Exhaust emission control device
In an exhaust emission control device, a selective reduction catalyst 5 having a property capable of selectively reacting NO x with ammonia even in the presence of oxygen is incorporated as NO x reduction catalyst in an exhaust pipe 4 and a particulate filter 13 is arranged upstream of the catalyst. Arranged in front of the particulate filter 13 is a burner 14 for injection of fuel in moderate quantity for ignition and combustion. Interposed between the particulate filter 13 and the selective reduction catalyst 5 is an oxidation catalyst 15 which conducts oxidation treatment of unburned HC in the exhaust gas 3 and urges oxidation reaction of NO in the exhaust gas 3 into NO 2 .
1. An exhaust emission control device wherein an aftertreatment device for depuration of exhaust gas through passing of the gas therethrough is arranged in a casing and incorporated in an exhaust passage, said casing having an outlet connected through a connecting flange with a gas gathering chamber which in turn provides an exhaust passage in a direction different from an axis of said casing, comprising:
said gas gathering chamber provided with a mounting portion which extends through the exhaust passage to provide a mounting opening for fastening of the connecting flange from outside, the mounting portion providing said mounting opening being provided at an outer periphery thereof with a curved surface for flow rectification of the exhaust gas,
wherein the gas gathering chamber has an outlet connected with a communication body which provides a second exhaust passage in a direction different from the flow direction of the exhaust passage, said gas gathering chamber being provided with a rectifying member which extends from the mounting portion providing the mounting opening to the inlet of said communication body.
2. An exhaust emission control device as claimed in claim 1 , wherein the exhaust passage is partitioned by the mounting portion and the rectifying member into a passage space where the exhaust gas is rectified to flow down and a detention space where the exhaust gas lingers.
3. An exhaust emission control device wherein an aftertreatment device for depuration of exhaust gas through passing of the gas therethrough is arranged in a casing and incorporated in an exhaust passage, said casing having an outlet connected through a connecting flange with a gas gathering chamber which in turn provides an exhaust passage in a direction different from an axis of said casing, comprising:
said gas gathering chamber provided with a mounting portion which extends through the exhaust passage to provide a mounting opening for fastening of the connecting flange from outside, the mounting portion providing said mounting opening being provided at an outer periphery thereof with a curved surface for flow rectification of the exhaust gas,
wherein the exhaust passage is partitioned by the mounting portion and a rectifying member into a passage space where the exhaust gas is rectified to flow down and a detention space where the exhaust gas lingers.