Device and methods for removing acid gases in flue gases

Abstract

PROBLEM TO BE SOLVED: To provide an acid gas removal apparatus and an acid gas removal method using the same.SOLUTION: The powdery absorbent recirculation type acid gas removal apparatus includes: a conical fluidization part that has a filtration layer through which combustion exhaust gas including at least one of sulfur oxide and boron oxide is passed from the lower part thereof, a support for supporting the filtration layer, and a supply device for supplying a powdery absorbent by using compressed air and that removes the acid gas from the combustion exhaust gas by fluidization of the powdery absorbent by means of the rising power of the filtration layer-passed combustion exhaust gas; a fluidization part that is arranged in the upper part of the conical fluidization part and has a water jetting nozzle for jetting water and that removes the acid gas from the combustion exhaust gas by circulation of jetted waterdrops and fluidized powdery absorbent; and a recirculation cyclone that has an inflow port to be connected to the upper end of the fluidization part and a recirculation pipe to be connected to the conical fluidization part and that collects the powdery absorbent discharged through the inflow port and recirculates the collected powdery absorbent to the conical fluidization part through the recirculation pipe.

Description

technical field [0001] The present invention relates to an apparatus for removing acid gas in exhaust gas by circulating a powdery absorbent inside and outside, and a method for removing acid gas using the apparatus. Background technique [0002] Combustion devices that generally use fossil fuels such as coal, heavy oil, or the like as a heat source include: a wet desulfurization device for removing sulfur oxides in exhaust gas, a denitrification unit for removing nitrogen oxides in exhaust gas, and a Electric vacuum cleaner or back filter (back filter) for particulate matter (such as dust) in the air. [0003] figure 1 A block diagram showing a method for removing air pollutants from exhaust gases from conventional coal or heavy oil fired boilers. Such as figure 1 As shown, the exhaust gas discharged from the combustion boiler with a temperature of 330°C-360°C passes through a high-temperature denitrification unit (SCR) to remove nitrogen oxides in the exhaust gas, and t...

AI Technical Summary

Problems solved by technology

[0010] However, the problem with this traditional semi-dry desulfurization device is that when the exhaust gas and liquid slurry absorbent settle to the bottom of the desulfurization device, the frequency of contact between the exhaust gas and the liquid slurry absorbent is reduced, resulting in semi-dry desulfurization. The desulfurization efficiency of the device becomes lower (60-70%), so it is necessary to increase the height of the desulfurization device to increase the desulfurization efficiency of the device by increasing the reaction time to 10 seconds or longer

[0011] In addition, the traditional semi-dry desulfurization device also has the following problems: when the temperature of the exhaust gas entering the desulfurization device rises to 160°C or higher, the water contained in the liquid slurry absorbent is quickly dried, so that the gas-liquid reaction time becomes shorter. Short, reducing the desulfurization efficiency, and when the temperature of the exhaust gas entering the desulfurization device is kept low, the water vapor contained in the exhaust gas is condensed so that these condensed water vapor layers are distributed on the inner wall of the desulfurization device, which increases the adhesion The amount of reaction solids 29 on the inner wall of the device and cause corrosion to the desulfurization device

[0012] In addition, the traditional semi-dry desulfurization device also has the following problems: the increase in the amount of reaction solids 29 attached to the inner wall of the desulfurization device will reduce the inner diameter of the desulfurization device, further reducing the desulfurization efficiency of the device, which leads to the need to stop using the desulfurization device. device to periodically remove the reaction solids adhering to the inner wall of the desulfurization device

Images