MVR (mechanical vapor recompression) evaporation crystallization system and method for high-salinity wastewater

Abstract

The invention discloses an MVR (mechanical vapor recompression) evaporation crystallization system and method for high-salinity wastewater[0]. The system comprises a raw material tank, a first preheater, a second preheater, an MVR evaporator, a gas-liquid separator, a compressor, a first circulating pump, a condensate tank, a forced circulation evaporator, a second circulating pump, a crystallizer, a centrifuge and a vapor generator. The full utilization of secondary vapor is realized after high-salinity wastewater is treated with the system, and the system has the advantages that the cost is low, the continuity and the energy saving effect are good, and the crystal salt quality is high.

Description

Technical field [0001] The invention relates to wastewater treatment technology, in particular to an evaporation crystallization system and method for mechanical vapor recompression of high-salt wastewater. Background technique [0002] In addition to organic pollutants, high-salt wastewater also contains a large amount of inorganic salts, such as Cl - , SO 4 2- , Na + , Ca 2+ Wait. When conventional biological treatment technology is used to treat high-salt wastewater, it is generally necessary to dilute this type of wastewater, which will cause a great waste of water resources. The multi-effect evaporation process not only consumes a large amount of steam, but also consumes a large amount of cooling water to cool the secondary steam. In this way, a large amount of latent heat of the low-grade secondary steam is wasted in vain, which also increases the cost of cooling water. . [0003] Mechanical Vapor Recompression (MVR) technology is currently the most advanced and energy-savi...

AI Technical Summary

Problems solved by technology

[0004] Although many continuous evaporation and crystallization systems using mechanical vapor recompression technology have been disclosed, generally only steam compressors are used to supply heat to the evaporator, and often there is no heat supply to the crystallization part, which easily leads to poor crystallization effect and crystallization. Problems such as too small particles

The invention patent with the publication number CN103007553A provides a mechanical vapor recompression continuous evaporation crystallization system and method. The method uses two mechanical vapor compressors to compress the secondary vapor of the evaporator and the crystallizer respectively, but the two Mechanical vapor compressors have high equipment costs and complex processes

In addition, the current method of using mechanical vapor recompression technology to treat high-salt wastewater by evaporation and crystallization generally has the defects of high operating costs and low quality of crystallized salt.

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