U.S. patent application number 12/241143 was filed with the patent office on 2010-04-01 for flow diffuser for an exhaust system.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS. Invention is credited to David Robert Ehlen, David M. Kiser, Patrick D. Murphy, Raj P. Ranganathan, Daniel Walilko.
Application Number | 20100077742 12/241143 |
Document ID | / |
Family ID | 42055939 |
Filed Date | 2010-04-01 |
United States Patent
Application |
20100077742 |
Kind Code |
A1 |
Ehlen; David Robert ; et
al. |
April 1, 2010 |
FLOW DIFFUSER FOR AN EXHAUST SYSTEM
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.
Inventors: |
Ehlen; David Robert;
(Rochester Hills, MI) ; Ranganathan; Raj P.;
(Rochester Hills, MI) ; Walilko; Daniel;
(Melvindale, MI) ; Murphy; Patrick D.; (Berkley,
MI) ; Kiser; David M.; (Shelby Township, MI) |
Correspondence
Address: |
Cantor Colburn LLP-General Motors
20 Church Street, 22nd Floor
Hartford
CT
06103
US
|
Assignee: |
GM GLOBAL TECHNOLOGY
OPERATIONS
Detroit
MI
|
Family ID: |
42055939 |
Appl. No.: |
12/241143 |
Filed: |
September 30, 2008 |
Current U.S.
Class: |
60/324 |
Current CPC
Class: |
F01N 3/0253 20130101;
F01N 2470/20 20130101; F01N 2260/20 20130101; Y02T 10/24 20130101;
B01F 5/0268 20130101; F01N 13/1822 20130101; F01N 3/2892 20130101;
B01F 3/04049 20130101; F01N 2240/20 20130101; Y02T 10/12 20130101;
F01N 3/2066 20130101; F01N 13/08 20130101; B01F 5/0616 20130101;
F01N 3/36 20130101 |
Class at
Publication: |
60/324 |
International
Class: |
F01N 7/00 20060101
F01N007/00 |
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: 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 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.
Description
FIELD OF THE INVENTION
[0001] 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
[0002] 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
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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
[0007] 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:
[0008] FIG. 1 illustrates a perspective view of an exhaust system
of a vehicle according to an exemplary embodiment of the present
invention;
[0009] 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;
[0010] 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;
[0011] 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;
[0012] FIG. 5 illustrates a bottom view of the exhaust gas diffuser
shown in FIG. 4;
[0013] 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;
[0014] 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;
[0015] 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;
[0016] FIG. 9 illustrates a cross-sectional view of the diffuser
shown in FIG. 3;
[0017] FIG. 10 illustrates an alternate configuration of the
diffuser shown in FIG. 9;
[0018] FIG. 11 illustrates an alternate configuration of the
diffuser shown in FIG. 9;
[0019] FIG. 12 illustrates a first end view of the diffuser shown
in FIG. 6;
[0020] FIG. 13 illustrates a second end view of the diffuser shown
in FIG. 6;
[0021] FIGS. 14 through 25 illustrate elevational and
cross-sectional views of different exhaust gas diffuser
configurations according to exemplary embodiments of the present
invention;
[0022] FIG. 26 illustrates a side view of a divider according to an
exemplary embodiment of the present invention;
[0023] FIG. 27 illustrates a top view of another divider according
to an exemplary embodiment of the present invention;
[0024] FIG. 28 illustrates an end view of yet another divider
according to an exemplary embodiment of the present invention;
[0025] FIG. 29 illustrates a perspective view of an exhaust gas
flow partition according to an exemplary embodiment of the present
invention;
[0026] FIG. 30 illustrates a perspective view of an exhaust gas
mixing device according to an exemplary embodiment of the present
invention;
[0027] FIG. 31 illustrates a perspective view of an exhaust gas
swirl device according to an exemplary embodiment of the present
invention;
[0028] FIGS. 32 and 33 illustrate two fluid flow profiles through a
conduit according to the teachings of the present invention;
and
[0029] FIGS. 34 through 37 illustrate different engine exhaust
systems according to exemplary embodiments of the present
invention.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.sub.o"
that is at least about 1.25% larger than an interior diameter of
the inlet opening "d.sub.i", or even at least about 1.5% larger
than an interior diameter of the inlet opening "d.sub.i" or even
2.0% larger than an interior diameter of inlet opening "d.sub.i".
Similarly, it is contemplated that the outlet opening
cross-sectional area "a.sub.o" that is at least about 1.25% larger
than a cross-sectional area of the inlet opening "a.sub.i", or even
at least about 1.5% larger than a cross-sectional area of the inlet
opening "a.sub.i" or even 2.0% larger than a cross-sectional area
of inlet opening "a.sub.i". Other configurations are possible.
[0036] 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.sub.i" and the outlet opening
"d.sub.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.
[0037] 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.
[0038] 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 1/4 of the length "L" of the conduit,
at least about 1/2 of the length of the conduit, at least about 3/4
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.
[0039] 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.degree. and
gradually decrease to at least 85.degree., 80.degree., 75.degree.,
70.degree., 60.degree. or less. Subsequently, the degree of the
elliptical shape may increase back up to 70.degree., 75.degree.,
80.degree., 85.degree. or even just below about 90.degree.. It is
contemplated that the degree of the non-circular elliptical portion
may change by as much as at least about 5.degree., 10.degree.,
15.degree., 30.degree. 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.
[0040] 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).
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] 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 1/4 of the length of the divider 30, at least about 1/2 of
the length of the divider, at least about 3/4 of the length of the
divider or otherwise. Further, these openings may extend over at
least about 1/4 of the width of the divider, at least about 1/2 of
the width of the divider, at least about 3/4 of the width of the
divider or otherwise.
[0047] 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.
[0048] 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.
[0049] In one exemplary embodiment, referring to FIG. 3, the
injector 36 is mounted at an angle ".alpha." 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.degree. to 45.degree., or even
between about 20.degree. to 40.degree. 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
* * * * *