Patent ID: 8429901

Claim:
An exhaust gas purification device connected to an exhaust passage on the engine side of an internal combustion engine or a burning appliance, the exhaust gas purification device comprising: a plurality of branch exhaust passages connected to the exhaust passage on the engine side; a junction exhaust passage formed by the union of the respective branch exhaust passages on the exhaust downstream side of the respective branch exhaust passages; an exhaust gas shutoff unit switching between allowing and shutting off the flow of exhaust gas into the respective branch exhaust passages from the exhaust passage on the engine side by opening or closing the exhaust inlets of the respective branch exhaust passages; a nitrogen oxide adsorbing material, disposed inside each of the respective branch exhaust passages, temporarily adsorbing nitrogen oxides in an excess air atmosphere, and detaching the adsorbed nitrogen oxides in a reducing atmosphere; a reducing atmosphere generator, disposed on the exhaust upstream side of the nitrogen oxide adsorbing material inside each of the branch exhaust passages, having an air supply unit, and changing the air supplied from the air supply unit into the reducing atmosphere; and a selective reduction catalyst, provided inside the junction exhaust passage, and selectively reducing the nitrogen oxides by using ammonia as a reducing agent.