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: An exhaust emission purifying apparatus of the present invention has a casing that includes therein a plurality of layered passages which is formed by partitioning an inside of the casing to thereby allow an exhaust passage from an exhaust emission inlet to an exhaust emission outlet to be folded in its direction once or more, a reduction catalyst that reductively purifies NOx by using a reducing agent, a nozzle that injects the reducing agent or a precursor thereof to an exhaust upstream side of the reduction catalyst, and a filter (DPF) that collects PM suspended in an exhaust emission. The reduction catalyst and the filter are disposed in the different layered passages. Consequently, a more compact exhaust emission purifying apparatus having both NOx removal function and PM collection function can be provided.

Abstract: For preventing clogging in an injection nozzle for supplying a reducing agent to exhaust gas flow on an upstream side of a reducing catalyst and for improving the efficiency of NOx purification processing, the injection nozzle 14 has a tip end portion 18 provided with a ring shaped protruding ridge 19 disposed on an outer peripheral surface of an exhaust gas downstream side end portion of the tip end portion 18 that is arranged substantially in parallel with an exhaust gas flow direction A inside an exhaust pipe 13, the ring shaped protruding ridge 19 being provided with injection hole or holes 20 drilled outward from the central axis of the injection nozzle 14, so that the reducing agent is ejected on the exhaust gas upstream side of the reduction catalyst, from the injection holes 20.

Abstract: In order to suppress deposition of constituent of a reducing agent (dissolved matter) in an exhaust passage of an engine enhancing an elimination rate of NOx even when temperature of an exhaust emission from the engine is low, an exhaust emission purifying apparatus is provided with an electro-generative-heat carrier provided on an upstream side of an injection nozzle that supplies the reducing agent into the exhaust emission on upstream side of a reduction catalyst in an exhaust pipe, the exhaust emission being heated to a temperature equal to or higher than a melting point of the dissolved matter whereby deposition of the dissolved matter on an inner wall surface of the exhaust pipe is suppressed to effectively use the supplied reducing agent for catalytic reduction reaction, even when the exhaust emission temperature is lower than the melting point of the dissolved matter of the reducing agent.

Abstract: An exhaust emission purifying apparatus for an engine having: a reduction catalytic converter disposed in an exhaust system of the engine, for reductively purifying nitrogen oxides in the exhaust emission with a reducing agent; an injection nozzle for injection-supplying the reducing agent to an exhaust upstream side of the reduction catalytic converter in an exhaust pipe of the exhaust system; and a reducing agent supply device supplying the reducing agent to the injection nozzle, in which a recess portion is formed on an inner wall on a lower portion of the exhaust pipe, by concaving a site to which at least the reducing agent injection-supplied from the injection nozzle is attached, and also, a bottom wall of the recess portion is made detachable.

Abstract: In order to suppress deposition of constituent of a reducing agent (dissolved matter) in an exhaust passage of an engine enhancing an elimination rate of NOx even when temperature of an exhaust emission from the engine is low, an exhaust emission purifying apparatus is provided with an electro-generative-heat carrier provided on an upstream side of an injection nozzle that supplies the reducing agent into the exhaust emission on upstream side of a reduction catalyst in an exhaust pipe, the exhaust emission being heated to a temperature equal to or higher than a melting point of the dissolved matter whereby deposition of the dissolved matter on an inner wall surface of the exhaust pipe is suppressed to effectively use the supplied reducing agent for catalytic reduction reaction, even when the exhaust emission temperature is lower than the melting point of the dissolved matter of the reducing agent.

Abstract: An exhaust emission purifying apparatus of the present invention has a casing that includes therein a plurality of layered passages which is formed by partitioning an inside of the casing to thereby allow an exhaust passage from an exhaust emission inlet to an exhaust emission outlet to be folded in its direction once or more, a reduction catalyst that reductively purifies NOx by using a reducing agent, a nozzle that injects the reducing agent or a precursor thereof to an exhaust upstream side of the reduction catalyst, and a filter (DPF) that collects PM suspended in an exhaust emission. The reduction catalyst and the filter are disposed in the different layered passages. Consequently, a more compact exhaust emission purifying apparatus having both NOx removal function and PM collection function can be provided.

Abstract: In relation to an exhaust gas purification system that mixes a liquid reducing agent with air and injection-supplies this mixture into an exhaust gas flowing on an upstream side of a reduction catalyst (20) to thereby effect reduction purification of NOx in exhaust gas, a technical attention is directed to the relation of respective elements of; the travel distance, the fuel consumption, the air consumption, or the running time and the like, and the liquid reducing agent consumption, to constitute a configuration such that a continual monitor as to whether the injection condition of liquid reducing agent is normal or abnormal is executed by judging whether or not the amount of liquid reducing agent consumed for a predetermined travel distance, a predetermined fuel consumption, a predetermined air consumption, or a predetermined running time, is within a predetermined range.

Abstract: For preventing clogging in an injection nozzle for supplying a reducing agent to exhaust gas flow on an upstream side of a reducing catalyst and for improving the efficiency of NOx purification processing, the injection nozzle 14 has a tip end portion 18 provided with a ring shaped protruding ridge 19 disposed on an outer peripheral surface of an exhaust gas downstream side end portion of the tip end portion 18 that is arranged substantially in parallel with an exhaust gas flow direction A inside an exhaust pipe 13, the ring shaped protruding ridge 19 being provided with injection hole or holes 20 drilled outward from the central axis of the injection nozzle 14, so that the reducing agent is ejected on the exhaust gas upstream side of the reduction catalyst, from the injection holes 20.

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: In an exhaust emission purifying apparatus for an internal combustion engine, for adding a reducing agent for NOx to the exhaust gas to thereby purify NOx in the exhaust gas, the mixing of the reducing agent injected by an injection nozzle with the exhaust gas is accelerated. To this end, in the apparatus of the present invention, the injection nozzle for the urea water is disposed to be opposite to the flow of the exhaust gas, or to face upward in a vertical direction.

Abstract: An exhaust emission purifying apparatus for an engine having: a reduction catalytic converter disposed in an exhaust system of the engine, for reductively purifying nitrogen oxides in the exhaust emission with a reducing agent; an injection nozzle for injection-supplying the reducing agent to an exhaust upstream side of the reduction catalytic converter in an exhaust pipe of the exhaust system; and a reducing agent supply device supplying the reducing agent to the injection nozzle, in which a recess portion is formed on an inner wall on a lower portion of the exhaust pipe, by concaving a site to which at least the reducing agent injection-supplied from the injection nozzle is attached, and also, a bottom wall of the recess portion is made detachable.

Abstract: In order to suppress deposition of constituent of a reducing agent (dissolved matter) in an exhaust passage of an engine enhancing an elimination rate of NOx even when temperature of an exhaust emission from the engine is low, an exhaust emission purifying apparatus is provided with an electro-generative-heat carrier provided on an upstream side of an injection nozzle that supplies the reducing agent into the exhaust emission on upstream side of a reduction catalyst in an exhaust pipe, the exhaust emission being heated to a temperature equal to or higher than a melting point of the dissolved matter whereby deposition of the dissolved matter on an inner wall surface of the exhaust pipe is suppressed to effectively use the supplied reducing agent for catalytic reduction reaction, even when the exhaust emission temperature is lower than the melting point of the dissolved matter of the reducing agent.