Rotary evaporators are mainly used for continuous distillation of large quantities of volatile solvents under reduced pressure. Especially for the concentration and crystallization of extracts and chromatographic separation of the receiving liquid distillation can be separated and purified reaction medium. The basic principle of the rotary evaporator is vacuum distillation, i.e. the distillation flask is rotated under reduced pressure as the solvent is distilled. The glass flask containing the reaction contents is rotated and heated uniformly at a constant temperature. With negative pressure on, the boiling point of the material is lowered, the liquid forms a film and evaporates, and the solvent is recovered by means of a glass coil condenser and collector. It is ideal for the concentration, crystallization, separation and solvent recovery of thermal materials.