1. The evaporation operation of the fin heat exchanger evaporator is divided according to the evaporation method:
Natural evaporation: that is, the solution evaporates at a temperature lower than the boiling point, such as sea salt. In this case, since the solvent is vaporized only on the surface of the solution, the vaporization rate of the solvent is low.
Boiling evaporation: The solution is heated to boiling point and allowed to evaporate under boiling conditions. Industrial evaporation operations are basically such.
2. The evaporating operation of the finned heat exchanger evaporator is divided according to the heating method:
Direct heat source heating is an evaporation process in which a fuel is mixed with air to generate a high-temperature flame and flue gas which is directly injected into the evaporated solution through a nozzle to heat the solution and vaporize the solvent. An indirect heat source heats the walls of the vessel to the evaporated solution. That is, the heat transfer process performed in the partition wall heat exchanger.
3. The evaporation operation of the finned evaporator is divided according to the operating pressure:
It can be divided into atmospheric pressure, pressurization and decompression (vacuum) evaporation operations. Obviously, heat sensitive materials such as antibiotic solutions, juices, etc. should be carried out under reduced pressure. High-viscosity materials should be heated by pressurized high-temperature heat source (such as heat transfer oil, molten salt, etc.).
4. The evaporation operation of the finned heat exchanger evaporator is determined by the number of effects:
Can be divided into single-effect and multi-effect evaporation. If the secondary vapor generated by evaporation is not directly utilized, it is called single-effect evaporation. If the secondary steam is used as the next heating steam and the plurality of evaporators are connected in series, the evaporation process is multi-effect evaporation.