The evaporator is a very important component of the four major components of refrigeration. The low-temperature condensed liquid passes through the evaporator and exchanges heat with the outside air, gasifies and absorbs heat, and achieves the effect of refrigeration. The evaporator is mainly composed of a heating chamber and an evaporation chamber. The heating chamber provides the heat required for evaporation to the liquid, causing the liquid to boil and vaporize; the evaporation chamber completely separates the gas and liquid phases.

The vapor generated in the heating chamber carries a large amount of liquid foam. After reaching the larger evaporation chamber, these liquids are separated from the vapor by their own condensation or the action of the demister. Usually the demister is located at the top of the evaporation chamber.