Coal Handling Plant
Transcript of Coal Handling Plant
e‐Learning Series Damodar Valley Corporation
Coal Handling Plant
Coal Handling PlantThe purpose of the Coal handling plant in a thermal power plant is toProcess raw coal & insure against the irregular supply of coal which isdependent on many players in the Supply chainThe function of a CHP is to receive, process, store ,feed the Coalbunkers consistently over the entire life of the Power plant.Coal is received from mines in the form of lumps, the sizes varyingfrom 100mm to 350mm, in two types of wagons through Rail; BOBRmeaning Bogie Open Bottom Rapid discharge & BOXN meaning BogieOpen High Sided Side discharge WagonBOBR wagons are unloaded in Track Hoppers & BOXN Wagons areunloaded by Wagon tipplers.Coal is then supplied to the crusher house through Roller screens orVibrating feeders to sieve the coal before feeding to the crusher; 20%of the coal that is received is already <20mm size so this is separated &only larger lumps are fed to the CrusherThe crusher breaks the lumps to sizes<20mm which is the input size tothe coal Pulverizers
Introduction
Coal Handling Plant
The crushed coal is fed to the conveyors in the crusher house throughBelt feeders; Coal is either directly fed to the coal bunkers or to theStacker/Reclaimers for stocking when the bunkers are full;The stacking is done to insulate the plant against the erratic supply ofcoal;CERC allows stocking of 1 ½ months stock of coal for Pit head plantsIn case of non receipt of wagons the coal from the stock pile isreclaimed through the Stacker/ Reclaimers & fed to the coal BunkersTo increase redundancy certain Plants also have Emergency reclaimHoppers near the Crushed coal Stock pile where the dozers are used tofeed coal to the bunkers when the Reclaimers breakdown.Coal is conveyed by means of conveyor Belts in the coal handlingplant
Introduction
Coal Handling Plant
Typical Coal Flow Diagram - CHP
Coal Handling Plant
STOCKYARD
TRACK HOPPER
Crusher House
CHP Control Room
PH
DS Pump House
S&T Control Room
CHP Pump HouseCHP
MCC
Roo
m
STOCKYARD
STOCKYARD
STOCKYARD
Typical Layout of a CHP
Coal Handling Plant
Key Equipments in CHP
Wagon Tippler, Side Arm ChargerTrack HopperStacker Re-claimer Paddle FeederApron FeederHydraulics for S/R, WT, SAC, PFCrusherLT SwitchgearPLC SystemVVVF DrivesLocomotive & Pay loaders
Coal Handling Plant
Weigh Bridge (In-motion Pit-less)
Purpose : To weigh the coal wagons on receipt before unloading into the Track Hopper
Coal Handling Plant
Types of Wagons
BOXN wagons unloaded through Wagon Tipplers BOBR wagons unloaded
through Track Hoppers
Coal Handling Plant
Typical GA of Wagon Tippler
Coal Handling Plant
Wagon tippler & Side arm charger
Side Arm Charger
Wagon Tippler
Dust Suppression system
Coal Discharge direction
WT Control Room
Coal Handling Plant
Wagon tippler
Purpose:To dump coal from BOXN wagons into the underground hopper from where it is transported to the Crusher House.Typical unloading cycle for wagons is approx 3 min i.e. 20 wagons can be unloaded from the Wagon Tippler
Coal Handling Plant
Apron Conveyor/Feeder
Purpose: to reduce direct impact on the conveyor below the Wagon tippler
Coal Handling Plant
Apron Conveyor/Feeder
Coal Handling Plant
Side Elevation of Track Hopper
Coal Handling Plant
Sectional elevation of Track Hopper
Coal Handling Plant
Track Hopper
Purpose: For unloading Coal from BOBR(Bogie open Bottom Rapid discharge)Wagons to Hoppers underneath; This system is preferred to the Wagon tippler asthe evacuation time is less (2 ½ Hrs compared to 5 Hrs for Wagon tippler); A rakeof 58 Wagons could be unloaded in 3 placements in a250m TH within 2 1/2 Hrs
Coal Handling Plant
Paddle Feeder
Table
Cable reeling drumImpact Idlers
Coal Tray
Track Hopper
Curved Paddle Blades
Cable reeling drumImpact IdlersWheels for movement of the Paddle feeder
Purpose: to scoop the raw coal from the table below the Track hopper to therespective conveyor; generally two feeders are provided on each side within aTrack hopper ; when not in use they are parked on either side;
Coal Handling Plant
Paddle Feeder
Cable reeling Drum
Table
Conveyor
Idlers
Curved Blades
Coal Handling Plant
Vibrating Screen
Grizzly Feeder/Vibrating Screen
Coal Handling Plant
Roller Screen
Purpose: Sieving the coal to reduce unnecessary loading on the Crusher; By sieving, the smaller particles (<20mm) are directly fed bypassing the crusher;
Boiler Tube Failures
Roller Screen
Coal <20 mm size is collected in this hopper & fed on the crushed coal conveyor after the crusher; typically 20‐25% of ROM is collected in this hopper
Coal >20mm is now fed to crusher ; typically 75‐80% of the coal received goes to the crusher
Drive motors for the Rollers
Coal Handling Plant
Ring Granulator
Purpose : To crush Raw coal (size 350mm) to < 20mm size which is stored in coal bunkers to be fed to Coal Pulverizers.
Coal Handling Plant
Ring Granulator
Boiler Tube Failures
Drive Pulley
Generally used for feeding the coal from the crusher to the conveyors; these are used to increase the redundancy/flexibility of the conveying system.
Belt Feeder
Coal Handling Plant
Stacker/Re-claimer
Purpose: To stack the coal after filling the bunkers for future use &reclaim the coal when the coal supply is irregular
Coal Handling Plant
Bucket Wheel Stacker/Re-claimer
Counter Weight
Operators Cabin
Bucket wheel for reclamation
Conveyor Belt
Carriage
Rail
Coal Handling Plant
Typical Conveyor Belting System
Purpose: To convey Coal continuously between the Transfer Points &ultimately to the coal storage silos.
Coal Handling Plant
Typical Conveyor gallery
Purpose: For providing weather proof housing & maintenance space for the conveyorbelting
Boiler Tube Failures
Conveyor Belt
Conveyor
Idlers
Boiler Tube Failures
Conveyor Pulley
These are the drivers of the conveyor Belts; the prime mover is a motor attached through Fluid coupling so that the starting current of the motor is restricted;
Pulley
Plummer Block
Drive Shaft
Rubber Lining
Coal Handling Plant
Impact idlers; they reduce the impact on the conveyor belts thereby increasing longevity; generally used on the tables of the paddle feeders in Track Hoppers or under the coal chutes.
Normal conveyor Idlers ; they are the supporting rollers for the conveyor belt on which the coal laden conveyor belt glides.
Conveyor Idlers
Coal Handling Plant
Metal detectorDetect non magnetic metal pieces &
heavy iron pieces
Removal/Detection of Metal Particles
ILMS : Inline Magnetic SeparatorRemove tramp iron & other magnetic
materials
Coal Handling Plant
PAY LOADER
Purpose : to stack coal in the stockpile area to be reclaimed by the Stacker/Re‐claimer
Coal Handling Plant
Dust Suppression
• As the coal Handling plant is prone to fugitive dust it is mandatory to install dust suppression systems in the CHP
• Spraying system: sprinklers are used in the stockpile area to suppress the dust ; the mechanism is simple; fine atomic particles of water are sprayed on the stock pile & this acts as a blanket
• DFDS: dry fog dust suppression system: this is used typically at transfer points & hoppers; The water is sprayed in conjunction with compressed air & these particles adhere to the dust & settle down
• Dust Extraction system: This is used in Bunker silos where the coal is fed from conveyors & falls from a height; The unsettled dust is sucked through fans installed on the roof through bag filters or cyclonic separators & the heavier dust particles are fed back to the bunkers
Coal Handling Plant
Dust Extraction System
Coal Handling Plant
Coal Trivia
• Coal provided the energy which fueled the Industrial Revolution of the 19th Century and also launched the electric era in the 20th Century
• Coal provides 26.5% of global primary energy needs and generates 41.5% of the world's electricity
• Total Global Hard Coal Production - 5845Mt (2008e)• Primary source of energy for India; accounts for 55% of Energy
need• Hard coal reserves of India 246 bn Tonnes & proven reserves of
92 bn tonnes; third largest producer of coal• Commercial coal Mining in India started in 1774 in Raniganj
coal field by M/S Sumner & Heatly of East India Company• Indian Coal production - 490 Mt
Coal Handling Plant
Grades of coal
Coal Handling Plant
Thank You