Hino Motors, Ltd.

Hkt Corporation

Mitsuru Hosoya

Shinya Sato

Yoshihiro Kawada

Hiroshi Hirabayashi

Keiichi Hayashizaki

Hiroshi Inoue

Masatoshi Shimoda

Kazunori Takahashi

Satoshi Sato

Tatsuki Igarashi

Takashi Takakura

Hironobu Mogi

An exhaust purification system includes an exhaust passage. Exhaust gas flows through the exhaust passage. A burner is arranged in the exhaust passage. A combustion space for fuel in the burner is a part inside the exhaust passage. A NOx adsorbent is located downstream of the combustion space in the exhaust passage. The NOx adsorbent adsorbs nitrogen oxide contained in the exhaust gas. A selective reduction catalyst is located downstream of the NOx adsorbent in the exhaust passage. An adding valve is located between the selective reduction catalyst and the combustion space in the exhaust passage. A connection passage is connected to the adding valve. Urea water flows through the connection passage toward the adding valve. A part of the connection passage runs through the combustion space.

Exhaust purification system

Incorporated in an exhaust pipe are an HC-SCR NOcatalyst capable of reducing NOat temperatures less than a set temperature T and a catalyzed particulate filter with an oxidation catalyst capable of reducing NOat temperatures not less than the set temperature T. When an exhaust gas temperature is less than the set temperature T, fuel with a set flow rate Q is intermittently added from a fuel addition unit on an entry side of the HC-SCR NOcatalyst to the HC-SCR NOcatalyst; when the exhaust gas temperature is not less than the set temperature T, the fuel with flow rate Q' not less than the set flow rate Q is temporarily rich-spike added from the fuel addition unit and is made arrival at a catalyzed particulate filter. With an active temperature range being expanded, exhaust emission control is performed in a wide temperature range.

Exhaust gas purifier

A carrier gas supplied from a carrier gas source is injected from a carrier gas injection nozzle. Also, a fuel including a hydrocarbon-based liquid and supplied from a fuel source is supplied to a tip end of the carrier gas injection nozzle, whereby this fuel is atomized with the carrier gas injected from the carrier gas injection nozzle. Furthermore, an inlet of a reforming part that decomposes the atomized fuel and reforms the atomized fuel into a reducing gas including either or both of hydrogen and an oxygen-containing hydrocarbon is provided so as to face the carrier gas injection nozzle and the fuel supply nozzle, and a reducing gas supply nozzle that supplies the reducing gas discharged from an outlet of the reforming part is provided in an exhaust pipe.

Fuel reformer and exhaust gas purifier using the same

A first selective reduction catalyst including a silver-based catalyst is provided in an exhaust pipe of an engine. An ozone generation device generates ozone by using oxygen in the atmosphere, and a hydrocarbon-based liquid supply device supplies a hydrocarbon-based liquid. A part of NO in the exhaust gas flowing through the exhaust pipe is oxidized to NOwith the ozone generated by the ozone generation device, and said NOis supplied to the first selective reduction catalyst. Also, a part of the hydrocarbon-based liquid supplied by the hydrocarbon-based liquid supply device is partially oxidized, with ozone generated by the ozone generation device, to an active reducing agent including an oxygen-containing hydrocarbon such as aldehyde, and this active reducing agent is supplied to the first selective reduction catalyst.

A selective catalytic reduction catalyst capable of reducing the NOin exhaust gas to Nis arranged in an exhaust pipe of an engine. Fluid feed has a fluid injecting nozzle facing the exhaust pipe on the exhaust gas upstream side from the selective catalytic reduction catalyst. The fluid feed is configured such that a urea fluid that functions as a reducing agent is fed with the selective catalytic reduction catalyst from the fluid injecting nozzle to the exhaust pipe. Ozone feed includes an ozone injecting nozzle that faces the exhaust pipe on the exhaust gas upstream side from the selective catalytic reduction catalyst, and on the exhaust gas upstream side or the exhaust gas downstream side from the fluid injecting nozzle. The ozone feed is configured such that ozone is fed from the ozone injecting nozzle to the exhaust pipe.

Exhaust gas purification device

A urea solution reformer and an exhaust gas purifier is configured to heat a carrier gas supplied from a carrier gas source by a carrier gas heating unit, to inject the carrier gas heated by the carrier gas heating unit from a carrier gas injecting nozzle, and to cause a urea solution to be supplied by a first urea solution supply nozzle to a tip end of the carrier gas injecting nozzle so that the urea solution is atomized by the carrier gas injected from the carrier gas injecting nozzle. Provided to face toward the carrier gas injecting nozzle is a catalyst unit for decomposing the atomized urea solution to reform it into an ammonia gas. An ammonia gas supply nozzle is attached to an exhaust pipe of an engine so as to supply the ammonia gas discharged from an outlet of the catalyst unit into the exhaust pipe.

Urea solution reformer and exhaust gas purifier using same

A first porous catalytic layer is provided in an exhaust passage, and a second porous catalytic layer is stacked on the exhaust-gas downstream-side surface of the first layer. The first layer includes an iron-zeolite catalyst to decrease 60% or more of NOx in the exhaust gas within an exhaust gas temperature range of 150-400&#xb0; C. The second layer includes one or more of a single catalyst, a mixed catalyst, and a complex oxide catalyst selected from iron-alumina, iron-zirconia, iron-ceria, and iron-titania, to decrease 60% or more of NOx in the exhaust gas within an exhaust gas temperature range of 400-700&#xb0; C. The first and second layers cooperatively exhibit catalytic activity to decrease 70% or more of NOx in the exhaust gas within an exhaust gas temperature range of 150 to 700&#xb0; C.

Selective reduction catalyst

A selective reduction catalyst includes a catalyst support in which a plurality of through holes partitioned by porous walls are formed in parallel with each other and an active component having a catalytic action and carried by the walls. Inlet portions and outlet portions, adjacent to each other, of the through holes are alternately sealed, and the wall carrying the active component is formed so that a particle-state solid matter ammonium nitrate cannot pass through it. The exhaust gas purifier includes the selective reduction catalyst, a liquid injection nozzle which is provided on the upstream side and can inject urea liquid toward the catalyst, a diesel particulate filter provided at an exhaust pipe on the upstream side, and filter temperature raising means capable of raising the temperature of the diesel particulate filter to a predetermined value or above.

Engine exhaust gas purifier

There is provided a filtering means regenerating system for a diesel engine, in which the filtering means provided in an exhaust gas passage oxidizes NO in exhaust gas of the engine into NO , and collects particulates in exhaust gas to thereby oxidize the particulates by NO and remove the same at a temperature higher than a predetermined exhaust gas temperature. Also, an in-line fuel injection system for injecting fuel into the engine is provided with a variable timer mechanism for regulating the injection timing of fuel, and the deposit of particulates deposited on the filtering means is detected by deposit detecting means. A controller controls the variable timer mechanism based on the detection output of the deposit detecting means. The filtering means is prevented from becoming in an excessively collecting state in all operation statuses of the engine, thereby preventing a decrease in fuel economy and power performance of the engine.

Filtering means regenerating system for diesel engine

An apparatus is disclosed for purifying the exhaust gas of a diesel engine by reducing the contents of soluble organic fractions which are particulates. The apparatus comprises a catalyzer provided on an exhaust pipe, a cooler provided around either a portion of the pipe between the catalyzer and the engine or the catalyzer in itself for cooling the gas flowing through the pipe, a temperature sensor for detecting the temperature of the gas flowing through the pipe, a tachometer for detecting the rotating speed of the engine, a load sensor for detecting the load on the engine, a controller for controlling the cooler on the basis of the respective detection outputs from the sensors.

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Tokyo, Japan

Mitsuru Hosoya