1. According to the evaporation method:
Natural evaporation: That is, the solution evaporates below the boiling temperature, such as obtaining salt by evaporating seawater. In this situation, the solvent evaporates only on the surface of the solution. Solvent evaporation rate is low.
Boiling evaporation: The solution is heated to the boiling point and allowed to evaporate under boiling. Industrial evaporative operation is basically all such method.
2. According to heating method:
Direct heat source heating: It mixes fuel with air, so that the combustion of high-temperature flame and flue gas through the nozzle directly into the evaporation of the solution to heat the solution. The solvent is finally vaporized.
Indirect heat source heating: The container trumeau is passed to the evaporated solution. That is a heat transfer process in the wall heat exchanger.
3. According to operating pressure:
It can be divided into atmospheric pressure, pressure and reduced pressure(vacuum) evaporation operation. Obviously, for heat-sensitive materials, such as antibiotic solution, fruit juice should be carried out under reduced pressure. The high-viscosity materials should be pressurized high-temperature heat source (such as HTF, molten salt, etc.) for evaporation.
4. According to effective number:
It can be divided into single-effect and multi-effect evaporation. If the secondary steam generated by evaporation is not used directly condensation, it is known as single-effect evaporation. If the secondary steam is used as the next effective heating steam, and make multiple evaporators in series, the evaporation process is multi-effect evaporation.