Wet desulfurization wastewater zero emission process and device thereof

Abstract

The invention discloses a wet desulfurization wastewater zero emission process and a device thereof; desulfurization wastewater behind a gypsum dewatering device is collected and enters a flocculation reactor, the desulfurization wastewater is softened, flocculated and clarified, and sludge is sent to a sludge processing device for dewatering; the clarified water after separation is desalted, the desalted water is reused in a desulfurization system, concentrated water is sent to an evaporation crystallization device, waste heat of a boiler flue gas is used for evaporation crystallization, and high-quality water steam is obtained after evaporation; an evaporated crystallized substance and the water steam are subjected to gas-solid separation, the high-quality water steam is sent into a desulfurization absorption tower for recycling, and the crystallized substance is discharged together with fly ash. The high-quality water steam can be completely recycled in the desulfurization adsorption tower; suspended solids, dissolved solids, heavy metals, high salt, and Ca<2+>, Mg<2+>, Cl<+> and F<-> ions and other substances are cured, separated and collected, the purpose of complete recycling of the desulfurization wastewater is achieved, and zero emissions of the desulfurization wastewater can be achieved. In addition, the method has no effect on other systems of a power plant, and has the advantages of high practicability, low investment, and wide popularization and use value.

Description

technical field [0001] The invention relates to the technical fields of energy and resource recovery and utilization in thermal power plants, energy conservation and environmental protection, and in particular to a zero-discharge process and device for wet desulfurization wastewater in thermal power plants. Background technique [0002] Wet desulfurization is currently the only large-scale commercial desulfurization method in the world, and it is the main technical means to control sulfur dioxide emissions from coal-fired power plants. Limestone-gypsum wet desulfurization is the most widely used flue gas desulfurization method at home and abroad. [0003] The flue gas produced by the boiler enters the wet desulfurization system after being dedusted by the electrostatic precipitator, and is washed and desulfurized in the absorption tower. After the mist is removed by the demister, it is discharged into the atmosphere through the chimney. In the absorption tower, as the flue ...

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Problems solved by technology

For example, the wastewater treatment system of Heyuan Power Plant in Guangdong pioneered the desulfurization wastewater treatment technology in China. It is the first power plant in my country to adopt the process of "pretreatment + evaporation + crystallization" for desulfurization wastewater. The desulfurization wastewater treatment capacity is about 20t / h, and the investment is about ~8000 10,000 yuan, but this method has the disadvantages of high investment cost, operating cost, and high energy consumption, and this technology has not been widely promoted

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