Question

Name of the evaporator which consists of one pass vertical shell and tube heat exchanger discharging the product to be evaporated into a relatively small vapor head?

(a) Horizontal tube evaporator

(b) Long tube vertical evaporator

(c) Vacuum pan evaporator

(d) Forced circulation evaporator

I have been asked this question in a job interview.

The query is from Evaporator topic in chapter Building Blocks of Dairy Processing of Dairy Engineering

Answer 1

Correct choice is (b) Long tube vertical evaporator

For explanation: In Long tube vertical evaporator, the feed enters at the bottom of the tube, starts boiling as it moves up the tube and the mixture of liquid and vapor leaving at the top at high velocity strikes against a deflector placed above the tube.