Nissan Diesel Motor Co., Ltd.

Tokyo Roki Co., Ltd.

Hitoshi Hiramoto

Isamu Kanaya

Daisuke Shirai

Naobumi Yamada

Koutarou Honda

Tomoko Amemiya

Kiminobu Hirata

Nobuhiko Masaki

Hiroki Ueno

Yuuji Naitou

Shinya Obana

Takefumi Mochizuki

A reduction catalyst is disposed in an exhaust passage of an engine. A reducing agent added to the exhaust gas is urged to react with NOx in the exhaust gas, catalyzed by the reduction catalyst. A member for distributing the exhaust gas to which the reducing agent has been added is provided. This member is formed by applying of an axial welding and is disposed in the exhaust passage such that the internal surface of its joining portion is disposed to overhang from the topmost position of the joining portion.

Exhaust emission purification apparatus for engine

An exhaust emission purifying apparatus has a NOx reduction catalytic converter in an exhaust passage of an engine, for purifying nitrogen oxides in the exhaust gas by reduction with urea aqueous solution; an injection nozzle injecting the urea solution toward an exhaust upstream side of the converter in the exhaust passage; and fins disposed on an exhaust upstream side of an injection position of the urea solution in the injection nozzle, for generating a spiral swirling flow of the gas swirling about a center corresponding to the central axis of an exhaust pipe. The swirling flow generated in the exhaust gas prior to the injection-supply of the urea aqueous solution promotes mixing of the solution with the gas to thereby promote the hydrolysis of the urea solution. And the exhaust gas and ammonia generated from the urea solution are uniformly mixed together.

Exhaust emission purifying apparatus for engine

The flow of exhaust gas flowing through the SCR muffler becomes good, thus improving the efficiency of purging nitrogen oxide (NOx) contained in exhaust gas. Further, vibrations that are caused by vibrations of the vehicle, exhaust gas, and the like, to which a reducing agent, etc., supplying nozzle is subject, are suppressed or reduced, thus improving the efficiency of an SCR catalyst purging nitrogen oxide (NOx) and the durability of the reducing agent, etc., supplying nozzle. The SCR muffler comprises an SCR catalystfor selectively reducing and purging nitrogen oxide (NOx) contained in exhaust gas; an exhaust pipethat allows the exhaust gas to flow into the SCR catalyst; and a reducing agent, etc., supplying meansthat supplies a reducing agent or a reducing agent precursor to the exhaust gas. A platehaving air holeswhich disperse and make a flow of the exhaust gas uniform is provided downstream of the reducing agent, etc., supplying means and upstream of the SCR catalyst. The air holesare arranged in only an area greater in diameter than the exhaust pipe and in a staggered fashion so as to form concentric circles. Further, the reducing agent, etc., supplying nozzleas the meansis inserted through a platehaving air holes, and the plate is held in the exhaust pipe.

SCR muffler

A muffling apparatusof the present invention having an exhaust emission purifying function, including a turning portionin an inside of an exhaust gas flow passage, and having an injection nozzledisposed in an upstream side exhaust gas flow passageof the turning portion, for injection-supplying a liquid reducing agent; and a reduction catalytic converterdisposed in a downstream side exhaust gas flow passageof the turning portion, for reductively purifying nitrogen oxides with the liquid reducing agent. The apparatus further includes a diffusing member, which generates a vortex flow of a gas traveling in a vertical plane of the turning portionto diffuse the liquid reducing agent.

Muffling apparatus having exhaust emission purifying function

Growing community of inventors

Yokohama, Japan

Hitoshi Hiramoto