Wastewater zero-discharge system for multi-stage treatment and method of system

Abstract

The invention provides a wastewater zero-discharge system for multi-stage treatment and a method of the system. The system comprises a boiler, a denitration system, a dry flue gas system, a desulfurization system, a wastewater conveying system, a wastewater concentration system, a wastewater spray evaporation system and a concentrated flue gas system, wherein the boiler, the denitration system, the dry flue gas system, the desulfurization system, the wastewater conveying system, the wastewater concentration system and the wastewater spray evaporation system are sequentially connected with oneanother; the wastewater concentration system is connected with the desulfurization system through the concentrated flue gas system; and the wastewater spray evaporation system is also connected with the dry flue gas system. According to the wastewater zero-discharge process for multi-stage treatment, secondary utilization of system waste heat is realized, operation energy consumption is reduced, and thus high-efficiency and stable zero discharge of desulfurization wastewater is realized.

Description

technical field [0001] The invention relates to the technical field of waste water treatment of flue gas wet desulfurization process, in particular to a multi-stage treatment waste water zero discharge system. Background technique [0002] At present, in the field of flue gas desulfurization of thermal power plants in my country, limestone-gypsum wet desulfurization has a market share of about 85%. The by-products of the wet desulfurization process include gypsum and desulfurization wastewater. The slurry in the desulfurization absorption tower is regularly discharged to control the concentration of harmful elements such as Cl-, F and heavy metals in the limestone slurry in the desulfurization absorption tower, which cause the slurry reaction ability to decrease. Reduce the concentration of fine dust particles in the slurry to ensure the normal and stable operation of the desulfurization system. [0003] As my country's environmental protection requirements become increasin...

AI Technical Summary

Problems solved by technology

When the desulfurization wastewater is concentrated with a filter membrane, due to the high salt content of the desulfurization wastewater and the large amount of impurities in the water quality, the filter membrane is often blocked, and some impurities in the desulfurization wastewater are likely to cause membrane poisoning. The operation needs to be replaced frequently, and the cost of the filter membrane is high. The operation cost of concentration is high; and the use of membrane concentration technology requires a water pump to provide a filter pressure difference. The filter pressure difference is large, the pump power is high, and the economy of the membrane concentration system is low.

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