Thermal-process evaporative crystallization treatment system and method for desulfurization wastewater

Abstract

The system comprises a pretreatment unit, a multi-effect flash evaporation and concentration unit, a mechanical vapor compression and crystallization unit, a thermal evaporation and crystallization unit, a thermal evaporation and crystallization unit, a thermal evaporation and crystallization unit, a thermal evaporation and crystallization unit and a thermal evaporation and crystallization unit, and is characterized in that the multiple-effect flash evaporation and concentration unit is used for producing a concentrated solution from desulfurization wastewater; the mechanical vapor compression crystallization unit is composed of an evaporator, a vapor compressor, a crystallizer and a crystal mush treatment module, and the vapor compressor pressurizes and heats secondary vapor and then conveys the secondary vapor back to the evaporator for secondary utilization; wherein the final steam of the negative pressure flash evaporation module is input into the mechanical steam compression crystallization unit to serve as initial steam, and the condensate water of the negative pressure flash evaporation module is input into the mechanical steam compression crystallization unit to serve as production water. When the system is used, the steam condensate water and the secondary steam of the multi-effect flash evaporation concentration unit are recycled, and the two treatment processes are communicated, so that the steam consumption and the water consumption are reduced, the heat consumption is reduced, and the system is simpler.

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