Question

To what size are the particles ground for an economic balance between heat transfer rate from combustion gases plus residence time?

(a) 200 mesh

(b) 100 mesh

(c) 50 mesh

(d) 18 mesh

I had been asked this question in examination.

This interesting question is from Inorganic Chemical topic in section Inorganic Chemical Industries of Chemical Technology

Answer 1

Right choice is (a) 200 mesh

The explanation is: The particle size range of 200 mesh was found to be an economic balance between heat transfer rate from combustion gases plus residence time, as dictated by rate of fall of particles, tower height, and grinding costs.