Abstract: 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.

Abstract: An exhaust gas pressure P, exhaust gas temperatures TU and TD on upstream and downstream of a DPF, a rotation speed Ne, a load Q, and an intake flow rate F as various operating conditions are read, and an amount of PM generated for short time ?t is obtained to be added to a PM deposited amount m, and thus, to obtain an initial deposited amount. Exhaust gas properties and a space velocity SV are obtained based on various operating conditions, and the PM deposited amount m after a lapse of the short time ?t is estimated from a PM deposited amount estimation equation “m=m·exp(?B·?t)” having been derived considering the exhaust gas properties and the space velocity SV. When the PM deposited amount m is equal to or more than a predetermined value, a forced regeneration processing in the DPF is executed, and thereafter, the PM deposited amount m is reset to 0.

Abstract: An exhaust gas pressure P, exhaust gas temperatures TU and TD on upstream and downstream of a DPF, a rotation speed Ne, a load Q, and an intake flow rate F as various operating conditions are read, and an amount of PM generated for short time ?t is obtained to be added to a PM deposited amount m, and thus, to obtain an initial deposited amount. Exhaust gas properties and a space velocity SV are obtained based on various operating conditions, and the PM deposited amount m after a lapse of the short time ?t is estimated from a PM deposited amount estimation equation “m=m·exp(?B·?t)” having been derived considering the exhaust gas properties and the space velocity SV. When the PM deposited amount m is equal to or more than a predetermined value, a forced regeneration processing in the DPF is executed, and thereafter, the PM deposited amount m is reset to 0.

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: Provided in a catalyst system are: a first reaction part fitted with a first catalyst containing, as active constituents, at least, a complex oxide consisting of two or more oxides selected from among silica, alumina, titania, zirconia, and tungsten oxide, and a rare earth metal or transition metal (except Cu, Co, Ni, Mn, Cr, and V); and a second reaction part fitted with a second catalyst containing, as active constituents, at least, a noble metal and a silica-alumina type complex oxide.

Abstract: 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 catalyst 1 for selectively reducing and purging nitrogen oxide (NOx) contained in exhaust gas; an exhaust pipe 2 that allows the exhaust gas to flow into the SCR catalyst; and a reducing agent, etc., supplying means 3 that supplies a reducing agent or a reducing agent precursor to the exhaust gas. A plate 4 having air holes 5 which 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.

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: 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.

Abstract: Provided in a catalyst system are: a first reaction part fitted with a first catalyst containing, as active constituents, at least, a complex oxide consisting of two or more oxides selected from among silica, alumina, titania, zirconia, and tungsten oxide, and a rare earth metal or transition metal (except Cu, Co, Ni, Mn, Cr, and V); and a second reaction part fitted with a second catalyst containing, as active constituents, at least, a noble metal and a silica-alumina type complex oxide.

Abstract: An SCR muffler retains the heat of a reducing agent, etc., supplying nozzle and an exhaust pipe, thereby preventing the reduction of the efficiency of an SCR catalyst purging nitrogen oxide (NOx) even at low temperatures and improving the durability of the reducing agent, etc., supplying nozzle. The SCRmuffler comprises an SCRcatalyst 1 for selectively reducing and purging nitrogen oxide (NOx) contained in exhaust gas; an exhaust pipe 2 that allows the exhaust gas to flow into the SCR catalyst; and a reducing agent, etc., supplying nozzle 3 that supplies a reducing agent or a reducing agent precursor to the exhaust gas. The reducing agent, etc., supplying nozzle 3 or the exhaust pipe 2 is of a heat-retaining double pipe structure.

Abstract: 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 catalyst 1 for selectively reducing and purging nitrogen oxide (NOx) contained in exhaust gas; an exhaust pipe 2 that allows the exhaust gas to flow into the SCR catalyst; and a reducing agent, etc., supplying means 3 that supplies a reducing agent or a reducing agent precursor to the exhaust gas. A plate 4 having air holes 5 which 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.

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.