Final Ppt Ntpc Dadri by Vikas

INDUSTRIAL TRAINING ON NTPC DADRI

submitted to:-Mr. A.S.PARMAR

Prepared by:-VIKAS Roll no.-0814340053B.Tech (ME) 4th year

CONSTRUCTIONAND WORKING OFCOAL HANDLING PLANT

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INDEX

Introduction. Availability of Coal in India. Transportation of Coal. Analysis of Coal. General Layout of CHP. CHP Auxiliary And Equipments

INTRODUCTION

What is CHP? CHP (C- Coal, H- Handling, P- Plant) Which properly handles the coal from its receipt to transferring it to bunkers.

Objective of CHP :-

To supply the quanta of processed coal to bunkers of Coal mills for Boiler operation.

To Stack the coal to coal yard.

AVAILABILITY OF COAL IN INDIA. Mostly E and F grade coal used in India. Blending Is Done To get Average D Grade.

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Grade C.V. ( K Cal / Kg. )

% Ash + Moisture

A > 6200 19.57

B 5601-6200 19.57 - 23.97

C 4941-5600 23.92 - 28.69

D 4201-5940 28.69 - 34.05

E 3361-4200 34.06 - 40.14

F 2401-3360 40.14 - 47.10

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TRANSPORTATION OF COAL

5 ways of Transportation.

• 1. Railways.• 2. Ropeways.• 3. Roadways.• 4. waterways.• 5. Airway.

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Available only for TPS nearer to coal

mines

Have to build Runway near TPS which is very

costly.

waterway may not be possible till TPS and

Problem of recalling arises if coal dip in water

Best and Cheap facility at Doorstep

Fear of thief

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•Daily on an average around 30,000 Tone of Coal is required for a typical 2000 MW Station.

•The required coal is supplied through Rail wagon. If the power station is away from coal mines then it is fed through Indian Railway system other wise for pit head station it is done through Merry Go Round railway system

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Main feature of MGR Loading System• This system calls for high-speed load- outstation at the mines •It consists of one or two loading silos depending upon the coal requirement of the linked power station

•The capacity of the silos for the NTPC project varies between 2400 ton/4000 ton.

•The silos are cylindrical and fed by twin belt conveyors.

•For accurate weighing of coal to each wagon, Load cells are provided with silos.

•A sampling unit suitable size coal is provided at the feed point of the loading silo to collect samples for quality analysis

The loading operation of the coal rake takes place while it is moving under the silo at a speed of 0.8 k.m. per hr.

•Wagons are provided with bottom discharge hoppers fitted with pneumatically operated automatic door actuating mechanism.

•Line side equipment is installed by the track hopper for initiating the opening of doors in groups of 10-14 wagons. The unloading operation of 60 tonne per load wagon takes about 20/30 seconds.

ANALYSIS OF COAL

Chemical Analysis of Coal:-Sample of coal is randomly collected from each rake and detailed chemical analysis, calculation of calorific value is carried out and is confirmed whether it is as per agreement with the coal mines or not.

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LOADING

COAL UN LOADING

At NTPC end, Coal is unloaded in the Track hoppers. Track Hopper, normally of 200-250m length.

After placing the wagons on the hopper, electrical pulse is given to the pneumatic device for opening the bottom doors.

Coal rushes down due to its own weight. When the track hopper is empty, it takes only 20 seconds

for unloading one wagon i.e. 60 Tons.

This coal falls on a ‘T’ table, over which a paddle feeder runs and pushes the coal on to a conveyor.

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TRACK HOPPER

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COAL-HANDLING SYSTEM:

•Coal handling system is the arrangement for transferring of coal from coal-wagons to coal-bunker or coal stock yard. •It also provide arrangement for separation of material impurities, crushing of coals, Coal sampling etc.

In the coal handling system of NTPC stations, three coal paths are normally availablePath A - direct conveying of coal from track hopper to boiler bunkers.Path B - from track hopper to stockyardPath C - from stockyard to boiler bunkers.The storage facilities at the stockyards have been provided only for crushed coal.

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COAL HANDLING PLANT LAYOUT

COAL HANDLING

The coal handling system is designed to provide 100% standby for all the equipment and conveyors.

The capacity of the coal handling system for super thermal stations varies from 1200 to 2000 t/h, normally, for a stage of 1000 MW,

GENERAL LAYOUT OF CHP

Wagon Tippler Crusher House

Bunkers

Tripper Trolley

Conv. Belts Vibrating Screens

Crushers

Feeder Surge Hopper

Hopper

OPERATIONAL CYCLE

BUNKERING CYCLE

Bunkers

From W/T

Bunkering Belts

Surge Hopper

Vibrating Feeder

Crusher House

Crusher

STACKING CYCLE

Bunkers

Stacking Belts

Crushed Yard

From W/T

Crusher House

Bunkering Belts

By-Passed Coal

Coal Is not required if bunker is full or Due

any maintenance

RECLAIMING CYCLE

Bunkers

Reclaiming Belts

Crushed Yard

Non-Crushed Yard

From W/T

Crusher House

Bunkering Belts

If Outer Supply of coal Is Not PresentIf Outer Supply of coal Is Not Present

Stacked Coal

STACKER – CUM -RECLAIMER

This is used for stacking and reclaiming the coal from stock yard. Generally two stacker claimers have been provided at each of the NTPC's projects. Their normal capacity is 200 tons per hour and maximum design capacity is 450 tons per hour.

The stacker reclaimer generally consists of (a) bucket wheel or digging wheel (b) boom conveyor. While the belt conveyor carrying the coal for the stock yard is in the same direction but the direction of the boom conveyor with respect to stacking and reclaiming is opposite.

Digging Wheel The digging wheel is use for cutting and lifting the coal from the stock yard to the belt used for transfering coal from the yard. The above transfer takes place in case of reclaiming the coal only.

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Stacker Reclaimer

STACKER – CUM -RECLAIMER During stocking operation, the coal from the

crusher house is diverted towards the stockyard conveyor at a transfer point TP2/ TP3. The above conveyor discharges coal to the boom conveyor through a discharge chute. The boom conveyor, running in the forward direction, creates coal stacks.

During reclaiming, coal from the stock yard falls on the boom conveyor with the help of the bucket wheel and the boom conveyor, during this period, rotates in backward direction. The coal from central chute falls on the conveyor belts used for transferring the coal from the stock yard. By this way, the coal moves on the underground conveyor belts connected to the main belts.

A 6.6 KV motor is used for running the stacker-cum-reclaimer and has a cable reeling drum on which flexible cable is wrapped.

STACKER – CUM -RECLAIMER

This is used for stacking and reclaiming the coal from stock yard. Generally two stacker claimers have been provided at each of the NTPC's projects. Their normal capacity is 200 tons per hour and maximum design capacity is 450 tons per hour.

The stacker reclaimer generally consists of (a) bucket wheel or digging wheel (b) boom conveyor. While the belt conveyor carrying the coal for the stock yard is in the same direction but the direction of the boom conveyor with respect to stacking and reclaiming is opposite.

Digging Wheel The digging wheel is use for cutting and lifting the coal from the stock yard to the belt used for transfering coal from the yard. The above transfer takes place in case of reclaiming the coal only.

STACKER-CUM- RECLAIMER

•Coal to/from stock yard

•Generally 2nos

•Capacity ---200T/hr

•Maximum---400T/hrBucket wheel

Boom conveyor

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WAGON TIPPLER

These are used to unload the coal wagons into coal hoppers in very less time (e.g. 20 wagons/hr. or more).

Weighing of coal is carried out at wagon tippler.

Normally 55-60 metric ton of coal come in each wagon.

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Wt of the coal =Wt. of loaded wagon – Wt. of empty wagon

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TRIPPERS

To stack material at desired bunkerProvided with wheels which moves on rails parallel to conveyor.

Three types motorized tripper

Belt propelled manually operated tripper

Winch driven tripper

WAGON TIPPLER DRIVE SYSTEM

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Motor

Pinion

Spur Gear

Thruster Brake

G / BG / B

Wagon tippler

Mesh of 250 mm * 250 mm

Hopper

Vibrating Feeder

Conveyor Belt

To crusher House

GENERAL LAYOUT OF W/T

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EQUIPMENT USED IN W/T

Water Sprinkler System. Dust Extraction System.

CONVEYOR BELT SYSTEM Construction of Conveyor Belt Conveyor Belt Drive System Counter Weight Idlers Protection System

Interlocking Magnetic Separator

CONSTRUCTION OF CONVEYOR BELT

Synthetic rubber. 4 ply means 4 nylon net in between 2 mm

thick rubber coating is used. At KTPS belt of 1000 mm width is used. Width varies from 500 mm -1400 mm.

Net

Strength = 600 N

1000 mm

CONVEYOR BELT DRIVE SYSTEM

Motor G / B

Fluid Coupling

Filled with 3/4th oil

Fusible plug

Head End Pulley

Tail End Pulley

oSpeed before crusher 2.4 m/secoSpeed After Crusher 2.7 m/sec

Belt Speed

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CONVEYOR BELTS

Made of diff. Layers or piles of fabric duck with rubber protected by a rubber cover on both sides & edges.Fabric duck are designed to withstand tension created in carrying the load .Nylon rubber cover protect the fabric duck.

Material =fire resistant grade.Belt Width=1600 mm.Strength= 1000/1250 kN.Belt speed=3.2-3 m/s.Belt length=20km.

IDLERS

Carry Side Return Side

Self Alignment Impact Return Roller

Return Adjustment Roller

( Installed after every 25m )

Below Discharge chute( rubber coating )

35°

ANGLE OF IDLERS

PROTECTION SYSTEM

Interlocking is used for safety purpose. If any belt fails all other belts stop working

which are interconnected.

Magnetic Separator is used to remove metal particle from coal conveyed through conveyor belt for improving boiler efficiency.

SEPARATING FOREIGN MATERIAL FROM CONVEYOR

MAGNETIC SEPARATOR Any ferrous material on

the conveyor will be lifted from the moving conveyor.

No Tripping involved. MS is interlocked with

Conveyor start up.When ferrous Metal is

picked up, the MS is moved from the Conveyor, de-magnatised and the metal piece is removed.

METAL DETECTOR Any Metal with an area

of 100 Sq Cm will be detected.

Conveyor is tripped after detection.

MD is not having interlock with start up.

A sandbag is dropped near the Metal piece for easy location

CRUSHING MECHANISM IN CHP

Three Stage Crushing System is used in Plant. 1.Double Roll Crusher 2.Rotary Breaker Crusher 3.Impact CrusherW / T No.4W / T No.4

DRCR RBCR Impact

250 mm

80 mm

600 mm

20-25 mm

Stage 1 Stage 2

Stage 3

DOUBLE ROLL CRUSHER ( DRCR )

Teeth

Roller

300 mm

ROTARY BREAKER CRUSHER ( RBC )

Striking Plate

Hole of diameter 100 mm

250 mm

80 mm

Stone shell

IMPACT CRUSHER0

4/1

1/2

3

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Hammer

30 mm

Rotor

Coal

TRACK HOPPER TO CRUSHER HOUSE

Below track hopper paddle feeder arrangement is provided to unload coal to coal conveyors.

The 200mm coal as received at the track hopper is fed to the crusher house through 1A & 1B conveyors.

IN THE CRUSHER HOUSE

Vibrating Screen :The function of the vibrating screen is: -

To send the coal having size of less than 20mm to belt feeder through the bypass chute bypassing the crusher and

To send the coal of more than 20mm size to the crusher.

CRUSHERSTo crush the coal from 200mmto 20mm size received from vibrating screenCrusher hammer are made of MAGNEESE STEEL .Hammer row -4(stage 1)

(a)Row-1 & 2 =18 hammer each(b)Row-3&4=20 hammers each

No of hammer in each Crusher-•stage-1 = 76 hammers•stage-2 = 92 hammers •Weight of each hammer=18.5kg•Crushing motor rating -740kw/3.3kv•Life of hammer =4 lac MT of coal•Normal capacity=600 tons/hr