System for concentrating and reducing desulfurization wastewater by using flue gas waste heat and process thereof

Abstract

The invention discloses a system for concentrating and reducing desulfurization wastewater by using flue gas waste heat. The system comprises a dust remover, an induced draught fan, a flue channel with a spraying device, a desulfurization island, a water collection tank, a solid-liquid separator, an intermediate water tank and a concentration tank which are successively in conduction connection with each other, wherein the concentration tank is communicated with the intermediate water tank. The invention also discloses a process for concentrating and reducing desulfurization wastewater by using flue gas waste heat. The process comprises the following steps: (1) flue gas dust removal; (2) mass transfer and heat transfer of flue gas and water; (3) condensation in the desulfurization island; and (4) post-treatment of desulfurization wastewater. The step (4) of post-treatment of desulfurization wastewater comprises the following substeps of successively treating the desulfurization wastewater through the water collection tank, the solid-liquid separator and the intermediate water tank; collecting the desulfurization wastewater through the water collection tank, separating the desulfurization wastewater into sludge and water through the solid-liquid separator, enabling the water to flow into the intermediate water tank for circulation concentration and applying the water to spraying of the step (2). Through the system for concentrating and reducing desulfurization wastewater by using flue gas waste heat and the process thereof, the high-temperature flue gas is used for evaporating and concentrating the desulfurization wastewater, so that the water load entering the curing unit is reduced, and the cost of the concentration technology of the desulfurization wastewater is reduced; when the temperature of the flue gas is reduced, the water consumption in the desulfurization island is reduced, so that the water consumed by the desulfurization process is indirectly supplemented; the process is obvious in economic benefit.

Description

technical field [0001] The invention relates to the field of desulfurization wastewater treatment, in particular to a desulfurization wastewater flue gas waste heat concentration and reduction system and a process thereof. Background technique [0002] With the new Environmental Protection Law promulgated in January 2015, the "Water Pollution Prevention and Control Action Plan" promulgated in April 2015, and the "Technical Specifications for Application and Issuance of Pollution Discharge Permits for Thermal Power Industry" promulgated in January 2017, power companies The need to realize zero discharge of waste water in the whole plant is becoming more and more urgent. Under the background of zero discharge of power plant wastewater, in order to improve the comprehensive utilization rate of water, power plant wastewater such as circulating water sewage, reverse osmosis concentrated water, and water plant drainage are all collected into the desulfurization system. The water q...

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Problems solved by technology

However, the existing thermal concentration and membrane concentration technologies have high requirements for influent water quality, which increases the cost of pretreatment accordingly; and thermal concentration and membrane concentration have high investment and operating costs, which are not conducive to the popularization and application of desulfurization wastewater concentration technology , such as Chinese patent CN201510955608 discloses a method for concentrated treatment of waste water based on flue gas waste heat evaporation and desulfurization, the process steps of this method are complicated, and the cost of waste water concentration treatment is high

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