Question

What is not the cause of mill fire?

(a) Hot startup with normal load

(b) Pyrite building from pyrite plows failure

(c) Accumulation of coal dust in mill devices

(d) Localized hot spots from poor primary air flow

The question was asked in an interview for internship.

My query is from Pulverised Mills topic in chapter Steam Power Plant of Energy Engineering

Answer 1

Right option is (a) Hot startup with normal load

Best explanation: Mill fires are more often caused due to pyrite building, hot startup on heavy load, accumulation of coal dust etc. the cause of fire is also dependent upon coal properties that exceed pulverizing rating.