Evaporators

Evaporator is the part of the refrigeration system where the refrigerant fluid undergoes a change of state, leaving the liquid phase for the gas phase. It is sometimes called a cooling coil, unit cooler, freezing coil, freezer, etc.
Although the evaporator is sometimes a very simple device, it is actually the most important part of the system. Any refrigeration system is designed, installed and operated with the sole purpose of removing heat from any substance.
As this heat has to be absorbed by the evaporator, the efficiency of the system depends on its design and proper operation.
The efficiency of the evaporator in a refrigeration system depends on three main requirements, which must be considered when designing and selecting it:
1 - Have a sufficient surface to absorb the necessary heat load, without an excessive temperature difference between the refrigerant and the substance to be cooled.
2 - It must have enough space for the liquid refrigerant and also adequate space for the refrigerant vapor to separate from the liquid.
3 - Have enough space for the circulation of the refrigerant without excessive pressure drop between the inlet and the outlet.