The single effect external circulation vacuum concentrator is composed of heater, evaporator, defoamer, condenser, cooler and liquid receiving tank. The parts that contact materials are all made of stainless steel.The equipment is applicable to evaporation and concentration of liquid materials in pharmacy, food, chemical industry and light industry etc. industries. The concentrating time is short and the evaporating speed is high, which can well protect the heat sensitive materials from being damaged. Model I. WZ single-effect external circulation vacuum concentrator is the ordinary type, which is used for evaporation of water solution. II. WZ Single Effect External Circulation Plate Type Condenser Vacuum Concentrator is the alcohol recovery type, which is used for evaporation of alcohol solution. It has higher cooling area to ensure the alcohol recovery. Its recovery strength reaches 70~85oC, the alcohol consumption rate is less than 5% and the alcohol temperature after the recovery is less than 40oC. III. WZS Single Effect External Circulation Cream Collection Vacuum Concentrator is used for single-effect evaporation and hick ointment collection. After the normal single-effect evaporation, the valves connecting the spraying tube and circulation tube in the heating chamber and evaporating chamber will be closed. The liquid materials will fully enter the evaporating chamber and through the jacket heating in the evaporating chamber, normal pressure type or pressure relief type concentration will be carried out. The concentration specific gravity of materials will be increased to 1.35-1.45.