US20100077742A1

US20100077742A1 - Flow diffuser for an exhaust system

Info

Publication number: US20100077742A1
Application number: US12/241,143
Authority: US
Inventors: David Robert Ehlen; Raj P. Ranganathan; Daniel Walilko; Patrick D. Murphy; David M. Kiser
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2008-09-30
Filing date: 2008-09-30
Publication date: 2010-04-01
Also published as: DE102009042978A1; CN101713319A

Abstract

Exemplary embodiments of the present invention provide devices, systems and methods for distribution of an engine exhaust gas to one or more exhaust treatment devices. In one embodiment, an exhaust flow diffuser is provided including a conduit defining an inlet opening, an outlet opening and a flow path therebetween. The conduit includes a first section disposed proximate to the inlet opening and a second section disposed proximate to the outlet opening. The second section has an increasing diameter along its length. The conduit is formed by a first member and a second member both of which extend between the inlet opening and outlet opening to form a portion of the first section and the second section. The first member and the second member each include an engagement feature that extends between the inlet opening and outlet opening.

Description

FIELD OF THE INVENTION

In accordance with the teachings of the present invention, devices, systems and methods for distribution of an engine exhaust gas to one or more exhaust gas treatment devices are provided.

BACKGROUND

Exhaust systems of internal combustion engines, particularly vehicle engines, often include one or more exhaust gas treatment devices for reducing the amount of regulated constituents within the exhaust gas. Such treatment systems may include a selective catalytic reduction (SCR) device, diesel particulate filter (DPF), diesel oxidation converter (DOC) or otherwise. Prior to the exhaust gas flowing into an exhaust gas treatment device, the exhaust gas may be pre-treated with urea solution, hydrocarbon fuel or otherwise for improving efficiency of the device. One challenge with these devices is in the even distribution of exhaust gas and fluid additives to the exhaust treatment device while still conforming to the space constraints for locating the device beneath a vehicle. Often, due to the natural flow of the exhaust gas, the exhaust gas is directed towards a center portion of the exhaust gas treatment device or other particular location. This results in a buildup of contaminants (e.g., particulate matter or otherwise) on a particular location of the exhaust treatment device which requires additional regenerative heating for removal of such buildup. In other words, prior treatment systems doe not efficiently use the entire device for conversion or treatment. Accordingly, there is a need for a device, system and method for providing even distribution of exhaust gas, and additives thereof, to an exhaust gas treatment device given a particular space constraint.

SUMMARY OF THE INVENTION

The present invention provide devices, systems and methods for distribution of an engine exhaust gas to one or more exhaust gas treatment devices. In one particular configuration, an exhaust flow diffuser for an exhaust system is provided. The diffuser includes a conduit defining an inlet opening, an outlet opening and a flow path therebetween. The conduit includes a first section disposed proximate to the inlet opening and a second section disposed proximate to the outlet opening. The second section has an increasing diameter along its length and the outlet opening includes a diameter that is larger than a diameter of the inlet opening. The conduit is formed by a first member extending between the inlet opening and outlet opening to form a portion of the first section and the second section, the first member including a first engagement feature extending between the inlet opening and outlet opening. The conduit is also formed by a second member extending between the inlet opening and outlet opening to form a portion of the first section and second section, the second member including a second engagement feature extending between the inlet opening and outlet opening. The first and second engagement feature being configured to matingly engage with each other to join the first and second member and to form the flow path.
In another configuration, an exhaust system for an internal combustion engine is provided. The exhaust system includes an exhaust conduit in fluid communication with the internal combustion engine to receive and guide an exhaust gas. The system also includes an exhaust gas treatment device for treatment of the exhaust gas. The system further includes a diffuser located between and in fluid communication with the exhaust conduit and the exhaust gas treatment device. The diffuser includes a conduit defining an inlet opening, an outlet opening and a flow path therebetween. The conduit includes a first section disposed proximate to the inlet opening and a second section disposed proximate to the outlet opening. The second section has an increasing diameter along its length and the outlet opening includes a diameter larger than a diameter of the inlet opening. The conduit is formed by a first member extending between the inlet opening and outlet opening to form a portion of the first section and the second section, the first member including a first engagement feature extending between the inlet opening and outlet opening. The conduit is also formed by a second member extending between the inlet opening and outlet opening to form a portion of the first section and second section, the second member including a second engagement feature extending between the inlet opening and outlet opening, the first and second engagement feature being configured to matingly engage with each other to join the first and second member and to form the flow path. The conduit further includes a fluid injector located between the internal combustion engine and the exhaust gas treatment device, the fluid injector providing injections of urea solution or combustible fuel into the exhaust gas.
In still another configuration, a method of disbursing exhaust gas form an internal combustion engine to an exhaust gas treatment device is provided. The method comprising: flowing exhaust gas through a diffuser that is fluidly coupled with and disposed between the internal combustion engine and the exhaust gas treatment device, the diffuser being formed of a first member having a first mating surface and a second member having a second mating surface, the first and second members being joinable to form an inlet opening, an outlet opening and a fluid flow path therebetween, diffuser defining a first section disposed proximate to the inlet opening and a second section disposed proximate to the outlet opening, the second section having a gradually increasing diameter along its length; and injecting urea solution into the exhaust gas prior to or during flow of the exhaust gas through the diffuser.
The above-described and other features and advantages of the exemplary embodiments of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features, advantages and details of the present invention appear, by way of example only, in the following detailed description of the exemplary embodiments, the detailed description referring to the drawings in which:

FIG. 1 illustrates a perspective view of an exhaust system of a vehicle according to an exemplary embodiment of the present invention;

FIG. 2 illustrates a perspective view of an exhaust gas diffuser in fluid communication with an exhaust gas treatment device according to an exemplary embodiment of the present invention;

FIG. 3 illustrates a perspective view of another exhaust gas diffuser in fluid communication with an exhaust gas conduit according to an exemplary embodiment of the present invention;

FIG. 4 illustrates a perspective view of another exhaust gas diffuser in fluid communication with an exhaust gas conduit according to an exemplary embodiment of the present invention;

FIG. 5 illustrates a bottom view of the exhaust gas diffuser shown in FIG. 4;

FIG. 6 illustrates a perspective view of another exhaust gas diffuser positioned over a frame member of a vehicle assembly according to an exemplary embodiment of the present invention;

FIG. 7 illustrates a perspective view of another exhaust gas diffuser in fluid communication with an exhaust gas treatment device according to an exemplary embodiment of the present invention;

FIG. 8 illustrates an elevational view of another exhaust gas diffuser in fluid communication with an exhaust treatment device according to an exemplary embodiment of the present invention;

FIG. 9 illustrates a cross-sectional view of the diffuser shown in FIG. 3;

FIG. 10 illustrates an alternate configuration of the diffuser shown in FIG. 9;

FIG. 11 illustrates an alternate configuration of the diffuser shown in FIG. 9;

FIG. 12 illustrates a first end view of the diffuser shown in FIG. 6;

FIG. 13 illustrates a second end view of the diffuser shown in FIG. 6;

FIGS. 14 through 25 illustrate elevational and cross-sectional views of different exhaust gas diffuser configurations according to exemplary embodiments of the present invention;

FIG. 26 illustrates a side view of a divider according to an exemplary embodiment of the present invention;

FIG. 27 illustrates a top view of another divider according to an exemplary embodiment of the present invention;

FIG. 28 illustrates an end view of yet another divider according to an exemplary embodiment of the present invention;

FIG. 29 illustrates a perspective view of an exhaust gas flow partition according to an exemplary embodiment of the present invention;

FIG. 30 illustrates a perspective view of an exhaust gas mixing device according to an exemplary embodiment of the present invention;

FIG. 31 illustrates a perspective view of an exhaust gas swirl device according to an exemplary embodiment of the present invention;

FIGS. 32 and 33 illustrate two fluid flow profiles through a conduit according to the teachings of the present invention; and

FIGS. 34 through 37 illustrate different engine exhaust systems according to exemplary embodiments of the present invention.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present invention provides devices, systems and methods for even distribution of exhaust gas from an engine to one or more exhaust treatment devices, such as a selective catalytic reduction (SCR) device, diesel oxidation converter (DOC), diesel particulate filter (DPF) or otherwise. Through this distribution, contaminants of exhaust gas, such as nitrogen oxides, hydrocarbons, particulate matter or otherwise, are evenly distributed across an inlet of the exhaust gas treatment device. This is particularly advantageous in a DPF as regeneration time for removal of contaminants collected across the exhaust gas treatment device may be reduced due to the reduction or elimination of localized buildup. Further, the even distribution of exhaust gas also reduces hot spots, which may affect durability, formed across the exhaust treatment device due to this localized build up.
Through the features of the present invention, fluid flow velocity and profile into and out of the exhaust gas treatment device will be improved, without deleterious effect to the fluid flow velocity. The improved fluid flow profile and velocity allows for optimized packaging of the exhaust gas treatment device and potentially reduces the substrate volume required for treatment of the exhaust gas. This reduction improves durability of the exhaust treatment device and potentially reduces cost of the overall engine exhaust system. The features of the present invention are particularly advantageous in certain vehicle configurations where packaging and design constraints are limiting. For example, through the shape configurations of the invention, e.g., diffuser or otherwise, it is possible to traverse certain vehicle components, without deleterious effects, such as frame members and more particularly laterally extending frame members as with ladder frame construction. These shapes allow fluid flow through relatively narrow spaces while avoiding excessive back pressure within the exhaust system while still providing even disbursement of exhaust gas to an exhaust gas treatment device and allowing for improved packaging.
In one configuration, even distribution of the exhaust gas is achieved through a shaped configuration of a fluid flow diffuser disposed between the engine and the exhaust treatment device. In another configuration, even distribution of the exhaust gas is achieved through strategic placement of an injector between the engine and the exhaust treatment device. In still another configuration, even distribution of the exhaust gas is achieved through placement of a flow divider of the present invention between the engine and the exhaust gas treatment device. In still other configurations, combinations of these or other features are contemplated, as shown and described herein, for causing even distribution of exhaust gas to an exhaust gas treatment device. Through these and other features of the present invention, it is possible to evenly disburse the flow of exhaust gas and fluid additives (e.g., urea solution, combustion fuel or otherwise) through a cross-sectional area of an inlet of an exhaust gas treatment device. For example, referring to FIG. 32, typical laminar flow of fluid through a pipe-like conduit 200 provides a fluid flow profile 202 with a larger volume of the exhaust gas and fluid additive traveling generally through a center portion of the pipe-like conduit 200. In one embodiment, referring to FIG. 33, the fluid flow profile 202 of the present invention includes a more dispersed fluid flow wherein the volume of the fluid traveling through the pipe-like conduit 200 is more evenly disbursed.
Referring to the embodiments shown in FIGS. 1, 3 and 7, a vehicle frame assembly 10 is shown providing support to an engine 12 and engine exhaust system 14. The engine exhaust system 14 includes a diffuser 16 for use with an exhaust treatment system 18 for providing disbursement of exhaust gas to an exhaust treatment device 20. The diffuser 16 includes a conduit 22 defining a cavity 24. The cavity is in fluid communication with an inlet opening 26 and an outlet opening 28 for forming a fluid flow path through the diffuser 16. In one configuration, the conduit includes one or more features for assisting in the disbursement of exhaust gas through the conduit 22. For example, the feature may comprise a divider 30 for forming one or more sub-passageways through the diffuser. In another configuration, the diffuser 16, exhaust treatment system 18 or exhaust system of the engine 14 includes an injector assembly 32, including an injector mount 34 and injector 36, for injection of urea solution or hydrocarbon fuel into the exhaust gas flowing through the diffuser 16. In still another configuration, the diffuser 16 is shaped to cause expansion and disbursement of the exhaust gas flowing from the inlet opening 26 to the outlet opening 28 of the diffuser 16.
Referring to FIG. 3, a first engagement feature 38 is provided for coupling the diffuser 16 to an exhaust component, such as an exhaust conduit 40, exhaust pre-treatment device (not shown) or otherwise. Similarly, a second engagement feature 44 is provided for coupling the diffuser 16 to an exhaust treatment device 20, such as an SCR, DOC, DOC or otherwise. The first and second engagement feature may comprise any suitable engagement feature such as a flange, lip, groove or otherwise. Further, engagement between diffuser 16 and the corresponding exhaust components may be maintained through any suitable attachment feature such as a weld, adhesive, mechanical fastener, combinations thereof or other suitable attachment.
Referring to FIGS. 12 and 13, the size and shape of inlet opening 26 and outlet opening 28 may comprise any suitable size and shape that correspond to an opening of the exhaust component, which they engage. In one configuration, the outlet opening 28 is larger than the inlet opening 26. For example, it is contemplated that the outlet opening may include at least one interior diameter “d_o” that is at least about 1.25% larger than an interior diameter of the inlet opening “d_i”, or even at least about 1.5% larger than an interior diameter of the inlet opening “d_i” or even 2.0% larger than an interior diameter of inlet opening “d_i”. Similarly, it is contemplated that the outlet opening cross-sectional area “a_o” that is at least about 1.25% larger than a cross-sectional area of the inlet opening “a_i”, or even at least about 1.5% larger than a cross-sectional area of the inlet opening “a_i” or even 2.0% larger than a cross-sectional area of inlet opening “a_i”. Other configurations are possible.
The shape of inlet opening 26 and outlet opening 28 may be similar or dissimilar and may include any suitable shape such as circular, oval, elliptical, square, rectangular or otherwise. The diameter of the inlet opening “d_i” and the outlet opening “d_o” may include any suitable diameter size. For example, the inlet opening 26 may include a diameter “di” that is between about 2-4 inches and more particularly in one exemplary embodiment about 3 inches. The outlet opening 28 may include a diameter “do” that is between about 6-10 inches, and more particularly in one exemplary embodiment 7 inches by 9 inches. In one embodiment, referring to FIGS. 6, 12 and 13, the inlet opening 26 includes a circular cross-sectional shape and the outlet opening 28 includes an oval cross-sectional shape. In this embodiment, the inlet opening includes a diameter “di” of about 3 inches and the outlet opening includes a width diameter “w-do” of about 9 inches and a height diameter “h-do” of about 7 inches. However, these are non-limiting dimensions as other dimensions are available including greater or less than the above referenced dimensions.
Similarly, the conduit 22 may include any suitable size or shape for fluidly connecting the inlet opening 26 and the outlet opening 28, which may include any of the sizes of the inlet opening and outlet opening. In one embodiment, as shown in FIG. 2 and 4-6, the conduit 22 is shaped to traverse about one or more frame members 46 of the vehicle frame assembly 10. In this embodiment, it is contemplated that the shape of the conduit may include a portion that is non-circular in shape, such as elliptical, oval or otherwise, for placement and maintaining fluid flow velocity about one or more vehicle frame members 46. Through these non-circular configurations, e.g., flattening, widening and/or narrowing certain portions of the conduit 22, it is possible to maintain fluid flow velocity between the inlet opening 26 and outlet opening 28, without excessive exhaust gas backpressure. Also, the conduit 22 may be configured to cause or maintain even disbursement of exhaust gases and particulate matter flowing through the conduit. The disbursement of exhaust gas may be achieved, at least in part, through one or more sections of the conduit 22 being formed with contours for causing gradual expansion of the gas between the inlet opening 26 and the outlet opening 28. For example, such contours may comprise shapes (cylindrical, frustroconcial or otherwise), twists, bends or other contours.
Referring to FIGS. 14-25, the contour of the conduit 22 may include a non-circular portion such as an elliptical or oval cross-sectional portion, or otherwise, extending along a length “l” of the length “L” of the conduit. This non-circular portion may comprise a widening or narrowing of the width, height, or otherwise of the conduit 22. The non-circular portion may be located towards the inlet opening 26, outlet opening 28, or in a center portion 88 of the conduit. The non-circular portion may include a substantially consistent cross-sectional area along a length of the conduit, variable cross-sectional area along a length of the conduit, increasing and/or decreasing cross-sectional area along a length of the conduit or otherwise. The non-circular portion may extend over all or a portion of the length of the conduit 22. For example, the non-circular portion may include a length “l” that extends over at least about ¼ of the length “L” of the conduit, at least about ½ of the length of the conduit, at least about ¾ of the length of the conduit or otherwise. Further, the non-circular portion may include a length “l” that extends over a substantial length “L” of the conduit. Other configurations are possible.
Further, with respect to elliptical type non-circular portions, the degree of the elliptical shape of conduit 22 may vary along the length “l” of the non-circular portion. For example, the elliptical shape may begin just below about 90° and gradually decrease to at least 85°, 80°, 75°, 70°, 60° or less. Subsequently, the degree of the elliptical shape may increase back up to 70°, 75°, 80°, 85° or even just below about 90°. It is contemplated that the degree of the non-circular elliptical portion may change by as much as at least about 5°, 10°, 15°, 30° or more. Similarly, a ratio of width to height of a cross sectional area of the non-elliptical portion may be at least about 1.25:1, 1.5:1, 1.75:1, 2:1 3:1 or more. As with the degree of the non-circular portion, the ratio may change over a length of the non-circular portion including a gradual increasing or decreasing change from a first end of the non-circular portion to a second end of the non-circular portion. Other configurations are possible.
As shown in the drawings, the conduit 22 is formed of a first section 48 having a first cross-sectional area and a second section 50 having a second cross-sectional area, wherein the first section is located proximate to the fluid inlet opening 26 and the second section is located proximate to the fluid outlet opening 28. In this configuration, the second section 50 includes an inner diameter larger than an inner diameter of the first section 48 for providing expansion of the exhaust gas as it flows through the conduit 22. For example, referring to the exemplary configurations shown in FIGS. 3 and 6, the conduit 22 may include a cylindrical first section 48 and a frustroconical second section 50 indirectly connected together through a third section 52, comprising an elbow or otherwise. In another configuration, referring to FIG. 8, the conduit may include a frustoconical first section 48 and a frustoconical second section 50 directly connected together. In these configurations, as gas exits the first section 48 and enters the second section 50 the gas is diffused and expands outwardly as it flows through the conduit 22. It should be appreciated that the conduit may include other sections, such as end sections 54 or otherwise, which may include any of the shape and size configurations described herein (e.g., circular or non-circular).
The diffuser 16 may be formed using any suitable material and forming technique common for forming exhaust components. For example, suitable materials include metal, metal alloys, ceramic or combinations thereof. Also, suitable forming techniques include molding, stamping, extruding techniques or otherwise. In one configuration, the diffuser 16 is composed of metal and formed, at least in part, through a stamping process. In this configuration, the diffuser 16 is formed as a two part member with corresponding mating structures for joining the components. More specifically, as shown in FIGS. 6, 12 and 13, the diffuser is formed of a first diffuser member 56 having a first mating structure 58 and a second diffuser member 60 having a second mating structure 62. The first and second mating structures 58, 62 are configured to be joined together to form a diffuser joint 64. Examples of joints that may be formed through the first and second mating structures include lap joint, tongue and groove joint or otherwise. This clam-shell configuration allows the first and second diffuser members 56, 60 to be brought together, aligned and attached through a suitable attachment means such as adhesive bonding, welding, mechanical fastening or otherwise. This clam-shell configuration is particularly advantageous as it allows for additional components, such as a divider 30, flow partition 124, mixing device 132, swirl device 140 or otherwise, to be placed within the diffuser for causing mixing or disbursement of the exhaust gas throughout the cross-sectional area of the diffuser.
In one configuration, the diffuser 16 includes a divider 30 extending through at least a portion of the conduit 22 and between inlet opening 26 and outlet opening 28. The divider 30 is configured to separate or maintain separation of the exhaust gas flowing through diffuser 16. The divider 30 is also configured to assist in the evaporation of injected fluids through the elevated temperature of the divider and/or impact of the injected fluid with the divider. For example, referring to the configurations of FIGS. 3, 7 and 9, the divider 30 separates the flow of exhaust gas through conduit 22 into a first sub-passageway 66 and a second sub-passageway 68. The first and second sub-passageways may generally have equal cross-sectional areas or may be proportionately divided. In another configuration, referring to FIG. 10, it is also contemplated that the divider 30 may be configured to form a first sub-passageway 70, a second sub-passageway 72 and a third sub-passageway 74, wherein the first, second and third sub-passageways include a generally equal cross-sectional areas. Also, referring to FIG. 11, it is further contemplated that the divider 30 may be configured to form a first sub-passageway 76, a second sub-passageway 78, a third sub-passageway 80 and a fourth sub-passageway 82, wherein the first, second, third and fourth sub-passageways include generally equal cross-sectional areas. Other configurations are possible including additional sub-passageways, different shaped sub-passageways, different proportions of cross-sectional areas or otherwise.
The divider 30 is suitable in length to assist in limiting or preventing the migrating or congregation of exhaust gas towards a central axis “A” of the conduit 22. For example, it is contemplated that divider 30 may extend at least about 50% of the length of the conduit, at least about 60% of the conduit, at least about 75% of the conduit, at least about 85% of the conduit or more. In one configuration, the divider 30 includes a first end 84 located proximate to the inlet opening 26 and a second end 86 which is located in a central portion 88 of the conduit. However, in an alternate configuration, the second end 86 of the divider 30 may extend to the outlet opening 28. Also, the second end 86 of the divider 30 may be located proximate to the outlet opening 28 and the first end 84 is located in a central portion 88 of the conduit 22. Other configurations are possible.
Referring to the embodiments shown in FIGS. 3, 7 and 9, the divider 30 includes a first side 90 having a first surface area and a second side 92 having a second surface area. The first and second sides act in combination with interior walls of the conduit 109 to form the first and second sub-passageway 66, 68. Similarly, referring to FIG. 10, the divider 30 may comprise a first arm 94, a second arm 96 and a third arm 98 extending from a central portion of the divider 30 and along the axis A of the conduit. In this configuration, each arm includes a first and second surface which in combination with the interior walls 109 of the conduit forms a first, second and third sub-passageway 70, 72, 74. In still another embodiment, referring to FIG. 11, the divider may comprise a first arm 100, a second arm 102, third arm 104 and a fourth arm 106, which forms the first, second, third and fourth sub-passageway 76, 78, 80, 82.
In any of the above referenced embodiments, it is contemplated that the divider 30 includes one or more peripheral edge 108 extending along the divider. For example, as shown in FIGS. 9-11, the peripheral edges have a corresponding shape to at least a portion of the interior walls 109 of the conduit 16 for attachment of the divider 30 to the conduit and maintaining separation of exhaust between the sub-passageways. Accordingly, the diameter or shape of the divider 30 may include any of the diameters or shapes of the conduit 22, particularly the cross-sectional areas of the first section 48, second section 50 or third section 52, as shown in FIG. 6. As such, it is contemplated that the divider 30 may include a continuously increasing or decreasing width or may include one or more changes in contour. Also, it is contemplated that the divider 30 may include one or more contours along its length. For example, referring to the embodiments shown in FIGS. 26-28, the divider may include one or more flat portions 110, one or more bends 112 (e.g., traverse or vertical bend with respect to the divider length), and one or more twists 114.
Optionally, as shown in FIG. 3, the divider 30 may include one or more, a plurality or even an array of perforations or openings 116 formed along a length and width of the divider and extending through the divider. However, as shown in FIGS. 6, 7 and 9, the divider 30 may comprise a continuous member substantially free of perforations or openings formed therethough. The openings 116, as shown in FIG. 3, allow for fluid communication between the first and second sub-passageways 72, 74. However, with reference to the divider configurations shown in FIGS. 10 and 11, the openings may further allow fluid communication between more than two sub-passageways. These configurations are particularly advantageous when used in conjunction with an injector assembly 32 providing a spray pattern that intersects at least some of the openings 116 formed through the divider 30. These openings 116 are further advantageous as they not only allow for mixing of exhaust gases flowing through the conduit 22 but also provide mixing of an injected fluid (e.g., urea solution, hydrocarbon fuel or otherwise) with the exhaust gas. In the exemplary embodiment shown in FIG. 3, this is achieved by allowing a first portion of the injected fluid to pass through the openings 116 and mix with the exhaust gas below the divider 30 and a second portion of the injected fluid impacts the divider or otherwise mixes with the exhaust fluid flowing above the divider. In one exemplary embodiment, with continued reference to FIG. 3, the summation of the open areas of openings 116 within a spray pattern of the fluid injector 36 is generally equal to the summation of the surface area of the divider 30 within the spray pattern of the fluid injector. This allows for roughly half of the fluid injected from the fluid injector 36 to travel to the second sub-passageway 68 while the other half remains within the first sub-passageway 66. These openings 116 may extend over at least about ¼ of the length of the divider 30, at least about ½ of the length of the divider, at least about ¾ of the length of the divider or otherwise. Further, these openings may extend over at least about ¼ of the width of the divider, at least about ½ of the width of the divider, at least about ¾ of the width of the divider or otherwise.
The divider 30 may be formed using any suitable material and forming techniques common for forming exhaust components, or the conduit described herein. For example, suitable materials include metal, metal alloys, ceramic or combinations thereof. Also, suitable forming techniques include molding, stamping, extruding techniques or combinations thereof. In one configuration, it is contemplated that the perforation openings 116 formed through the divider may be stamped through the divider. It should be appreciated that other suitable materials and forming techniques are possible and within the scope of the present invention.
As previously mentioned, the exhaust treatment system 18 may include one or more injector assemblies 32 for the injection of fluids into an exhaust gas stream for treatment thereof. Such fluids may include hydrocarbon fuels or other combustible fluid such as gas, diesel, alcohol or otherwise. Such fluid may also include ammonia containing fluids such as urea solutions. Other fluids are possible as well. As shown in FIGS. 3, 4 and 9, the injector assembly may include an injector 36 in fluid communication with an exhaust gas flowing through an injector opening 118 formed through an exhaust conduit 40, diffuser 16, exhaust treatment device 20, exhaust pre-treatment device (not shown) or other conduit for the engine exhaust system 14. Accordingly, the injector assembly may be formed with or mounted to the diffuser 16, exhaust conduit 40, exhaust treatment device 20 or otherwise. In one particular embodiment, one or more injector assemblies 32 are placed upstream from an exhaust treatment device 20. In one configuration, the injector assembly 32 and injector opening 118 are located proximate to a plurality of openings formed through divider 30. Still further, in another configuration, the injector assembly is disposed on the first section 48 of the diffuser. In still another configuration the injector assembly is located closer to the engine 12 than the diffuser 16 for allowing thorough mixing of injected fluids. Other configurations are available.
In one exemplary embodiment, referring to FIG. 3, the injector 36 is mounted at an angle “α” with respect to the first or second side 90, 92 of the divider 30 and is configured to generate a spray pattern that intersects the divider. Suitable angles include between about 15° to 45°, or even between about 20° to 40° or otherwise. Advantageously, in certain configurations, the spray pattern is orientated such that it intersects a portion of openings 116 formed by a perforated divider 30. In this particular configuration, as previously discussed, a certain amount of spray enters the sub-passageway through the openings and a certain amount of spray remains in the sub-passageway in which the injector opening 118 is located. In another particular configuration, the divider 30 is substantially free of openings 116 formed therethrough. In this configuration, fluid may be injected on one or both sides 90, 92 of the divider 30 wherein the injected fluid impacts the divider and/or interior walls 109 of the conduit 22.
The diffuser 16 may include one or more additional modifiers for controlling the flow pattern of exhaust into, through or out of the diffuser. The flow modifiers are configured to cause further mixing of an injected fluid with the exhaust gas flowing through the diffuser 16. Such flow modifier may be located anywhere throughout the conduit 16 including the inlet opening 26, outlet opening 28, or therebetween. It is also contemplated that the flow modifier may be located outside of the conduit 16 such as adjacent the inlet opening 26, outlet opening 28 or otherwise.
Referring to FIG. 29, a first exemplary flow modifier is provided comprising a flow partition 124. In this configuration, the flow partition is located at an inlet opening 26 of the conduit 22 for causing mixing and distributing of exhaust gas entering through the inlet opening. The flow partition includes a plurality of vertically and horizontally extending walls 126 forming an array of openings 128 for controlling the flow of exhaust gas entering the inlet. Optionally, the flow partition includes deflectors 130 for deflecting or redirecting the flow of exhaust gas through the openings. Referring to FIG. 30, a second exemplary flow modifier is provided comprising a mixing device 132. In this configuration, the mixing device is located at an inlet opening 26 of the conduit 22 for mixing exhaust gas entering through the inlet opening. The mixing device includes a base portion 134 and one or more engagement features 136 located on a periphery of the base portion for engagement with the interior walls 109 of the conduit 22. The mixing device 132 further includes one or more angularly extending or flow modifying tabs 138 extending from the base portions to cause mixing or deflection of exhaust gas and fluid passing thereby. In one configuration, the tabs extend in a direction which is non-parallel to an axis “A” of the conduit. Referring to FIG. 31, a third exemplary flow modifier is provided comprising a swirl device 140. In this configuration, the swirl device includes a main body 142 and fins 144 extending therefrom to cause rotational movement of exhaust gas passing thereby. The swirl device 140 is located towards a central portion 88, see FIG. 7, of the conduit 22 and extends partially into the second frustroconical section 50 of the conduit 22.
Referring to FIGS. 34 through 37, exemplary exhaust treatment systems 18 and fluid flow patterns 146 are shown. In a first configuration, as shown in FIG. 34, a diffuser 16 is provided having injector assembly 32 for introduction of a fluid such as urea solution, combustible fluid or otherwise. Upon injection, the fluid disburses to form an expanded fluid flow pattern 146. In a second configuration, as shown in FIG. 35, a diffuser 16 is provided having an injector assembly 32 for introduction of a fluid. Upon injection, the fluid disburses to form an expanded fluid flow pattern 146. The pattern is further modified through a swirl device 140 to form a rotating fluid flow pattern for further mixing and distribution of the exhaust gas. Referring to FIG. 36, a diffuser 16 is provided having an injector assembly 32 for introduction of a fluid and further includes a divider 30. Upon injection, a portion of the fluid impacts the divider and travels along a first sub-passageway 66. Another portion of the fluid travels through openings 116, formed through the divider, and impacts an interior wall 109 of the conduit and further travels along a second sub-passageway 68, wherein the injected fluid forms an expanded fluid flow pattern 146. Referring to FIG. 37, a diffuser 16 is provided having an injector assembly 32 for introduction of a fluid and further includes a divider 30. Upon injection, a portion of the fluid impacts the divider and travels along a first sub-passageway 66. Another portion of the fluid travels through openings 116, formed through the divider, and impacts an interior wall 109 of the conduit and further travels along a second sub-passageway 68, wherein the injected fluid forms an expanded fluid flow pattern 146. The pattern is further modified through a swirl device 140 to form a rotating fluid flow pattern.
The present invention further provides a method of providing disbursement of exhaust gas from an engine 12 to an exhaust treatment system 18 is provided. The method includes fluidly coupling a diffuser 16 with an exhaust conduit 40 extending from the engine. The diffuser is further fluidly coupled to an exhaust treatment device 20, as described herein. The diffuser includes a conduit 22 defining a flow path between an inlet opening 26 and outlet opening 28. The conduit 22 is formed of a first diffuser member 56 and second diffuser member 60 operable to matingly join to define a first section 48 defining a cylindrical or frustroconical shape and a second section 50 defining a frustroconical shape. In one particular configuration, the method further includes placing a divider 30 within the conduit 22 for forming a first sub-passageway 66 and a second sub-passageway 68. In one configuration, the divider includes a plurality of openings 116 for providing fluid flow between the first sub-passageway 66 and the second sub-passageway 68. In this particular configuration, the method further include injecting a urea solution or combustible fluid into an exhaust gas flowing through the conduit, with injector assembly 32, such that the at least part of the injected fluid impacts the divider 30.
The diffusers 16, including the associated components, may be used in various engine applications including diesel engines, gasoline engines or other internal combustion engines. Such engines may be used in vehicle industry, e.g., mass transit vehicles, personal automotive vehicles, trucks or otherwise. The diffuser may also be used in non-vehicle applications such stationary engines used for mechanical or electrical power generation or otherwise. The diffuser 16 may be used to provide improved disbursement of exhaust gas, including particulate matter and other combustion gaseous product, to one or more exhaust treatment device 20. Such exhaust treatment devices 20 may comprise selective catalytic reduction device, diesel oxidation catalyst device, diesel particulate filter, diesel particulate traps, closed coupled converter, catalytic converters or otherwise. In one configuration, referring to FIG. 1, it is contemplated that a single diffuser 16 is used for the engine exhaust system 14 and is connected to a selective catalytic reduction device for providing disbursement of exhaust gas thereto. In another configuration, it is also contemplated that multiple diffusers 16 are used to provide disbursement of exhaust gas to more than one exhaust treatment device 20, as described herein. It is also contemplated that a diffuser 16 may be located downstream, e.g., attached or in fluid communication, with one or more exhaust treatment devices 20.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents maybe substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. An exhaust flow diffuser for an exhaust system, comprising:

a conduit defining an inlet opening, an outlet opening and a flow path therebetween, the conduit including a first section disposed proximate to the inlet opening and a second section disposed proximate to the outlet opening, the second section having an increasing diameter along its length and the outlet opening includes a diameter larger than a diameter of the inlet opening, the conduit being formed by:

a first member extending between the inlet opening and outlet opening to form a portion of the first section and the second section, the first member including a first engagement feature extending between the inlet opening and outlet opening,

a second member extending between the inlet opening and outlet opening to form a portion of the first section and second section, the second member including a second engagement feature extending between the inlet opening and outlet opening, and

the first and second engagement feature being configured to matingly engage with each other to join the first and second members and to form the flow path.

2. The diffuser of claim 1, further comprising a divider extending between the inlet opening and the outlet opening, the divider being configured to separate the flow path into a first sub-passageway and a second sub-passageway.

3. The diffuser of claim 2, wherein the divider is perforated to form a plurality of openings extending from a first side of the divider to a second side of the divider.

4. The diffuser of claim 3, wherein the divider includes at least one change in contour along a length of the divider.

5. The diffuser of claim 4, wherein the divider includes a first end located within the first section and a second end located within the second section.

6. The diffuser of claim 1, wherein the diffuser further includes an injector mount for attachment of a fluid injector.

7. The diffuser of claim 6, wherein the injector mount is disposed on the first section of the diffuser.

8. The diffuser of claim 7, further comprising a divider extending between the inlet opening and the outlet opening, the divider being configured to separate the flow path into a first sub-passageway and a second sub-passageway.

9. The diffuser of claim 8, wherein the divider is perforated to form a plurality of openings extending between a first side of the divider to a second side of the divider, the injector mount configured to orientate an attached injector towards the plurality of openings of the divider.

10. An exhaust system for an internal combustion engine, comprising:

an exhaust conduit in fluid communication with the internal combustion engine to receive and guide an exhaust gas;

an exhaust gas treatment device for treatment of the exhaust gas;

a diffuser located between and in fluid communication with the exhaust conduit and the exhaust gas treatment device, the diffuser including a conduit defining an inlet opening, an outlet opening and a flow path therebetween, the conduit including a first section disposed proximate to the inlet opening and a second section disposed proximate to the outlet opening, the second section having an increasing diameter along its length and the outlet opening includes a diameter larger than a diameter of the inlet opening, the conduit being formed by:

the first and second engagement feature being configured to matingly engage with each other to join the first and second member and to form the flow path; and

a fluid injector located between the internal combustion engine and the exhaust treatment device, the fluid injector providing injections of urea solution or combustible fuel into the exhaust gas.

11. The exhaust system of claim 10, wherein the fluid injector is mounted to the first section of the diffuser.

12. The exhaust system of claim 10, wherein the fluid injector is mounted to the exhaust conduit.

13. The exhaust system of claim 12, wherein the urea injector is located closer to the engine than the diffuser.

14. The exhaust system of claim 10, wherein the diffuser includes a divider extending between the inlet opening and outlet opening, the divider being configured to separate the flow path into a first sub-passageway and a second sub-passageway.

15. The exhaust system of claim 14, wherein the divider is perforated and includes a plurality of openings extending between a first side of the divider to a second side of the divider.

16. A method of disbursing exhaust gas form an internal combustion engine to an exhaust gas treatment device, the method comprising:

flowing exhaust gas through a diffuser that is fluidly coupled with and between the internal combustion engine and the exhaust gas treatment device, the diffuser being formed of a first member having a first mating surface and a second member having a second mating surface, the first and second members being joinable to form an inlet opening, an outlet opening and a fluid flow path therebetween, diffuser defining a first section disposed proximate to the inlet opening and a second section disposed proximate to the outlet opening, the second section having a gradually increasing diameter along its length; and

injecting urea solution into the exhaust gas prior to or during flow of the exhaust gas through the diffuser.

17. The method of claim 16, wherein an injector is mounted to an exhaust conduit located between the diffuser and the internal combustion engine for injection of the urea solution into the exhaust gas.

18. The method of claim 16, wherein an injector is mounted to the diffuser for injection of the urea solution into the exhaust gas.

19. The method of claim 16, wherein the diffuser includes a divider extending between the inlet opening and outlet opening, the divider being configured to separate the flow path into a first sub-passageway and a second sub-passageway.

20. The method of claim 19, wherein the divider includes a plurality of openings extending between a first side of the divider to a second side of the divider, the injection of the urea solution being proximate to the plurality of openings.