EXHAUST EMISSION CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain excellent NOx reducing effect from an exhaust temperature lower than a conventional one even in a vehicle of such an operating form that an operating state at a low exhaust temperature continues for a long time period.

SOLUTION: An exhaust emission control device which includes at some midpoint of an exhaust pipe 4 a selective reduction type catalyst 5 obtained by selectively reacting NOx with ammonia even in the presence of oxygen and which reduces and controls NOx by adding urea water 6 as a reducing agent in the exhaust pipe 4 on the upstream side from the selective reduction type catalyst 5, is provided with an oxidation catalyst 9 in the exhaust pipe 4 on the upstream side from an adding position of the urea water 6 and with a fuel addition means (a fuel injection device 14) for adding fuel in exhaust 3 on the upstream side from the oxidation catalyst 9.

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