Question

How is the coal fed to the grate in over feed system?

(a) Above the point of air admission

(b) Between the beds of incandescent coke and green coal

(c) Above the ash bed

(d) Between the point of air admission

The question was asked by my college director while I was bunking the class.

Question is from Principle of Stoker in section Steam Power Plant of Energy Engineering

Answer 1

Right choice is (a) Above the point of air admission

The explanation: The coal is fed on the grate above the point of air admission. The pressurized air coming from forced draught fan enters under the bottom of the grate. The air passing through the grate is heated by absorbing the heat from the ash and grates itself. Due to this the ash and grate are cooled.