Multi-effect membrane distillation and multi-effect evaporation comprehensive crystallization device

Abstract

The invention discloses a multi-effect membrane distillation and multi-effect evaporation comprehensive crystallization device which comprises a multi-effect membrane distillation system and a multi-effect evaporation system which are connected in sequence, the multi-effect membrane distillation system comprises a multi-effect membrane distillation assembly, the multi-effect membrane distillation assembly is an air gap type membrane distillation assembly with an internal latent heat recovery function, and the multi-effect evaporation system is a vacuum evaporation system. The comprehensive integrated device design is adopted, the whole device is optimized, valuable inorganic salt, precious metal and condensed water sources can be recycled, energy is saved, consumption is reduced, and good investment benefits are achieved.

Description

Technical field [0001] The present invention relates to the field of sewage treatment, and more particularly to a multi-active film distillation and a multi-effect evaporation integrated crystallization device. Background technique [0002] During the oil field mining, the underground water and injection water will dissolve a large amount of mineralization in the formation of the mineralization, resulting in a high mineralization in the water, and the return water of high mineralization will greatly reduce the recovery rate, and corrode the pipeline Many puzzles for mining and conveying. High concentrations of mineralized aqueous solutions are concentrated, and the desalination process of salt can be used. [0003] Conventional concentration techniques include multi-stage flash, more efficient evaporation, reverse osmosis, electrodialysis and membrane distillation. The current reverse osmosis technology has been widely used in seawater dilution, wastewater treatment and desalinat...

AI Technical Summary

Problems solved by technology

However, the thermal efficiency of the multi-effect evaporation process commonly used in chemical plants is very low, and the water production ratio is generally not more than 5. Therefore, the operating cost is relatively high when dealing with dilute solutions, and the salt solution is highly corrosive. Multi-effect evaporation equipment needs to use expensive Corrosion-resistant materials, which greatly increase the investment cost

Reverse osmosis technology is a non-phase change process, which has the advantages of low energy consumption and easy operation, but the process requires strict pretreatment and cannot handle high-concentration inorganic salt solutions

Electrodialysis technology can concentrate the salt solution to 15% or even higher, but when the salt concentration is too high, the process consumes a lot of electricity, and the fresh water produced has a high salt content, which cannot be directly discharged or used

Membrane distillation technology has the advantages of mild operating conditions, high rejection rate, low-grade heat source, and the ability to handle high-concentration salt solutions that reverse osmosis technology cannot handle. However, the thermal efficiency of traditional membrane distillation technology is generally relatively low at present. The thermal efficiency of the characterization is only between 0.2-1.0, so it is difficult to realize industrial application

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