Wiped Film Falling Evaporator

Film evaporator is through rotating film scraper device forced into a film, high speed flow, high heat transmission efficiency, short duration of stay time (about 10~50s).This type film evaporator is a new and high efficiency evaporator which could do falling film evaporation under vacuum conditions.Film evaporator consists of one or more cylinder body with jacket heating and film scraper device which is rotating in the cylinder body. Use film scraper device to let feedstock material into uniform liquid film at heating surface and move down, during this process,the lowboiling component is evaporating, and residue is discharged through the evaporator bottom.
 

1. Vacuum pressure drop is small There exists certain differential pressure when the material evaporating gas arrives condenser through heating surface. For ordinary evaporator, the vacuum pressure drop is high and even higher than accepting range. But for scraped film evaporator, it has enough big space for gas running, the pressure in evaporator is about as the same as the pressure of condenser, so, vacuum pressure drop is small, vacuum degree could arrived 5mmHg. 2. Operating temperature is low Whole evaporation process is done under high vacuum degree condition, and the related material boiling point reduce quickly, so it could operating under lower temperature and reduce material thermal decomposition. 3. Heating time is short The special structure of scraped film evaporator and the pumping action of scraped film device, let the material staying time in evaporator is short. Besides this, on the heating evaporation device, the material will not stay at the evaporator surface as high speed film flow. So this kind scraped film evaporator is suitable for heat sensitive material evaporation. 4. Evaporation intensity is strong The boiling point of material is reduced, then the temperature difference is bigger between same thermal medium. The function of scraped film device has reduced the thickness of liquid film and reduced the thermal resistance. At the same time, it could prevent material attachment and scaling, with good heat exchange, so as to improve the film evaporator overall coefficient of heat transfer. 5. Operating flexibility is big The unique characteristics of scraped film evaporator has made it be suitable for heat sensitivity material and high viscosity & viscosity sharply increased with concentration increasing material, so the evaporating process is stable and reliable. It can also successfully applied to the material (which contains solid particles, crystallization, aggregation, scaling, etc.) evaporation and distillation.