EXHAUST PURIFICATION DEVICE AND EXHAUST PURIFICATION METHOD FOR DIESEL ENGINE

摘要

Disclosed are: an exhaust purification device for a diesel engine, which is reduced in size and capable of effectively using the heat of the exhaust gas by contriving an arrangement of various post-processing units; and an exhaust purification method using the exhaust purification device for a diesel engine. Specifically disclosed is an exhaust purification device (17) which comprises: an oxidation catalyst (19) that is arranged in an exhaust passage (7) of a diesel engine (1) and removes CO and HC contained in the exhaust gas; a urea spraying nozzle (22) that is arranged in the downstream of the oxidation catalyst (19) so as to produce ammonia by spraying urea water into the exhaust gas; a turbine (13) of a turbo charger (9), said turbine (13) being arranged in the downstream of the urea spraying nozzle (22) so as to accelerate the decomposition of urea by stirring the sprayed urea water; a DPF (20) that is arranged in the downstream of the turbine (13) so as to collect PM in the exhaust gas; and a selective reduction catalyst (23) that is arranged in the downstream of the DPF (20) so as to detoxify NOx in the exhaust gas through a reduction reaction with ammonia.