Experimental study of mechanical vapor compression wastewater distillation system using twin screw compressor

An experimental study is carried out to a domestic developed mechanical vapor compression(MVC) wastewater distillation system that applied a twin screw compressor and had a treatment capacity of 60 t/d aiming to supply some reference for the system optimal design and marketization. According to the results, the system can operate stably with a distillate product rate of 1.03 t/h at a feed water flow rate of 60 t/d and the corresponding energy consumption is 35 kW·h. Purity of the water injects into twin screw compressor should be guaranteed to avoid the scaling on rotor surfaces. With the increase of compressor rotor speed, the system product rate increases linearly and the energy consumption had a minimum value which means that there exists an optimal rotor speed for each system operation condition. The system product rate increases and energy power consumption decreased separately with the first effect inlet temperature which is not affected by the compressor speed. Meanwhile, the product rate increases with the circulation volume of second effect outlet water and the growth rate decreased with the increase of first effect inlet water temperature.