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