With easy-to-open access door and the easy-to-remove heat exchanger cover make machine maintenance and cleaning easier. Heat exchanger is designed with high flow rate forced circulation to reduce the scaling maintenance. Adopt four-effect evaporation and concentration design , which saves 75% energy comparing to one-effect evaporation. Evaporation and concentration under low temperature and vacuum can realize continuous feeding and continuous discharging. Multi-stage low-temperature evaporation concentration can effectively control discharge concentration, and live concentration monitoring control can realize automatic discharge.