Raising Falling Film Evaporator

The raising falling film evaporator can be divided into raising, falling, plate, scraper, centrifugal film evaporator etc. There are mainly two frequently-used types: raising film evaporator and falling film evaporator.

The falling film evaporator: the feed liquid distributes in the heat exchange tube as a film after it passes through the distributor. The liquid film will be heated by the steam at the outside of the tube when it flows down because of the gravity. The light component with low boiling point will turn into gas phase when it reaches the evaporating temperature. Then it will be discharged from the gas phase outlet at the top of the tube. The liquid phase will enter the separation chamber to realize product concentration. This falling film evaporator has the following advantages: large heat transfer coefficient, high evaporation intensity and simple operation etc.

The raising film evaporator: the feed liquid enters the heating tube from the bottom. It will rapidly evaporated after boiling. The steam will rise fast in the tube. The feed liquid will form film along the tube wall and rise along with the rapidly raising steam. The evaporation continuously happens during this course. The steam produced and the liquid phase will enter the separation chamber of the evaporator together. After being separated thoroughly, the gas phase will condensed at the outside of the tube while the liquid phase will be discharged from the separation chamber. This raising film evaporator has the following advantages: large evaporating quantity, high thermal sensitivity, short retention time, high condensation efficiency etc.