I have tried to post this thread thrice but somehow it does not appear.
This is a query with regard to requirement of blending of coal in existing power stations whose coal handling plants are not designed considering blending.
The power stations are linked to specific mine and coal is brought to the power plant in captive railway system and unloaded in track hopper . Each station has minimum two track hoppers. Coal received is (-)250 mm size. This coal is conveyed to a crusher house where ist size is reduced to (-)20 mm.
After crusher house coal can be conveyed either to stockyard or to boiler bunkers. Coal reclaimed from the stockyard cannot be sent back to the stockyard and can go only to bunkers.
Each power plant has a stockyard with minimum 15 days coal consumption volume. Minimum two nos rail mounted ,travelling, cantilevered boom, slewing and luffing bucket wheel type stacker cum reclaimer operating in conjunction with a tripper are provided over two nos yard conveyors which serve to bring coal to the S/R for stacking as well as receiving reclaimed coal. These two yard conveyors feed coal onto common reclaiming stream of conveyors which carry coal to the boiler bunkers. Essentially ant blending requirement must be met either during the process of stacking or has to achieved during reclaiming. The stockpile cross section is trapezoidal with a base of 37 metres and a height of 10 metres. Minimum four such piles each of 500 metres length are available.
Since there is a steep shortfall in supply of coal from linked mine import of coal may have to be resorted to. The linked coal has a calorific value in the range of 3000-3500 Kcal/kg while the imported coal is likely to have a calorific value of 6000 Kcal/ kg. Since the boiler is not designed to receive such high calorific value coal, there is need to blend it with linked mine coal.
Coal from imported sources will be moved from the port to the power plant by the state railway system. The arrival of rakes by this system cannot be predicted and coal as and when received in rakes either single or bunched will have to be unloaded and sent to stockpile. Hence a planned creation of blended stockpile using chevron or windrow method of linked and imported coal may not be feasible.
What is thought of is to keep 3 piles of linked mine coal and one pile of imported coal and use both S/Rs in reclaiming mode and adjust the capacity in line with blend requirement and feed the reclaimed coal onto the reclaim conveyor which will carry one layer of imported coal with another layer of linked coal (Since both yard conveyors will be feeding a common reclaim conveyor. Now, this reclaimed coal will reach the boiler bunker after passing through 3 transfer points passing through chute work in each transfer point and hopefully getting mixed up reasonably.
Blending of coal at thermal power station
Hello,
I have tried to post this thread thrice but somehow it does not appear.
This is a query with regard to requirement of blending of coal in existing power stations whose coal handling plants are not designed considering blending.
The power stations are linked to specific mine and coal is brought to the power plant in captive railway system and unloaded in track hopper . Each station has minimum two track hoppers. Coal received is (-)250 mm size. This coal is conveyed to a crusher house where ist size is reduced to (-)20 mm.
After crusher house coal can be conveyed either to stockyard or to boiler bunkers. Coal reclaimed from the stockyard cannot be sent back to the stockyard and can go only to bunkers.
Each power plant has a stockyard with minimum 15 days coal consumption volume. Minimum two nos rail mounted ,travelling, cantilevered boom, slewing and luffing bucket wheel type stacker cum reclaimer operating in conjunction with a tripper are provided over two nos yard conveyors which serve to bring coal to the S/R for stacking as well as receiving reclaimed coal. These two yard conveyors feed coal onto common reclaiming stream of conveyors which carry coal to the boiler bunkers. Essentially ant blending requirement must be met either during the process of stacking or has to achieved during reclaiming. The stockpile cross section is trapezoidal with a base of 37 metres and a height of 10 metres. Minimum four such piles each of 500 metres length are available.
Since there is a steep shortfall in supply of coal from linked mine import of coal may have to be resorted to. The linked coal has a calorific value in the range of 3000-3500 Kcal/kg while the imported coal is likely to have a calorific value of 6000 Kcal/ kg. Since the boiler is not designed to receive such high calorific value coal, there is need to blend it with linked mine coal.
Coal from imported sources will be moved from the port to the power plant by the state railway system. The arrival of rakes by this system cannot be predicted and coal as and when received in rakes either single or bunched will have to be unloaded and sent to stockpile. Hence a planned creation of blended stockpile using chevron or windrow method of linked and imported coal may not be feasible.
What is thought of is to keep 3 piles of linked mine coal and one pile of imported coal and use both S/Rs in reclaiming mode and adjust the capacity in line with blend requirement and feed the reclaimed coal onto the reclaim conveyor which will carry one layer of imported coal with another layer of linked coal (Since both yard conveyors will be feeding a common reclaim conveyor. Now, this reclaimed coal will reach the boiler bunker after passing through 3 transfer points passing through chute work in each transfer point and hopefully getting mixed up reasonably.
Is it likely to work?
Any suggestions.
G.Ravindra ■