Question

The pulverization is completed by a combination of crushing impact and _______ between grinding surfaces.

(a) Accretion

(b) Erosion

(c) Attrition

(d) Dissolution

I had been asked this question by my school teacher while I was bunking the class.

This question is from Pulverised Mills topic in portion Steam Power Plant of Energy Engineering

Answer 1

Correct option is (c) Attrition

The explanation is: The pulverization is completed by a combination of crushing impact and attrition between grinding surfaces. The coal is crushed between two moving surfaces: balls and races. The upper stationary race and lower rotating race is driven by a worm and gear, hold the balls between them.