Apparatus for treating discharge gas and system for treating discharge gas

Abstract

An apparatus for discharge gas treatment (10) having a denitration catalyst layer (13) which removes nitrogen oxides from a discharge gas and in which hydrochloric acid is sprayed in the discharge gas to oxidize mercury. The apparatus has a spiral-flow generation member (15A) in each of passages (14) of the denitration catalyst layer (13). The member (15A) comprises: a vertical shaft (22) disposed in the passage (14) of the honeycomb catalyst; and sets of four spiral-flow generation blades (23) which have been disposed radially on the vertical shaft (22) and cause a turbulent flow in the discharge gas, the sets of the spiral-flow generation blades (23) having been arranged at a given interval in the direction of the vertical shaft (22). By thus generating a spiral flow in the discharge gas in each passage (14) of the denitration catalyst layer (13), the time period of contact of the discharge gas with the denitration catalyst is prolonged to improve the efficiency of the oxidation reaction of the mercury contained in the discharge gas with the denitration catalyst.

Description

technical field [0001] The present invention relates to an exhaust gas treatment device and an exhaust gas treatment system for treating exhaust gas discharged from a combustion device. Background technique [0002] For example, since exhaust gas discharged from a coal-fired boiler, which is a combustion device such as a thermal power plant, contains highly toxic mercury, various systems for removing mercury in exhaust gas have been considered conventionally. [0003] Generally, a coal-fired boiler is provided with a wet desulfurization device for removing sulfur components in exhaust gas. In the flue gas treatment equipment formed by attaching a desulfurization device to the boiler as a waste gas treatment device, it is known that when the chlorine (Cl) component in the waste gas increases, the divalent metallic mercury (Hg) soluble in water The proportion is increased, so that mercury is easily captured by the desulfurization device. [0004] Therefore, in recent years, ...

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Problems solved by technology

[0023] However, conventionally, the gas flow of the exhaust gas 12 supplied to the denitration catalyst layer 13 is rectified by a rectifying mechanism (not shown) in front of the denitration catalyst layer 13 to become a laminar flow state, and flows into the denitration catalyst layer 13 in this state. Therefore, the contact area with the denitration catalyst is limited, and as a result, there is a problem that it is difficult to further improve the oxidation reaction efficiency of mercury.

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