What is mist entrainment, as it is often referred to in heat transfer processes? How does it occur, and what are its effects?
Thread Content
What is mist entrainment, as commonly referred to in heat transfer processes? How does it occur, and what are its effects?
Foam entrainment refers to the phenomenon in distillation column operation where the gas phase, as it passes through the pores and over the inlet weir, causes intense agitation of the liquid, resulting in the formation of bubbles or foam layers. The heat and mass transfer between the gas and liquid phases primarily take place within these foam layers. After coming into contact with the liquid, the gas phase rises upward, often carrying some liquid droplets with it. The main reason for this is an excessively high gas flow rate.
Are there any ways to reduce this impact?
It depends on whether it is a tower or a heat exchanger. When using a K-type kettle reboiler, mist entrainment must be taken into account, and the requirements regarding the rate of mist entrainment are related to the process. Generally, the ratio of the maximum diameter to the tube bundle diameter is not less than 1.5 times; if a higher requirement is placed on the mist entrainment rate, a demisting screen can be installed at the outlet. At the same time, there are requirements regarding the location of imports and exports; the farther, the better.