BOTTOM ASH SYSTEM
Bottom ash resulting from the combustion of coal in the boiler shall fall into the over ground, refractory lined, water impounded, maintained level, double V-Section type/ W type steel- fabricated bottom ash hopper having a hold up volume to store bottom ash and economizer ash of maximum allowable condition with the rate specified. The slurry formed shall be transported to slurry sump through pipes.
a) Pneumatic Conveying System
b) Mechanical System
c) De-Watering Bin System
d) Chain Conveyor System
e) Highly efficient Turbo jet pumping System
Coarse Ash collected in the different Coarse Ash Hoppers of Boilers namely, Economizer, Air heater, Duct, Bed Ash etc., can be removed by any of the systems adopted either for Bottom Ash or Fly Ash depending upon the quantity and quality of ash.
Coarse Ash (Economizer Ash) handling System
Ash generated in Economizer hoppers shall be evacuated continuously through flushing boxes. Continuous generated Economizer slurry shall be fed by gravity into respective bottom ash hopper pipes with necessary slope.
Air Pre Heater ash handling system
Ash generated from APH hoppers shall be evacuated once in a shift by vacuum conveying system connected with the ESP hopper vacuum conveying system.
Ash Slurry Disposal System
Bottom Ash slurry, Fly ash slurry and the Coarse Ash slurry shall be pumped from the common ash slurry sump up to the dyke area which is located at a distance from Slurry pump house.