1. Concentrate the dilute solution to directly prepare the product or reprocess the concentrated solution (such as cooling and crystallization) to prepare the solid product, such as the concentration of electrolytic caustic soda, the concentration of aqueous sugar solution, and the concentration of various fruit juices.
2. Concentrate the solution and recover the solvent at the same time, such as the concentrated debenzene of organic phosphorus pesticide benzene solution, the evaporation of alcohol extract in the production of traditional Chinese medicine, etc.
3. In order to obtain pure solvents, such as seawater desalination, etc.
