Coal-fired power plant desulfurization waste water zero-emission treating technology and device special for treating technology

Abstract

The invention relates to a coal-fired power plant desulfurization waste water zero-emission treating technology and a device special for the treating technology. The treating technology comprises the steps that the treating process of pretreating desulfurization waste water, carrying out membrane concentration and MVR falling membrane evaporation and concentration and separating salt is adopted, meanwhile, about 60% of membrane-produced water and about 40% of condensate water are obtained and recycled, and thus zero emission of the desulfurization waste water in a coal-fired power plant is achieved. According to the coal-fired power plant desulfurization waste water zero-emission treating technology, membrane concentration is additionally carried out after pretreatment, the salt content of pretreatment outlet water of the desulfurization waste water reaches 5%-10% from 2%-3% through condensation, a less amount of evaporation is achieved, and energy consumption is reduced; in addition, MVR falling membrane evaporation condensation and MVR forced circulation evaporation crystallization are adopted in an evaporation crystallization system, the energy consumption loss of the evaporation crystallization system is lowered, the separating effect of salt is also improved, and good environment benefits and economic benefits are achieved.

Description

technical field [0001] The invention belongs to the technical field of industrial wastewater treatment, and in particular relates to a zero-discharge treatment process for desulfurization wastewater in a coal-fired power plant and a special device thereof. Background technique [0002] The wet flue gas desulfurization process is widely used in coal-fired power plants. The wet flue gas desulfurization process absorbs sulfur dioxide efficiently, and also absorbs impurities such as hydrogen chloride, hydrogen fluoride, and heavy metals in the flue gas. In order to maintain the balance of substances in the slurry circulation system of the desulfurization device To prevent the corrosion of the main equipment caused by the enrichment of chloride ions in the absorption liquid and to ensure the quality of gypsum, a certain amount of wastewater must be discharged from the system. This wastewater is desulfurization wastewater. The water quality of desulfurization wastewater is relativ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a zero-discharge treatment process for desulfurization wastewater in coal-fired power plants and its special device for the technical defects of the existing zero-discharge treatment process for desulfurization wastewater in coal-fired power plants. Treatment, MVR falling film evaporation concentration and MVR forced circulation evaporation crystallization and salt separation treatment have realized the resource recovery of salt in desulfurization wastewater, and reused the membrane-produced water and condensed water in the treatment process to realize the desulfurization wastewater of coal-fired power plants Zero emissions, saving water, reducing environmental pollution, reducing energy consumption, and saving resources

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