Thin film or wiped film evaporators are used to separate a mixture of liquids having different boiling points. It is also used to increase the concentration of liquids.

Principle of Operation
The liquid feed is distributed on the heated wall of the evaporator to form a uniform thin film with the help of suitable configuration of blades. The volatile component or the component with lower boiling point gets evaporated and is vacuumed out of the evaporator, while the component with higher boiling point flows down the wall and is collected at the bottom. The vapours are passed through a condenser and collected separately.