Patent ID: 8636970

Claim:
An exhaust purification device for a diesel engine, the device comprising: an oxidation catalyst that is disposed in an exhaust passage of the diesel engine and purifies CO and HC in exhaust gas; a urea injection nozzle that is disposed in the exhaust passage downstream of the oxidation catalyst and generates ammonia through atomization of urea water into the exhaust gas; a turbine of a turbocharger, this turbine being disposed in the exhaust passage downstream of the urea injection nozzle and accelerating decomposition of urea through agitation of the atomized urea water; a diesel particulate filter that is disposed in the exhaust passage downstream of the turbine and that traps particulate matter in the exhaust gas; and a selective reduction catalyst that is disposed in the exhaust passage downstream of the diesel particulate filter and detoxifies NOx in the exhaust gas through a reduction reaction with ammonia; wherein the oxidation catalyst has a first oxidation catalyst and a second oxidation catalyst, the first oxidation catalyst being superior to the second oxidation catalyst in CO purification, and the second oxidation catalyst being superior to the first oxidation catalyst in HC purification; wherein the exhaust passage and an intake passage of the diesel engine are connected by an EGR passage; and wherein the EGR passage is connected to the exhaust passage between the first oxidation catalyst and the second oxidation catalyst.