Low-cost deep flue gas purification device and purifying, dewatering and white-smoke-eliminating process thereof

Abstract

The invention relates to a low-cost deep flue gas purification device and a purifying, dewatering and white-smoke-eliminating process thereof. The purification device comprises a desulfurization tower, and the desulfurization tower is sequentially provided with a desulfurizing and spraying unit, a cooling condenser, a defogging and dehydrating layer, a first outlet heat exchanger and a second outlet heat exchanger; an inlet flue heat exchanger is connected to an inlet flue channel, and a heat-exchange-liquid buffer tank, a heat-exchange-liquid circulation pump, a circulating-liquid cooling tower and a coolant circulation pump are arranged outside the desulfurization tower. The low-cost deep flue gas purification device and the purifying, dewatering and white-smoke-eliminating process thereof have the advantages that through cooling, condensation and coagulation of flue gases, deep purification of multiple pollutants is realized while moisture in the flue gases is recovered; after moisture recovery of the flue gases, the specific heat of the flue gases decreases, heat exchange energy consumption required for white smoke elimination of the outlet flue gases is reduced, and heat exchange energy consumption and costs for white smoke elimination of the outlet flue gases are reduced; inlet flue channel condensation and cooling are adopted, the volume of the flue gases is reduced, thestaying time of the flue gases in the tower is prolonged, the efficiency of the desulfurization tower is improved, and operation energy consumption is reduced; through heat exchange of the outlet flue gases and the self-cleaning process of the heat exchangers, the problems of scaling and blocking of the heat exchangers are solved.

Description

technical field [0001] The invention relates to the technical fields of chemical industry and environmental protection, in particular to a low-cost flue gas deep purification device and a process for purifying, collecting water and eliminating white smoke. Background technique [0002] After desulfurization in coal-fired power plants, the wet flue gas contains a large amount of moisture. The moisture content per kilogram of dry flue gas in the flue gas is about 80g, and about 70% of the heat energy is discharged in the form of latent heat of water vapor. The saturated flue gas discharged from the desulfurization system outlet is relatively low. After the low-temperature ambient atmosphere, after the flue gas cools and reaches supersaturated wet flue gas, water mist begins to precipitate, thus producing a "white plume". The "white plume" after wet desulfurization emits a large amount of water vapor into the air, resulting in waste of water resources. In addition, various pol...

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Problems solved by technology

[0004] The whitening process of heating flue gas method has the following problems: 1. Only by reheating the flue gas at the outlet of the absorption tower of the desulfurization system, the lifting height and diffusion range of the flue gas can be increased to a certain extent, and the "white plume" of the chimney and the power plant can be reduced. The surrounding "gypsum rain" is formed, but the emission concentration and total amount of pollutants in the desulfurization tail gas have not changed, which cannot produce environmental benefits; To eliminate the "white plume" by directly heating the flue gas, the temperature of the flue gas needs to be increased by 20-30°C or even higher, and the energy consumption is relatively large. The coal consumption of the unit increases by at least 2 g / kWh, and the operating cost is high; 3. Heat exchanger The lower part is in contact with the wet flue gas, and the residual acid gas in the flue gas is easy to corrode the heat exchanger. The evaporated particles in the upper part of the heat exchanger are easy to stick and block the heat exchanger. The service life of the heat exchanger is short and it is difficult to stabilize for a long time run

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