In the Multi-effect evaporator with falling film system, the material covers the whole inner wall of the heat exchange tube in a membrane shape, and flows down along the heat exchange tube. It is possible to obtain a higher heat transfer coefficient even when the evaporation temperature difference is low. The middle of the heat exchange tube is filled with the secondary vapor formed by the evaporation of the material. In the design, the secondary steam and the material can flow in the same direction or reverse direction in the heat exchange tube according to the situation. The secondary steam leaving the heat exchange pipe then enters the separator to complete the liquid separation.
The separator can be conventional centrifugal or impact type; it can be a split type independent of the drop film heater or integrated with the heater. The all-in-one design can reduce the footprint and reduce installation costs.
The material with slight scaling problem requires circulating evaporation; even if the material is recycled, the falling film design is much more energy saving than the forced cycle. Thermal sensitive materials can be designed with direct process drop film to shorten the material residence time and reduce the energy consumption of the pump.
The descending film evaporation system is suitable for handling materials with no scaling problem or low scaling coefficient, and usually can not be used for crystallization. However, according to the characteristics of evaporating materials, two forms of falling film and forced circulation can be combined in the design to deal with scaling materials and continuous crystallization system.
In MVR (mechanical steam compression) and TVR (steam power heat pump) design, low evaporation temperature difference can reduce power consumption and steam consumption, and the lower film design can be used for low evaporation temperature difference, so it is more suitable for this kind of design. Due to the characteristics of the material itself or the use of low temperature waste heat evaporation (such as tube bundle exhaust or liquefied flash steam), the maximum material temperature in the evaporator is limited, compared with the lower film design to put more efficiency to reduce energy consumption. Falling film system is widely used in food, pharmaceutical, chemical, paper / pulp, and coal chemical industry and other industries.
Due to the high heat transfer coefficient, adapt to the temperature difference is small, the characteristics of high vacuum evaporation, can be widely used low quality waste heat (such as dryer hot air and flue gas), waste heat (condensate water, process water and flash steam) waste heat evaporation unit can use less or no fresh steam and enrichment task, realize evaporation with raw steam "zero" breakthrough. It has the advantages of high heat transfer efficiency, small temperature difference, no boiling point loss caused by liquid column, and less power consumption.
Multi-effect lowering film evaporator is widely used in the evaporation concentration and crystallization of starch and derivatives industry, alcohol industry, chemical industry and so on.
Alabin degree waste water evaporation
Daqing Bo run wine grains clear liquid
SDIC Helen
Heilongjiang China Resources corn corn pulp
Kaifeng Drone glycerol
Yixing linked citric acid
