1.
1. Rising film evaporator
Rising film evaporator is suitable for evaporation of large (i.e., dilute solution), heat-sensitive and easy to foam solution, but is not suitable for high viscosity, crystal precipitation or easy to scale solution.
2. external heating evaporator
The structure of external heating evaporator is characterized by heating chamber and separation chamber separately, which is not only easy to clean and replace, but also can reduce the total height of evaporator. Because of its heating tube is longer (tube length and tube diameter ratio of 50~100), at the same time because of the circulating tube of the solution is not heated, so the circulating speed of the solution is big, up to 1.5m/s.
3. Central circulating tube evaporator
Central circulating tube evaporator has the advantages of compact structure, convenient manufacture, reliable operation, so it is very widely applied in the industry, and it has the so-called The "standard evaporator" is called.
But in fact, due to the structural limitations, its circulation speed is low (generally below 0.5m/s); And because the solution in the heating tube constantly circulating, so that its concentration is always close to the concentration of the completion of the liquid, and thus the boiling point of the solution is high, the effective temperature difference is reduced. In addition, the cleaning and overhaul of the equipment is not convenient enough.
4. MVR forced circulation evaporator
Lower heat transfer coefficient;
Heat exchange surface is not easy to form scale or crystallization.
5. MVR falling film evaporator
High heat transfer efficiency
Small footprint
Short material residence time, not easy to cause material deterioration.
Suitable for higher viscosity materials.
6. Suspended basket evaporator
Suspended basket evaporator is suitable for evaporating the solution which is easy to scale or have crystal precipitation. Its disadvantage is that the structure is complex, the unit heat transfer surface requires a larger amount of equipment material.
7. Levin evaporator
The advantage of Levin evaporator is circulating speed is big, heat transfer effect is good, because the solution in the heating tube does not boil, can avoid the precipitation of crystals in the heating tube, so it is suitable for dealing with the solution which has crystal precipitation or is easy to scale. The disadvantage is that the equipment is huge and requires high plant. In addition, due to the liquid layer static pressure, it requires a higher pressure of the heating steam.