Question

What controls the overall heat transfer coefficient in falling film evaporators?

(a) Film thickness

(b) Velocity

(c) Liquid properties

(d) Film thickness, velocity, liquid properties

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I need to ask this question from Heat Transfer in Evaporators in division Evaporation of Food Processing Unit Operations

Answer 1

Correct answer is (d) Film thickness, velocity, liquid properties

Explanation: Falling film evaporators controls the overall heat transfer coefficient by difference in temperature, thickness of the film, properties of the liquid, velocity across the film layer. These are important design modules which help in high heat transfer rates.