In the evaporation process, concentration of a product is accomplished by boiling the solution. Finally product should be recovered in the form of solid or evaporated liquid. . The recovered end product should have an optimum solids content consistent with desired product quality and operating economics. It is a unit operation that is used extensively in Effluent treatment, metal salt industries, processing foods, chemicals, pharmaceuticals, fruit juices, dairy products, paper and pulp, and both malt and grain beverages. Also it is a unit operation, which, with the possible exception of distillation, is the most energy intensive.

Different type of combinations is used in the evaporation system to take into account different product characteristics and operating parameters.