Question

In what form is the coal used in boiler?

(a) Big chunks.

(b) Medium size crushed

(c) Powder form

(d) Mixed with fluid

I got this question during an interview for a job.

This intriguing question originated from Feed Water and Steam Generation System, Working of Thermal Power Plant topic in portion Steam Power Plant of Energy Engineering

Answer 1

The correct answer is (c) Powder form

To explain I would say: The coal used for boiler is in powder form, in order to increase thermal efficiency. The different types of coal used in boiler are generally bituminous coal, brown coal and peat.  Commonly bituminous coal is most preferred boiler fuel since it has volatile matter from 8 to 33% and ash content of 5 to 16 %.