System and technology for concentration and crystallization treatment of high-salinity water

Abstract

The invention relates to the technical field of sewage discharge, and concretely relates to a system and a technology for concentration and crystallization treatment of high-salinity water. The treatment system sequentially comprises a sewage collection tank, a pretreatment device, a flocculent precipitation device, an ultrafiltration device, a reverse osmosis device and an MVR evaporation concentration device according to the treatment use sequence, the MVR evaporation concentration device sequentially comprises a plate heat exchanger, a first precipitation and crystallization tank, a secondprecipitation and crystallization tank and a feed liquid circulating pump according to the treatment use sequence, and the steam outlet end of the first precipitation and crystallization tank and thesteam outlet end of the second precipitation and crystallization tank are communicated with the plate heat exchanger through a steam compressor; and the plate heat exchanger is provided with a feedingend, and the feeding end of the plate heat exchanger is communicated with the output end of the reverse osmosis device through a feeding pipeline. The system for concentration and crystallization treatment of high-salinity water has the advantages of novel structure, simplicity in operation, and ensuring of the integrity of crystals by precipitation, crystallization and growth of crystals of high-salinity water at the bottoms of the tank bodies of the first precipitation and crystallization tank and the second precipitation and crystallization tank.

Description

technical field [0001] The invention relates to the technical field of sewage discharge, in particular to a high-salt water concentration and crystallization treatment system and process. Background technique [0002] In recent years, in order to save the concentration cost, many enterprises, MVR production enterprises and multi-effect concentration enterprises have carried out research and production experiments on the concentration crystallization of zero discharge of sewage. During the research and production experiments, they all got the same result: The crystal particles of the mixed salt are fine, the concentrated solution is a suspension, the liquid-solid separation is difficult, the pipeline and heat exchanger are seriously blocked in the production process, and the crystal dehydration is difficult, so that the zero discharge cannot be implemented and operated continuously and benignly. [0003] Since the reverse osmosis concentrated water crystallization crystal its...

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Problems solved by technology

[0002] In recent years, in order to save the concentration cost, many enterprises, MVR production enterprises and multi-effect concentration enterprises have carried out research and production experiments on the concentration crystallization of zero discharge of sewage. During the research and production experiments, they all got the same result: The crystal particles of the mixed salt are fine, the concentrated solution is a suspension, the liquid-solid separation is difficult, the pipeline and heat exchanger are seriously blocked in the production process, and the crystal dehydration is difficult, so that zero discharge cannot be implemented and operated continuously and benignly.

[0003] Since the reverse osmosis concentrated water crystallization crystal itself has the defects of small crystal particles and poor mechanical strength of the crystallization crystal, during the production process of MVR, the feed liquid is forced to circulate by the forced circulation pump, because the separator does not promote crystal and solution The separation device or lack of effective separation device makes the separation of the crystal and the solution incomplete. In addition, the inlet of the circulation pump is located at the bottom of the separator. In the process of circulation, it is constantly subjected to high-speed shearing by the impeller of the circulating pump, which causes the crystals to be continuously broken, resulting in finer crystal particles or the formation of a suspended concentrated solution, making it difficult to separate the liquid from the solid.

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