Exhaust Gas Purification Device

Abstract

An exhaust gas purification device (1) comprising a main exhaust passage (2) and a branch exhaust passage (3) connected to an exhaust passage (100) on the engine side; shutoff valves (4A) and (4B) capable of shutting off exhaust gas at the exhaust inlets (2a) and (3a) of the main exhaust passage (2) and the branch exhaust passage (3); a nitrogen oxide adsorbing material (5); an adsorbed material detachment unit (6), having an air nozzle (61); and a combustion device (7) including an air nozzle (71), a fuel nozzle (72) and an ignition plug (73), wherein the exhaust gas from the exhaust passage (100) on the engine side is discharged directly from the exhaust outlet (3b) of the branch exhaust passage (3).

Description

TECHNICAL FIELD[0001]The present invention relates to a device for purifying exhaust gas discharged from internal combustion engines, such as diesel engines, gas engines, gasoline engines or gas turbine engines, or burning appliances, such as combustion furnaces and boilers, more particularly, to an exhaust gas purification device, connected to the exhaust passage of an internal combustion engine or the like performing normal operation in an excess air state, for eliminating nitrogen oxides.BACKGROUND ART[0002]Harmful components, such as nitrogen oxides, carbon monoxide and hydrocarbons, are contained in exhaust gas discharged from internal combustion engines, etc. Various kinds of devices have been developed conventionally to eliminate such substances from the exhaust gas thereby to purify the exhaust gas.[0003]The applicant of the present invention developed an exhaust gas purification device and has already applied for a patent (Patent document 1). FIG. 5 shows an exhaust gas pur...

AI Technical Summary

Benefits of technology

[0013]According to the first aspect of the present invention, since the branch exhaust passage for allowing the exhaust gas to pass therethrough directly is provided, the exhaust gas purification device can shut off the flow of the exhaust gas into the main exhaust passage, and can detach the nitrogen oxides from the nitrogen oxide adsorbing material inside the main exhaust passage. For this reason, the exhaust gas purification device can maintain the capability of adsorbing the nitrogen oxides while the nitrogen oxide adsorbing material, the adsorbed material detachment unit and the combustion device relating to the adsorption, detachment and reduction of the nitrogen oxides are disposed in only one exhaust passage (the main exhaust passage). As a result, an exhaust gas purification device being low in cost is provided.

[0014]In addition, according to the configuration (a), since the exhaust gas purification device comprises the filter member, the exhaust gas purification device can eliminate the particulate matter from the exhaust gas. Furthermore, the exhaust gas purification device can maintain the trapping capability of the filter member by the operation of the adsorbed material detachment unit.

[0015]Furthermore, according to the configuration (b), since the exhaust gas purification device comprises the sulfur oxide adsorbing material on the exhaust upstream side of the nitrogen oxide adsorbing material, the exhaust gas purification device can prevent the sulfur oxides from flowing into the nitrogen oxide adsorbing material. Moreover, the exhaust gas purification device can maintain the adsorption capability of the sulfur oxide adsorbing material for adsorbing the sulfur oxides by the operation of the adsorbed material detachment unit. Besides, when the sulfur oxides are detached, the nitrogen oxide adsorbing material is also placed in the rising temperature atmosphere and the reducing atmosphere, whereby the sulfur oxides do not attach to the nitrogen oxide adsorbing material. In other words, performance degradation of the nitrogen oxide adsorbing material due to poisoning by sulfur oxides is prevented.

[0016]According to the second aspect of the present invention, since the branch exhaust passage for allowing the exhaust gas to pass therethrough directly is provided, the exhaust gas purification device can shut off the flow of the exhaust gas into the main exhaust passage, and can detach the nitrogen oxides from the nitrogen oxide adsorbing material inside the main exhaust passage. For this reason, the exhaust gas purification device can maintain the capability of adsorbing the nitrogen oxides while the nitrogen oxide adsorbing material, the adsorbed material detachment unit and the combustion device relating to the adsorption, detachment and reduction of the nitrogen oxides are disposed in only one exhaust passage (the main exhaust passage). As a result, an exhaust gas purification device being low in cost is provided.

[0017]In addition, since the exhaust gas purification device comprises the filter member, the exhaust gas purification device can eliminate the particulate matter from the exhaust gas. Furthermore, the exhaust gas purification device can maintain the trapping capability of the filter member by the operation of the adsorbed material detachment unit.

[0018]Furthermore, since the exhaust gas purification device comprises the sulfur oxide adsorbing material on the exhaust upstream side of the nitrogen oxide adsorbing material, the exhaust gas purification device can prevent the sulfur oxides from flowing into the nitrogen oxide adsorbing material. Moreover, the exhaust gas purification device can maintain the adsorption capability of the sulfur oxide adsorbing material for adsorbing the sulfur oxides by the operation of the adsorbed material detachment unit. In particular, when the adsorbed material detachment unit is operated, the air flow to the exhaust upstream side is formed, whereby the sulfur oxides do not flow into the nitrogen oxide adsorbing material. In other words, performance degradation of the nitrogen oxide adsorbing material due to poisoning by the sulfur oxides is prevented.

Problems solved by technology

The three-way catalyst serving as a catalyst capable of decomposing nitrogen oxides, carbon monoxide and hydrocarbons simultaneously does not act effectively in an excess air condition.

In the case of a purification device that uses ammonia, etc., the device itself is very complicated and expensive.

In addition, maintenance cost is necessary for ammonia, etc. serving reducing agents, and it is necessary to provide a system for supplying ammonia, etc., whereby many problems occur.

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