Classification of evaporator

1. According to evaporation method:

Natural evaporation: that is, the solution evaporates at a temperature lower than the boiling point, such as salt exposure with seawater. In this case, the solvent vaporizes only on the solution surface, so the solvent vaporization rate is low.

Boiling evaporation: Heating the solution to the boiling point to make it evaporate in boiling state. Industrial evaporation operations are basically of this type.

2. According to heating method:

Direct heat source heating refers to the evaporation process in which the fuel and air are mixed to make the high-temperature flame and flue gas generated by its combustion directly spray into the evaporated solution through the nozzle to heat the solution and vaporize the solvent.

Indirect heat source heats the walls of containers and transfers them to the evaporated solution. It refers to the heat transfer process in the intermediate wall heat exchanger.

3. According to the operating pressure:

It can be divided into normal pressure, pressurized and reduced pressure (vacuum) evaporation operations. Obviously, heat sensitive materials, such as antibiotic solution and fruit juice, 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.) for evaporation

4. Score according to the number of effects:

It can be divided into single effect evaporation and multi effect evaporation. If the secondary steam generated by evaporation is directly condensed and no longer used, it is called single effect evaporation. If the secondary steam is used as the next heating steam and multiple evaporators are connected in series, the evaporation process is called multi effect evaporation.