Evaporator is one of the most important parts in the four big pieces of refrigeration. The low-temperature condensing liquid will exchange heat with the outside air through the evaporator, vaporize and absorb heat to achieve the effect of refrigeration.The evaporator is mainly composed of heating chamber and evaporation chamber.The heating chamber provides the liquid with the heat needed for evaporation, and makes the liquid boil and vaporize.The evaporation chamber completely separates the gas-liquid phase.The steam produced in the heating chamber contains a large number of liquid droplets, which can be separated from the steam by means of self-condensation or defrosting devices in the larger evaporation chamber.
Usually the defuser is located at the top of the evaporation chamber.The evaporator is divided into three types according to operating pressure: normal pressure, pressure and pressure reduction.According to the solution in the evaporator of the movement of the state:
(1) circulation.The boiling solution passes through the heating surface several times in the heating chamber, such as the central circulation tube type, the hanging basket type, the external heat type, the lieven type and the forced circulation type.
(2) one-way.The boiling solution passes through the surface once in the heating chamber, and the concentrated solution is discharged without circulating, such as rising, falling, stirring, and centrifugal.
(3) direct contact.Heat transfer by direct contact between a heating medium and a solution, such as a submerged combustion evaporator.During the operation of the evaporator, a large amount of heated steam is consumed. In order to save heated steam, multi-effect evaporator and steam recompression evaporator can be used.Evaporator is widely used in chemical industry, light industry and other sectors.