Rising Film Evaporator

Rising Film Evaporator

A Rising Film Evaporator (RFE) is a vertical shell and tube heat exchanger with a vapor – liquid separator mounted at the top.

The liquid to be concentrated is fed at the bottom of the heated tube bundle. As the liquid feed receives the heat, the vapors generated lift the liquid upwards. The velocities generated by the vapor lift are quite high, giving good thermal performance. The vapor and balance liquid are separated in the vapor- liquid separator.


1. Thermosiphon action eliminates the need for circulation pump

2. Trace quantities of suspended particles in the feed are tolerated

3. Can operate under reasonable vacuum

4. Multiple effect arrangement provides steam economy


1. Concentration of dilute solutions such as plant extracts

2. As a reboiler to distillation column

3. Economical alternative to falling film evaporator for moderate vacuum