U.S. patent application number 13/961989 was filed with the patent office on 2015-02-12 for mirrored two-stage mixer.
This patent application is currently assigned to Tenneco Automotive Operating Company Inc.. The applicant listed for this patent is Tenneco Automotive Operating Company Inc.. Invention is credited to Alan Brockman, Michael Golin.
Application Number | 20150040547 13/961989 |
Document ID | / |
Family ID | 52447401 |
Filed Date | 2015-02-12 |
United States Patent
Application |
20150040547 |
Kind Code |
A1 |
Brockman; Alan ; et
al. |
February 12, 2015 |
Mirrored Two-Stage Mixer
Abstract
A mixer for an exhaust aftertreatment system may include a
housing and first and second groups of deflectors. The first group
of deflectors may be disposed within the housing and may be
arranged relative to each other to direct fluid flowing through the
first group of deflectors into a first pair of vortices that rotate
in opposite directions relative to each other. The second group of
deflectors may be disposed within the housing and may be arranged
relative to each other to direct fluid flowing through the second
group of deflectors into a second pair of vortices that rotate in
opposite directions relative to each other. The first and second
groups of deflectors may be rotationally symmetric with each other
about a longitudinal axis of the housing.
Inventors: |
Brockman; Alan; (Ann Arbor,
MI) ; Golin; Michael; (Dexter, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tenneco Automotive Operating Company Inc. |
Lake Forest |
IL |
US |
|
|
Assignee: |
Tenneco Automotive Operating
Company Inc.
Lake Forest
IL
|
Family ID: |
52447401 |
Appl. No.: |
13/961989 |
Filed: |
August 8, 2013 |
Current U.S.
Class: |
60/324 |
Current CPC
Class: |
B01F 5/0617 20130101;
F01N 1/16 20130101; F01N 2240/20 20130101; F01N 2610/02 20130101;
F01N 3/2892 20130101; B01F 2005/0639 20130101 |
Class at
Publication: |
60/324 |
International
Class: |
F01N 1/16 20060101
F01N001/16 |
Claims
1. An exhaust aftertreatment system comprising: an exhaust
passageway receiving exhaust gas from an engine; an exhaust
aftertreatment device disposed within the exhaust passageway; and a
mixer disposed in the exhaust passageway upstream of the exhaust
aftertreatment device, the mixer including a housing, a first group
of deflectors disposed within the housing and arranged relative to
each other to direct fluid flowing through the first group of
deflectors into a first pair of vortices that rotate in opposite
directions relative to each other, and a second group of deflectors
disposed within the housing and arranged relative to each other to
direct fluid flowing through the second group of deflectors into a
second pair of vortices that rotate in opposite directions relative
to each other, wherein the first and second groups of deflectors
are rotationally symmetric with each other about a longitudinal
axis of the housing.
2. The exhaust aftertreatment system of claim 1, wherein the
exhaust aftertreatment device includes a catalyst.
3. The exhaust aftertreatment system of claim 1, further comprising
a reductant delivery system including a reductant injector arranged
to inject reductant into the exhaust passageway upstream of the
first and second groups of deflectors.
4. The exhaust aftertreatment system of claim 1, further comprising
a reductant delivery system including first and second reductant
injectors arranged to inject reductant into the exhaust passageway
upstream of the first and second groups of deflectors.
5. The exhaust aftertreatment system of claim 4, wherein the
housing includes first and second ports through which reductant is
injected into the housing from the first and second reductant
injectors, respectively, the first and second ports being arranged
relative to the first and second groups of deflectors such that a
majority of reductant injected through the first port flows through
the first group of deflectors and a majority of reductant injected
through the second port flows through the second group of
deflectors.
6. The exhaust aftertreatment system of claim 1, wherein the mixer
includes a third group of deflectors disposed within the housing
and arranged relative to each other to direct fluid flowing through
the third group of deflectors into a third pair of vortices that
rotate in opposite directions relative to each other.
7. The exhaust aftertreatment system of claim 6, wherein the first,
second and third groups of deflectors are rotationally symmetric
with each other about the longitudinal axis.
8. The exhaust aftertreatment system of claim 7, further comprising
a central mixer centered on the longitudinal axis, the central
mixer including a plurality of deflectors.
9. The exhaust aftertreatment system of claim 6, wherein the
housing includes first, second and third ports arranged relative to
the first, second and third groups of deflectors such that a
majority of reductant injected through the first port flows through
the first group of deflectors, a majority of reductant injected
through the second port flows through the second group of
deflectors, and a majority of reductant injected through the third
port flows through the third group of deflectors.
10. The exhaust aftertreatment system of claim 6, wherein the
aftertreatment device includes a triangular shape.
11. The exhaust aftertreatment system of claim 6, wherein the mixer
includes a fourth group of deflectors disposed within the housing
and arranged relative to each other to direct fluid flowing through
the fourth group of deflectors into a fourth pair of vortices that
rotate in opposite directions relative to each other.
12. The exhaust aftertreatment system of claim 11, wherein the
first, second, third and fourth groups of deflectors are
rotationally symmetric with each other about the longitudinal
axis.
13. The exhaust aftertreatment system of claim 12, further
comprising a central mixer centered on the longitudinal axis, the
central mixer including a plurality of deflectors.
14. The exhaust aftertreatment system of claim 11, wherein the
housing includes first, second third and fourth ports arranged
relative to the first, second, third and fourth groups of
deflectors such that a majority of reductant injected through the
first port flows through the first group of deflectors, a majority
of reductant injected through the second port flows through the
second group of deflectors, a majority of reductant injected
through the third port flows through the third group of deflectors,
and a majority of reductant injected through the fourth port flows
through the fourth group of deflectors.
15. The exhaust aftertreatment system of claim 11, wherein the
aftertreatment device includes a square shape.
16. The exhaust aftertreatment system of claim 1, wherein each of
the first and second groups of deflectors include a plurality of
plates extending parallel to the longitudinal axis of the housing
and each including a plurality of tabs that are angled relative the
plate and the longitudinal axis.
17. The exhaust aftertreatment system of claim 16, wherein the
plurality of tabs of each of the plurality of plates includes a
plurality of first tabs extending from a first side of the
corresponding plate in a first direction and a plurality of second
tabs extending from a second opposite side of the corresponding
plate in a second direction.
18. The exhaust aftertreatment system of claim 1, wherein the
housing is a generally tubular member.
19. A mixer for an exhaust aftertreatment system comprising: a
housing; a first group of deflectors disposed within the housing
and arranged relative to each other to direct fluid flowing through
the first group of deflectors into a first pair of vortices that
rotate in opposite directions relative to each other; and a second
group of deflectors disposed within the housing and arranged
relative to each other to direct fluid flowing through the second
group of deflectors into a second pair of vortices that rotate in
opposite directions relative to each other, wherein the first and
second groups of deflectors are rotationally symmetric with each
other about a longitudinal axis of the housing.
20. The mixer of claim 19, wherein the housing includes first and
second ports arranged relative to the first and second groups of
deflectors such that a majority of reductant injected through the
first port flows through the first group of deflectors and a
majority of reductant injected through the second port flows
through the second group of deflectors.
21. The mixer of claim 19, further comprising a third group of
deflectors disposed within the housing and arranged relative to
each other to direct fluid flowing through the third group of
deflectors into a third pair of vortices that rotate in opposite
directions relative to each other.
22. The mixer of claim 21, wherein the first, second and third
groups of deflectors are rotationally symmetric with each other
about the longitudinal axis.
23. The mixer of claim 21, wherein the housing includes first,
second and third ports arranged relative to the first, second and
third groups of deflectors such that a majority of reductant
injected through the first port flows through the first group of
deflectors, a majority of reductant injected through the second
port flows through the second group of deflectors, and a majority
of reductant injected through the third port flows through the
third group of deflectors.
24. The mixer of claim 21, further comprising a fourth group of
deflectors disposed within the housing and arranged relative to
each other to direct fluid flowing through the fourth group of
deflectors into a fourth pair of vortices that rotate in opposite
directions relative to each other.
25. The mixer of claim 24, wherein the first, second, third and
fourth groups of deflectors are rotationally symmetric with each
other about the longitudinal axis.
26. The mixer of claim 24, wherein the housing includes first,
second third and fourth ports arranged relative to the first,
second, third and fourth groups of deflectors such that a majority
of reductant injected through the first port flows through the
first group of deflectors, a majority of reductant injected through
the second port flows through the second group of deflectors, a
majority of reductant injected through the third port flows through
the third group of deflectors, and a majority of reductant injected
through the fourth port flows through the fourth group of
deflectors.
27. The mixer of claim 19, wherein each of the first and second
groups of deflectors include a plurality of plates extending
parallel to the longitudinal axis of the housing and each including
a plurality of tabs that are angled relative the plate and the
longitudinal axis.
28. The mixer of claim 27, wherein the plurality of tabs of each of
the plurality of plates includes a plurality of first tabs
extending from a first side of the corresponding plate in a first
direction and a plurality of second tabs extending from a second
opposite side of the corresponding plate in a second direction.
29. The mixer of claim 19, wherein the housing is a generally
tubular member.
30. A mixer for an exhaust aftertreatment system comprising: a
housing; a first group of deflectors disposed within the housing
and arranged to generate a first pair of counter-rotating vortices;
and a second group of deflectors disposed within the housing and
arranged to generate a second pair of counter-rotating vortices,
wherein the first and second groups of deflectors are arranged in a
circular array about a longitudinal axis of the housing.
31. The mixer of claim 30, further comprising a third group of
deflectors disposed within the housing and arranged to generate a
third pair of counter-rotating vortices.
32. The mixer of claim 31, wherein the circular array includes the
third group of deflectors.
33. The mixer of claim 31, further comprising a fourth group of
deflectors disposed within the housing and arranged to generate a
fourth pair of counter-rotating vortices.
34. The mixer of claim 33, wherein the circular array includes the
fourth group of deflectors.
35. The mixer of claim 34, further comprising a fifth group of
deflectors centered on the longitudinal axis and surrounded by the
first, second, third and fourth groups of deflectors.
36. The mixer of claim 35, wherein all of the first, second, third,
and fourth groups of deflectors are rotationally oriented
differently from each other.
37. The mixer of claim 30, wherein the first and second groups of
deflectors are surrounded by first and second collars,
respectively.
38. The mixer of claim 37, wherein the first and second collars
include first and second longitudinal axes, respectively, that are
angled relative to each other and relative to the longitudinal axis
of the housing.
Description
FIELD
[0001] The present disclosure relates to a mixer for an exhaust
aftertreatment system for a combustion engine.
BACKGROUND
[0002] This section provides background information related to the
present disclosure and is not necessarily prior art.
[0003] Selective catalytic reduction technology has been used in
conjunction with reducing nitrogen oxides present in the exhaust of
combustion engines. Many vehicles utilizing combustion engines are
equipped with exhaust aftertreatment devices for reducing nitrogen
oxide emissions. Some of these systems are constructed using
urea-based technology including a container for storing a reductant
(e.g., urea) and a delivery system for transmitting the reductant
from the container to the exhaust stream. A mixer is typically
provided downstream of a reductant injector for mixing the injected
reductant with the exhaust gas before the reductant reaches a
catalyst with which the reductant reacts. While these systems may
have performed well in the past, it may be desirable to provide an
improved mixer to more efficiently and effectively mix the
reductant with the exhaust stream and provide a more even
distribution of reductant over a larger area of the catalyst.
SUMMARY
[0004] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features.
[0005] In one form, the present disclosure provides an exhaust
aftertreatment system that may include an exhaust passageway, an
exhaust aftertreatment device, and a mixer. The exhaust passageway
may receive exhaust gas from an engine. The exhaust aftertreatment
device may be disposed within the exhaust passageway. The mixer may
be disposed in the exhaust passageway upstream of the exhaust
aftertreatment device. The mixer may include a housing and first
and second groups of deflectors. The first group of deflectors may
be disposed within the housing and may be arranged relative to each
other to direct fluid flowing through the first group of deflectors
into a first pair of vortices that rotate in opposite directions
relative to each other. The second group of deflectors may be
disposed within the housing and may be arranged relative to each
other to direct fluid flowing through the second group of
deflectors into a second pair of vortices that rotate in opposite
directions relative to each other. The first and second groups of
deflectors may be rotationally symmetric with each other about a
longitudinal axis of the housing.
[0006] In some embodiments, the exhaust aftertreatment device may
include a catalyst.
[0007] In some embodiments, the aftertreatment device may include a
circular shape. In some embodiments, the aftertreatment device may
include a triangular shape. In some embodiments, the aftertreatment
device may include a square shape.
[0008] In some embodiments, the exhaust aftertreatment system may
include a reductant delivery system having a reductant injector
arranged to inject reductant (e.g., urea or ammonia) into the
exhaust passageway upstream of the first and second groups of
deflectors.
[0009] In some embodiments, the exhaust aftertreatment system may
include a reductant delivery system including first and second
reductant injectors arranged to inject reductant into the exhaust
passageway upstream of the first and second groups of
deflectors.
[0010] In some embodiments, the housing may include first and
second ports through which reductant is injected into the housing
from the first and second reductant injectors, respectively. The
first and second ports may be arranged relative to the first and
second groups of deflectors such that a majority of reductant
injected through the first port flows through the first group of
deflectors and a majority of reductant injected through the second
port flows through the second group of deflectors.
[0011] In some embodiments, the mixer may include a third group of
deflectors disposed within the housing and arranged relative to
each other to direct fluid flowing through the third group of
deflectors into a third pair of vortices that rotate in opposite
directions relative to each other.
[0012] In some embodiments, the first, second and third groups of
deflectors may be rotationally symmetric with each other about the
longitudinal axis.
[0013] In some embodiments, the housing may include first, second
and third ports arranged relative to the first, second and third
groups of deflectors such that a majority of reductant injected
through the first port flows through the first group of deflectors,
a majority of reductant injected through the second port flows
through the second group of deflectors, and a majority of reductant
injected through the third port flows through the third group of
deflectors.
[0014] In some embodiments, the mixer may include a fourth group of
deflectors disposed within the housing and arranged relative to
each other to direct fluid flowing through the fourth group of
deflectors into a fourth pair of vortices that rotate in opposite
directions relative to each other.
[0015] In some embodiments, the first, second, third and fourth
groups of deflectors may be rotationally symmetric with each other
about the longitudinal axis.
[0016] In some embodiments, the housing may include first, second
third and fourth ports arranged relative to the first, second,
third and fourth groups of deflectors such that a majority of
reductant injected through the first port flows through the first
group of deflectors, a majority of reductant injected through the
second port flows through the second group of deflectors, a
majority of reductant injected through the third port flows through
the third group of deflectors, and a majority of reductant injected
through the fourth port flows through the fourth group of
deflectors.
[0017] In some embodiments, each of the first and second groups of
deflectors may include a plurality of plates extending parallel to
the longitudinal axis of the housing and each including a plurality
of tabs that are angled relative the plate and the longitudinal
axis.
[0018] In some embodiments, the plurality of tabs of each of the
plurality of plates may include a plurality of first tabs extending
from a first side of the corresponding plate in a first direction
and a plurality of second tabs extending from a second opposite
side of the corresponding plate in a second direction.
[0019] In some embodiments, the housing may be a generally tubular
member.
[0020] In some embodiments, the aftertreatment device may include a
circular shape. In some embodiments, the aftertreatment device may
include a triangular shape. In some embodiments, the aftertreatment
device may include a square shape.
[0021] In another form, the present disclosure provides a mixer for
an exhaust aftertreatment system that may include a housing and
first and second groups of deflectors. The first group of
deflectors may be disposed within the housing and may be arranged
to generate a first pair of counter-rotating vortices. The second
group of deflectors may be disposed within the housing and may be
arranged to generate a second pair of counter-rotating vortices.
The first and second groups of deflectors may be arranged in a
circular array about a longitudinal axis of the housing.
[0022] In some embodiments, the mixer may include a third group of
deflectors disposed within the housing and arranged to generate a
third pair of counter-rotating vortices.
[0023] In some embodiments, the circular array may include the
third group of deflectors.
[0024] In some embodiments, the mixer may include a fourth group of
deflectors disposed within the housing and arranged to generate a
fourth pair of counter-rotating vortices.
[0025] In some embodiments, the circular array may include the
fourth group of deflectors.
[0026] In some embodiments, the mixer may include a fifth group of
deflectors centered on the longitudinal axis and surrounded by the
first, second, third and fourth groups of deflectors.
[0027] In some embodiments, some or all of the first, second,
third, and fourth groups of deflectors are rotationally oriented
differently from each other.
[0028] In some embodiments, the first and second groups of
deflectors may be surrounded by first and second collars,
respectively.
[0029] In some embodiments, the first and second collars may
include first and second longitudinal axes, respectively, that are
angled relative to each other and relative to the longitudinal axis
of the housing. Such an orientation of the first and second groups
of deflectors may urge fluid flow into corners of a non-circular
SCR (selective catalytic reduction) catalyst or other
aftertreatment device.
[0030] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples
in this summary are intended for purposes of illustration only and
are not intended to limit the scope of the present disclosure.
DRAWINGS
[0031] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0032] FIG. 1 is a schematic representation of an engine and
exhaust system having an aftertreatment system according to the
principles of the present disclosure;
[0033] FIG. 2 is a perspective view of a mixer of the
aftertreatment system of FIG. 1 according to the principles of the
present disclosure;
[0034] FIG. 3 is another perspective view of the mixer of FIG.
2;
[0035] FIG. 4 is a cross-sectional view of the mixer;
[0036] FIG. 5 is a plan view of the mixer illustrating rotational
directions of vortices generated by the mixer as fluid flows
therethrough;
[0037] FIG. 6 is a perspective view of another mixer according to
the principles of the present disclosure;
[0038] FIG. 7 is another perspective view of the mixer of FIG.
6;
[0039] FIG. 8 is a cross-sectional view of the mixer of FIG. 6;
[0040] FIG. 9 is a plan view of the mixer of FIG. 6 illustrating
rotational directions of vortices generated by the mixer as fluid
flows therethrough;
[0041] FIG. 10 is a perspective view of another mixer according to
the principles of the present disclosure;
[0042] FIG. 11 is another perspective view of the mixer of FIG.
10;
[0043] FIG. 12 is a cross-sectional view of the mixer of FIG.
10;
[0044] FIG. 13 is a plan view of the mixer of FIG. 10 illustrating
rotational directions of vortices generated by the mixer as fluid
flows therethrough;
[0045] FIG. 14 is a perspective view of another mixer having a
plurality of groups of deflectors according to the principles of
the present disclosure;
[0046] FIG. 15 is a perspective view of one of the groups of
deflectors of the mixer of FIG. 14;
[0047] FIG. 16 is another perspective view of the group of
deflectors of FIG. 15; and
[0048] FIG. 17 is a plan view of the group of deflectors of FIG. 15
illustrating rotational directions of vortices generated by the
group of deflectors as fluid flows therethrough.
[0049] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0050] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0051] Example embodiments are provided so that this disclosure
will be thorough, and will fully convey the scope to those who are
skilled in the art. Numerous specific details are set forth such as
examples of specific components, devices, and methods, to provide a
thorough understanding of embodiments of the present disclosure. It
will be apparent to those skilled in the art that specific details
need not be employed, that example embodiments may be embodied in
many different forms and that neither should be construed to limit
the scope of the disclosure. In some example embodiments,
well-known processes, well-known device structures, and well-known
technologies are not described in detail.
[0052] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a," "an," and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. The
method steps, processes, and operations described herein are not to
be construed as necessarily requiring their performance in the
particular order discussed or illustrated, unless specifically
identified as an order of performance. It is also to be understood
that additional or alternative steps may be employed.
[0053] When an element or layer is referred to as being "on,"
"engaged to," "attached to," "connected to," or "coupled to"
another element or layer, it may be directly on, engaged, attached,
connected or coupled to the other element or layer, or intervening
elements or layers may be present. In contrast, when an element is
referred to as being "directly on," "directly engaged to,"
"directly attached to," "directly connected to," or "directly
coupled to" another element or layer, there may be no intervening
elements or layers present. Other words used to describe the
relationship between elements should be interpreted in a like
fashion (e.g., "between" versus "directly between," "adjacent"
versus "directly adjacent," etc.). As used herein, the term
"and/or" includes any and all combinations of one or more of the
associated listed items.
[0054] Although the terms first, second, third, etc. may be used
herein to describe various elements, components, groups of
components, regions, layers and/or sections, these elements,
components, groups of components, regions, layers and/or sections
should not be limited by these terms. These terms may be only used
to distinguish one element, component, group of components, region,
layer or section from another element, component, group of
components, region, layer or section. Terms such as "first,"
"second," and other numerical terms when used herein do not imply a
sequence or order unless clearly indicated by the context. Thus, a
first element, component, region, layer or section discussed below
could be termed a second element, component, region, layer or
section without departing from the teachings of the example
embodiments.
[0055] Spatially relative terms, such as "inner," "outer,"
"beneath," "below," "lower," "above," "upper," and the like, as
well as directional terms, such as upward, downward, clockwise,
counterclockwise, and the like, may be used herein for ease of
description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures.
Spatially relative terms may be intended to encompass different
orientations of the device in use or operation in addition to the
orientation depicted in the figures. For example, if the device in
the figures is turned over, elements described as "below" or
"beneath" other elements or features would then be oriented "above"
the other elements or features. Thus, the example term "below" can
encompass both an orientation of above and below. The device may be
otherwise oriented (rotated 90 degrees or at other orientations)
and the spatially relative descriptors used herein interpreted
accordingly.
[0056] With reference to FIG. 1, an exhaust aftertreatment system
10 is provided that may include an exhaust passageway 12, a
reductant delivery system 14, an aftertreatment device 16 and a
mixer 18. The exhaust passageway 12 may receive exhaust gas
discharged from a combustion engine 20. Exhaust gas discharged into
the exhaust passageway 12 may flow through the mixer 18 and the
aftertreatment device 16 before being discharged to the ambient
environment. The reductant delivery system 14 may pump reductant
(e.g., urea or ammonia) from a tank 22 to one or more reductant
injectors 24 that may spray the reductant into the exhaust stream
at or upstream of the mixer 18. The mixer 18 may mix the reductant
with the exhaust gas to provide a more uniform mixture of reductant
and exhaust gas before the mixture enters the aftertreatment device
16.
[0057] The aftertreatment device 16 can be an SCR (selective
catalytic reduction) catalyst, for example. A reaction between the
reductant and the aftertreatment device 16 may convert nitrogen
oxides in the exhaust gas to nitrogen (N.sub.2), water and/or
carbon dioxide, for example. The aftertreatment device 16 can have
any suitable shape, such as a circular shape (as shown in FIG. 5),
a triangular shape (as shown in FIG. 9), or a rectangular or square
shape (as shown in FIG. 13).
[0058] Referring now to FIGS. 2-5, the mixer 18 may include a
housing 26, a first group of deflectors 27, and a second group of
deflectors 28. The housing 26 may be a generally tubular member
having a longitudinal axis A and first and second injector ports
30, 32. The first and second injector ports 30, 32 may be disposed
between an upstream end 33 of the housing 26 and a downstream end
35 of the housing 26. Each of the injector ports 30, 32 may receive
a corresponding one of the reductant injectors 24 (as shown
schematically in FIG. 4). The reductant injectors 24 may inject
reductant into the mixer 18 upstream of the first and second groups
of deflectors 27, 28. While the injectors 24 are shown in the
figures as being positioned to spray reductant in a direction
perpendicular to the direction of the exhaust gas flow, in some
embodiments, the injectors 24 and injector ports 30, 32 could be
positioned at an angle relative to the direction of the exhaust gas
flow. It will be appreciated that the injectors 24 and injector
ports 30, 32 could be positioned in any location and at any
orientation.
[0059] The first group of deflectors 27 may include first and
second plates 34, 36 and a first half or portion 37 of a third
plate 38. The second group of deflectors 28 may include fourth and
fifth plates 39, 41 and a second half or portion 43 of the third
plate 38. The first, second, fourth and fifth plates 34, 36, 39, 41
may be generally parallel to each other and may be parallel to the
longitudinal axis A of the housing 26. The third plate 38 may be
generally parallel to the first, second, fourth and fifth plates
34, 36, 39, 41 and may extend along the longitudinal axis A.
Lateral ends of the first, second, third, fourth and fifth plates
34, 36, 38, 39, 41 may be fixedly attached to the housing 26 by any
suitable means, such as welding, fasteners and/or interference fit,
for example. For example, in some embodiments, the lateral ends of
the plates 34, 36, 38, 39, 41 may include legs (not shown) that
extend upward or downward therefrom and engage the inner diameter
of the housing 26. The legs may be welded, for example, or
otherwise joined to the inner diameter of the housing 26.
[0060] The first plate 34 may include an upstream end 40, a
downstream end 42, a plurality of cutouts 44 (shown best in FIG.
3), a plurality of first deflectors 46, a plurality of second
deflectors 48 and one or more third deflectors 50. The cutouts 44
and first deflectors 46 may be disposed between the upstream and
downstream ends 40, 42. The first deflectors 46 may be partially
cut or stamped out of the first plate 34 (thereby forming the
cutouts 44) and bent upward (relative to the frame of reference of
FIGS. 2-5) at an angle relative to the first plate 34. In this
manner, as fluid flows through the housing 26 from the upstream end
33 to the downstream end 35, the first deflectors 46 may deflect
fluid downward through the cutouts 44.
[0061] The second deflectors 48 may be disposed at or adjacent the
downstream end 42 of the first plate 34 and may extend from the
first plate 34 downward and toward the downstream end 35 of the
housing 26. The third deflector 50 may be disposed at or adjacent
the downstream end 42 of the first plate 34 and between the second
deflectors 48. The third deflector 50 may extend from the first
plate 34 upward and toward the downstream end 35 of the housing 26.
The third deflector 50 may include a slot 52 formed therein. As
fluid flows through the housing 26 from the upstream end 33 to the
downstream end 35, the second deflectors 48 may deflect fluid
downward and the third deflector 50 may deflect fluid upward.
[0062] The second plate 36 may be substantially similar to the
first plate 34 and may include an upstream end 54, a downstream end
56, a plurality of cutouts 58 (shown best in FIG. 3), a plurality
of first deflectors 60, a plurality of second deflectors 62 and one
or more third deflectors 64. The cutouts 58 and deflectors 60, 62,
64 may be similar or identical to the cutouts 44 and deflectors 46,
48, 50 of the first plate 34, and therefore, will not be described
again in detail.
[0063] The third plate 38 may include an upstream end 66 and a
downstream end 68. The first portion 37 of the third plate 38 may
include a plurality of cutouts 70, a plurality of first deflectors
72 and a second deflector 74. The cutouts 70 and first deflectors
72 may be disposed between the upstream and downstream ends 66, 68.
The first deflectors 72 may be partially cut or stamped out of the
third plate 38 (thereby forming the cutouts 70) and bent downward
(relative to the frame of reference of FIGS. 2-5) at an angle
relative to the third plate 38. In this manner, as fluid flows
through the housing 26 from the upstream end 33 to the downstream
end 35, the first deflectors 72 may deflect fluid upward through
the cutouts 70.
[0064] The second deflector 74 may be disposed at or adjacent the
downstream end 42 of the third plate 38 and may extend from the
third plate 38 upward and toward the downstream end 35 of the
housing 26. As fluid flows through the housing 26 from the upstream
end 33 to the downstream end 35, the second deflector 74 may
deflect fluid generally upward.
[0065] The second group of deflectors 28 may be similar or
identical to the first group of deflectors 27, except the second
group of deflectors 28 may be rotationally positioned
one-hundred-eighty degrees apart from the first group of deflectors
28. That is, the first and second groups of deflectors 27, 28 may
be rotationally symmetric with each other about the longitudinal
axis A. Because the second portion 43 of the third plate 38 is
substantially similar to the first portion 37 and the fourth and
fifth plates 39, 41 are substantially similar to the second and
first plates 36, 34, respectively, the second portion 43 and the
fourth and fifth plates 39, 41 will not be described again in
detail. Briefly, the second portion 43 may include cutouts 76,
upwardly extending deflectors 78 and a downwardly extending
deflector 80. The fourth plate 39 may include cutouts 82,
downwardly extending first deflectors 84, upwardly extending second
deflectors 86 and a downwardly extending third deflector 88. The
fifth plate 41 may include cutouts 90, downwardly extending first
deflectors 92, upwardly extending second deflectors 94 and a
downwardly extending third deflector 96.
[0066] With continued reference to FIGS. 1-5, operation of the
system 10 will be described in detail. During operation of the
engine 20, exhaust gas is discharged from the engine 20 into the
exhaust passageway 12 and flows through the mixer 18. As the
exhaust flows through the mixer 18, the reductant delivery system
14 may inject reductant into the exhaust stream upstream of the
first and second groups of deflectors 27, 28 (e.g., through the
injector ports 30, 32). By flowing through the first and second
groups of deflectors 27, 28, the reductant becomes mixed with the
exhaust gas so that the reductant is more evenly distributed in the
exhaust gas as the mixture flows into the aftertreatment device
16.
[0067] As shown in FIG. 5, the first and second groups of
deflectors 27, 28 cause the fluid flowing therethrough to form
first and second pairs of vortices. That is, the first group of
deflectors 27 may generate a first vortex V1 rotating in a
counterclockwise direction and a second vortex V2 rotating in a
clockwise direction. The second group of deflectors 28 may generate
a third vortex V3 rotating in a clockwise direction and a fourth
vortex V4 rotating in a counterclockwise direction. The first and
second vortices V1, V2 may be arranged side-by-side with each other
and disposed generally above the third plate 38. The arrangement of
the third and fourth vortices V3, V4 may be rotationally symmetric
to the arrangement of the first and second vortices V1, V2 about
the longitudinal axis A.
[0068] By producing the two pairs of counter-rotating vortices V1,
V2, V3, V4, the mixer 18 may improve the overall uniformity of the
fluid flow pattern at the upstream face of the aftertreatment
device 16 (i.e., flow rates across the upstream face of the
aftertreatment device 16 may be more uniform). Providing two pairs
of counter-rotating vortices (rather than just a single pair of
counter-rotating vortices) may reduce a distance downstream of the
mixer 18 over which the vortices V1, V2, V3, V4 may dissipate prior
to flowing through the aftertreatment device 16. The configuration
of the first and second groups of deflectors 27, 28 may be
particularly beneficial when used in conjunction with an
aftertreatment device 16 having a circular cross section (as shown
in FIG. 5), but may also be beneficial when used with an
aftertreatment device having any other shape.
[0069] As described above, the mixer 18 may include a pair of
injectors 24 that inject reductant through the injector ports 30,
32. In this manner, each of the injector ports 30, 32 may allow
reductant to be injected into the gas flow of a corresponding one
of the pairs of counter-rotating vortices V1, V2, V3, V4. In some
embodiments, a majority of the reductant injected though the first
injector port 30 may flow through the first group of deflectors 27,
and a majority of the reductant injected through the second
injector port 32 may flow through the second group of deflectors
28. Having multiple injectors 24 that each corresponds to a
particular group of deflectors 27, 28 may be particularly
beneficial for large-diameter mixers (such as mixers having a
twelve-inch diameter, for example), as an injector 24 for each
group of deflectors may provide a more even distribution of
reductant in the exhaust flow.
[0070] With reference to FIGS. 6-9, another mixer 118 is provided
that may be incorporated into the system 10 in place of the mixer
18. The mixer 118 may include a housing 126, a first group of
deflectors 127, a second group of deflectors 128, a third group of
deflectors 129 and a central mixer 130. The first, second and third
groups of deflectors 127, 128, 129 may be arranged in a circular
array about a longitudinal axis A of the housing 126 such that
adjacent groups of deflectors are spaced one-hundred-twenty degrees
apart from each other. That is, the first, second and third groups
of deflectors 127, 128, 129 may be evenly distributed about the
longitudinal axis A such that the first, second and third groups of
deflectors 127, 128, 129 form a rotationally symmetric pattern
about the longitudinal axis A.
[0071] The housing 126 may be a tubular member including first,
second and third injection ports 131, 132, 133. The first, second
and third injection ports 131, 132, 133 may be rotationally aligned
with the first, second and third groups of deflectors 127, 128,
129, respectively. As described above, reductant injectors 24 may
be received into corresponding injection ports 131, 132, 133. While
the injector ports 131, 132, 133 are shown in the figures as being
positioned for the injectors 24 to spray reductant in a direction
perpendicular to the direction of the exhaust gas flow, in some
embodiments, the injectors 24 and injector ports 131, 132, 133
could be positioned at an angle relative to the direction of the
exhaust gas flow. It will be appreciated that the injectors 24 and
injector ports 131, 132, 133 could be positioned in any location
and at any orientation.
[0072] The first, second and third groups of deflectors 127, 128,
129 may be substantially similar to each other and may each include
first and second generally parallel plates 134, 136. The first
plate 134 may include an upstream end 138, a downstream end 140, a
plurality of cutouts 142, a plurality of first deflectors 144, a
plurality of second deflectors 146 and a third deflector 148. The
cutouts 142 and first deflectors 144 may be disposed between the
upstream and downstream ends 138, 140. The first deflectors 144 may
be partially cut or stamped out of the first plate 134 (thereby
forming the cutouts 142) and bent outward so that the first
deflectors 144 extend at an angle from the first plate 134 toward
the inner diametrical surface of the housing 126 (i.e., away from
the longitudinal axis) and toward the upstream end 138. In this
manner, as fluid flows through the housing 126 from the upstream
end 138 to the downstream end 140, the first deflectors 144 may
deflect fluid through the cutouts 142 toward the second plate
136.
[0073] The second deflectors 146 may be disposed at or adjacent the
downstream end 140 of the first plate 134 and may extend from the
first plate 134 toward the longitudinal axis A and toward the
downstream end of the housing 126. The third deflector 148 may be
disposed at or adjacent the downstream end 140 of the first plate
134 and between the second deflectors 146. The third deflector 148
may extend from the first plate 134 toward the inner diametrical
surface of the housing 126 (i.e., away from the longitudinal axis
A) and toward the downstream end of the housing 126. The third
deflector 148 may include a slot 150 formed therein. As fluid flows
through the housing 126, the second deflectors 146 may deflect
fluid toward the longitudinal axis A and the third deflector 148
may deflect fluid away from the longitudinal axis A.
[0074] The second plate 136 may include an upstream end 152, a
downstream end 154, a plurality of cutouts 156, a plurality of
first deflectors 158, and a second deflector 160. The cutouts 156
and first deflectors 158 may be disposed between the upstream and
downstream ends 152, 154. The first deflectors 158 may be partially
cut or stamped out of the second plate 136 (thereby forming the
cutouts 156) and bent outward so that the first deflectors 158
extend at an angle from the second plate 136 toward the inner
diametrical surface of the housing 126 (i.e., away from the
longitudinal axis) and toward the upstream end 152. In this manner,
as fluid flows through the housing 126 from the upstream end 152 to
the downstream end 154, the first deflectors 158 may deflect fluid
through the cutouts 156 toward the central mixer 130. The second
deflector 160 may be disposed at or adjacent the downstream end 154
of the second plate 136 and may extend from the second plate 136
away from the longitudinal axis A and toward the downstream end of
the housing 126. The second deflector 160 may be disposed between
the second deflectors 146 of the first plate 134. The second
deflector 160 may include a slot 162 formed therein. As fluid flows
through the housing 126, the second deflector 160 may deflect fluid
away from the longitudinal axis A.
[0075] The central mixer 130 may include a collar 164 and a
plurality of central deflectors 166. The collar 164 may be centered
on the longitudinal axis A and may engage the second plates 136 of
the first, second and third groups of deflectors 127, 128, 129. The
central deflectors 166 may be disposed within the collar 164 and
may include curved plates arrayed about the longitudinal axis A.
The central deflectors 166 may impart a swirling motion to fluid
that flows through the collar 164. In some embodiments, the central
deflectors 166 may be generally S-shaped.
[0076] With continued reference to FIGS. 6-9, operation of the
mixer 118 will be described in detail. As described above, the
reductant delivery system 14 may inject reductant into the exhaust
stream upstream of the first, second and third groups of deflectors
127, 128, 129 (e.g., through the injector ports 131, 132, 133). By
flowing through the first, second and third groups of deflectors
127, 128, 129, the reductant becomes mixed with the exhaust gas so
that the reductant is more evenly distributed in the exhaust gas as
the mixture flows into the aftertreatment device 16.
[0077] As shown in FIG. 9, the first, second and third groups of
deflectors 127, 128, 129 cause the fluid flowing therethrough to
form first, second and third pairs of vortices. That is, the first
group of deflectors 127 may generate a first vortex V1 rotating in
a counterclockwise direction and a second vortex V2 rotating in a
clockwise direction. The second group of deflectors 128 may
generate a third vortex V3 rotating in a clockwise direction and a
fourth vortex V4 rotating in a counterclockwise direction.
Similarly, the third group of deflectors 129 may generate a fifth
vortex V5 rotating in a clockwise direction and a sixth vortex V6
rotating in a counterclockwise direction. The first and second
vortices V1, V2 may be arranged side-by-side with each other. The
arrangement of the third and fourth vortices V3, V4 may be
rotationally symmetric to the arrangement of the first and second
vortices V1, V2 about the longitudinal axis A. Similarly, the
arrangement of the fifth and sixth vortices V5, V6 may be
rotationally symmetric to the arrangement of the first and second
vortices V1, V2 about the longitudinal axis A.
[0078] By producing the three pairs of counter-rotating vortices
V1, V2, V3, V4, V5, V6, the mixer 118 may improve the overall
uniformity of the fluid flow pattern at the upstream face of the
aftertreatment device 16 (i.e., flow rates across the upstream face
of the aftertreatment device 16 may be more uniform). Providing
three pairs of counter-rotating vortices (rather than just a single
pair of counter-rotating vortices) may reduce a distance downstream
of the mixer 118 over which the vortices V1, V2, V3, V4, V5, V6 may
dissipate prior to flowing through the aftertreatment device 16.
The configuration of the first, second and third groups of
deflectors 127, 128, 129 may be particularly beneficial when used
in conjunction with an aftertreatment device 16 having a triangular
cross section (as shown in FIG. 9), but may also be beneficial when
used with an aftertreatment device having any other shape. For
example, when used with an aftertreatment device 16 having a
non-circular shape, such as a triangular shape, for example, the
pairs of counter-rotating vortices V1, V2, V3, V4, V5, V6 may force
the mixture of exhaust gas and reductant into the corners of the
aftertreatment device 16.
[0079] As described above, the mixer 118 may include multiple
injectors 24 that inject reductant through the injection ports 131,
132, 133. In this manner, each of the injection ports 131, 132, 133
may allow reductant to be injected into the gas flow of a
corresponding one of the pairs of counter-rotating vortices V1, V2,
V3, V4, V5, V6. In some embodiments, a majority of the reductant
injected though the first injector port 131 may flow through the
first group of deflectors 127, a majority of the reductant injected
through the second injector port 132 may flow through the second
group of deflectors 128, and a majority of the reductant injected
through the third injector port 133 may flow through the third
group of deflectors 129. Having multiple injectors 24 that each
corresponds to a particular group of deflectors 127, 128, 129 may
be particularly beneficial for large-diameter mixers (such as
mixers having a twelve-inch diameter, for example), as an injector
24 for each group of deflectors may provide a more even
distribution of reductant in the exhaust flow.
[0080] With reference to FIGS. 10-13, another mixer 218 is provided
that may be incorporated into the system 10 in place of the mixer
18. The mixer 218 may include a housing 226, a first group of
deflectors 227, a second group of deflectors 228, a third group of
deflectors 229, a fourth group of deflectors 230 and a central
mixer 231. The first, second, third and fourth groups of deflectors
227, 228, 229, 230 may be arranged in a circular array about a
longitudinal axis A of the housing 226 such that adjacent groups of
deflectors are spaced ninety degrees apart from each other. That
is, the first, second, third and fourth groups of deflectors 227,
228, 229, 230 may be evenly distributed about the longitudinal axis
A such that the first, second, third and fourth groups of
deflectors 227, 228, 229, 230 form a rotationally symmetric pattern
about the longitudinal axis A.
[0081] The housing 226 may be a tubular member including four
injection ports 232. Each of the injection ports 232 may be
rotationally aligned with a corresponding one of the first, second,
third and fourth groups of deflectors 227, 228, 229, 230. As
described above, corresponding reductant injectors 24 may be
received into the injection ports 232. While the injector ports 232
are shown in the figures as being positioned for the injectors 24
to spray reductant in a direction perpendicular to the direction of
the exhaust gas flow, in some embodiments, the injectors 24 and
injector ports 232 could be positioned at an angle relative to the
direction of the exhaust gas flow. It will be appreciated that the
injectors 24 and injector ports 232 could be positioned in any
location and at any orientation.
[0082] The first, second, third and fourth groups of deflectors
227, 228, 229, 230 may be substantially similar to each other and
may each include first and second generally parallel plates 234,
236. The first plate 234 may include an upstream end 238, a
downstream end 240, a plurality of cutouts 242, a plurality of
first deflectors 244, a plurality of second deflectors 246 and a
third deflector 248. The cutouts 242 and first deflectors 244 may
be disposed between the upstream and downstream ends 238, 240. The
first deflectors 244 may be partially cut or stamped out of the
first plate 234 (thereby forming the cutouts 242) and bent outward
so that the first deflectors 244 extend at an angle from the first
plate 234 toward the inner diametrical surface of the housing 226
(i.e., away from the longitudinal axis) and toward the upstream end
238. In this manner, as fluid flows through the housing 226 from
the upstream end 238 to the downstream end 240, the first
deflectors 244 may deflect fluid through the cutouts 242 toward the
second plate 236.
[0083] The second deflectors 246 may be disposed at or adjacent the
downstream end 240 of the first plate 234 and may extend from the
first plate 234 toward the longitudinal axis A and toward the
downstream end of the housing 226. The third deflector 248 may be
disposed at or adjacent the downstream end 240 of the first plate
234 and between the second deflectors 246. The third deflector 248
may extend from the first plate 234 toward the inner diametrical
surface of the housing 226 (i.e., away from the longitudinal axis
A) and toward the downstream end of the housing 226. The third
deflector 248 may include a slot 250 formed therein. As fluid flows
through the housing 226, the second deflectors 246 may deflect
fluid toward the longitudinal axis A and the third deflector 248
may deflect fluid away from the longitudinal axis A.
[0084] The second plate 236 may include an upstream end 252, a
downstream end 254, a plurality of cutouts 256, a plurality of
first deflectors 258, and a second deflector 260. The cutouts 256
and first deflectors 258 may be disposed between the upstream and
downstream ends 252, 254. The first deflectors 258 may be partially
cut or stamped out of the second plate 236 (thereby forming the
cutouts 256) and bent outward so that the first deflectors 258
extend at an angle from the second plate 236 toward the inner
diametrical surface of the housing 226 (i.e., away from the
longitudinal axis) and toward the upstream end 252. In this manner,
as fluid flows through the housing 226 from the upstream end 252 to
the downstream end 254, the first deflectors 258 may deflect fluid
through the cutouts 256 toward the central mixer 231. The second
deflector 260 may be disposed at or adjacent the downstream end 254
of the second plate 236 and may extend from the second plate 236
away from the longitudinal axis A and toward the downstream end of
the housing 226. The second deflector 260 may be disposed between
the second deflectors 246 of the first plate 234. The second
deflector 260 may include a slot 262 formed therein. As fluid flows
through the housing 226, the second deflector 260 may deflect fluid
away from the longitudinal axis A.
[0085] The central mixer 231 may include a plurality of central
deflectors 266 that engage the second plates 236 of the first,
second, third and fourth groups of deflectors 227, 228, 229, 230.
The central deflectors 266 may include curved plates arrayed about
the longitudinal axis A. The central deflectors 266 may impart a
swirling motion to fluid that flows through the space bounded by
the second plates 236 of the first, second, third and fourth groups
of deflectors 227, 228, 229, 230. In some embodiments, the central
deflectors 266 may be generally S-shaped.
[0086] With continued reference to FIGS. 10-13, operation of the
mixer 218 will be described in detail. As described above, the
reductant delivery system 14 may inject reductant into the exhaust
stream upstream of the first, second, third and fourth groups of
deflectors 227, 228, 229, 230 (e.g., through the injector ports
232). By flowing through the first, second, third and fourth groups
of deflectors 227, 228, 229, 230, the reductant becomes mixed with
the exhaust gas so that the reductant is more evenly distributed in
the exhaust gas as the mixture flows into the aftertreatment device
16.
[0087] As shown in FIG. 13, the first, second, third and fourth
groups of deflectors 227, 228, 229, 230 cause the fluid flowing
therethrough to form first, second, third and fourth pairs of
vortices. That is, the first group of deflectors 227 may generate a
first vortex V1 rotating in a counterclockwise direction and a
second vortex V2 rotating in a clockwise direction. The second
group of deflectors 228 may generate a third vortex V3 rotating in
a clockwise direction and a fourth vortex V4 rotating in a
counterclockwise direction. Similarly, the third group of
deflectors 229 may generate a fifth vortex V5 rotating in a
clockwise direction and a sixth vortex V6 rotating in a
counterclockwise direction. The fourth group of deflectors 230 may
generate a seven vortex V7 rotating in a clockwise direction and a
eighth vortex V8 rotating in a counterclockwise direction. The
first and second vortices V1, V2 may be arranged side-by-side with
each other. The arrangement of the third and fourth vortices V3, V4
may be rotationally symmetric to the arrangement of the first and
second vortices V1, V2 about the longitudinal axis A. Similarly,
the arrangement of the fifth and sixth vortices V5, V6 may be
rotationally symmetric to the arrangement of the first and second
vortices V1, V2 about the longitudinal axis A. The arrangement of
the seventh and eight vortices V7, V8 may be rotationally symmetric
to the arrangement of the first and second vortices V1, V2 about
the longitudinal axis A.
[0088] By producing the four pairs of counter-rotating vortices V1,
V2, V3, V4, V5, V6, V7, V8, the mixer 218 may improve the overall
uniformity of the fluid flow pattern at the upstream face of the
aftertreatment device 16 (i.e., flow rates across the upstream face
of the aftertreatment device 16 may be more uniform). Providing
four pairs of counter-rotating vortices (rather than just a single
pair of counter-rotating vortices) may reduce a distance downstream
of the mixer 218 over which the vortices V1, V2, V3, V4, V5, V6,
V7, V8 may dissipate prior to flowing through the aftertreatment
device 16. The configuration of the first, second, third and fourth
groups of deflectors 227, 228, 229, 230 may be particularly
beneficial when used in conjunction with an aftertreatment device
16 having a square or rectangular cross section (as shown in FIG.
13), but may also be beneficial when used with an aftertreatment
device having any other shape. For example, when used with an
aftertreatment device 16 having a non-circular shape, such as a
square or rectangular shape, for example, the pairs of
counter-rotating vortices V1, V2, V3, V4, V5, V6, V7, V8 may force
the mixture of exhaust gas and reductant into the corners of the
aftertreatment device 16.
[0089] As described above, the mixer 218 may include multiple
injectors 24 that inject reductant through multiple injection ports
232. In this manner, each of the injection ports 232 may allow
reductant to be injected into the gas flow of a corresponding one
of the pairs of counter-rotating vortices V1, V2, V3, V4, V5, V6,
V7, V8. Having multiple injectors 24 that each corresponds to a
particular group of deflectors 227, 228, 229, 230 may be
particularly beneficial for large-diameter mixers (such as mixers
having a twelve-inch diameter, for example), as an injector 24 for
each group of deflectors may provide a more even distribution of
reductant in the exhaust flow.
[0090] With reference to FIGS. 14-17, another mixer 318 is provided
that may be incorporated into the system 10 in place of the mixer
18. The mixer 318 may include a housing 326 and a plurality of
groups of deflectors 328. In the particular embodiment illustrated
in FIGS. 14-17, six groups of deflectors 328 are arranged in a
circular array about a longitudinal axis Al of the housing 326 such
that adjacent groups of deflectors are spaced sixty degrees apart
from each other. That is, the six groups of deflectors 328 are
evenly distributed about the longitudinal axis Al such that the six
groups of deflectors 328 form a rotationally symmetric pattern
about the longitudinal axis Al. A seventh group of deflectors 328
may be centered on the longitudinal axis Al and may be surrounded
by the other six groups of deflectors 328. The housing 326 may
include one or more injection ports (not shown) that may each
receive a corresponding one or more reductant injectors 24. In some
embodiments, the housing 326 may include six injector ports and
injectors 24 that each correspond to one of the six groups of
deflectors 328 arranged in the circular pattern. Such an
arrangement may provide a more even distribution of reductant in
the exhaust flow, as described above.
[0091] Each of the groups of deflectors 328 may be similar or
identical to each other and may include a collar 330 surrounding a
first plate 332, a second plate 334 and a plurality of central
plates 336 disposed between the first and second plates 332, 334.
The first, second and central plates 332, 334, 336 of within a
particular group of deflectors 328 may be generally parallel to
each other and may be retained in slots 337 in the corresponding
collar 330. Each of the groups of deflectors 328 may be oriented
such that longitudinal axes A2 of the collars 330 are substantially
parallel to the longitudinal axis Al of the housing 326 (or in the
case of the seventh group of deflectors 328 centered on the
longitudinal axis Al, the longitudinal axis A2 of the collar 330
may be collinear with the longitudinal axis A1). In some
embodiments, however, the longitudinal axes A2 of the collars 330
may be angled relative to the longitudinal axis A1 and/or each
other.
[0092] The first plate 332 may include an upstream end 338, a
downstream end 340, a plurality of cutouts 342, and a plurality of
deflectors 344. The cutouts 342 and deflectors 344 may be disposed
between the upstream and downstream ends 338, 340. The deflectors
344 may be partially cut or stamped out of the first plate 332
(thereby forming the cutouts 342) and bent outward so that the
deflectors 344 extend at an angle from the first plate 332 toward
the inner diametrical surface of the collar 330 (i.e., away from
the longitudinal axis A2) and toward the upstream end 338. In this
manner, as fluid flows through the collar 330 from the upstream end
338 to the downstream end 340, the deflectors 344 may deflect fluid
through the cutouts 342 toward the central plates 336.
[0093] The second plate 334 may include an upstream end 352 (FIG.
16), a downstream end 354 (FIG. 17), a plurality of cutouts 356
(FIG. 16), a plurality of first deflectors 358 (FIG. 16), and a
second deflector 360 (FIGS. 15 and 17). The cutouts 356 and first
deflectors 358 may be disposed between the upstream and downstream
ends 352, 354. The first deflectors 358 may be partially cut or
stamped out of the second plate 334 (thereby forming the cutouts
356) and bent inward so that the first deflectors 358 extend at an
angle from the second plate 334 toward the longitudinal axis A2 of
the collar 330 and toward the downstream end 254. In this manner,
as fluid flows through the collar 330 from the upstream end 252 to
the downstream end 254, the first deflectors 258 may deflect fluid
toward the central plates 336. The second deflector 360 may be
disposed at or adjacent the downstream end 354 of the second plate
334 and may extend from the second plate 334 toward the
longitudinal axis A2. The second deflector 360 may include a slot
362 formed therein. As fluid flows through the collar 330, the
second deflector 360 may deflect fluid toward the longitudinal axis
A2.
[0094] The central plates 336 may each include an upstream end 364,
a downstream end 366, a plurality of cutouts 368, a plurality of
first deflectors 370, a plurality of second deflectors 372 and a
third deflector 374. The cutouts 368 and first deflectors 370 may
be disposed between the upstream and downstream ends 364, 366. The
first deflectors 370 may be partially cut or stamped out of the
central plate 336 (thereby forming the cutouts 368) and bent so
that the first deflectors 370 extend at an angle from the central
plate 336 toward the first plate 332 and toward the upstream end
364. In this manner, as fluid flows through the collar 330 from the
upstream end 364 to the downstream end 366, the first deflectors
370 may deflect fluid through the corresponding cutouts 368.
[0095] The second deflectors 372 may be disposed at or adjacent the
downstream end 366 of the central plate 336 and may extend from the
central plate 336 toward the second plate 334. The third deflector
374 may be disposed at or adjacent the downstream end 366 of the
central plate 336 and between the second deflectors 372. The third
deflector 374 may extend from the central plate 336 toward the
first plate 332. The third deflector 374 may include a slot 376
formed therein. As fluid flows through the collar 330, the second
deflectors 372 may deflect fluid toward the second plate 334 and
the third deflector 374 may deflect fluid toward the first plate
332.
[0096] With continued reference to FIGS. 14-17, operation of the
mixer 318 will be described in detail. As described above, the
reductant delivery system 14 may inject reductant into the exhaust
stream upstream of the groups of deflectors 328. By flowing through
the groups of deflectors 328, the reductant becomes mixed with the
exhaust gas so that the reductant is more evenly distributed in the
exhaust gas as the mixture flows into the aftertreatment device
16.
[0097] As shown in FIG. 17, each of the groups of deflectors 328
cause the fluid flowing therethrough to form a pair of vortices V1,
V2 that rotate in opposite directions. By producing the seven pairs
of counter-rotating vortices V1, V2 (i.e., one pair in each of the
seven groups of deflectors 328), the mixer 318 may improve the
overall uniformity of the fluid flow pattern at the upstream face
of the aftertreatment device 16 (i.e., flow rates across the
upstream face of the aftertreatment device 16 may be more uniform).
Providing seven pairs of counter-rotating vortices (rather than
just a single pair of counter-rotating vortices) may reduce a
distance downstream of the mixer 318 over which the vortices V1, V2
may dissipate prior to flowing through the aftertreatment device
16. The configuration of the groups of deflectors 328 may be used
in conjunction with an aftertreatment device 16 having a circular,
triangular, square or rectangular cross section, for example, or
any other shape cross section.
[0098] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
* * * * *