Second, the flow of the secondary steam: feed the waste heat from the waste liquid pump input (tangent enter) heat flash tank were separated, respectively, into an effective, three-way heating chamber (temperature 125 ℃) After separation after heat exchange, enters the cyclone After emptying the exhaust fan (temperature 55 ℃). One effect, secondary steam three-way separation chamber respectively and 4th effect into the second heating chamber for heat exchange, secondary steam second effect, four-way separation chamber before entering the condenser after preheating to preheat the incoming high factory direct evaporation salt crystals into the water cooled condenser is discharged from the vacuum pump cooling backward cyclone. ② one-way type. Boiling the solution in the heating chamber by heating the surface of a high salt crystallization process evaporators, without circulation, i.e. concentrate discharge line, such as rising film, falling film, the film was stirred and centrifugal thin film and the like.