Presentation on

Rexnord Addax® Composite Cooling Tower Drive Shafts

By

Duane ByerlyCTI – Vice Chair for Vibrations Task Group, 2009-present.

Rexnord Addax, 1989- Present

Workshop on Cooling Tower and Circulating Water System

NTPC – PMI

Rexnord: Company Overview

PRECISION. POWER. PERFORMANCE

Water Management

Infrast., 51%

Bus., 30%

Res., 19%

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Power Transmission

PowerTransmission

OEM, 56%

After-Market,

44%

WaterManagement

Business FocusBusiness Focus

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Power Transmission PlatformPower Transmission Platform

Products:• TableTop Chain

• MatTop• Conveyor

Components

Products:• Mounted Roller

Bearings• Mounted Ball

Bearings• Cylindrical and

Filament Bearings

Products:• Drive OneTM

• Planetary Gears• Shaft Mounted

Gears• Service

Products:• Disc Couplings

• Elastomeric Couplings

• Gear & Grid Couplings

Products:• Engineered

Chain• Conveying

Equipment• Roller Chain

Products:• Rolling Element

Airframe Control Bearings

• Slotted Entry and Split Ball

Bearings

• Seals

Products:• Brakes and

Clutches• Miniature Motion

Control Devices• Valves and Security Locks

FlattopSpecial

ComponentsAerospace Chain & OtherCouplingGearBearing

Power Transmission

Rexnord is a $ 2 Billion Company

aerospace bearings

LINK BELT

47 Rexnord Worldwide Locations Providing Global Consistency with

Localized Support.

47 Rexnord Worldwide Locations Providing Global Consistency with

Localized Support.

Rexnord is an international company with:• 45 total locations serving

over 75 countries worldwide

• 27 manufacturing locations, 6 repair facilities

• Over 4400 associates worldwide ready to serve our partners and end users

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Worldwide PresenceWorldwide Presence

NY001ZJ1_1.wor

Rexnord Facilities

HeadquartersAerospaceCouplingFlattopGearIndustrial BearingsIndustrial ChainSpecial Components

NY001ZJ1_1.wor

Rexnord Facilities

HeadquartersAerospaceCouplingFlattopGearIndustrial BearingsIndustrial ChainSpecial Components

Rexnord Sales Offices

Australia

India

Korea

Miami

Singapore

South Africa

China

Brazil

Canada

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29

4500

6

7

8

TRADITIONAL STEEL SHAFT

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TRADITIONAL STEEL SHAFT

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Heavy 150kg +

Commercial Grade Tube Uneven thickness - Unbalance

Multiple Parts 16 sets of pin & bush totally

HEAVY – 150kg

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OVERHEAD CRANE ADDITIONAL MANPOWER

DANGEROUS WORKING ENVIRONMENT

ALIGNMENT TIME LONGER

Corrosion Prone

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Effects of Corrosion

1. Loss of Material cause Imbalance – Vibration

2. Entire assembly has to be replaced.Assembly Balance is done – Part (hub) replacement ot possible

3. Service Life is 5-7 years. Results in RECURRING CAPITAL COSTS

Degraded Rubber bushing

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Multiple Parts 16 sets of Pin & Bush

Rubber bush degraded by Chlorine

Misalignment capacity gone – Vibration Frequent Replacement

Bearing problems in gearbox with steel shaft

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Heavy Driveshaft = Shorter Gear Life

HIGH OVERHUNG MOMENT

MASS

Disadvantage of Steel Drive shaftsSteel Problems

Weight Heavy ( 100- 150kg)

Slower Removal / Installation Slower Alignment = Longer Down time during maintenance

Thermal expansion problemHigh Overhung Moment = Lower Bearing Life in Motor and Gear Reducer

Vibration Higher( > 10mm/sec)

Greater mass Greater Mass = Greater Unbalanced Greater Unbalanced = Greater Vibration

Corrosion Affected Lower service lifeRepeated Maintenance required

High Cost of Ownership

Service Life 5-7 yrs Recurring Capital Cost

Flexible element

Pin & Bush Multiple Parts to be frequently replaced Repeated Maintenance reqd

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Addax Composite Drive Shaft

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• Hub • (SS 316)

• Spacer ( Composite)

Flexible Element ( Composite)

CORROSION RESISTANT MATERIALS

Ultra light weight

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LOW MASS = LOW VIBRATION

LONGER BEARING & EQUIPMENT LIFE

EASY TO HANDLE – INSTALL / REMOVE

Corrosion Resistant

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Spacer & Flex Elements – Composite Corrosion Resistant

Hub & Hardware – SS316 Corrosion Resistant

2.Part replacement possible – Spacer Balanced

InterchangeabilityReduced Inventory

3. Service Life is Life Time of Cooling Tower NO Recurring Capital Costs

STEEL – CORROSION PRONE

Flexible Joint Differences

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8 sets of Pin & Bush per End Unitized ( 1 piece) Disc per End

Low service life rubber Min 5 years – Composite

Misalignment capacity min And lost due to hardening

Misalignment capacity 3 times standard

Comparison of Steel vs Rexnord

Steel Rexnord Composite

How you WIN ?

Weight Heavy (100-150kg)

Ultra Light (15-25kg)

Faster Installation & AlignmentEasy Maintenance

Vibration Higher( > 10mm/sec)

Minimal( < 2mm/sec)

Longer Bearing and End Equip life. Lesser Down Time

Corrosion High No Corrosion

Min Ownership cost during for life of Cooling Tower

Service Life 5- 7 Yrs CT Life time No Recurring Capital Cost

Flexible joint Pin & Bush( 8 sets )

Unitized ( 1 Piece)Disc Type

Simple ReplacementReplacement in 5 yrsReduced Maintenance cost & time

DowntimeTime & Cost

Higher Min Trouble free operation

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The Rexnord Solution• So why does Rexnord Addax Composite

Drive Shafts have all these Wonderful Qualities ?

• Lets go a little deeper into composite technology…..

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• Advanced composites are generally understood to be high-performance materials consisting of a polymer matrix reinforced with high-strength continuous fibers of predefined orientation.

• Types of Fiber Used• Fiberglass• Carbon/Graphite*

Definition:

1500x Magnification

Composite Materials Overview

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lbs./cubic inchDensity Comparison

0.00

0.10

0.20

0.30

E-Glass Carbon T6061 304 SS

Low weight for ease of handling, reduced bearing loads, reduced vibrationHigher critical speeds – reduced tendency for “whirling”

Composite Materials Overview

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ModulusDensity

0

100

200

300

E-GlassCarbon T6061 304 SS

x 106 inches

Specific Stiffness

Enables long spans with smaller diameter compared to steelNo cantenary deflection (no sag) – no need for center support

Composite Materials Overview

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Tensile StrengthDensity

x 104 inches

0

100

200

300

400

E-Glass Carbon T6061 304 SS

Specific Strength

Stronger than steel - for given weight

Composite Materials Overview

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Problem - Thermal expansion of steel on non rotating shaft

Issue:- Top surface of shaft experiences thermal expansion vs. lower surface due to solar

exposure- The nominally cylindrical shape now become curved- At start-up, this curved shape creates serious imbalance and creates vibrations and

excess wear on the bearings

Carbon fiber shafts do not experience this issue as they do not experience any thermal expansion

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CT

E -

in./

in./

F x

10-6

-2

0

2

4

6

8

10

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E-Glass Carbon T6061 304 SSCarbon fiber is dimensionally stable regardless of temperature:- Reduced wear on bearing- Dependably straight shaft reduces imbalance and vibration

Composite Materials OverviewDimensional Stability - Axial Coefficient of Thermal Expansion (CTE)

Rexnord Product TestingRexnord meets all the requirements

• Torque test

- Can demonstrate peak rating with no failure

• Fatigue test – simulated motor starts– Flex elements tested to 43,000 cycles– Spacer tested to 20 year life of the tower

• UV Test – Conducted in India – Resulted in NO loss of properties

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Addax Experience• The Addax coupling has been the

standard for new construction globally for 25 years

• Exclusively used with all US cooling tower manufactures with the exception of SPX Marley (Marley purchases Addax when spec’d).

• More than 85,000 Rexnord / Addax couplings in service globally – believed to be the world leader 29

NTPC Credentials • Existing Install at NTPC –RGPPL• Order received for NTPC Muzzafarpur• Order from NTPC Sipat

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1000+ Installation

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