Principle of scraper film evaporator:
The scraper film evaporator is a new type of evaporator with strong adaptability, which is applicable to materials with high viscosity, heat sensitivity and easy crystallization and scaling,

Process description:
The material preheated to the set temperature is added into the evaporator from the material nozzle of the scraper evaporator. Under the centrifugal force of the rotary scraper movement, the material is thrown onto the surrounding wall. The shell side is heated by saturated water vapor or heat transfer oil. Because the distance between the scraper and the heat exchange surface is very close, usually 0.5~1.5 mm, the heat transfer efficiency is very high, and the residence time is short, about 5-15 seconds, which is especially suitable for the evaporation and concentration of heat-sensitive materials. The concentrated solution is discharged from the bottom of the system. If there is crystallization demand, the concentrated solution circulation evaporation form can be considered; The secondary steam is discharged from the evaporator from the top and cooled into liquid phase in the condenser. When vacuum operation is required, the vacuum system is connected to the condensate tank.

Process characteristics:
With large heat transfer coefficient, short residence time of materials, and large operating flexibility, it is suitable for evaporation of high-viscosity materials and crystallizable materials containing solids, and can handle materials with viscosity as high as honey and paint.

advantage:
High vacuum operation can be realized; High heat transfer coefficient and high evaporation intensity; The residence time is short, and the movable scraper can change the residence time of materials; It has strong adaptability, can handle high viscosity, contains solids, is easy to crystallize, and has large operating flexibility.

Disadvantages:
Due to its complex structure and large power consumption, the heat transfer area cannot be large due to the influence of jacket, so the treatment capacity is small, which can be used as the follow-up treatment equipment of MVR or multi-effect evaporator.