Abstract: 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.

Abstract: A muffling apparatus 1 of the present invention having an exhaust emission purifying function, including a turning portion 8 in an inside of an exhaust gas flow passage, and having an injection nozzle 12 disposed in an upstream side exhaust gas flow passage 9 of the turning portion 8, for injection-supplying a liquid reducing agent; and a reduction catalytic converter 13 disposed in a downstream side exhaust gas flow passage 10 of the turning portion 8, for reductively purifying nitrogen oxides with the liquid reducing agent. The apparatus further includes a diffusing member 15, which generates a vortex flow of a gas traveling in a vertical plane of the turning portion 8 to diffuse the liquid reducing agent.

Abstract: 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.

Abstract: A muffling apparatus 1 of the present invention having an exhaust emission purifying function, including a turning portion 8 in an inside of an exhaust gas flow passage, and having an injection nozzle 12 disposed in an upstream side exhaust gas flow passage 9 of the turning portion 8, for injection-supplying a liquid reducing agent; and a reduction catalytic converter 13 disposed in a downstream side exhaust gas flow passage 10 of the turning portion 8, for reductively purifying nitrogen oxides with the liquid reducing agent. The apparatus further includes a diffusing member 15, which generates a vortex flow of a gas traveling in a vertical plane of the turning portion 8 to diffuse the liquid reducing agent.