Process and device for dehumidifying wet flue gas purification tail gas

Abstract

The invention belongs to the technical field of boiler flue gas purification and discloses a process and a device for dehumidifying wet flue gas purification tail gas. The process comprises the following steps that: desulfurized flue gas enters the washing section of a desulfurizing tower from a gas raising cap (9) and washing liquid sprayed by a washing nozzle (10) is sprayed to remove SO2 and NH3 escaping along with the desulfurized flue gas; the flue gas rises continually and enters a two-stage baffle plate demister, the two-stage baffle plate demister removes liquid drops of which the particle sizes are more than 5 microns from the flue gas and nozzles above and below the baffle plate demister rinse inorganic salt and fume attached to the baffle plate demister out; and the flue gas enters a smoke pipe (17), a water collecting sump (18) on the lower part of a horizontal pipe at the tail end of the smoke pipe (17) intercepts condensate in the smoke pipe and the condensate enters a condensate collecting groove (19) and is recycled into a liquid storage tank (3) through a liquid return pipe (28). In the process and the device, water spraying, demisting, liquid flow intercepting, recycling and the like are performed on the desulfurized flue gas, so that purified flue gas entering a flue and a chimney does not contain liquid water, desulfurization efficiency is improved and byproduct recovery rate is increased.

Description

technical field [0001] The invention belongs to the technical field of boiler flue gas purification, and mainly relates to a dehumidification process and device for tail gas of wet flue gas purification. Background technique [0002] In the wet desulfurization and denitrification process, because a large amount of liquid materials are sprayed in the purification tower, some liquid droplets with small particle sizes are easily carried out of the tower by the flue gas and enter the flue. As the flue gas temperature decreases in the flue, the water vapor will further condense and gather, forming a more obvious flue runoff. If the liquid runoff is not removed and recovered before the flue gas enters the chimney, it will not only affect the recovery rate of by-products, but also increase the corrosion of the flue, induced draft fan, and chimney. [0003] The net flue gas after desulfurization contains moisture and various corrosive components, and the water droplets brought out ...

AI Technical Summary

Problems solved by technology

If the liquid runoff is not removed and recovered before the flue gas enters the chimney, it will not only affect the recovery rate of by-products, but also increase the corrosion of the flue, induced draft fan, and chimney

[0003] The net flue gas after desulfurization contains moisture and various corrosive components, and the water droplets brought out by the flue gas contain NH 4 + , SO 4 2-、 SO 3 2- , NO 2 - , NO 3 - If the water droplets are taken out of the tower or condensed on the wall of the flue pipe, they will flow into the cement flue, boiler induced draft fan, chimney, etc. along the flue pipe, causing corrosion to the above-mentioned equipment or components. Seepage from joints or crevices pollutes the environment

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