Hydrochloric acid regenerating device and process for flue gas cooling

Abstract

The invention discloses a hydrochloric acid regenerating device and process for flue gas cooling. The hydrochloric acid regenerating device comprises an absorption tower, a first-stage washing tower,a spray cooling tower, an exhaust fan, a first-stage gas-liquid separator, a second-stage washing tower, a second-stage gas-liquid separator and a chimney; the spray cooling tower is an empty tower filled with no filler; circulating liquid pipelines of the spray cooling tower and the second-stage washing tower are respectively provided with a first heat exchanger and a second heat exchanger; and each of the heat exchangers is connected with a circulating cooling water pipeline. The hydrochloric acid regenerating device is used for treating and cooling flue gases generated after a hydrochloricacid regenerating reaction realized by a spray roasting method or a fluidized bed method and ensuring that the concentration of pollutants in the flue gases reaches a relatively low concentration, thetemperature of the discharged flue gas can reach about 45-50 DEG C, the content of water vapor discharged into the atmosphere is low, the contents of hydrogen chloride and dust pollutants are extremely low, and no obvious "white steam" is generated, so that the psychologically-unpleasant sensation of the public to the "white steam" is avoided.

Description

technical field [0001] The invention relates to a hydrochloric acid recycling and treatment process, in particular to a flue gas cooling hydrochloric acid regeneration device and process, which is suitable for the regeneration of hydrochloric acid waste liquid produced in cold rolling pickling, chemical industry, hydrometallurgy, titanium dioxide and other industries. Background technique [0002] Hydrochloric acid is an important industrial production product, which is used in cold rolling mills in the steel industry, pickling sections in the pipe industry, acid leaching systems in the chemical industry, and etching industries. When the consumption of hydrochloric acid waste liquid is large, spray roasting method and fluidized bed method which can be recycled and reused are generally used. The principle of the two treatment methods is the same, that is, the concentrated waste acid liquid is injected into the high-temperature area of ​​the roaster (or other roasting equipmen...

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Problems solved by technology

[0003] Some units in China are also trying to conduct research on flue gas cooling, but most of them use graphite heat exchangers to exchange heat and cool down flue gas. These processes can achieve the effect of reducing flue gas temperature to a certain extent in the short term, but The flue gas contains a certain amount of iron oxide powder dust. Long-term operation will cause the internal heat exchange holes of the graphite heat exchanger to be blocked by iron powder, which seriously affects the heat exchange effect of the heat exchanger.

In addition, the heat exchange efficiency of the gas entering the heat exchanger is relatively low, often requires a large heat exchange area, and the equipment price is relatively high

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