Forced Circulation Evaporator

This is ideal for concentration of high viscous material and products with higher solids. This is also used as evaporative crystallizer. Some times these are used in series with falling film evaporator as finishing effect for achieving higher concentration. In this type of evaporator, liquid is pumped through heat exchanger tubes at high velocity (1.5-4.0 m/s) avoiding precipitation and creating high turbulence; liquid is then passed through vapour separator for separation of vapour and finally condensing the vapour in the condenser. Concentrated liquid is continuously discharged from bottom of vapour separator.

In a Rising Film Evaporator liquid feed enters from the bottom of steam heated tubes. The parallel movement of liquid and vapor along tube surface imparts effective water evaporation from the liquid feed. This type of evaporator is ideal for liquids which attain high viscosity or have fouling tendency.

The agitated thin film evaporator is well suited for concentration of viscous and heat sensitive liquids such as gelatin, antibiotics, fruit juices, and solvent mix etc. The thin film evaporator reduces fouling and liquid residence time in the evaporator. In the vertical agitated thin film evaporator feed liquid is feed at the top of evaporator and is uniformly distributed in the form of thin film by the wiper blades on vertical cylindrical heat transfer area, inside the unit. Evaporation of water / solvent takes place as the thin film moves down the heat transfer area.