Question

Which of the following evaporator is not used for heat sensitive materials?

(a) Vacuum evaporators

(b) Vertical type evaporators

(c) Plate-and-frame type evaporators

(d) Agitated thin-film evaporators

I got this question in semester exam.

Question is taken from Evaporation of Heat Sensitive Materials in chapter Evaporation of Food Processing Unit Operations

Answer 1

Right option is (b) Vertical type evaporators

The best I can explain: Vacuum evaporators, plate-and-frame type evaporators and agitated thin-film evaporators are used for heat sensitive materials. Vertical type evaporators have long residence time and high pressure which can degrade the quality of the product.