An exhaust system of an internal combustion engine of a motor vehicle includes a particulate filter where particles are filterable out from the exhaust gas by the particulate filter. A selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine is flowable for denitrifying the exhaust gas from the internal combustion engine is disposed downstream of the particulate filter. The exhaust gas of the internal combustion engine is heatable by a combustor at a point disposed upstream of the SCR catalytic converter and downstream of the particulate filter where the combustor provides an exhaust gas of the combustor. Particles are filterable out from the exhaust gas of the combustor by a filter element.

An exhaust system for an internal combustion engine, in the exhaust duct of which a sensor is arranged for determining the exhaust gas composition. Furthermore, upstream of the sensor a guide vane is arranged, which is designed to increase the flow velocity of the exhaust gas in a local flow cross-section of the exhaust duct at the height of the sensor. This makes it possible to provide sufficiently high flow velocities of the exhaust gas at the sensor.

An exhaust structure for a saddle riding vehicle includes: an exhaust pipe connected to an internal combustion engine; and a catalyst disposed in the exhaust pipe; the exhaust pipe including a catalyst case unit housing the catalyst and upstream side exhaust pipes disposed on an upstream side of the catalyst case unit; the catalyst case unit having a larger diameter than the upstream side exhaust pipes; the upstream side exhaust pipes being connected to the catalyst case unit in a connecting portion located on an upstream side of the catalyst in a flow of exhaust; in the connecting portion, axes of the upstream side exhaust pipes and an axis of the catalyst case unit being in substantially right-angled positional relation to each other.

A selective catalytic reduction system control system (10) and method of its use include an ammonia (“NH.sub.3”) slip sensor (13) located within an interior space (27) of an exhaust stack (15) of a selective catalytic reactor (31), toward an inlet end (25) of the stack (15); a housing (17) located within the interior space of the exhaust stack; the housing including face panels 19; a nitrogen oxides (“NOx”) sensor (11) contained within an interior space (29) defined by the face panels of the housing, at least two of the face panels (19.sub.I, 19.sub.O) containing an oxidation catalyst; and a dosing controller (59) in communication with the NH.sub.3 and NOx sensors, the dosing controller including a microprocessor with dosing logic embedded thereon. The housing with oxidation catalyst acts as a linear box, isolating the NOx sensor from NH.sub.3 slip, linearizing the NOx sensor signal.

The invention relates in particular to a method for adjusting the loading (19) of a particulate filter (9) and to an assembly designed to carry out the method, wherein the exhaust gas aftertreatment unit (8) comprises at least two SCR systems (11, 12) and a particulate filter (9), a first operating material amount being introduced in a metered manner before the first SCR system (11), and a second operating material amount being introduced in a metered manner before the second SCR system (12), the operating material being convertible into a reducing agent. The state of loading of the particulate filter (9) is determined using a model, and, if the determined state of loading is below a previously defined loading range (16), the first operating material amount is adjusted in such a way that the amount of reducing agent is greater than or equal to the amount of reducing agent necessary for nitrogen oxide reduction in accordance with the reaction stoichiometry in the first SCR system (11), and/or, if the determined state of loading is above a previously defined loading range (16), the first operating material amount is adjusted in such a way that the amount of reducing agent is less than the amount of reducing agent necessary for nitrogen oxide reduction in accordance with the reaction stoichiometry in the first SCR system (11).

A mixer assembly for a vehicle exhaust system includes a mixer shell defining an internal cavity, wherein the mixer shell includes an upstream end configured to receive exhaust gases and downstream end, and a reactor positioned within the internal cavity. The reactor has a reactor inlet configured to receive injected fluid and a reactor outlet that directs a mixture of exhaust gas and injected fluid into the internal cavity. An inlet baffle is mounted to the upstream end of the mixer shell. The inlet baffle includes at least one opening that directs exhaust gas into at least one exhaust gas inlet to the reactor and a plurality of bypass openings that direct exhaust gas to bypass entry into the reactor. The inlet baffle includes a crowned portion that curves away from the reactor to provide for an increased open area within the internal cavity between the inlet baffle and the reactor.

An exhaust passage including a protrusion which is less likely to receive heat from a gas and hence has high heat-resistance reliability is provided. An exhaust passage includes an exhaust pipe, and a protrusion continuously formed over a range of a part of an inner surface of the exhaust pipe in a circumferential direction thereof, the protrusion being inclined toward a direction in which the exhaust pipe extends, and being configured in such a manner that a cross-sectional area of the exhaust pipe becomes smaller toward a downstream side thereof, in which the exhaust passage further includes a convex part on an inner surface of the protrusion.

A vehicle exhaust gas purification system and a control method thereof that may effectively remove nitrogen oxides in an exhaust gas even in a cold state, which is the initial stage of an engine starting, is disclosed. A control method of an exhaust gas purification system of a vehicle may include: a step of performing a rich control for controlling a concentration of non-combusted fuel contained in the exhaust gas flowing into the housing to be a rich fuel directly after the starting of the engine; a step of performing a lean control for controlling the concentration of the non-combusted fuel contained in the exhaust gas flowing into the housing to be a lean fuel; a step of determining whether a temperature of the exhaust gas flowing into the housing is a predetermined temperature or more; and a step of performing a normal control for controlling the concentration of the non-combusted fuel contained in the exhaust gas flowing into the housing so that a lean fuel and a rich fuel are periodically repeated with a regular interval.

An inlet assembly for a housing containing an aftertreatment component of an aftertreatment system comprises an inlet conduit configured to be disposed substantially perpendicular to a longitudinal axis of the housing. A flow redirection conduit is disposed downstream of the inlet conduit and is coupled to the end of the housing. A plurality of protrusions project from a sidewall of the flow redirection conduit towards an inlet face of the aftertreatment component and are configured to provide a uniform exhaust gas flow to the inlet face. Alternatively, a flow distribution plate having a plurality of slots defined substantially perpendicular to the longitudinal axis is disposed in the flow redirection conduit, the plate being inclined with respect to the longitudinal axis. The slots are configured to provide a uniform exhaust gas flow to the inlet face.

A utility vehicle includes an exhaust assembly fluidly coupled to an engine. Depending on various parameters, such as the size and/or performance of the vehicle, the exhaust assembly is required to meet certain emissions regulations. Such emissions regulations may be met by increasing the temperature within the exhaust assembly, however, at particularly high temperatures, a catalyst of the exhaust assembly may be damaged. Therefore, the exhaust assembly includes various options for cooling portions thereof to remove heat from the assembly.