VEHICLE EXHAUST SYSTEM WITH END CAP MIXER
20210404367 · 2021-12-30
Inventors
Cpc classification
F01N3/2821
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N3/035
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N3/2892
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N2240/20
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01F25/45211
PERFORMING OPERATIONS; TRANSPORTING
F01N2610/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N3/103
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N2610/1453
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N3/2066
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N2490/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N13/009
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N2470/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N2610/085
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A vehicle exhaust system includes an upstream exhaust component comprising at least a first catalyst having a first outer dimension, a downstream exhaust component comprising at least a second catalyst having a second outer dimension, and a mixer that connects the upstream and downstream exhaust components. The mixer comprises a first portion associated with an outlet from the first catalyst and a second portion associated with an inlet to the second catalyst. The first portion includes a swirl component having a first length and the second portion includes an additional component having a second length. A connection interface between the first and second portions allows the upstream and downstream exhaust components to be arranged in different positions relative to each other. A combined length of the first and second lengths is adjusted relative to the first and second outer dimensions to achieve a desired position of the upstream and downstream exhaust components relative to each other.
Claims
1. A vehicle exhaust system comprising: an upstream exhaust component comprising at least a first catalyst surrounded by a first outer housing and having a first outer dimension; a downstream exhaust component comprising at least a second catalyst surrounded by a second outer housing and having a second outer dimension; a mixer that connects the upstream and downstream exhaust components, wherein the mixer comprises a first portion associated with an outlet from the first catalyst and a second portion associated with an inlet to the second catalyst, and wherein the first portion comprises a first mixer housing to provide a first end cap for the first outer housing and the second portion comprises a second mixer housing to provide a second end cap for the second outer housing; a swirl component positioned at least partially within the first end cap and having a first length: an additional component positioned at least partially within the second end cap and having a second length; and a connection interface between the first and second portions to allow the upstream and downstream exhaust components to be arranged in different positions relative to each other, and wherein a combined length of the first and second lengths is adjusted relative to the first and second outer dimensions to achieve a desired position of the upstream and downstream exhaust components relative to each other.
2. The vehicle exhaust system according to claim 1, including a doser opening formed in the first mixer housing that is configured to receive a doser to inject a fluid into the swirl component, and wherein the swirl component comprises a swirl chamber having an inlet associated with the doser and an outlet that directs a mixture of exhaust gas and injected fluid into the second portion.
3. The vehicle exhaust system according to claim 2, wherein the additional component comprises a perforated pipe that is enclosed within the second mixer housing.
4. The vehicle exhaust system according to claim 3, wherein the perforated pipe comprises a straight pipe or has a trumpet shape.
5. The vehicle exhaust system according to claim 4, wherein the perforated pipe comprises the straight pipe and has a first end open to the first portion and a second end that is closed by a solid concave surface provided by a bowl-shaped component.
6. The vehicle exhaust system according to claim 2, wherein the additional component comprises a non-perforated pipe that is enclosed within the second mixer housing, and wherein the non-perforated pipe comprises a straight pipe or has a trumpet shape.
7. The vehicle exhaust system according to claim 6, wherein the non-perforated pipe comprises the straight pipe and has a first end open to the first portion and a second end that is closed by a bowl-shaped component that provides a solid concave surface for the second end, and wherein the bowl-shaped component includes a plurality of openings circumferentially spaced apart from each other about an outer wall of the bowl-shaped component.
8. The vehicle exhaust system according to claim 1, including a baffle plate positioned downstream of the additional component and upstream of the second catalyst.
9. The vehicle exhaust system according to claim 1, wherein the connection interface comprises a direct connection between the first and second portions, or the connection interface comprises pipe sections selected from a group of: elbow pipe, straight pipe, flexible pipe.
10. The vehicle exhaust system according to claim 1, wherein the upstream exhaust component defines a first center axis and the downstream exhaust component defines a second center axis, and wherein the combined length is smaller than the second outer dimension for an inline configuration where the first and second center axes are coaxial, and wherein the combined length is greater than the second outer dimension and smaller than a combined outer dimension of the first outer dimension added to the second outer dimension for a non-inline configuration where the first and second center axes are non-coaxial.
11. A vehicle exhaust system comprising: an upstream exhaust component defining a first center axis and including at least a first catalyst surrounded by a first outer housing and having a first outermost dimension; a downstream exhaust component defining a second center axis and including at least a second catalyst surrounded by a second outer housing and having a second outermost dimension; a mixer that connects the upstream and downstream exhaust components, wherein the mixer comprises a first portion associated with an outlet from the first catalyst and a second portion associated with an inlet to the second catalyst, and wherein the first portion comprises a first mixer housing to provide a first end cap for the first outer housing and the second portion comprises a second mixer housing to provide a second end cap for the second outer housing; a swirl component positioned at least partially within the first end cap and having a first length; an additional component positioned at least partially within the second end cap and having a second length; and a connection interface between the first and second mixer housings to allow the upstream and downstream exhaust components to be arranged in different positions relative to each other, and wherein the connection interface can comprise a direct connection or can include one or more additional connection components, and wherein a combined length of the first and second lengths is adjusted relative to the first and second outermost dimensions to achieve a desired position of the upstream and downstream exhaust components relative to each other.
12. The vehicle exhaust system according to claim 11, wherein the swirl component comprises a swirl chamber with an increasing diameter and having an inlet associated with an injector and an outlet that directs a mixture of exhaust gas and injected fluid into the second portion, and wherein the additional component comprises a pipe that is enclosed within the second mixer housing.
13. The vehicle exhaust system according to claim 12, wherein the pipe comprises a trumpet-shaped pipe or comprises a straight pipe having a first end open to the first portion and a second end that is closed by a bowl-shaped component that provides a solid concave surface at the second end.
14. The vehicle exhaust system according to claim 13, including a baffle plate positioned downstream of the pipe and upstream of the second catalyst.
15. The vehicle exhaust system according to claim 11, wherein the one or more additional connection components comprises pipe sections selected from a group of: elbow pipe, straight pipe, flexible pipe.
16. The vehicle exhaust system according to claim 11, wherein the combined length is smaller than the second outermost dimension for an inline configuration where the first and second center axes are coaxial, and wherein the combined length is greater than the second outermost dimension and smaller than a combined outer dimension of the first outermost dimension added to the second outermost dimension for a non-inline configuration where the first and second center axes are non-coaxial.
17. A method of assembling a mixer for a vehicle exhaust system comprising: providing an upstream exhaust component defining a first center axis and including at least a first catalyst surrounded by a first outer housing and having a first outer dimension; providing a downstream exhaust component defining a second center axis and including at least a second catalyst surrounded by a second outer housing and having a second outer dimension; connecting the upstream and downstream exhaust components with a mixer, wherein the mixer comprises a first portion associated with an outlet from the first catalyst and a second portion associated with an inlet to the second catalyst, and wherein the first portion comprises a first mixer housing to provide a first end cap for the first outer housing and the second portion comprises a second mixer housing to provide a second end cap for the second outer housing; positioning a swirl component having a first length at least partially within the first end cap; positioning an additional component having a second length at least partially within the second end cap; providing a connection interface between the first and second mixer housings to allow the upstream and downstream exhaust components to be arranged in different positions relative to each other, and wherein the connection interface comprises either a direct connection between the first and second mixer housings or includes one or more additional pipe sections selected from a group of: elbow pipe, straight pipe, flexible pipe; and adjusting a combined length of the first and second lengths relative to the first and second outer dimensions such that the first and second center axes can be arranged to achieve a desired mounting configuration.
18. The method according to claim 17, wherein the swirl component comprises a swirl chamber with an increasing diameter and having an inlet associated with an injector and an outlet that directs a mixture of exhaust gas and injected fluid into the second portion, and wherein the additional component comprises a pipe that is enclosed within the second mixer housing, and including forming the pipe to have a first end open to the first portion and a second end that is closed by a bowl-shaped component that provides a solid concave surface.
19. The method according to claim 17, wherein the additional component comprises a trumpet shaped pipe.
20. The method according to claim 17, wherein the combined length is smaller than the second outer dimension for an inline configuration where the first and second center axes are coaxial, and wherein the combined length is greater than the second outer dimension and smaller than a combined outer dimension of the first outer dimension added to the second outer dimension for a non-inline configuration where the first and second center axes are non-coaxial.
21. The method according to claim 17, including directly connecting the first end cap to the first outer housing and directly connecting the second end cap to the second outer housing.
22. The vehicle exhaust system according to claim 11, wherein the first end cap is directly connected to the first outer housing and the second end cap is directly connected to the second outer housing.
23. The vehicle exhaust system according to claim 1, wherein the first end cap is directly connected to the first outer housing and the second end cap is directly connected to the second outer housing.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0024] The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures that accompany the detailed description can be briefly described as follows:
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DETAILED DESCRIPTION
[0043] This disclosure details an exemplary mixer with first and second portions that can be directly connected or can be connected via a connection interface including additional connecting components to allow flexibility for different mounting configurations.
[0044]
[0045] In one example, a mixer 30 is positioned downstream from the outlet 20 of the DOC 16 or an outlet 23 of the DPF 21, and upstream of the inlet 24 of the SCR catalyst 22. The upstream catalyst and downstream catalyst can be in-line as shown in
[0046] An injection system 32 is used to inject a reducing agent, such as a solution of urea and water for example, into the exhaust gas stream upstream from the SCR catalyst 22 such that the mixer 30 can mix the urea and exhaust gas thoroughly together via a swirling generated flow. The injection system 32 includes a fluid supply 34, an injector/doser 36 defining a doser axis A, and a controller 38 that controls injection of the urea as known.
[0047] The mixer 30 has an inlet end 42 configured to receive the engine exhaust gases and an outlet end 44 to direct a mixture of swirling engine exhaust gas and products transformed from urea to the SCR catalyst 22.
[0048] The first portion 46 is associated with the outlet 20 from the DOC or the outlet 23 from the DPF 21, and the second portion 48 is associated with the inlet 24 to the SCR 22. The first portion 46 includes a swirl component 52 (
[0049] In one example shown in
[0050] The swirl chamber 64 has an upstream end 80 fixed to the doser mount 62 and a downstream end 82 that is open to the internal cavity within the first mixer housing 56. The upstream end 80 is defined by a first outer dimension C1 and the downstream end 82 is defined by a second outer dimension C2 that is greater than the first outer dimension C1 to form the chamber shape. In one example, the swirl chamber 64 has a constantly increasing outer dimension toward the downstream end 82 to provide a tapering body portion 84.
[0051]
[0052] The doser mount opening 70 of the doser mount 62 is positioned at the doser opening 66 of the first mixer housing 56. Fluid is injected through the aligned openings and into an interior of the swirl chamber 64 to mix with exhaust gas. The mixture of exhaust gas and fluid exits the downstream end 82 of the swirl chamber 64, and is then directed into the second mixer housing 58.
[0053] In one example, the plurality of flow elements 72 each have an upstream end fixed to the doser mount 62 and a downstream end. As discussed above, the plurality of flow elements 72 are attached to each other to form the swirl chamber 64. The inlet reactor 60 and swirl chamber 64 are described in greater detail in U.S. application Ser. No. 16/834,182 filed on Mar. 30, 2020, which is also assigned to the assignee of the present application and is hereby incorporated by reference.
[0054] In one example shown in
[0055] In another example, the second component 54 can comprise a perforated component such as a trumpet pipe 77 as shown in
[0056] In one example, the pipes 77, 79 have an axial length where one side has a greater length L1 than the length L2 of the opposite side (see
[0057] The perforated trumpet pipe 77 includes a plurality of openings 85 that extend circumferentially about the pipe 77 and extend along a length of the pipe 77. The openings 85 can have the same or different sizes, and can be arranged in different patterns. In one example, the first open end 81 has a first portion that is solid along a pipe length, i.e. does not have any openings, and then the openings 85 are provided from a termination of the solid potion to the second open end 83. The non-perforated trumpet pipe 79 has a solid surface along its entire length.
[0058] In one example, a bowl-shaped component 86 provides the solid surface of the closed end for the non-perforated second component 54 as a concave surface as shown in
[0059] In one example, the bowl-shaped component 86 includes openings 87 as shown in
[0060] In one example, a first outer housing 92 surrounds the DOC 16 and DPF 21 and a second outer housing 94 surrounds the SCR 22. A first connection at 96 connects an outlet of the first outer housing 92 to the inlet end 42 of the mixer 30. A second connection at 98 connects the outlet end 44 of the mixer 30 to an inlet end of the second outer housing 94.
[0061] In one example, a baffle plate 100 is positioned at the outlet end 44 of the mixer 30 downstream of the perforated pipe 74 and upstream of the SCR 22 as shown in
[0062] The connection interface 50 between the first 46 and second 48 portions allows the first outer housing 92 and the second outer housing 94 to be arranged in different positions relative to each other. The connection interface 50 can be a direct connection or can comprise pipe sections 104 that are elbow pipes, straight pipes, or flexible pipes. The pipe sections can be made from rigid or flexible material. The pipe sections 104 are selected in any of various combinations to provide the desired packaging arrangement.
[0063] For example,
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[0065] The subject disclosure provides for a configuration that achieves high SCR mixing performance in a non-inline configuration. The use of the reactor 60 with a swirl around the spray cone makes better use of the available space to spread out the droplets and reduce the local cooling effect that is generated by a localized impingement. According to substrate size, and to be more compact, the injector/doser 36 is at least partially recessed within the inlet substrate packaging (see 47 in
[0066] The second portion 48 of the mixer 30 further comprises a catalyst inlet cone and a second component 54 that terminates in an outlet end that can be bounded by a substantially concave surface or which can be open. The connector interface 50 couples the first 46 and second 48 portions of the mixer 30 together. As such, the exhaust gas flows between the two portions of the mixer via the connector interface 50.
[0067] In one example shown in
[0068] In the first portion 46, a majority of exhaust flow is collected by the swirling reactor 60 in order to generate a swirling mixture between exhaust and injected fluid. This swirling mixture reduces risk for deposits and extends through the axial length of the first 46 and second 48 portions. The exhaust gas from the DPF 21 will enter the first portion 46 of the mixer and the swirling chamber 64 inside the first portion 46 will spread injected fluid around swirling chamber. The fluid will be spread inside the inlet reactor 60, which is heated by flow coming from the upstream catalyst. This improves deposit performances by limiting cooling effect due to spray impingement.
[0069] The height of first portion 46 will depend on a maximum flowrate and injector spray angle. The pipe sections 104 between the first 46 and second 48 portions allow for a plurality of different configurations. Direct connection between the first 46 and second 48 portions via the pipe sections 104 uses a flange or clamp system, with potential different clocking of the sections to fit vehicle clearance space. Also, the housings 56, 58 can be welded together. The clocking can provide U-Shape, L-Shape, S-Shape, etc. configurations.
[0070] The second portion 48 is a radial inlet component providing good Flow Uniformity Index and fluid distribution at the SCR catalyst inlet surface. When exhaust flow reaches second portion 48, the perforated pipe 74 distributes the mixture to the SCR. The second portion 48 can have different shapes including a trumpet shape, for example. The perforated pipe 74 has the outlet closed by the bowl-shaped component 86 to collect droplets that have not been evaporated yet to protect catalyst from erosion and improve reductant conversion rate of the mixer. The bowl-shaped component 86 does not allow the mixture to be exposed to cooler temperatures present on the housing 58, which limits the cooling down effect due to the cold droplets and thus limits liquid film creation and improves deposit performances. If liquid happens to be created at a low temperature, the bowl-shaped component 86 will retain the liquid from entering the SCR. The external heated surface of the bowl reduces the cooling effect from impingement, thus reducing risk of deposit and liquid film accumulation. Adding the downstream baffle plate 100 improves Flow Uniformity Index and reductant distribution.
[0071] The subject disclosure provides an assembly where a combined length D1+D2 of the swirl inlet reactor 60 and the second component 54 is adjusted relative to the first Du and second Dd outermost dimensions of the substrates/catalysts of the upstream and downstream exhaust components to provide a desired mounting configuration. In one example, the combined length D1+D2 of the swirl inlet reactor 60 and the second component 54 is smaller than the outermost catalyst dimension Dd of the downstream exhaust component for an inline configuration where the first and second center axes of the upstream and downstream exhaust components are coaxial. In another example, the combined length D1+D2 of the swirl inlet reactor 60 and the second component 54 is greater than the outermost catalyst dimension Dd of the downstream exhaust component and smaller than a combined outermost catalyst dimension Du+Dd of the upstream and downstream exhaust components for a non-inline configuration where the first and second center axes are non-coaxial. This allows the same mixer structure, e.g. components 54 and 60, to be used for both inline and non-inline configurations simply by adjusting the length of the components.
[0072] Although a specific component relationship is illustrated in the figures of this disclosure, the illustrations are not intended to limit this disclosure. In other words, the placement and orientation of the various components shown could vary within the scope of this disclosure. In addition, the various figures accompanying this disclosure are not necessarily to scale, and some features may be exaggerated or minimized to show certain details of a particular component.
[0073] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.