Question

Falling rate period of the batch drying curve = _______ + ___________

(a) Internal movement, unsaturated surface drying

(b) Internal movement, saturated surface drying

(c) External movement, unsaturated surface drying

(d) External movement,  saturated surface drying

I have been asked this question in semester exam.

I'm obligated to ask this question of Time period Calculation in Batch Drying in chapter Drying of Mass Transfer

Answer 1

Right answer is (a) Internal movement, unsaturated surface drying

Best explanation: From the drying curve we know the falling rate period represents the bound moisture removal so it includes internal movement and unsaturated surface drying.