The evaporator is mainly composed of a heating chamber and an evaporation chamber. The heating chamber supplies the liquid with the heat required for evaporation, causing the liquid to boil and vaporize; the evaporation chamber completely separates the gas-liquid two phases. The vapor generated in the heating chamber is filled with a large amount of liquid foam, and after reaching the evaporation chamber of a large space, the liquid is separated from the vapor by the action of self-aggregation or demister. The tube condenser is usually provided with a demister on top of the evaporation chamber.
The evaporator is divided into two categories: cyclic type and membrane type. According to the movement state of the solution in the evaporator, it is divided into a cyclic type. The boiling solution passes through the heating surface multiple times in the heating chamber, such as a central circulation tube type, a hanging basket type, an external heating type, a column type, and a forced circulation type. One-way type. The boiling solution passes through the heating surface once in the heating chamber, and does not circulate, that is, discharges the concentrated liquid, such as a rising film type, a falling film type, a stirring film type, and a centrifugal film type.
Direct contact type. The heating medium is in direct contact with the solution for heat transfer, such as a submerged combustion evaporator. The evaporation device consumes a large amount of heating steam during operation. To save heating steam, a multi-effect evaporation device and a steam recompression evaporator can be used.