Patent Description:
In an exhaust aftertreatment system, a reductant injector introduces a reductant (e.g. a urea solution, an anhydrous ammonia, an aqueous ammonia, and/or the like) into an exhaust conduit, which guides an exhaust stream from an engine to a selective catalytic reduction (SCR) module. Once the exhaust stream enters the SCR module, the reductant selectively reacts with nitrous oxides (NOx) within the exhaust stream to convert the NOx into other compounds that satisfy emissions standards, such as dinitrogen (N2), water (H2O), carbon dioxide (CO2), and/or the like.

However, once the reductant is introduced into the exhaust stream, the reductant tends to settle onto surfaces of the exhaust conduit and, over time, may form crystallized deposits (e.g., urea, biuret, and/or cyanuric acid) that obstruct flow of the exhaust stream and/or damage the system. Additionally, the reductant, as introduced by the reduction injector, tends to non-uniformly mix with the exhaust stream, which may result in undesirable compounds passing through the SCR module. For example, due to the exhaust stream having too little reductant in some portions thereof, the exhaust aftertreatment system may discharge an excess of nitrous oxides and thus fail to satisfy emission standards. As a further example, due to the exhaust stream having an excess of reductant in other portions thereof, the exhaust aftertreatment system may discharge unreacted ammonia (NH3), often referred to as ammonia slip. Furthermore, due to the placement of the reductant injector within the exhaust stream, which may have a temperature in a range of <NUM> degrees Celsius to <NUM> degrees Celsius, the reductant injector may be susceptible to overheating.

<CIT>, discloses an engine exhaust assembly that includes a curved exhaust line having an exhaust flow from an upstream end to a downstream end. An indentation includes an upstream wall extending at least partially into the exhaust line curved portion and disposed in the exhaust flow, and a downstream wall formed integrally with and located downstream of the upstream wall, the downstream wall extending at least partially into the exhaust line curved portion and disposed in the exhaust flow, the downstream wall having an interior surface oriented to substantially face the exhaust line downstream end and an exterior surface facing substantially away from the exhaust line downstream end. A recess is formed integrally with the downstream wall and extends from the downstream wall in a direction away from the exhaust line downstream end, and a recess aperture is formed in the recess. An injector is coupled to the downstream wall exterior surface and has a nozzle aligned with the recess aperture.

<CIT> discloses an engine exhaust after treatment system including a bend routing an exhaust flow in a curved direction to a straight part. A nozzle is mounted in the bend to introduce a spray of fluid with an axis of symmetry into the exhaust flow. The axis of symmetry intersects the exhaust flow traveling in a curved direction at an intersection angle of less than <NUM> degrees.

<CIT> discloses a reductant injector mount including a mounting region configured to connect to an exhaust conduit. The reductant injector includes a contoured region formed in a mounting region. The contoured region is configured to increase a velocity of an exhaust gas flow through the contoured region.

The exhaust pipe of the present disclosure solves one or more of the problems set forth above and/or other problems in the art.

According to the disclosure an exhaust pipe includes a first end having a first opening; a second end having a second opening within a plane, wherein the second opening fluidly communicates with the first opening to define a bore for guiding an exhaust stream; and a wall connecting the first end to the second end, wherein the wall includes: an inner portion comprising: a first inner linear section that is adjacent to the first opening, a second inner linear section that is adjacent to the second opening, and an inner curved section connecting the first inner linear section to the second inner linear section, and an outer portion comprising: a first outer linear section that is adjacent to the first opening, a second outer linear section that is adjacent to the second opening, and an outer curved section connecting the first outer linear section to the second outer linear section and including an indentation for supporting a reductant injector, the indentation including: a first inwardly extending part that is substantially perpendicular to the plane, a second inwardly extending part that is substantially parallel to the plane and includes a through hole, and a curved part that connects the first inwardly extending part to the second inwardly extending part, wherein a first linear distance between the curved part and the inner curved section is substantially equal to a second linear distance between a first curve end and a second curve end of the inner curved section; characterised in that the through hole is eccentric to the second opening and extends at an obtuse angle α relative to the plane, wherein the through hole includes an inner opening, which has an oblong shape, and an outer opening, which has a circular shape, the inner opening being located between the outer opening and the second opening.

According to the disclosure there is also provided an exhaust pipe includes a first end having a first opening; a second end having a second opening within a plane, wherein the second opening fluidly communicates with the first opening to define a bore; and a wall connecting the first end to the second end, wherein the wall includes: an inner curved section, and an outer curved section that includes an indentation, the indentation comprising: a first inwardly extending part that is substantially perpendicular to the plane, and a second inwardly extending part that is substantially parallel to the plane and includes a through hole having an inner opening and an outer opening, characterised in that the through hole is eccentric to the second opening and extends at an obtuse angle α relative to the plane the inner opening has an oblong shape and is located between the outer opening and the second opening, the outer opening has a circular shape and has a diameter which is less than a diameter of the inner opening, and a thickness of the second inwardly extending part is less than the diameter of the outer opening.

This disclosure relates to an exhaust pipe, which is applicable to any system involved in combining two or more fluids. For example, the system may be a power system, an exhaust aftertreatment system, and/or the like. The system may be implemented in a machine, such as a motor vehicle, a railed vehicle, a watercraft, an aircraft, or another type of machine.

To simplify the explanation below, the same reference numbers may be used to denote like features. The drawings may not be to scale.

<FIG> depicts an exemplary exhaust aftertreatment system <NUM>. The exhaust aftertreatment system <NUM> includes a first filtration cannister <NUM>, a second filtration cannister <NUM>, an exhaust conduit <NUM> that connects the first filtration cannister <NUM> to the second filtration cannister <NUM>, and a reductant injector mounted to the exhaust conduit <NUM>. The first filtration cannister <NUM> is configured to filter an exhaust stream <NUM> flowing from an engine (not shown) into the exhaust conduit <NUM>. The exhaust stream <NUM> may include emission compounds, such as hydrocarbons, particulate matter (e.g., soot and/or ash), and/or nitrous oxides (NOx). To treat the hydrocarbons in the exhaust stream <NUM>, the first filtration cannister <NUM> may include a diesel oxidation catalyst (DOC). The DOC is a flow-through filter that oxidizes the hydrocarbons. Additionally, or alternatively, the first filtration cannister <NUM> may include a diesel particulate filter (DPF) to filter the particulate matter in the exhaust stream <NUM>. The DPF is wall-flow filter that traps the particulate matter therein.

The second filtration cannister <NUM> is configured to filter the exhaust stream <NUM> flowing from the exhaust conduit <NUM> into an environment. The second filtration cannister <NUM> includes a selective catalytic reduction (SCR) catalyst that is configured to reduce a concentration of the NOx in the exhaust stream <NUM>. To allow the exhaust stream <NUM> to pass therethrough, the SCR catalyst may have a honeycomb or otherwise porous structure.

The exhaust conduit <NUM> is configured to guide the exhaust stream <NUM> from the first filtration cannister <NUM> into the second filtration cannister <NUM>. The exhaust conduit <NUM> includes a first exhaust pipe <NUM>, which will be described below in connection with <FIG>, a second exhaust pipe <NUM>, and a third exhaust pipe <NUM> that connects the first exhaust pipe to the second exhaust pipe <NUM>. While the first exhaust pipe <NUM>, the second exhaust pipe <NUM>, and the third exhaust pipe <NUM> (collectively referred to herein as the exhaust pipes) are shown as separate components held together via annular clamps, it should be understood that two or more of the exhaust pipes may be integrally formed or attached via a different type of fastener.

The reductant injector <NUM>, which will be described below in connection with <FIG>, is configured to be mounted to the first exhaust pipe <NUM> to dispense reductant flowing from a reductant source (not shown) into the exhaust stream <NUM>. The reductant is a fluid that is configured to react with the NOx in the exhaust stream <NUM> to convert the NOx into other compounds (e.g., dinitrogen (N2), water (H2O), and/or carbon dioxide (CO2)) prior to entering the second filtration cannister <NUM>. For example, the reductant may be a urea solution (e.g., diesel exhaust fluid (DEF)), an anhydrous ammonia, and/or an aqueous ammonia.

For example, the number and arrangement of components may differ from that shown in <FIG>. Thus, there may be additional components, fewer components, different components, differently shaped components, differently sized components, and/or differently arranged components than those shown in <FIG>.

<FIG> depicts the reductant injector <NUM> and the first exhaust pipe <NUM> (hereinafter referred to as the exhaust pipe <NUM>). As shown in <FIG>, the reductant injector <NUM> includes an injector body <NUM>, a gasket <NUM>, and a plurality of fasteners <NUM> connecting the injector body <NUM> and the gasket <NUM> to the exhaust pipe <NUM>. The injector body <NUM> includes a reductant port <NUM>, a nozzle <NUM>, a pair of coolant ports <NUM>, and a plurality of apertures <NUM>. The reductant port <NUM> is configured to receive the reductant from the reductant source and route the reductant through the nozzle <NUM> into the exhaust pipe <NUM>. The pair of coolant ports <NUM> are configured to receive coolant (e.g., an inorganic additive technology (IAT) type of coolant, an organic acid technology (OAT) type of coolant, and/or hybrid organic acid technology (HOAT) type of coolant) from a coolant source (not shown). The coolant may be configured to cool components of the exhaust aftertreatment system <NUM> and/or thaw the reductant. The plurality of apertures <NUM> are configured to receive the plurality of fasteners <NUM> to allow the injector body <NUM> to be fixedly attached to the exhaust pipe <NUM>. The gasket <NUM> has a central hole <NUM>, to receive the nozzle <NUM>, and a plurality of peripheral holes <NUM>, to receive to the plurality of fasteners <NUM>. The plurality fasteners <NUM> may include screws, bolts, bushings, washers, and/or a combination thereof.

The exhaust pipe <NUM>, as will be further described below in connection with <FIG>, is structured and arranged to facilitate uniform dispersion of the reductant into the exhaust stream <NUM>. The exhaust pipe <NUM> includes a first end <NUM>, a second end <NUM>, and a wall <NUM> connecting the first end <NUM> to the second end <NUM>. The first end <NUM>, which may have a radius of curvature that matches a radius of curvature of the first filtration cannister <NUM>, includes a first opening <NUM> to receive the exhaust stream <NUM> from the first filtration cannister <NUM>. The second end <NUM>, which may be planar (e.g., as illustrated by the plane <NUM> in <FIG>) to mate with a planar end of the third exhaust pipe <NUM>, includes a second opening <NUM> that fluidly communicates with the first opening <NUM> to define a bore <NUM> for guiding the exhaust stream <NUM>. To facilitate attachment of the exhaust pipe <NUM> between the first filtration cannister <NUM> and the second filtration cannister <NUM>, the wall <NUM> includes a first flange <NUM> proximate to the first end <NUM> and a second flange <NUM> proximate to the second end <NUM>. To support the reductant injector <NUM> and allow the reductant to pass therethrough, the wall <NUM> includes an indentation <NUM> having a through hole <NUM> and a plurality of recesses <NUM>. The through hole <NUM> is configured to receive the nozzle <NUM>, and the plurality of recesses are configured to receive the plurality of fasteners <NUM>. The indentation <NUM> and the through hole <NUM>, in addition to other interior features of the exhaust pipe <NUM>, will be described in detail below in connection with <FIG>.

For example, the number and arrangement of components may differ from that shown in <FIG>. Thus, there may be additional components, fewer components, different components, differently shaped components, differently sized components, and/or differently arranged components than those shown in <FIG>. For example, to simplify manufacturing and/or assembly, the injector body <NUM> may be mounted directly to the indentation <NUM>, without the gasket <NUM> being positioned therebetween.

<FIG> depict the exhaust pipe <NUM>. As shown in <FIG>, the wall includes an inner portion <NUM> and an outer portion <NUM> that has a surface area larger than a surface area of the inner portion <NUM>. The inner portion <NUM> includes a first inner linear section <NUM>, a second inner linear section <NUM>, and an inner curved section <NUM> connecting the first inner linear section <NUM> to the second inner linear section <NUM>. The first inner linear section <NUM> is adjacent to the first opening <NUM>, and the second inner linear section <NUM> is adjacent to the second opening <NUM>. In order to prevent stagnation within the exhaust stream <NUM> as the exhaust stream <NUM> flows along the inner curved section <NUM>, a radius of curvature of the inner curved section <NUM> increases as the inner curved section <NUM> extends from the first inner linear section <NUM> to the second inner linear section <NUM>. In other words, the inner curved section <NUM> has a flattened curvature that maintains a velocity of the exhaust stream <NUM> while guiding the exhaust stream <NUM> to a central region of the exhaust pipe <NUM>.

The outer portion <NUM> has a first outer linear section <NUM>, a second outer linear section <NUM>, and an outer curved section <NUM> connecting the first outer linear section <NUM> to the second outer linear section <NUM>. The first outer linear section <NUM> is adjacent to the first opening <NUM>, and the second outer linear section <NUM> is adjacent to the second opening <NUM>. The outer curved section <NUM> includes the indentation <NUM>, which opposes the inner curved section to form a neck <NUM> of the exhaust pipe <NUM>. The indentation <NUM> includes a first inwardly extending part <NUM>, a second inwardly extending part <NUM>, and a curved part <NUM> that connects the first inwardly extending part <NUM> to the second inwardly extending part <NUM>. To prevent stagnation within the exhaust stream <NUM> as the exhaust stream <NUM> passes along the curved part <NUM>, a radius of curvature of the curved part <NUM> is less than the radius of curvatures of the inner curved section <NUM>.

The first inwardly extending part <NUM>, which has a thickness that is less than a thickness of the second inwardly extending part, is substantially perpendicular to the plane <NUM>. The second inwardly extending part <NUM> is substantially parallel to the plane <NUM>. The second inwardly extending part <NUM> includes the through hole <NUM>, which is eccentric to the second opening <NUM> and extends at an obtuse angle α relative to the plane <NUM>. The through hole <NUM> includes an inner opening <NUM>, which has an oblong shape, and an outer opening <NUM>, which has a circular shape. The inner opening <NUM> is located between the outer opening <NUM> and the second opening <NUM>. The through hole <NUM> is shaped and sized to facilitate dispersion of the reductant into the exhaust stream <NUM>. For example, as shown in <FIG>, the inner opening <NUM> has an upper portion <NUM> and a lower portion <NUM> that is narrower than the upper portion <NUM>. As a further example, a diameter of the inner opening <NUM> is greater than a diameter of the outer opening <NUM>. The diameter of the outer opening <NUM> is greater than the thickness of the second inwardly extending part <NUM>.

The exhaust pipe <NUM> is made of single, integral piece of metal (e.g., stainless steel). For example, the exhaust pipe <NUM> may be formed by casting. To guide the exhaust stream to the central region within the exhaust pipe <NUM>, a first linear distance between the curved part <NUM> and the inner curved section <NUM> is substantially equal to a second linear distance between a first curve end <NUM> and a second curve end <NUM> of the inner curved section <NUM>. The first linear distance, which forms the neck <NUM>, is less than a diameter of the first opening <NUM> and a diameter of the second opening <NUM>. A ratio of the first linear distance to a diameter of the second opening <NUM> is less than <NUM>:<NUM>. A ratio of a length of the first inwardly extending part <NUM> to the diameter of the second opening <NUM> is less than <NUM>:<NUM>.

For example, the number and arrangement of components may differ from that shown in <FIG>. Thus, there may be additional components, fewer components, different components, differently shaped components, differently sized components, and/or differently arranged components than those shown in <FIG>.

The exhaust pipe <NUM> of the present disclosure is particularly applicable in a system for mixing two or more fluids, such as the exhaust aftertreatment system <NUM>. The exhaust aftertreatment system <NUM> may be implemented in a machine powered by an internal combustion engine, such as a motor vehicle, a railed vehicle, a watercraft, an aircraft, or another type of machine.

Claim 1:
An exhaust pipe (<NUM>), comprising:
a first end (<NUM>) having a first opening (<NUM>);
a second end (<NUM>) having a second opening (<NUM>) within a plane (<NUM>),
wherein the second opening (<NUM>) fluidly communicates with the first opening (<NUM>) to define a bore (<NUM>) for guiding an exhaust stream (<NUM>); and
a wall (<NUM>) connecting the first end (<NUM>) to the second end (<NUM>), wherein the wall (<NUM>) includes:
an inner portion (<NUM>) comprising:
a first inner linear section (<NUM>) that is adjacent to the first opening (<NUM>),
a second inner linear section (<NUM>) that is adjacent to the second opening (<NUM>), and
an inner curved section (<NUM>) connecting the first inner linear section (<NUM>) to the second inner linear section (<NUM>), and
an outer portion (<NUM>) comprising:
a first outer linear section (<NUM>) that is adjacent to the first opening (<NUM>),
a second outer linear section (<NUM>) that is adjacent to the second opening (<NUM>), and
an outer curved section (<NUM>) connecting the first outer linear section (<NUM>) to the second outer linear section (<NUM>) and including an indentation (<NUM>) for supporting a reductant injector (<NUM>), the indentation (<NUM>) including:
a first inwardly extending part (<NUM>) that is substantially perpendicular to the plane (<NUM>),
a second inwardly extending part (<NUM>) that is substantially parallel to the plane (<NUM>) and includes a through hole (<NUM>), and
a curved part (<NUM>) that connects the first inwardly extending part (<NUM>) to the second inwardly extending part (<NUM>),
wherein a first linear distance between the curved part (<NUM>) and the inner curved section (<NUM>) is substantially equal to a second linear distance between a first curve end (<NUM>) and a second curve end (<NUM>) of the inner curved section (<NUM>);
characterised in that the through hole (<NUM>) is eccentric to the second opening (<NUM>) and extends at an obtuse angle α relative to the plane (<NUM>), wherein the through hole (<NUM>) includes an inner opening (<NUM>), which has an oblong shape, and an outer opening (<NUM>), which has a circular shape, the inner opening (<NUM>) being located between the outer opening (<NUM>) and the second opening (<NUM>).