This query is related to a number of power stations whose coal supply is from deicated mines and coal transport is by captive railway system. The power stations receive coal of (-) 250 mm size in track hopper. The coal is conveyed by belt conveyors to crusher house where coal is crushed to (-) 20 mm size. Coal from crusher house can be conveyed either to the stockyard or conveyed to Boiler bunkers. Each stockyard has minimum two(2) cantilevered boom, travelling, slewing and luffing bucket whell type stacker cum reclaimer operating over yard conveyor in conjunction with a tripper. The stockpile cross section is trapezoidal, base is 37 metres wise, height is 10 metres and is about 500 metres long , two(2) nos on either side of each s/r ie total minimum 4 such stockpile. Coal once reclaimed cannot come back to the stockyard and has to go only to the bunkers. Both yard conveyors reclaim coal and ultimately drop it onto common conveyors.
Now, the issue is that these plants are not receiving adequate quatity of coal and there is need to import coal to meet the shortfll. The calorific value of linked mine coal is in the range of 3000-3500 Kcal/ kg while imported coal could could be in the range of 6000 Kcal/ kg necessitating blending.
The proposal is to create 3 piles of linked mine coal and 1 pile of imported coal. Using both S/R operating in reclamation mode and by setting the reclaim TPH of linked mine coal and imported coal in the blend ratio needed. feed both types of coal onto the common reclaim conveyor which will feed coal through minimum three transfer houses before it reaches boiler bunkers and get mixed in the process.
It is pertinent to mention that two track hoppers are available in each of the power stations and the imported coal coal has to be brought in by the state railway system.
The issues are:
1) The beds of imported and linked coal formed on the reclaim conveyor gets mixed in the process of passing through transfer chutes.
2) Since timing of receipt of state railway rakes cannot be prdicted forming of chevron piles with alternate layers of linked and imported coal may notbe practicable.
3) Mixing of coal in the stockyard by mechanical(bulldozer) means may not be feasible.
4) Powr plants are in the range of 1000- 1500 MW capacity and quantum of coal handled is high.
Blending of coal in thermal power stations
Hello,
This query is related to a number of power stations whose coal supply is from deicated mines and coal transport is by captive railway system. The power stations receive coal of (-) 250 mm size in track hopper. The coal is conveyed by belt conveyors to crusher house where coal is crushed to (-) 20 mm size. Coal from crusher house can be conveyed either to the stockyard or conveyed to Boiler bunkers. Each stockyard has minimum two(2) cantilevered boom, travelling, slewing and luffing bucket whell type stacker cum reclaimer operating over yard conveyor in conjunction with a tripper. The stockpile cross section is trapezoidal, base is 37 metres wise, height is 10 metres and is about 500 metres long , two(2) nos on either side of each s/r ie total minimum 4 such stockpile. Coal once reclaimed cannot come back to the stockyard and has to go only to the bunkers. Both yard conveyors reclaim coal and ultimately drop it onto common conveyors.
Now, the issue is that these plants are not receiving adequate quatity of coal and there is need to import coal to meet the shortfll. The calorific value of linked mine coal is in the range of 3000-3500 Kcal/ kg while imported coal could could be in the range of 6000 Kcal/ kg necessitating blending.
The proposal is to create 3 piles of linked mine coal and 1 pile of imported coal. Using both S/R operating in reclamation mode and by setting the reclaim TPH of linked mine coal and imported coal in the blend ratio needed. feed both types of coal onto the common reclaim conveyor which will feed coal through minimum three transfer houses before it reaches boiler bunkers and get mixed in the process.
It is pertinent to mention that two track hoppers are available in each of the power stations and the imported coal coal has to be brought in by the state railway system.
The issues are:
1) The beds of imported and linked coal formed on the reclaim conveyor gets mixed in the process of passing through transfer chutes.
2) Since timing of receipt of state railway rakes cannot be prdicted forming of chevron piles with alternate layers of linked and imported coal may notbe practicable.
3) Mixing of coal in the stockyard by mechanical(bulldozer) means may not be feasible.
4) Powr plants are in the range of 1000- 1500 MW capacity and quantum of coal handled is high.
Will it work out?
Any suggestions.
G. Ravindra ■