Exhaust emission control device

摘要

An exhaust emission control device with a particulate filter and a selective reduction catalyst (exhaust purification catalyst) incorporated in an exhaust pipe such that the former and the latter are arranged on downstream and upstream sides, respectively, has a burner for generating high-temperature exhaust gas by combustion, an exhaust distribution pipe capable of guiding the exhaust gas from the burner to entry sides of the filter and the catalyst, respectively, and valves as a path switcher in the pipe for selectively sorting the exhaust gas from the burner any one of the entry sides of the filter and the catalyst.

主权项

1. An exhaust emission control device, comprising:
an exhaust pipe in which exhaust gas flows, an exhaust purification catalyst arranged on an upstream side of the exhaust pipe, a particulate filter arranged in parallel with and downstream of the exhaust purification catalyst, an oxidation catalyst arranged upstream of an entry end of the exhaust purification catalyst for facilitating an oxidation reaction of NO in the exhaust gas into NO2 , a urea water injector arranged downstream of the oxidation catalyst for adding urea water into the exhaust gas, a burner for generating high-temperature exhaust gas by combustion, an exhaust distribution pipe capable of guiding the exhaust gas from the burner to entry sides of the particulate filter and the exhaust purification catalyst, respectively, and path switching valves in the exhaust distribution pipe for selectively sorting the exhaust gas from the burner any one of the entry sides of the particulate filter and the exhaust purification catalyst, wherein the exhaust pipe is S-shaped for interconnecting a discharge end of the exhaust purification catalyst and an entry end of the particulate filter, wherein the burner is arranged adjacent to the entry end of the exhaust purification catalyst and the entry end of the particulate filter and independently of the exhaust pipe, and wherein an end of a branch of the exhaust distribution pipe is arranged downstream of the oxidation catalyst and upstream of the urea water injector.