Question

What is the problem in the evaporation in the climbing film evaporator?

• A. Boiling point of liquid
• B. Droplet formation
• C. Entrainment of liquid
• D. Film formation

Answer 1

The Correct Option is C

Step 1: Understanding climbing film evaporators. - A climbing film evaporator is designed to evaporate liquids by utilizing thermal gradients that promote liquid rise due to vapor expansion. 

Step 2: Identifying key problems in operation. - As the liquid climbs, there is a risk of entrainment, where droplets of liquid are carried away by the vapor stream. - This reduces efficiency and may contaminate the final product. 

Step 3: Explanation of incorrect options. - (A) Boiling point of liquid: Not a major issue as evaporators are designed for specific boiling ranges. - (B) Droplet formation: While droplet formation occurs, it is not the primary operational concern. - (D) Film formation: The design of the evaporator ensures proper film formation. 

Step 4: Selecting the correct option. Since entrainment of liquid is the main operational issue, the correct answer is (C) Entrainment of liquid.