Dosing and mixing exhaust gas includes directing exhaust gas towards a periphery of a mixing tube that is configured to direct the exhaust gas to flow around and through the mixing tube to effectively mix and dose exhaust gas within a relatively small area. Some mixing tubes include a slotted region and a non-slotted region. Some mixing tubes include a louvered region and a non-louvered region. Some mixing tubes are offset within a mixing region of a housing.

A catalytic converter is provided with: an inlet-side diffuser part; an outlet-side diffuser part; a case including an upstream-side cylindrical part and a downstream-side cylindrical part; an inner liner provided in the upstream-side cylindrical part; a first catalyst retained inside the inner liner; and a second catalyst retained inside the downstream-side cylindrical part. An end face of the second catalyst faces a peripheral surface of the inner liner. An annular flow path is provided between the upstream-side cylindrical part and the inner liner, and the first catalyst is insulated from heat by the annular flow path. A part of exhaust flows into the second catalyst via the annular flow path.

A spray/gas mixer includes a main body having a circumferential wall defining an inlet opening at one end and an outlet opening at another end; a divider baffle within the main body; a swirl duct having a first end adjacent to the wall and a second end extending to the divider baffle; an injector orifice at the first end of the swirl duct; a swirl promoting means; and a restrictor. The swirl promoting means is arranged between the divider baffle and the restrictor. Gas passing through the swirl promoting means is swirled around the first longitudinal axis (A) before passing through the restrictor. The restrictor is disposed between the swirl promoting means and the second end, forcing gas reaching it from an upstream side away from a peripheral region of the interior towards a center axis of the main body.

An exhaust gas aftertreatment system includes a housing assembly and a reductant delivery system. The housing assembly includes an upstream housing, a first inlet tube, a second inlet tube, and a mixing housing. The first inlet tube is coupled to the upstream housing and configured to receive a first portion of exhaust gas from the upstream housing. The second inlet tube is coupled to the upstream housing and configured to receive a second portion of the exhaust gas from the upstream housing. The mixing housing is coupled to the first inlet tube and the second inlet tube. The mixing housing is configured to receive the first portion of the exhaust gas from the first inlet tube and receive the second portion of the exhaust gas from the second inlet tube. The mixing housing is separated from the upstream housing by the first inlet tube and the second inlet tube.

Systems and methods for reducing heat loss to a turbocharger during cold engine starting are described. In one example, a turbocharger bypass pipe and a turbocharger turbine pipe are oriented at forty five degrees relative to a longitudinal axis of a catalyst so that a turbocharger turbine may be completely bypassed, thereby increasing the amount of energy that may be transferred to the catalyst.

A vortex flow apparatus including a cylindrical housing that contains a fluid that flows in a swirling circular path. The apparatus may be utilized as a muffler for a combustion engine, a particle separator, or an energy conversion device that physically or chemically acts upon the fluid flow and particles contained within the apparatus. The housing defines an inlet opening that opens into the first end of the housing proximate a first end wall. An outlet tube defines an outlet opening through a first end wall. A projection is attached to a second end wall of the housing and extends into the housing. The outlet tube and projection are aligned with and centered relative to a central axis.

The dual function exhaust system attachment, which is preferably used with an all-terrain vehicle, includes a muffler, a silencing cap, and a sound-enhancing plug. In a quiet configuration, the silencing cap is mounted to conceal a primary outlet of the muffler. In a loud configuration, the sound-enhancing plug is mounted to conceal a secondary outlet of the muffler. A set of screw threads or sealing mechanism may be used to mount the silencing cap and the sound-enhancing plug. A primary perforated barrier, a solid barrier, at least one secondary perforated barrier, and a pipe section are positioned within a hollow structural body of the muffler to guide the exhaust gas flow from an inlet of the muffler to the primary outlet or the secondary outlet.

An exhaust gas purification device having such a structure that exhaust gas can uniformly flow into without depending on a shape of an exhaust gas inlet pipe. A gas purification body which purifies the exhaust gas, a purification casing which accommodates the gas purification body, an exhaust gas inlet pipe which communicates with an exhaust gas inflow port of the purification casing, and an exhaust gas outlet pipe which communicates with an exhaust gas outflow port of the purification casing. The exhaust gas inlet pipe is attached to the purification casing in such a manner as to cover the exhaust gas inflow port and extend in a longitudinal direction of the purification casing. An introduction passage of the exhaust gas is formed by an outside surface of the purification casing and an inside surface of a pipe wall of the exhaust gas inlet pipe. A portion extending along the purification casing in the pipe wall is inclined so as to come close to the outside surface of the purification casing in proportion to heading for an exhaust gas outlet side from an exhaust gas inlet side.

An exhaust gas duct system for an internal combustion engine includes an upstream, first exhaust gas pipe area (30), a downstream, second exhaust gas pipe area (34) adjoining the first exhaust gas pipe area (30) in a transition area (38) in an exhaust gas flow direction (G), and a liquid drain channel area (60) in the transition area. The drain channel area is open from the exhaust gas flow volume (78) in the first exhaust gas pipe area (30) or/and in the second exhaust gas pipe area (34) to a liquid collection volume (80).

An exhaust aftertreatment system may include an exhaust gas passageway and a mixer assembly. The exhaust gas passageway may receive exhaust gas output from a combustion engine. The mixer assembly may be disposed along the exhaust gas passageway and may receive the exhaust gas. The mixer assembly may include a mixer housing, a mixing bowl and an injector housing. The mixing bowl may be disposed within the mixer housing and may include an outer diametrical surface that engages an inner diametrical surface of a wall of the mixer housing. The injector housing may extend through the wall and into an aperture in the mixing bowl. The aperture may define a flow path through which at least a majority of the exhaust gas entering the mixer assembly flows. The mixing bowl may include an upstream end portion having contours directing the exhaust gas toward the injector housing.