Vacuum evaporation system is mainly used for distillation and extraction. In the condition of normal/negative pressure, constant heating, by the theory of different boiling point of different liquid material, after distillation and collection to get your target solvent. 
For example, by using rotary evaporator to get alcohol from a mixture of water and alcohol.
Vacuum evaporation system is widely applied in Bio-chemical, Pharmaceutical & Fine-Chemical Trades. For process like Concentration, Refining, Separation, Crystallization, drying, etc.
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