOx C o n t r o l , October 1980.

S i e g e l , R. e t a l . "A S t r a t e g y o f Reduc t ion o f P a r t i c u l a t e Emiss ions i n t h e Boston Area. " - JAPCA, Volume 25 , No. 3, March 1975.

132. Brummer, J . and C . G a l l a e r . " C o n t r o l l i n g P o l l u t i o n f rom O i l - F i r e d B o i l e r s , P a r t V , Power f rom O i l . " Power, September, 1976.

Lee, G . , F. F r e i d r i c h , and E . M i t c h e l l . " C o n t r o l o f SO2 i n Low-Pressure H e a t i n g B o i l e r s by an A d d i t i v e . " Jou rna l o f t h e I n s t i t u t e o f F u e l , February , 1969.

Moore, W . W. e t a l . "Panel Session on t h e Performance o f Modern P r e c i p i t a t o r s . " Proceedings I n t e r n a t i o n a l Conference on E l e c t r o s t a t i c P r e c i p i t a t i o n , October , 1981.

" C o n t r o l o f P a r t i c u l a t e s and V i s i b 1 e Emi s s i o n s f rom O i l - F i r e d B o i l e r s . " Houston L i g h t i n g and Power Company, 1973.

Cato, G . A . , e t a l . " F i e l d T e s t i n g : A p p l i c a t i o n o f Combust ion M o d i f i c a t i o n s t o C o n t r o l P o l l u t a n t Emissions from I n d u s t r i a l B o i l e r s . " EPA-650/2-75-078a, U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e P a r k , NC, October , 1974.

M a r t i n , G. B . , D. W. Persh ing, and E . E . Berkau. " E f f e c t s o f Fuel A d d i t i v e s on A i r P o l l u t a n t Emiss ions f rom D i s t i l l a t e - O i l - F i r e d Furnaces." U.S. Env i ronmenta l P r o t e c t i o n Agency AP-87, U.S. Env i ronmenta l P r o t e c t i o n Agency, Research T r i a n g l e Park , NC, 1971.

Sem, G. e t a l . " S t a t e o f t h e A r t : 1971 I n s t r u m e n t a t i o n f o r Measurement o f P a r t i c u l a t e Mass - D e t a i l Repor t . " Prepared f o r t h e U.S. Env i ronmenta l P r o t e c t i o n Agency by Thermo-Systems, i n c . , A p r i l , 1971.

P r i v a t e communicat ion w i t h R e s e a r c h - C o t t r e l l , I n c

P r i v a t e communicat ion w i t h Long I s l a n d L i g h t i n g Company.

" P l a n t d e s i g n Repor t " 1955 t h r o u g h 1982 i n c l u s i v e , Power Magazine.

Cons tan t ine , 3 . G. and F. J. McGarry. "A Comparison o f t h e S i z e D i s t r i b u t i o n o f P a r t i c u l a t e s E m i t t e d f rom A i r , Mechanica l , and Steam Atomized O i l - F i r e d Burners , " JAPCA, Volume 22, No. 8, August 1972.

P i l o t , M. and D. Ensor . "Plume O p a c i t y and P a r t i c u l a t e Mass C o n c e n t r a t i o n . " Atmospher ic Environment, Volume 4, i 9 7 0 .

H a l l , F . D . , e t a l . " A i r P o l l u t i o n C o n t r o l Technology Development Waste-as-Fuel Processes." Proceedings o f t h e 1978 N a t i o n a l Waste Process ing Conference, May, 1978.

Conne l l , J. M . "Refuse F i r e d B o i l e r s . " F o s t e r Wheeler C o r p o r a t i o n , May 1967.

Smock, R . "Trash-Power P r o j e c t s Turn t o European Mass Burn Technique. " E l e c t r i c L i q h t and Power, August 1983.

Rigo, H. G . , J. Raschko, and S . Wors te r . "Conso? ida ted Data Base f o r Waste-to-Energy P l a n t Emissions." Proceedings o f t h e 1982 N a t i o n a l Waste P rocess ing Conference, 1982.

H a l l , J . L . , e t a l . "Env i ronmenta l Emissions f rom a Suspension F i r e d B o i l e r Wh i le B u r n i n g Refuse D e r i v e d Fuel and Coal M i x t u r e s . " Proceedings o f t h e 1980 N a t i o n a l Waste P rocess ing Conference, 1980.

149. Bump, R . L. " D i s c u s s i o n on A i r P o l l u t i o n C o n t r o l Technology Development Waste-as-Fuel Processes. " Proceedings o f t h e 1978 N a t i o n a l Waste P rocess ing Conference, May, 1978.

150. Gar, R . " F a b r i c F i l t e r and E l e c t r o s t a t i c P r e c i p i t a t o r F i n e P a r t i c u l a t e Emiss ion Cornparisan." EPRI , A p r i l 1977.

151. A l t i n , C . L I C o s t - E f f e c t i v e Deci s ion-Making f o r A i r Qua1 i t y C o n t r o l Systems and By-Products . " Ebasco S e r v i c e s I n c o r p o r a t e d , 1981.

152. Buon ico re , A. " C o n t r o l o f F l y Ash f rom Conven t iona l Coal F i r e d U t i l i t y B o i l e r s . " York Research C o r p o r a t i o n , May 1980.

M e y l e r , J. A. "The P r e c i p i t a t o r As An O p t i o n f o r Dry FGD Scrubb ing . "

Burgess, R. J . , Lane, W. R . , and Takvoryzn, N. " P i l o t E l e c t r o s t a t i c P r e c i p i t a t o r T e s t R e s u l t s : San fo rd COM P r o j e c t , F l o r i d a Power a n d L i g h t Company." Paper p r e s e n t e d t o t h e Coal Water Mix Symposium; Or lando, FL., 1981. The d i s c u s s i o n o f t h e c o a l o i l m i x t u r e (pp. 8-72 t h r o u g h 8-84) i s e s s e n t i a l l y a d e t a i l e d copy o f t h e r e f e r e n c e d paper .

A l t i n , Char les A. " S t r u c t u r a l I n v e s t i g a t i o n o f Large Hot -S ide E l e c t r o s t a t i c P r e c i p i t a t o r s . " Paper p r e s e n t e d a t t h e EPA/EPPI S i x t h Symposium on t h e T r a n s f e r and U t i l i z a t i o n o f P a r t i c u l a t e C o n t r o l Techno1 ogy, February 1986.

I N D E X

SUBJECT

A Method for Precipitator Performance Evaluation ASME Performance Test Code ASTM Method Abnormal Meter Readings, Guide for Interpreting Accelerated Life Test Acceleration, Rapping Access Doors, Platforming, Stairways,

Inter-Field Walkways Access Openings Access, Hopper Access, Internal Acoustical Treatment Adjustments, Air Load Administration and Record Keeping Aerators, Hopper Aids, General Diagnostic Air Inleakage Air Load Air Load Adjustments Air Load Test Procedure A Method for ESP Performance Evaluation Alabama Coal

Alarm and Monitoring Features Alternative Economic Comparison Methods AnaLyses of Ash, Mineral Analyses, Coal and Ash Analyses, Proximate Analyses, Ultimate Anti-Sway Devices Application to ESfs (Key Interlock) Arrangement, Ductwork Arrangement, General Arrangement, Precipitator Ash Deposits

Ash Handling, Integration with Ash Handling System

Ash Handling System and Precipitator Interface Ash Hopper System Ash Resistivity Aspect Ratio

Attenuation Monitors, Beta Particle Automatic Voltage Control

111, 6-2 111, 5A-5 111, 5A-3 11, 4-24 I , 4B-3 I, 4B-1

I, 6-18 11, 5-12 I, 4-38 11, 1-12 I, 6-24 11, 4-12 11, 5-18 I, 4-36 I, 7-10 Ii, 4-14 11, 4-5 11, 4-12 11, 4-5 111, 6-2 I, 2-31; 11, 2-14 I, 5-6 I, 7-93 11, 2-8 Ii, 2-8 11, 2-8 11, 2-8 I, 4-33 I, 6-4 I, 4-13 I, 4-10 I, 4-11 I, 2-35; 11,

2 - 18 1, 8-16 I, 2-37; T I , 2-20 I, 4-39 11, 3-28 111, 5-40 I, 2-44; I, 4-8; 11, 2-27 111, 5-5 I, 5-13; 111, 8-34

INDEX

Automatic Voltage ControlsfPower Units Auxiliary Controls, Energization of Auxiliary Equipment Controls Aaxiliary Systems, Deenergization of

Back Corona Bearings, Slide Bearings, Sliding Beta Particle Attentuation Monitors Blending, Fuel Selection Boiler

Boiler Conditions

Boilers, Oil-Fired Bracing, Internal vs. External Bus Sections, Deenergization of Bus Sections, Energization of High Voltage Buses, High Voltage Cabinets, Control Calculated Performance, Compare Actual and Capacity, Spare Casing Cascade Impactor, A. P . T . Cascade Impactor, Andersen Cascade Impactor, Brink Cascade Impactor, Flow Sensor Cascade Impactor, MRI Cascade Impactor, Pilot/U. of W. Cascade Impactor, Sierra Instruments Cascade Impactors

Casing and Hoppers Category 1 Evaluation Category 1 Testing Category 2 Evaluation Category 2 Testing Category 3 Evaluation Category 3 Testing Central versus Localized Control Chambers, Number of Characteristics, Fly ash

characteristics, Fuel

Characteristics, Particulate Checklist Checklist, Internal Inspection Checklist, Preventive Maintenance Chemical Composition and Fly ash Resistivity

Clearances, Precipitator

Coal Mills

Coal-Oil Mixture

11, 5-13 11, 6-13 11, 6-12 11, 6-14 11, 6-19 11, 6-15 1 1 , 6-23 I, 5-3 I, 4-2 I, 2-26; 11,

2-8 I, 2-25; 11, 2-7 11, 6-17 11, 4-5 11, 4-40 11, 6-9 I, 2-28; 11, 2-11 I, 2 - 3 5 ; 11, 2-17 I, 2-37; 11, 2-20 I, 8-72

SUBJECT

Coal Properties, Design Coal Quality

Coal Variability

Coal-Water Slurrey (CWS) Coal and Ash Analyses Coal, Alabama

Coal, Eastern High Sulfur

Coal, Wyoming

Cold-Side Precipitator Designs Cold-Side, Hot-Side versus Collecting Electrode Design Collecting Electrodes

Collecting Electrodes and Support System Collecting Electrodes, Inspection of Discharge and

Collecting Plate Acceleration Collecting Plate Area Collecting Plate Area, Enlargement of Collecting Plate Height Collecting Plate Spacing Collecting Plates Collection Area, Specific

Commercial Evaluation Commercial Terms and Conditions, Preparation of Common Division Walls Compare Actual and Calculated Performance Compare Actual with Expected Performance Components, Electrostatic Precipitator Components, Miscellaneous Concentration

Concentration, Fly ash Concepts for Material Supply Condensation Nuclei Counters Conditioning, Gas Conditions, Boiler

Conduct an Internal Inspection Construction and Thickness, Materials of Construction, Materials of Contemporary Sizing Practices Contractor's Employees Contractor, Obligations of

SUBJECT INDEX

Control Adjustments, Load Savings and Control Cabinets Control Centers, Motors/Motor Control Room Equipment Location Control Vibrator Control, Central versus Localized Control, Hopper Heater Control, Rapper Controls, Auxiliary Equipment Controls, Electrical

Controls, Optimization of

Controls, Power Supplies and Controls, Rapper Controls, Rappers and Conventional Transmissometers Cooling and Purging for Personnel Entry Counters, Condensation Nuclei Critical Equipment List CRTs, Keyboards, Printers Curves, Current vs. Voltage

Curves, Voltage vs. Current

Cycle, Rapping Cyclones Dampers Dampers, Flue Gas Dampers, Isolation Data Analysis, Size Distribution Data Review Data, Precipitator and Boiler Deenergization of Auxiliary Systems Deenergization of High Voltage Bus Sections Default, Termination for Defeat of the System (Key Interlock) Density, Power Deposits, Ash

Description of the ESP Model Design Coal Properties Design/Callecting Plate Acceleration, Rapper Design Factors Affecting ESP Performance

Design Gas Velocity

Design Margins Design Methods (Grounding) Design Philosophy Design Range, Performance Fuel versus

11, 4-34 I, 5-11 11, 5-4 I, 5-4 I, 5-15 I, 5-3 I, 5-15 I, 5-14 11, 5-3 I, 2-34; 11, 2-16

11, 4-19, 11, 4-27 111, 8-22 111, 8-57 111, 8-45 111, 5-6 11, 4-36 111, 5-29 11, 6-5 I, 5-19 111, 1-4; 111, 3-7

111, 1-3; 111, 3-7

111, 8-51 111, 5-26 11, 5-12 I, 4-14 I, 6-28 111, 5B-1 111, 7-4 11, 4-25 TI, 4-35 11, 4-35 I, 7D-13 I, 6-6 11, 1-4 I, 2-35; 11, 2-17 111, 6-24 I, 3-3 I, 4-27 I, 2-38; 11, 2-20 I, 2-41; 11, 2-25 I, 3-35 I, 6-9 I, 5-1 I, 7-6

SUBJECT INDEX

Discharge Electrodes and Support System Discharge and Collecting Electrode Rapping

Systems Discharge and Collecting Electrodes,

Inspection of Distribution Devices, Gas

Design, Collecting Electrode Design, Discharge Electrode Design, Electrode System

Design, Hopper Design, Rapper

Design, Weighted Wire, Rigid Frame, and Rigid Electrode

Designs, Cold-Side Designs, Hot-Side Design Specifications, Performance Oriented versus

Determine Whether an Internal Inspection Is Required

Deutsch-Anderson Equation Diagnostic Aids, General Diagnostic Methods Differential Pressure Loads Direction of Gas Flow, Number of Fields Discharge Electrode Design Discharge Electrodes

Distribution, Flow Distribution, Gas Flow Distribution, Particle Size

Distribution, Particulate Loading Distribution, Temperature Division Walls, Common Documentation, System Drop Rod Rappers Ductwork Ductwork Arrangement Ductwork and Expansion Joints Ductwork/Precipitator Gas Velocities and Distribution

Dust and Ash Handling Equipment Loads-Hoppers Dust Loads Eastern High Sulfur Coal

111, 7-5 I, 3-21 111, 7-10 111, 1-6 I, 4-25 I, 2-46 I, 4-29 I, 7-44; 11, 1-4; 11, 5-8 11, 3-8

SUBJECT

EPA Computer Simulation EPA Method 17 EPA/SRI Computer Simulation EPS Mass Sampling Methods ESP Control Room (BVAC) ESP Hopper Areas ESP Inspection Guidelines ESP Model, Description of the ESP Performance Determination ESP Performance Evaluation, A Method for ESP Performance, Design Factors Affecting ESP Performance, Factors Affecting

ESP Performance, Operating Factors Affecting

ESP Roof (Enclosures) ESP Terminology ESPs, Theoretical Simulation of Eastern High Sulfur Coal

Economic Comparison Methods, Alternative Economic Evaluation Effects of Dry Scrubbers on Precipitators Efficiency, Penetration Electrical Controls

Electrical Equipment Electrical Inspection Electrical Insulators, Inspection of Electrical Operating Points

Electrical Performance Evaluation Electrical Power Systems Electrical Resistivity Electrical Sectionalization

Electrical and Control Equipment Considerations Electrical/Control Features, Specification of Electrode Systems Electrode System Design

Electrodes, Collecting Electrodes, Discharge

Electrostatic Precipitation, Theory of

Electrostatic Precipitator Components Electrostatic Precipitator Terminology

Emissions, Stack Visible Employees, contractor' s

I, 3-25 111, 5A-5 I, 3-26 111, 5-4 I , 6-17 I, 6-15 11, 5-15 111, 6-24 111, 5-1 111, 6-2 11, 2-20 I , 2-23; I, 2-40; 11, 2-7

I , 2-25; 11, 2-7 I, 6-14 11, 1-4 I, 2-9 I, 2-32; 11, 2 - 14 I, 7-61 I, 7-61 I , 9-1 1 1 1 , 5-17 I, 2-34; 11, 2-16

11, 5-1 11, 4-4 111, 4-20 I, 3-19; 111, 3-3 111, 3-1 I, 5-i 111, 1-5 I, 2-50; I, 4-7; 11, 2-32

I, 5-8 I, 5-1 I, 4-25 I, 2-39; 11,

2 -2 3 11, 5-8 11, 1-4; 11, 5-8 11, 2-1; 111, 2-1

11, 3-1 11, 1-4; 11, Appendix A I, 4D-4 I, 7-72

SUBJECT

Enclosure, Hopper Enclosures

Energization of Auxiliary Controls Energization of High Voltage Bus Sections Energization, Pulse Enlargement of Collecting Plate Area Environmental Agency Reporting EPA/SRI Computer Simulation Equation, Deutsch Anderson Equation, Matts-Ohnfeldt Equipment Configuration Equipment Reliability Evaluation, Investment Equipment, Electrical Equipment List, Critlcal Equipment, Mechanical Evaluation, A Method for Precipitator Performanc Evaluation, Commercial Evaluation, Economic Evaluation, Electrical Performance Evaluation, Investment Evaluation, Mechanical Condition Evaluation, Performance Warranty Evaluation, Three Categories of Evaluations, Technical Merit Examine Actual Electrical Conditions Example of Purchaser Provided Technical Data Example of Seller Provided Microprocessor Based Control System Data

Example of Seller Provided Technical Data Example Scope of Supply Statement Exceptions and Negotiations, Treatment of Excursions, Temperature Expansion Joints

Expected Performance, Compare Actual with Factors Affecting ESP Design Performance Factors Affecting ESP Performance

Factors, Design Failure Analysis, Summary of Failure Frequencies of Precipitator Components Failure Probabilities Field Leakage Test Field Performance Tests

Field Velocity Distribution Test

Fields, Number of Final Analysis and Report

I, 4-39 I, 6-14; 11, 3 - 18 11, 4-18 11, 4-18 111, 8-83 111, 8-91 11, 4-28 I, 3-26 I, 3-21 I, 3-23 111, 8-91 11, 6-1 1, 7-53 11, 5-1 11, 6-5 11, 5-6

:e 111, 6-2 I, 7-56 I, 7-61 111, 3-1 I, 7-53 111, 4-1 I, 7-54 11, 6-11 1, 7-54 111, 7-2 I, 7B

SUBJECT

Flow Distribution

Flow Modeling

Flue Gas Characterization Flue Gas Dampers Flue Gas Flow Flue Gas Opacity

Flue Gas Volume Flow Fluidizing Stones Fly ash Characteristics

Fly ash Concentration Fly ash Resistivity

Fly ash Resistivity, Chemical Composition and

Force Ma j eure Fuel Characteristics

Fuel, Refuse Derived Fuel Selection/Blending Fuels Other than Coal Gas Analysis, Quantitative Gas Composition Gas Conditioning Gas Conditioning, Size Reduction with Gas Distribution Devices

Gas Flow Direction, Number of Fields Gas Flow Distribution Gas Passages, Number of Gas Sneakage, Untreated Gas Stream Uniformity Gas Temperature Gas Velocities and Distribution, Ductwork/ Precipitator

Gas Velocity, Design

Gas Velocity, Precipitator General Arrangement General Diagnostic Aids General Grid (Grounding) GLossary of Terms

Ground System Grounding (Lightning) Guide for Interpreting Abnormal Meter Readings

INDEX

I, 4-4 I, 2-41; 11,

2-23 I, 3-9 I, 4-10 111, 7-10 I, 6-9 11, 1-4; 11, Appendix A 11, 5-6 I, 6-8 11, 4-24

SUBJECT INDEX

Hardware, Precipitator Control System Heater Control, Hopper Heaters, Hopper

Heaters, Insulator Air Purge Heating and Ventilation System, Insulator

Compartment Heating, Ventilation and Air Conditioning (WAC) High Sulfur Coal, Eastern High Voltage Bus Sections, Energization of High Voltage Bus Sections, Deenergization of High Voltage Buses, Switches, and Insulators High Voltage Support Insulators, Enclosures, and Purge Air System

High Voltage System Historical Perspective Hoist, Personnel Hoists, Monorails/Equipment Hopper Hopper Hopper Hopper Hopper Hopper Hopper

Hopper

Hopper Hopper Hopper Hopper Hopper Hopper Hopper

- -

Access Aerators Areas (Enclosures) Design Enclosure Heater Control Heaters

Level Indicators

Level Meters Materials of Construction Pokeholes and Anvils Reentrainment System, Ash Vibration/Fluidizing Stones Vibrators

Hoppers Hoppers and Accessories Hoppers, Casing and Hoppers-Dust and Ash Handling Equipment Loads Hot-Side Precipitator Designs Hot Side versus Cold Side Impactors, Cascade Importance of Effective Operation and Maintenance Programs

Improvements in Transformer-Rectifier Set Design In Situ Measurements Indicators, Hopper Level Inleakage, Air Inlet Data Analysis Inlet Mass Loading

I, 4-19 I, 4-33 11, 5-12 I, 4-19 11, 1-12 I, 3-38 111, 5-20

SUBJECT INDEX

Inlet Particle Size Distribution Inspect and Test all Rappers Inspecting and Reporting Internal Condition Inspection Guidelines, ESP Inspection and Checkout of System Components Inspection for Effects of Thermal Expansion Inspection of Discharge and Collecting Electrodes Inspection of Electrical Insulators Inspection of the Precipitator Casing and Hardware

Inspection of the Rapping System Inspection, Electrical Inspection, Internal

Inspection, On-Line Inspection, Support System Inspections, Tests and Installation Considerations Instrumentation

Instrumentation, Light Scattering Instrumentation, Troubleshooting Insulation System, Thermal Insulation, Thermal Insulator Air Purge/Heaters Insulator Compartment - Heating and Ventilation System

Insulators, High Voltage Support Insurance Requirements Integration with Ash Handling Interfaces with Other Plant Systems Intensity, Rapper Internal Access Internal Condition, Inspection and Reporting Internal Inspection

Internal vs. External Bracing Introduction Introduction, Manual 1 Introduction, Manual I I Introduction, Manual III Inventory, Spare Parts Investment Evaluation Isolation Dampers Joints, Expansion Key Interlock System

Key Interlock System Design Laboratory Measurements Lagging

Level Indicators, Hopper

Liability, Limitation of Light Scattering Instrumentation Lighting Lignite, North Dakota

Lime Spray Dryer Process Limestone Injection Multistage Burners (LIMB) Modified Boilers

Limitation of Liability Load Swings and Control Adjustments Loading Distribution, Particulate Loading, Inlet Mass Loading, Mass Loads, Dust Loads; Wind, Ice and Snow Lock Components Low Load Operation Maintainability Review of Drawings Maintenance Maintenance Drawings and Check Sheets Maintenance (of ESP)

Maintenance Program Maintenance Request Form Maintenance, Preventive Ma j eure , Force Management System, Precipitator Control

Management System, Precipitator Power Manual, Scope of Margins, Design Mass Concentration

Mass Concentration Measurement Methods Mass Loading Mass Loading, Inlet Mass Sampling Methods Mass Sampling, Precipitator Inlet and Outlet Material Only versus Deliver and Erect Contracts Material Supply, Concepts for Material Thickness Material Type and Thickness Materials of Construction and Thickness Materials of Construction, Hopper Matts-Ohnfeldt Equation Measurement Methods Measurement Methods, Mass Concentration Measurement Methods, Voltage Waveforms and Measurement Techniques

SUBJECT

Measurements, In Situ Measurements, Laboratory Mechanical Condition Evaluation Mechanical Equipment Mechanical Features, Specification of Mechanical Sectionalization Meter Readings, Guide for Interpreting Abnormal Meters, Hopper Level Meters, Opacity

Meters, Secondary Voltage and Current Meters, Spark Rate Method, ASTM Method, Prediction Methods, Diagnostic Methods, Measurement Mills, Coal

Mineral Analyses of Ash Miscellaneous Components Mixture, Coal-Oi 1 Modeling, Flow Monorai ls/Equipment Hoists Motors/Motor Control Centers North Dakota Lignite

Nuclei Counters, Condensation Number of Chambers Number of Fields in Direction of Gas Flow

Number of Gas Passages Number of Precipitators Number of Rappers Number of Transformer-Rectifier Sets O&M Related Systems, Specification for Obligations of Contractor

Obligations of Owner

Occupational Safety and Health Act Oil-Fired Boilers On-Line Inspection Opacity

Opacity Meters

Opacity, Flue Gas

Openings, Access Operating Data, Precipitator Design and Operating Factors

111, 5-24 111, 5-24 111, 4-1 11, 5-6 I, 4-1 I, 4-6 IT, 4-24 111, 5-3 I, 6-18; 111, 5-3

111, 5-2 111, 5-2 111, 5A-3 111, 5-33 111, 1-6 111, 5-22 I, 2-37; 11, 2-19

iI, 2-8 11, 3-33 I, 8-72 I, 4-42 I, 6-22 11, 5-4 I, 2-31; 11, 2-12

111, 5-29 I, 4-2 I, 2-46; 11, 2-29 I, 4-2 I, 4-1 111, 8-51 111, 8-31 I, 6-1 I, 7D-5; I, 7D-2 6 I, 7D-6; I, 7D-28

I, 7D-19 I, 8-4 11, 4-25 111, 1-6; 111, 5-56

I, 6-18; 111, 5-3 I, 3-37; 11,

3 - 3 5 1 1 , 5-12 11, 6-10 11, 2-6

SUBJECT INDEX

Operating Factors Affecting ESP Performance

Operating Points, Electrical

Operation Operation Routine Operation and Maintenance Programs, Importance of Operation, Low Load Optimization of Controls

Outage - Internal Inspection/Action/Report Outlet Data Analysis Overview of Principles of Precipitator Design Owner, Obligations of

Parameter Selection Particle Size Distribution

Particle Size Distribution, Inlet Particulate Characteristics Particulate Emissions Testing Particulate Loading Distribution Particulate Manual Sampling Patents Penetration/Efficiency Performance Determination, ESP Performance Fuel versus Design Range Performance Oriented versus Design Specifications Performance Tests Performance Warranty Evaluation Performance, Design Factors Affecting Performance, Factors Affecting

Performance, Operating Factors Affecting Performance, Upgrading Personnel Entry, Cooling and Purging for Personnel Hoist Physics and Principles of Operation Plate Area, Collecting Plate Height, Collecting Plates, Collecting Plate Spacing, Collecting Pokeholes and Anvils, Hopper Power Consumption Power Density Power Distribution Equipment Power Management System/Supervisory Control

System Power Supplies and Controls

SUBJECT INDEX

Power Supply

Power Systems, Electrical Power Units Power-Off/Power-Reduced Rapping Pre-Test Site Survey Pre-startup Precautions, Safety Precipitation Process

Precipitator Precipitator Precipitator

Precipitator

Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator Precipitator

Arrangement Casing and Hardware, Inspection of Clearances

Control Management System

Control System Hardware Control System Philosophy Design and Operating Data Design, Overview of Principles of Gas Velocity Inlet and Outlet Mass Sampling Operation Safety Precautions Performance Calculation Performance Evaluation, A Method for Power Management System She 11 Size Selection Sizing Models Survey and Boiler Data

f recipitators, Number of Prediction Method Preparation of Commercial Terms and Conditions Preparation of Technical Specifications Pressure Drop Pressure Loads, Differential Pre-startup Pretest Site Survey Preventive Maintenance Preventive Maintenance Checklist Principles of Precipitator Design, Overview of Probabilities, Failure Problems, Symptomatic Procedure, Air Load Test Procurement Aspects (Key Interlock) Profile, Velocity Program/Evaluation, Testing Properties, Design Coal Proximate Analyses Pulse Energization

I, 4-1 111, 5-34 I, 7-46 I, 7-7 I, 4D-6 I, 4-25 11, 4-1 11, 6 - 2 0 11, 6-7 11, 6-9 I, 2-1 11, 6-1 111, 7 - 1 0 11, 4-5 1, 6-7 11, 4-12 11, 6-8 I, 3-3 11, 2-8 111, 8-83

SUBJECT INDEX

Purchasing Process Purge Air System Quality, Coal

Quantitative Gas Analysis Rapper Control

Rapper Design

Rapper Design/Discharge Electrode Acceleration Response

Rapper Intensity Rappers

Rappers and Controls Rappers, Drop Rod Rappers, Inspect and Test Rappers, Number of Rapping Acceleration Rapping Cycle Rapping System, Inspection of Rapping Systems

Rapping Systems, Discharge and Collecting Electrode

Rapping Tests

Rapping, Power-Off/Power-Reduced Rating, Transformer-Rectifier Set Ratio, Aspect

Recommended Spare Parts List Record Keeping, Administration and Reentrainment, Hopper Refuse Derived Fuel (RDF) Reliability, Equipment Reliability of Operation (Key Interlock) Reporting, Environmental Agency Requirements, Insurance Requiremects, Structural Resistivity, Chemical Composition and Fly ash

Resistivity, Electrical Resistivity, Fly ash

Review Available Plant Data Rigid Electrode Design Rigid Frame Design Roof, ESP Routine Operation

INDEX

Safety and Health Act, ~ccupational Safety Precautions

Sample Ports Sampling Methods, EPS Mass Sampling Methods, Mass Scope of the Manual

Secondary Voltage and Current Meters Sectionalization Sectionalization, Electrical

Sectionalization, Mechanical Seismic Considerations Sets, Transformer Rectifier Shipping and Storage Shutdown Simulation of ESPs, Theoretical Simulation, EPA/SRI Computer Size Distribution Data Analysis Size Estimating Techniques Size Reduction with Gas Conditioning Size Selection, Precipitator Sizing Models, Precipitator Sizing Practices, Contemporary Slide Bearings Sliding Bearings Sneakage, Untreated Gas Spacing, Collecting Plate Spare Casing Capacity Spare Parts Inventory Spare Parts ii st, Recommenced Spark Rate Meters Special Considerations (Grounding) Special Tools Specific Collection Area (SCA)

Specification Preparation, inquiry, Proposal Evaluation and Coctract Administration

Specification Requirements, (Access Doors . . . ) Specification Requirements (Enciosures) Specification Requirements (Grounding) Specification Requirements (Key Interlock) Specification for O&M Related Systems Specification of Electrical/Control Features Specification of Mechanical Features Specifications, Performance Oriented versus Design

Stack Visible Emissions Startup Structural Failure

SUBJECT INDEX

Structural Requirements Supplier Qualification Supplies and Controls, Power Supply, Power

Support Insulator Material, Suspension System and Support System, Coliecting Electrodes and Support System, Discharge Electrodes and Support System Inspection Suspension System and Support Insulator Material Switches and Insulators Symptomatic Problems System Architecture System Components, Inspection and Check of System Design, Electrode

System Design, Key Interlock System Documentation System, Ash Handling

System, Ash Hopper System, Collecting Electrodes and Support System Design, Electrode System, Discharge Electrodes and Support System, Electrical Power System, Electrode

System, Ground System, High Voltage System, Key Interlock

System, Power Management System/Supervisory Control

System, Precipitator Control Management

System, Precipitator Power Management System, Purge Air System, Rapping

System, T/R Removal System, Tumbling Hammer System, Thermal Insulation System, Voltage Control T/R Removal System Technical Merlt Evaluations Technical Specifications, Preparation of Techniques, Measurements Temperature Considerations Temperature Distribution Temperature Excursions Temperature, Gas

SUBJECT

Termination for Default Terminology, Electrostatic Precipitator

Terms, Glossary of

Test Code, ASME Test, Accelerated Life Test, Field Leakage Test, Field Velocity Distribution

Test Procedure, Air Load Testing Testing Program/Evaluation Testing, Category 1 Testing, Category 2 Testing, Category 3 Testing, Particulate Emissions Tests and Inspections

Tests, Field Leakage Tests, Field Performance

Tests, Rapping

Theoretical Simulation of ESPs Theory of Electrostatic Precipitation

Thermal Expansion, Inspection for Effects of Thermal Insulation

Thermal Insulation System Thickness, Material Three Categories for Precipitator Evaluation Transformer Rectifier Sets, Number of Transformer-Rectifier Sets Transformer-Rectifier Set Rating Transformer, Rectifiers/Linear Reactors Transmissorneters, Conventional Treatment Time Treatment of Exceptions and Negotiations Troubleshooting Guide Troubleshooting Instrumentation Tumbling Hammer Systems Ultimate Analyses Uniformity, Gas Stream Untreated Gas Sneakage Upgrading Performance Vacuum Cleaning Systems Variability, Coal

Velocity, Precipitator Gas

I, 7D-13 11, 1-3; 11, Appendix A 11, 1-3; 11, Appendix A 111, 5A-5 I, 4B-3 I, 4-45 I, 4-46; I, 4C- 1 11, 4-5 I, 4-41 11, 6-8 11, 6-10 11, 6-18 11, 6-22 I, 4D-1 1, 5-20; I, 7-73

r , 4-45 I, 4-46; I, 4D- 1 I, 4-44; I, 4B- 1 I, 2-9 11, 2-1; 111,

2 - 1 11, 4-19 I, 4-40; 11, 5-13 I, 4-40 I , 4-27 11, 6-11 111, 8-31 I, 5-8 111, 8-27 11, 5-1 111, 5-6 1, 4-10 I, 7-47 111, 7-1 111, 5-2 11, 5-7 11, 2-8 111, 8-9 111, 8-21 111, 8-1 I, 6-23 I, 2-25; 11, 2 - 8 I, 3-9

SUBJECT

Velocity Profile Vibrator Control Vibrators, Hopper

Voltage Control System Voltage Controls, Automatic

Voltage versus Current Curves Voltage Waveforms and Measurement Methods Volume Flow, Flue Gas Warranties Water Washing Weighted Wire Design Weighted Wire, Rigid Frame, and Rigid Electrode

Design Wind, Ice and Snow Loads Wyoming Coal

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the global energy and energy servrces mdusay U S

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