Question

What is the purpose of the portholes on the plates of plate heat exchangers?

(a) To have a even flow of the fluid throughout the plate

(b) To drain the excess liquid from the plate

(c) To maintain the pressure inside the heat exchanger

(d) To stack the plates

I got this question during an internship interview.

Question is taken from Heat Transfer Applications topic in chapter Heat Transfer Applications of Food Processing Unit Operations

Answer 1

Right option is (a) To have a even flow of the fluid throughout the plate

Easy explanation: The main purpose of the portholes on the plates of plate heat exchangers is to ensure that flow of the liquid is even throughout the plate. It also increases the heat transfer efficiency and reduces the fouling.