OPERATION AND CONTROL OF VIBRO FEEDERS AND ITS APPLICATIONS

CONTENTS:

Introduction to VSPOver view of SMSVIBRO FEERDERSDesign of vibro feedersOperation principle of VIBRO FEEDERSStorage and HandlingControlling Installation processTypes of VIBRO FEEDERSApplicationsAdvantages & DisadvantagesConclusion

INTRODUCTION TO VSP:

Visakhapatnam Steel Plant (VSP), the first integrated shore

based ( bay of Bengal shore at east side) steel plant in the public

sector, is located at Visakhapatnam in the State of Andhra Pradesh

with a capacity of 3 MT liquid steel production per year. Expansion

works going on to increase capacity to 6.3 MT per year. Planning to

expand to 16MT capacity by 2020 in phased manner.

The Technological features are:

7m tall Coke Oven Batteries with coke dry quenching.

Biggest Blast Furnaces in the country with 3200 cum useful volume.

Bell less top charging system in Blast Furnaces (BF).

100% slag granulation at the BF cast house.

LD gas recovery system.

100% Continuous Casting of Liquid Steel.

High speed and high capacity Rolling Mills.

Extensive Waste heat recovery systems.

Comprehensive pollution control measures.

OVERVIEW OF SMS:STEEL MELT SHOP (SMS):-

Steel is an alloy iron and carbon, where carbon should be less than 2%. Hot metal produced in B.F contains impurities like carbon, sulphur, phosphorous, silicon etc., these impurities will be removed in steel making by oxidation process.

The steel melt shop comprises two 1300-ton hot metal mixers, three 130-ton LD converters and six 4-stand bloom casters.

SECTIONS OF SMS

Mixer shop

Converter shop

Continuous casting department

EOT cranes

VIBRO FEEDERS

INTRODUCTION:

Electromagnetic Vibro feeder is well known as a

kind of linear direction feeding device. It features

smooth vibration, reliable operation, long service life

and reliable for discharging bulk materials from bins,

transporting them over limited distances, for charging

and dosing them continuously or batch wise.

Definition:

A vibro feeder is an electro magnetic instrument that uses

vibration to transport ( feed ) material to a process or machine. Vibro

feeders use both vibration and gravity to move material. This action is

called micro throw principle.

The Electro magnetic Vibrating Feeder consists basically of A tray for conveying the material.

This is usually of Fabricated mild Steel

construction, Either open, enclosed, tubular.

A vibrator unit of cast iron construction which is

generally mounted below the tray.

A spring system under compression which connects

together the trough and the vibrator unit.

An Electro magnet consisting of a laminated

armature attached to the trough and E or U shaped

laminated core attached to vibrator unit.

DESIGN OF VIBRO FEEDERS

The vibro feeder consists of 3 sections1. Bunker2. Hopper3. Trough (tray)

VIBRO FEEDER DIAGRAM

OPERATING PRINCIPLE OF VIBRO FEEDERS

The vibrator coils are energized by a unidirectional pulsating current

derived from the A.C mains supply by means of half wave

rectification.

Thus 50 impulses per second are produced when operating on the

standard 50 cycles supply.

When current is allowed to flow, magnetic attraction takes place

between the core and armature of the electromagnet.

The trough and the vibrator unit are therefore drawn towards each

other, and at the same time the spring system is deflected

SINGLE LINE DIAGRAM

STORAGE

Store the machine under the cover of roof if possible or otherwise it should be necessarily covered by tarpaulins.

The springs must not be taken out or loosened and the

trough should not be separated from the casting while storing or installing the equipment.

Take extra care to avoid the possibility of water entering

the coil & making it damp. The suspension rods should be carefully stored to avoid

the possibility of bending and threads being spoiled.

HANDLING

Avoid dragging, bumping and side jacking to prevent

distortion.

Do not sling around springs and around the tray.

Do not open out or cut off any part of the feeder. The

suspension rods can be opened if it is necessary.

Extra precautions should be taken not to disturb the position

of the springs while handling or installing.

All the spare parts should be stored in a dry and clean area

protected from the weather.

INSTALLATION PROCESS

Feeders can usually be erected in position without any

dismantling of the machines being required.

High strength friction grip bolts should be tightened in

accordance with the torque values.

All bolts should be further checked for tightness after a

week’s operation.

ANGLE OF INSTALLATION :-

For free –flowing materials the normal angle of installation of

the feeder trough is 10 deg downhill.

For sticky materials provision should be made to enable the

angle to be increased to at least 15 deg in order to facilitate the

flow of material.

VIBRO FEEDERS CONTROLLING

Electromagnetic Feeders are fitted with ELECTRONIC CONTROLLERS housed in a sheet steel enclosure.

The unit consists of a rotary ON/OFF switch , protective fuses, potentiometer, thyristor, indicating meters and lamps, flush mounted on the front door.

The controller is suitable for operating on 415 volts , single phase 50 Hz AC supply system and the DC output can be varied from ‘0’ TO 100% of the rated value.

Block diagram of control circuit

HWR

Sampling gate (thyristor)

Gating waveform generator

(monostable ckt)

Zero crossing detector

DividerN:1

output

Schematic diagram of control circuit

Amplitude control

LOCATION OF CONTROLLER

Wherever possible the controller is located adjacent to the feeder as this allows the operator to observe the effect of adjustment on the feeder discharge rate and also will facilitate maintenance and tuning adjustments.

Where site requirements dictate the positioning of the control equipment at a central point, adjustment of feeder discharge rate, local to the feeder may be done by the provision of a remote control station.

In common with other electrical, apparatus the controller must be protected from damp and in out door locations

TYPES OF FEEDERS

SUSPENDED TYPE

FLOOR MOUNTED TYPE

SUSPENDED FEEDERS Suspension rods should always be attached to a main structure. Suspension from long un supported spans of structural steel work

should be avoided as loss of effective vibration in the machine will occur if the structure is insufficiently rigid and likely to flex.

Suspension rods should be supported by a plate or bracket not less

than ¾ ‘thick mounted at 90 deg to the line of the rods.

When a feeder is suspended directly from the inclined sides of a bunker the fixing brackets must be set out sufficiently to allow adequate adjustment.

FLOOR MOUNTED FEEDERS A concrete base is recommended wherever possible but

if the feeder is to be mounted on a steel structure it is

essential that the members carrying the feeder are sufficiently

substantial prevent bending or whipping .

Floor mounting plates with locating rings attached for

bolting down the concrete base or supporting structure .

Clearances between chute work ,trough And base of a

floor mounted feeder should be approximately ‘1m’ this is

also applied to liner fixing bolts.

APPLICTIONS This vibro feeders are being used in LD converters for required

amount of materials used are coke, dolomite, lime stone, dolo chips, iron ore etc.

Vibro feeders also being used in calcining plants for the chemical requirements in plant acquisitions.

In general we see these in filling of urea bags certain amount of weight is filled it completes closing same in case of rice bags that we generally use in our daily life.

SINTER PLANT and RMHP are department which are in use of these vibro feeders.

ADVANTAGES

Vibro feeders are meant to be in the automatic system process to fulfill the requirement of the needed for large machines.

These are having machine made systems manual usage will be difficult as well as risky so more machines are used in this vibro feeder in steel plant.

More time is being saved because machines are replaced by man and operations which are done in larger system is made easy.

DISADVANTAGES Protection is less and if damage occurs we have to check for this

problem in all entire machines.

More health problems are occurred at these working places. This is the main disadvantage.

CONCLUSION

We can observed that how the material can be transmitted from one place to other place by magnetizing a coil in a vibro feeder. And how to control the vibro feeder. By Using DUST EXHAUST(D.E) system we can reduce the health problems that are occurred due to the divergence of dust from the tray of vibro feeder.