Abstract: The invention relates to a catalyst device for purifying exhaust gases containing nitrogen oxide by using selective catalytic reduction (SCR), the catalyst device comprising at least two catalytic layers, the first layer containing vanadium oxide and a mixed oxide comprising titanium oxide and silicon oxide and the second layer containing a molecular sieve containing iron, wherein the first layer is applied onto the second layer. The invention also relates to uses of the catalyst device and a method for purifying exhaust gases.

Abstract: There is provided a motorcycle which includes an engine including an exhaust port; an exhaust pipe connected to the exhaust port of the engine; and a catalyst disposed within the exhaust pipe. The exhaust pipe includes a catalyst case accommodating the catalyst, and a pipe connecting the exhaust port of the engine and the catalyst case. The catalyst is disposed in front of the engine. An occupied area of the catalyst in a direction orthogonal to a flow direction of exhaust gas is larger than an opening area of the pipe in a direction orthogonal to a flow direction of exhaust gas. A central axis of the catalyst is inclined with respect to a vehicle width direction in a vehicle front view. And the central axis of the catalyst and a center line of the engine in the vehicle width direction intersect at a position overlapping with the catalyst in the vehicle front view.

Abstract: An exhaust gas purification device including: a first case communicating with an exhaust manifold of an engine and internally including a first exhaust gas purification body for removing a carbon compound; and a second case communicating with an exhaust outlet of the first case and internally including second exhaust gas purification bodies for removing a nitrogen compound. The first case and the second case are arranged above the engine and in an L-shape to respectively extend along two side surfaces of the engine, the two side surfaces being adjacent to each other.

Abstract: An exhaust gas aftertreatment system is disclosed. The system may include an inlet to receive an exhaust gas produced by an engine and a first section to receive the exhaust gas from the inlet. The system may include a mixing tube to receive the exhaust gas from the first section and a reductant injector to inject a reductant into the mixing tube. The system may include a second section to receive the exhaust gas from the mixing tube and to facilitate mixing of the reductant and the exhaust gas after the exhaust gas exits the mixing tube and a diffuser to receive the exhaust gas from the second section. The system may include a plurality of catalysts to receive the exhaust gas from the diffuser and at least one outlet to receive the exhaust gas from the plurality of catalysts.

Abstract: A gas seal for a pipe joint in an exhaust system configured to receive an exhaust gas flow from internal combustion (IC) engine includes a seal element. The seal element includes an outer surface and an inner surface arranged concentrically about a first axis. The outer surface is configured to seal against a pipe of the exhaust system. The gas seal also includes a flow-guide element fixed to the seal element at the inner surface of the seal element. The flow-guide element defines an aperture having a shape configured to direct and focus the exhaust gas flow away from the first axis. An exhaust system and a vehicle having such a gas seal are also disclosed.

Abstract: An engine device for a work vehicle, in which an exhaust purification unit can be placed on an engine in the neighborhood of the final process in the assembly work of the engine, thereby improving the assembly workability of the engine. The engine device includes a first case that removes particulate matter in the exhaust gas of the engine and a second case that removes nitrogen oxides in the exhaust gas of the engine and connects the first case to the second case via a urea mixing pipe. The first case and the second case are integrally adhered by means of clamping bodies, and, thereby forming an exhaust purification unit, and the exhaust purification unit is configured to be supported by the engine via the clamping bodies, and in a detachable manner.

Abstract: An exhaust elbow component may be located upstream of a decomposition reactor pipe and/or may be integrated with decomposition reactor pipe. The exhaust elbow component includes a mounting area for mounting a dosing module to the exhaust elbow component. The mounting area may be configured to limit the heat transfer from the elbow component to the dosing module via the mounting area. The mounting area may include a boss and one or more mounting legs. The one or more legs and/or the boss may have a surface area for convective cooling of the mounting area. The boss may include an opening through an exterior wall of the exhaust elbow component through which an injection tip of the dosing module may dose reductant into an interior chamber of the exhaust elbow. A central axis of the opening may be substantially coaxial with a central axis of the exhaust gas outlet.

Abstract: The invention relates to an exhaust gas cleaning device (2) for an internal combustion engine, with an injection module (1) for a reduction agent, particularly urea, having a housing (3) with a main chamber (4), in which main chamber (4) a mixing tube (5) is arranged downstream of a metering chamber (6) into which the reduction agent is injected by means of an injection device (11). The injection module (1) for exhaust gas has at least one first inlet (8) into the main chamber (4) and at least one first outlet (7b) out of the mixing tube (5). In order to achieve a high exhaust gas quality in as simple and space-saving a manner as possible, the metering chamber (6) has at least one second inlet (12) for exhaust gas, the main chamber (4) has at least one second outlet (9) for exhaust gas, and the main chamber (4) is separated in a gas-tight manner from the metering chamber (6) and from the interior (5a) of the mixing tube (5).

Abstract: Disclosed is an outboard motor including an exhaust manifold having a plurality of first openings connected to exhaust ports to form a first passage vertically extending, and an exhaust passage having a second passage extending upward along the exhaust manifold, a third passage that is connected to an upper end portion of the second passage and passes over the exhaust manifold, a fourth passage that is connected to the third passage, turns over to the downside, and then extends downward along the exhaust manifold, so that a lower end portion thereof communicates with a fifth passage provided in the engine holder, the second, third, and fourth passages being arranged in one side of the left-right direction of the cylinder block, wherein the exhaust passage is arranged in a swirling shape, and an exhaust gas cleaning catalyst is installed in a middle portion of the second passage.

Abstract: Various systems are provided for an exhaust aftertreatment system that includes a support platform, a plurality of isolated legs coupled to the support platform, a plurality of catalysts arranged in parallel with one another and supported above the support platform by the plurality of isolated legs, and an aftertreatment outlet manifold coupled above the plurality of catalysts.

Abstract: An exhaust system for an internal combustion engine includes an outer housing having a front shell and a rear shell, a prechamber in which exhaust gas from the combustion chamber enters, and an intermediate shell having a front and back as well as a catalytic converter holder. A catalytic converter element is arranged on the catalytic converter holder where an exhaust port directs exhaust gas from the catalytic converter element. To place the center of gravity of the exhaust system near the internal combustion engine or cylinder, the intermediate shell forms the prechamber and the exhaust port.

Abstract: Methods and systems are provided for injecting water during an engine cylinder deactivation event so as to reduce an exhaust catalyst regeneration requirement following the cylinder deactivation. In one example, water is injected at one or more deactivated engine cylinders to reduce oxidation of the exhaust catalyst. Then, during engine cylinder reactivation, a degree of richness of a combustion air-to-fuel ratio may be reduced to decrease fuel penalty to the engine while reducing NOx emission.

Abstract: Embodiments of a pre-turbo catalyst positioned within a turbine in a turbocharger of an engine are disclosed. In one example approach, a turbocharger for an engine comprises a turbine and a catalyst substrate mounted directly within the turbine.

Abstract: An exhaust emission reduction system for a fuel injected engine system has a plurality of emission reduction components configured to process the exhaust gas. The emissions reduction components include of one or more NOX reduction components and one or more filtration components configured to reduce particulate matter, hydrocarbons and/or carbon monoxide emissions. Each engine cylinder is associated with a respective one of the emission reduction components, such that exhaust gas from each engine cylinder flows through the respective one emission reduction component in parallel with the exhaust gas flows from the other cylinders through their respective emission reduction components.

Abstract: An internal combustion engine is provided with a heat-generation chamber disposed so as to be adjacent to a combustion chamber, a heat-generation chamber valve capable of setting up either a communicating state or a shut-down state between the heat-generation chamber and the combustion chamber, and a heat-recovery pipe for recovering heat of a gas guided into the combustion chamber and utilizing the heat as recovered for warm-up. The heat-generation chamber is provided with a heat-generation-chamber spark plug. A catalytic unit is provided between the heat-generation-chamber spark plug and the heat-recovery pipe.

Abstract: An exhaust manifold cooling jacket has internal passages for the circulation of liquid coolant and encloses an exhaust manifold such that a gap is created between the exhaust manifold and cooling jacket. Flowing coolant through the jacket regulates outer jacket temperature while enabling high intra-manifold exhaust gas temperatures for thorough intra-manifold combustion and improved emissions. A liquid-cooled exhaust system includes a turbocharger disposed between manifold and elbow, with liquid coolant flowing from manifold to elbow through the turbocharger. Another liquid-cooled exhaust manifold contains an internal exhaust combustion catalyst wrapped in an insulating blanket. In some marine applications, seawater or fresh water coolant is discharged into the exhaust gas stream at an attached exhaust elbow.

Abstract: An internal combustion engine is coupled to an electric power generator. An exhaust manifold for the engine includes an exhaust gas conduit. A housing includes a catalyst in fluid communication with the conduit to receive exhaust produced by the engine. The catalyst is operable to reduce one or more constituents of the exhaust.

Abstract: A method of heating an engine exhaust gas of an engine, including flowing a first exhaust gas at a first temperature within and along internal flow channels of a catalyst brick, and flowing a second exhaust gas at a second, different, temperature around an exterior of the catalyst brick. Heat may be transferred between the gases and the catalyst brick to achieve various operations.

Abstract: A method and system for controlling a temperature of an exhaust gas being introduced to a catalyst is provided. Using an adjustable flow controller, an adjustable amount of tempering fluid is provided to the exhaust gas prior to the exhaust gas proceeding to the catalyst. A sensor senses a parameter indicative of a temperature of the exhaust gas being introduced to the catalyst. A computer processor uses a relationship to relate the parameter to an adjustment of the adjustable flow controller that will adjust the amount of tempering fluid provided to the exhaust gas and change the temperature of the exhaust gas being introduced to the catalyst toward a target temperature. Adjustment of the adjustable flow controller is initiated by the computer processor to change the flow of the tempering fluid, and the relationship between the parameter and the adjustment of the adjustable flow controller is updated.

Abstract: An exhaust system for an agricultural and/or industrial tractor (10) having an internal combustion engine (11) located in an engine compartment covered by an engine hood (11a). The system includes an exhaust gas treatment unit (16) located inside the engine compartment hood and having a main chamber (18) fed by an inlet pipe (15) which receives exhaust gases from the engine and an outlet pipe (17) which passes treated gases into a final portion (14a,14b) of the exhaust system. The inlet and outlet pipes (15,17) are non-aligned and extending alongside the main chamber (18) in opposite directions to reduce the overall length of the treatment unit. The treatment unit (16) may be installed above the engine (11) with the exhaust gases passing through the unit either generally normal or parallel to the direction of driving (D) of the tractor.

Abstract: An exhaust gas treating system for a gasoline engine, comprising an exhaust gas manifold comprising an annular reforming catalyst mounted within an annular housing and fuel supply means in direct fluid connection with the catalyst, an outlet for reformed fuel products in direct fluid connection with the catalyst, and means to permit a proportion of the engine-out exhaust gases to enter the annular catalyst to mix with fuel from the fuel supply means and to pass through the catalyst, the annular housing being located such that hot engine-out exhaust gases can flow around and through the center of the housing, such that heat is transferred from the exhaust gases to the catalyst within the housing. The reformate may be passed to the inlet side of the engine, to improve overall efficiency of the engine, and/or may be mixed with exhaust gas before catalytic aftertreatment, to improve the control of emissions.

Abstract: An exhaust purification device and an exhaust purification method that utilizes this exhaust purification device enable effective utilization of exhaust gas heat and allow reduction in the size of the device. The exhaust purification device has an oxidation catalyst that is disposed in an exhaust passage of a diesel engine and purifies CO and HC in exhaust gas; a urea injection nozzle that is disposed downstream of the oxidation catalyst and generates ammonia through atomization of urea water into the exhaust gas; a turbine of a turbocharger, this turbine being disposed downstream of the urea injection nozzle and accelerating decomposition of urea through agitation of the atomized urea water; a DPF that is disposed downstream of the turbine and traps PM in the exhaust gas; and a selective reduction catalyst that is disposed downstream of the DPF and detoxifies NOx in the exhaust gas through a reduction reaction with ammonia.

Abstract: An air-fuel ratio control device is provided for controlling the air-fuel ratio of an engine. The device includes an exhaust passage having a main catalytic converter and a bypass passage having a bypass catalytic converter, the bypass passage diverging from the exhaust passage at an upstream junction and rejoining the exhaust passage at a downstream junction. A valve mechanism disposed in the exhaust passage between the upstream junction and the downstream junction moves between a closed state and an open state. During a predetermined period of time after the valve mechanism opens to permit flow in the exhaust passage, the air-fuel ratio of the engine is controlled based on a signal from a first air-fuel ratio sensor in the bypass passage using a low response correction value that is less than a normal response correction value that would be used when the valve mechanism is closed.

Abstract: An exhaust gas purifying device is provided with an exhaust manifold having a collecting section, and a catalytic converter provided downstream of the exhaust manifold. The catalytic converter has upstream and downstream catalysts. The upstream catalyst includes a carrier, a first layer located on the carrier containing Pd, a second layer located on the first layer containing Rh, and a third layer located on the second layer containing Pd. The downstream catalyst includes a carrier, a first layer located on the carrier containing Pd, and a second layer located on the first layer containing Pt and Rh. The collecting section connects to the catalytic converter after passing, in order from the upstream side, through a flow regulating path and a neck section which is provided in the flow regulating path. The flow regulating path has a predetermined length and a width which is gradually reduced to the downstream side.

Abstract: An aftertreatment module for use with an engine is disclosed. The aftertreatment module may have a plurality of inlets configured to direct exhaust in a first flow direction into the aftertreatment module. The aftertreatment module may also have a mixing duct configured to receive exhaust from the plurality of inlets, and a branching passage in fluid communication with the mixing duct. The branching passage may be configured to redirect exhaust from the mixing duct into separate flows that exit the aftertreatment module in a second flow direction opposite the first flow direction.

Abstract: An exhaust pipe structure of a vehicle having a left manifold disposed in front of an engine and a right manifold disposed behind the engine along a longitudinal direction of the vehicle, which are connected by an underbody catalytic converter, the exhaust pipe structure may include a left exhaust pipe connected to the left manifold and extending toward the rear of the engine, a right exhaust pipe having a straight portion connected to the right manifold and extending toward the front of the engine and a curved portion bending from the straight portion toward the rear of the engine, and a conjunction, one end of which is connected to and communicates with the end of the curved portion of the right exhaust pipe and the end of the left exhaust pipe and the other end of which is connected to the underbody catalytic converter.

Abstract: A combustion device for an exhaust treatment system is disclosed. The combustion device may have a fuel injector configured to inject fuel toward an exhaust flow. The combustion device may also have an ignition source configured to ignite the injected fuel. The combustion device may further have a deflector configured to redirect at least a portion of the ignited fuel towards a center of the exhaust flow.

Abstract: The present disclosure relates to a static mixer for mixing a urea solution and engine exhaust gas. The static mixer includes: an external tube including one end portion connected to an exhaust manifold of a diesel engine, the other end portion connected to an SCR (Selective Catalytic Reduction), and a part with which a urea solution injection adaptor is provided; an internal tube installed inside the external tube so as to have a constant gap between at least a part of an outer wall surface and an inner wall surface of the external tube; and a channel unit comprising a plurality of guiding channels provided inside the internal tube in a longitudinal direction, and having an inlet portion facing a lower end portion of the urea solution injector adaptor.

Abstract: An aftertreatment module for use with an engine is disclosed. The aftertreatment module may have a first chamber with an inlet, and at least one catalyst substrate disposed in the first chamber in a flow path through the inlet and having a flow direction from an inlet face to an outlet face in general alignment with the flow path. The aftertreatment module may also have a second chamber with at least one outlet in general alignment with the flow direction through the inlet. The aftertreatment module may further have at least one noise attenuation passage fluidly connecting the first chamber with the second chamber. The at least one noise attenuation passage may be oriented generally orthogonal to the inlet and the at least one outlet and be located between the inlet and the outlet face of the at least one catalyst substrate.

Abstract: An engine system for a combustion engine that has an intake manifold and an exhaust manifold has a turbine having a turbine inlet for receiving exhaust gas and a turbine outlet for discharging exhaust gas, and a diesel particulate filter (DPF) having a DPF inlet in flow-communication with the exhaust manifold and a DPF outlet in flow-communication with the turbine inlet. The exhaust at the exhaust manifold has a sufficiently high temperature to maintain passive regeneration of the DPF during normal operating conditions. If the engine system includes an exhaust gas recirculation (EGR) system, the EGR inlet is in flow-communication with the DPF outlet, and an EGR outlet is in flow-communication with the intake manifold. High pressure, high temperature, filtered EGR gas is available for EGR recirculation.

Abstract: An end cap for an exhaust treatment device is disclosed. The end cap has a cylindrical housing with an axial direction, a radial direction substantially orthogonal to the axial direction, a first open end, and a second closed end opposing the first open end in the axial direction. The end cap also has an integral port member extending from an annular surface of the cylindrical housing. The integral port member has a central axis aligned in the radial direction, and an exterior surface of the integral port member tangentially connects to an exterior surface of the cylindrical housing.

Abstract: An exhaust manifold cooling jacket has internal passages for the circulation of liquid coolant and encloses an exhaust manifold such that a gap is created between the exhaust manifold and cooling jacket. Flowing coolant through the jacket regulates outer jacket temperature while enabling high intra-manifold exhaust gas temperatures for thorough intra-manifold combustion and improved emissions. A liquid-cooled exhaust system includes a turbocharger disposed between manifold and elbow, with liquid coolant flowing from manifold to elbow through the turbocharger. Another liquid-cooled exhaust manifold contains an internal exhaust combustion catalyst wrapped in an insulating blanket. In some marine applications, seawater or fresh water coolant is discharged into the exhaust gas stream at an attached exhaust elbow.

Abstract: An exhaust system for an engine comprises a cylinder head having an integral exhaust manifold to collect exhaust gas exiting the engine combustion chambers. An exhaust gas conduit in fluid communication with the exhaust manifold comprises an inlet end connected to the cylinder head, a portion that extends towards an upper end of the internal combustion engine and an outlet end configured to define an inlet end of a multistage catalytic converter. The catalytic converter comprises a canister having an inlet end located adjacent the top of the engine and includes first and second catalyst substrates and a collector closing an outlet end of the canister. The outlet end of the canister is located adjacent to the bottom of the engine, and the first and the second catalyst substrates receive and convert constituents of exhaust gas passing from the inlet end of the canister to the outlet end.

Abstract: The present invention relates to an exhaust gas treatment unit for an exhaust system of a combustion engine, in particular of a motor vehicle, includes a housing, a plurality of exhaust gas treatment elements, which are arranged in the housing and through which a parallel flow is possible. The unit further includes an outlet nozzle, which penetrates a side face of the housing, and an outlet space disposed in the housing, whereby the outlet of at least one of the exhaust gas treatment elements opens into the outlet space. The rigidity and/or effectiveness of the exhaust gas treatment unit can be improved by means of a funnel body disposed in the outlet space, and comprising a funnel surface which is permeable to exhaust gas. The funnel body connects an outlet end of one of the exhaust gas treatment elements with the outlet nozzle.

Abstract: Disclosed herein is a method and apparatus for reducing a nitrogen oxide, and the control thereof.

Abstract: A muffler (1) for an exhaust system (2) of an internal combustion engine, especially of a motor vehicle, with a muffler housing (3), which encloses a housing interior space (5), and with at least one exhaust gas-carrying hollow body (4) with two half shells in a half shell construction. The hollow body is arranged in the housing interior space (5). The two half shells (14, 15) of the hollow body (4) are fastened to one another in the area of a separating plane (16). The assembly of the muffler (1) or of the hollow body (4) can be simplified if the two half shells (14, 15) are fastened to one another by fastening elements (17, 18), which are formed directly on the half shells (14, 15).

Abstract: An exhaust gas treatment device for internal combustion engines and the like includes inlet and outlet end caps, two catalyst substrates, and a two-piece housing. A first, cylindrically-shaped housing member has a hollow interior in which one of the substrates is retained, a first end sealingly connected with the inlet end cap, and an opposite second end with a radially reduced section. A second cylindrically-shaped housing member has a hollow interior in which the other one of the substrates is retained, a first end sealingly connected with the outlet end cap, and an opposite second end with a radially enlarged section sized to receive therein the second end of the first housing member, whereby the reduced section of the first housing member and the enlarged section of the housing member are spaced radially apart a predetermined distance to define an annularly-shaped space or gap which thermally insulates the associated portion of the exhaust gas treatment device.

Abstract: Mounting close-coupled catalysts for internal combustion engines. In one aspect, supporting a catalyst in an internal combustion engine includes a mounting bracket coupled to a base surface of an engine block. One or more support rods are coupled between the mounting bracket and a housing of the catalyst, such that the catalyst is coupled to and supported by the base surface of the engine block.

Abstract: Exhaust manifold of a turbo-supercharged reciprocating engine with any number of cylinders ranging from 2 to 6 and equipped with an EGR system which comprises: a) an outer casing (21) which includes flanges (23, 25) for effecting joining, respectively, to the cylinder head (13) of the engine and the turbine (15) and an opening towards an EGR outlet duct (27) and an inner wall (31) with low thermal inertia defining a regulating chamber (33) for the exhaust gases introduced into it, after passing through a particle filter (45), via a plurality of orifices (35) located in the inner wall (31); b) inner branches (41) for entry of the exhaust gases, situated opposite the exhaust pipes (17); c) an outlet duct (59) for conveying the exhaust gases to the turbine (15), designed as an extension of the inner wall (31).

Abstract: A removable exhaust treatment unit for an aftertreatment assembly is provided. The removable exhaust treatment unit include a housing, at least one exhaust treatment element coupled within the housing, and a flange on one end of the housing. The removable exhaust treatment unit also includes a plurality of apertures on the flange configured to receive a plurality of fasteners. The removable exhaust treatment unit further includes at least one handle coupled to the flange.

Abstract: An exhaust system of an outboard motor includes: an exhaust passage forward portion including exhaust passages for leading exhaust in the exhaust passage of an exhaust manifold; an exhaust passage reversed portion formed in parallel with the exhaust passage of the exhaust passage forward portion and including exhaust passages communicating with an exhaust passage in an engine holder; and an exhaust passage U-turn portion including an exhaust passage communicating with the exhaust passage of the exhaust passage forward portion and the exhaust passage of the exhaust passage reversed portion. A catalyst for purifying the exhaust is disposed at a junction between the exhaust passages.

Abstract: The present invention relates to an exhaust system having a riser adapted to be mounted to the exhaust inlet of a marine engine and a turndown connected to the riser. The riser and turndown define a primary exhaust passage to direct exhaust gases downwardly toward the discharge opening. A secondary passage, a tube, is integrated to the turndown within the primary exhaust passage. An O2 sensor is mounted within the tube. The tube has a diameter that is less than the diameter of the primary exhaust passage. With the diameter being less, the exhaust gases in the secondary passage have a pressure that is greater than in the primary exhaust passage which eliminates or at least reduces the ability for water to enter the secondary passage protecting the O2 sensor from damage.

Abstract: Apparatus for reducing emissions of PCDD and PCDF in exhaust gas of an internal combustion engine includes a transition metal-containing catalyzer for the selective catalytic reduction of nitric oxides, and a molecular sieve upstream of the catalyzer, either as a layer on the catalyzer or on a separate structure. The molecular sieve blocks hydrocarbons from reaching the transition metal-containing catalyzer.

Abstract: A catalyst system to be used in an automobile exhaust gas purification apparatus which exerts excellent purification capability to a nitrogen oxide, even when hydrocarbon concentration varies, by subjecting exhaust gas discharged from an automotive internal engine to contacting with a catalyst, an exhaust gas purification apparatus using the same, and an exhaust gas purification method. A catalyst system etc.

Abstract: This invention relates to a cerium-zirconium-base composite oxide, which is useful, e.g., for the purification of exhaust gas discharged from combustion engines such as internal combustion engines and boilers and can release a high level of oxygen in a low temperature region, a method for producing the same, an oxygen storage/release component using the same, an exhaust gas purification catalyst, and an exhaust gas purification method. The cerium-zirconium-base composite oxide satisfies requirements (1) that the oxygen release initiation temperature is 380° C. or below, (2) that the oxygen release amount is not less than 485 ?mol/g, and further (3) that the oxygen release amount at 400° C. is not less than 15 ?mol/g.

Abstract: An engine exhaust after-treatment system is provided, which may include a particulate trap configured to remove at least some constituents of the exhaust flowing from an engine through an exhaust system. The system may also include a controller configured to collect in-service data related to an operating parameter indicative of the amount of time the engine operates. In addition, the system may include a memory device attached to the particulate trap and including a memory. The memory may be configured to store usage data indicative of how much time the particulate trap has been used in service. The memory may be configured to communicate with the controller to receive information related to the in-service data collected by the controller and update the usage data in the memory, based on the communication with the controller, to reflect a total amount of time the particulate trap has been in service.

Abstract: An air-fuel ratio control device is provided for controlling the air-fuel ratio of an engine. The device includes an exhaust passage having a main catalytic converter and a bypass passage having a bypass catalytic converter, the bypass passage diverging from the exhaust passage at an upstream junction and rejoining the exhaust passage at a downstream junction. A valve mechanism disposed in the exhaust passage between the upstream junction and the downstream junction moves between a closed state and an open state. During a predetermined period of time after the valve mechanism opens to permit flow in the exhaust passage, the air-fuel ratio of the engine is controlled based on a signal from a first air-fuel ratio sensor in the bypass passage using a low response correction value that is less than a normal response correction value that would be used when the valve mechanism is closed.

Abstract: A silencer for a two-stroke engine includes a first chamber and a second chamber, wherein a flow channel is provided between an outlet of a combustion chamber and the first chamber. A high charge degree of the combustion chamber has a pressure ratio in the region of the outlet which reduces or prevents an escape of fresh gas from the combustion chamber. The flow channel between the outlet and the first chamber is flow-favorably shaped in such a manner that the exhaust gas that flows out of the outlet because of its mass inertia predominantly flows into the first chamber and following charging of the first chamber flows back again and as a result a back pressure is formed in the direction of the combustion chamber.

Abstract: A method for injection reductant into an exhaust gas and for evaporating and decomposing the reductant at an elevated temperature includes providing an exhaust pipe having an interior surface and disposing the pipe in fluid communication with and upstream of a catalyst. The method includes the steps of disposing an internal cone within the pipe generally parallel to the pipe, mounting an injector to the exterior of the pipe in fluid communication with the cone, injecting the reductant into the cone, and directing the exhaust gas in a passage between the interior surface of the pipe and the cone. The exhaust gas is directed within the cone. The flow of exhaust gas has an elevated temperature compared to an ambient. A further step includes creating a drag force on the injected reductant to increase travel time of the injected reductant from the injector to the catalyst.

Abstract: A transition metal-containing catalyzer is arranged on a particle filter installed in the exhaust gas line of an internal combustion engine and cannot be separated therefrom without being destroyed. To reduce emissions, at least one molecular sieve which retains polychlorinated dibenzodioxins and polychlorinated dibenzofurans is arranged between the transition metal-containing catalyzer and the exhaust gas outlet. Further, the input side of the molecular sieve and/or the output side of the catalyzer has an oxidation activity for hydrocarbons, polychlorinated dibenzodioxins and polychlorinated dibenzofurans upstream of the molecular sieve.