Question

Statement 1: In a rising film evaporator, the feed can be very viscous.

Statement 2: In a rising film evaporator, the feed cannot be heat sensitive.

(a) True, False

(b) True, True

(c) False, False

(d) False, True

This question was addressed to me in semester exam.

This is a very interesting question from Unit Operations topic in section Heat Transfer Equipment, Microwave Heating, Evaporation, Diffusion and Mass Transfer and Dehydration of Food Engineering

Answer 1

Right option is (c) False, False

Easy explanation: In a rising film evaporator, the feed cannot be very viscous as the feed is made to flow against gravity. But, it can be heat sensitive because the residence time of the feed inside the evaporator is very low.