Working Principle
The qualified feed water is input into the condenser after increased the pressure by multilevel pump.And then enters into each preheater(the feed water will be heated by the secondary steam and distilled water in the condenser ,in the frist stage preheater ,the feed water heated by the industrial steam condenstate water ,after enters the other stages preheater,it is heated by the secondary steam condensate water).Next the feed water is input into the water distributor of the 1st stage evaporator ,which is spouted to the inside of the heating tubes and flowed as film.The produced second steam with drips enters into the gas and steam separating setting from the bottom of the heating tubes .The separated pure steam enters into the next stage as heating steam ,meanwhile ,the feed water ,which is not evaporated ,enters into the next stage .And then it is repeated above mentioned process .The pure steam from last stage is converged with each stage condensed water (except 1st stage),after cooling and drainage of the non-condensable gas ,(according to different model ,there should be a device for discharge the non-condensable gas continuously) itis became the WFI.There is an on-line conductivity test at the output orifice .the qualified distilled water will be output as the WFI,and the unqualified will be discharged .
