U.S. patent application number 14/628836 was filed with the patent office on 2016-08-25 for reductant injector mount.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to David A. Akers, James J. Driscoll, Jayaraman Venkataraghavan.
Application Number | 20160245142 14/628836 |
Document ID | / |
Family ID | 56448560 |
Filed Date | 2016-08-25 |
United States Patent
Application |
20160245142 |
Kind Code |
A1 |
Venkataraghavan; Jayaraman ;
et al. |
August 25, 2016 |
REDUCTANT INJECTOR MOUNT
Abstract
A reductant injector mount is provided. The reductant injector
mount includes a mounting region configured to connect to an
exhaust conduit. The reductant injector also includes a contoured
region formed in the mounting region. The contoured region is
configured to increase a velocity of an exhaust gas flow through
the contoured region. The contoured region is also configured to
reduce a recirculation of the exhaust gas flow through the
contoured region. Further, the reductant injector mount includes a
cut out portion provided on the contoured region. The cut out
portion is configured to receive a reductant injector tip
therethrough.
Inventors: |
Venkataraghavan; Jayaraman;
(Dunlap, IL) ; Driscoll; James J.; (Dunlap,
IL) ; Akers; David A.; (Morton, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
56448560 |
Appl. No.: |
14/628836 |
Filed: |
February 23, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02T 10/24 20130101;
F01N 2590/08 20130101; F01N 2610/02 20130101; F01N 2610/1453
20130101; F01N 2340/00 20130101; Y02T 10/12 20130101; F01N 3/2066
20130101; F01N 3/2892 20130101 |
International
Class: |
F01N 3/28 20060101
F01N003/28; F01N 3/20 20060101 F01N003/20 |
Claims
1. A reductant injector mount comprising: a mounting region
configured to connect to an exhaust conduit; a contoured region
formed in the mounting region, the contoured region configured to:
increase a velocity of an exhaust gas flow through the contoured
region; and reduce a recirculation of the exhaust gas flow through
the contoured region; and a cut out portion provided on the
contoured region, the cut out portion configured to receive a
reductant injector tip therethrough.
2. The reductant injector mount of claim 1, wherein the contoured
region includes a first lobe and a second lobe provided on either
side of the cut out portion, wherein the first lobe is positioned
at a location upstream of the cut out portion and the second lobe
is positioned downstream of the cut out portion, with respect to an
exhaust gas flow direction.
3. The reductant injector mount of claim 2, wherein the cut out
portion is positioned in a throat portion of the contoured region,
the throat portion connecting the first and second lobes of the
contoured region.
4. The reductant injector mount of claim 2, wherein a ratio of a
width of the first lobe with respect to a diameter of the cut out
portion is from 0.75 to 5, wherein the width of the first lobe is
measured along an axis of the reductant injector mount
perpendicular to the exhaust gas flow direction.
5. The reductant injector mount of claim 2, wherein a ratio of a
width of the second lobe with respect to a diameter of the cut out
portion is from 0.75 to 5, wherein the width of the first lobe is
measured along an axis of the reductant injector mount
perpendicular to the exhaust gas flow direction.
6. The reductant injector mount of claim 2, wherein a ratio of a
thickness of the reductant injector mount at a downstream end of
the first lobe with respect to a thickness of the reductant
injector mount at a downstream end of the second lobe is from 0.4
to 0.9, with respect to the exhaust gas flow direction.
7. The reductant injector mount of claim 2, wherein an angle of
incidence of the contoured region at the first lobe is from
3.degree. to 45.degree., wherein the angle of incidence is defined
by the angle formed by the upstream end of the first lobe with
respect to the mounting region of the reductant injector mount.
8. The reductant injector mount of claim 1 further comprising
receiving elements projecting from the mounting region, the
receiving elements configured to connect to a reductant
injector.
9. The reductant injector mount of claim 1, wherein the contoured
region has an oblong shape.
10. The reductant injector mount of claim 1, wherein a
circumference of the cut out portion tapers along a thickness of
the reductant injector mount.
11. The reductant injector mount of claim 1, wherein an orientation
of the contoured region provided on the mounting region is aligned
with respect to an exhaust gas flow direction.
12. The reductant injector mount of claim 1, wherein the cut out
portion is positioned closer to a downstream end of the contoured
region with respect to the exhaust gas flow direction as compared
to an upstream end of the contoured region.
13. An aftertreatment system comprising: an exhaust conduit having
a cut out region provided thereon; a selective catalytic reduction
module coupled to the exhaust conduit; a reductant injector mount
received into the cut out region provided on the exhaust conduit,
the reductant injector mount positioned upstream of the selective
catalytic reduction module with respect to an exhaust gas flow, the
reductant injector mount comprising: a mounting region connected to
the exhaust conduit; a contoured region formed in the mounting
region, the contoured region facing an inner side of the exhaust
conduit, the contoured region being configured to: increase a
velocity of the exhaust gas flow through the contoured region; and
reduce a recirculation of the exhaust gas flow through the
contoured region; and a cut out portion provided on the contoured
region; and a reductant injector in fluid communication with the
exhaust conduit, wherein the reductant injector mount is received
through the cut out portion provided on the reductant injector
mount.
14. The aftertreatment system of claim 13, wherein the reductant
injector mount is attached to a top portion of the exhaust
conduit.
15. The aftertreatment system of claim 13, wherein the reductant
injector mount is disposed in a direction parallel to a direction
of the exhaust gas flow.
16. The aftertreatment system of claim 13, wherein the reductant
injector mount is disposed in a direction angular to a direction of
the exhaust gas flow.
17. The aftertreatment system of claim 13, wherein the reductant
injector mount further comprises receiving elements projecting into
an interior space of the exhaust conduit from the mounting region,
the receiving elements configured to receive mechanical fasteners
associated with the reductant injector.
18. A method of controlling exhaust gas flow in an exhaust conduit,
the method comprising: receiving a reductant injector through a
mounting region of a reductant injector mount; flowing an exhaust
gas flow on a contoured region of the reductant injector mount;
increasing a velocity of the exhaust gas flow through the contoured
region based on the flow; and reducing a recirculation of the
exhaust gas flow through the contoured region based on the
flow.
19. The method of claim 18, wherein the flowing step further
comprises receiving the exhaust gas flow at an angle of incidence
defined at an upstream end of the contoured region of the reductant
injector mount with respect to a direction of flow of the exhaust
gas, wherein the angle of incidence is defined by the angle formed
by contoured region with respect to the mounting region of the
reductant injector mount.
20. The method of claim 18 further comprising discharging the
exhaust gas flow towards a selective catalytic reduction module.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to an injector mount, and
more particularly to a reductant injector mount associated with an
aftertreatment system of an engine.
BACKGROUND
[0002] An aftertreatment system is associated with an engine
system. The aftertreatment system is configured to treat and reduce
oxides of nitrogen (NOx) present in an exhaust gas flow, prior to
the exhaust gas flow exiting into the atmosphere. In order to
reduce NOx, the aftertreatment system may include a reductant
delivery module, a reductant injector, and a Selective Catalytic
Reduction (SCR) module.
[0003] The reductant injector is configured to inject a reductant
into the exhaust gas flowing through a mixing tube of the
aftertreatment system. The reductant may include urea. In order to
achieve improved levels of NOx conversion, better flow distribution
and mixing of the reductant with the exhaust gases must be
achieved. A mixing system is affixed inside the mixing tube so that
increased turbulence and improved distribution of the reductant
within the exhaust gases may be achieved within a length of the
mixing tube.
[0004] A reductant injector mount is used to couple the reductant
injector to the mixing tube. However, urea deposit formation may
take place in an area near to an injection point of the reductant
injector. Such urea deposition may hinder or prevent reductant
spray and/or interaction with the exhaust gas flow, and may also
cause a reduction in NOx conversion in the aftertreatment
system.
[0005] U.S. Pat. No. 8,079,211 describes systems and methods
provided for injecting liquid reductant into an engine exhaust. In
one example, the system includes a gas deflector positioned
upstream of an injector where the gas deflector is configured to
create a high pressure zone upstream of the deflector and a low
pressure zone downstream of the deflector surrounding the injector
outlet. A bypass flow passage diverts exhaust flow from the high
pressure zone upstream of the deflector to allow the bypassed
portion of exhaust to flow into the exhaust gas stream to form a
gas shield for a liquid reductant spray from the injector.
SUMMARY OF THE DISCLOSURE
[0006] In one aspect of the present disclosure, a reductant
injector mount is provided. The reductant injector mount includes a
mounting region configured to connect to an exhaust conduit. The
reductant injector also includes a contoured region formed in the
mounting region. The contoured region is configured to increase a
velocity of an exhaust gas flow through the contoured region. The
contoured region is also configured to reduce a recirculation of
the exhaust gas flow through the contoured region. Further, the
reductant injector mount includes a cut out portion provided on the
contoured region. The cut out portion is configured to receive a
reductant injector tip therethrough.
[0007] In another aspect of the present disclosure, an
aftertreatment system is provided. The aftertreatment system
includes an exhaust conduit having a cut out region. The
aftertreatment system also includes a selective catalytic reduction
module coupled to the exhaust conduit. The aftertreatment system
further includes a reductant injector mount disposed on the exhaust
conduit. The reductant injector mount is positioned upstream of the
selective catalytic reduction module with respect to an exhaust gas
flow. The reductant injector mount includes a mounting region
connected to the exhaust conduit. The reductant injector mount also
includes a contoured region formed in the mounting region. The
contoured region faces an inner side of the exhaust conduit. The
contoured region is configured to increase a velocity of the
exhaust gas flow through the contoured region. The contoured region
is also configured to reduce a recirculation of the exhaust gas
flow through the contoured region. Further, the reductant injector
mount includes a cut out portion provided on the contoured region.
The aftertreatment system includes a reductant injector in fluid
communication with the exhaust conduit, wherein the reductant
injector mount is received through the cut out portion provided on
the reductant injector mount.
[0008] In yet another aspect of the present disclosure, a method of
controlling an exhaust gas flow in an exhaust conduit is provided.
The method includes receiving a reductant injector through a
mounting region of a reductant injector mount. The method also
includes flowing an exhaust gas flow on a contoured region of the
reductant injector mount. The method further includes increasing a
velocity of the exhaust gas flow through the contoured region based
on the flow. The method includes reducing a recirculation of the
exhaust gas flow through the contoured region based on the
flow.
[0009] Other features and aspects of this disclosure will be
apparent from the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side view of an exemplary machine, according to
one embodiment of the present disclosure;
[0011] FIG. 2 is a schematic view of an exemplary engine system
associated with the machine, according to one embodiment of the
present disclosure;
[0012] FIG. 3 is a perspective view of a portion of an
aftertreatment system associated with the engine system;
[0013] FIG. 4 is a perspective view of a reductant injector mount,
according to one embodiment of the present disclosure;
[0014] FIG. 5 is a cross sectional view of the reductant injector
mount and a reductant injector received therein;
[0015] FIG. 6 is a cross sectional view of the reductant injector
mount of FIG. 4;
[0016] FIGS. 7 to 9 are perspective views of reductant injector
mounts, according to various embodiments of the present disclosure;
and
[0017] FIG. 10 is a flowchart for a method of controlling exhaust
gas flow in an exhaust conduit.
DETAILED DESCRIPTION
[0018] Wherever possible, the same reference numbers will be used
throughout the drawings to refer to the same or the like parts. An
exemplary embodiment of a machine 100, according to the present
disclosure is shown in FIG. 1. The machine 100 may be a mining
truck, as shown, or may include any off-highway or on-highway
vehicle using a fuel-powered engine, as described herein. The
machine 100 generally includes a machine frame 102 for supporting,
among other systems and components, an engine system 104 (see FIG.
2) which will be discussed in greater detail in connection with
FIG. 2.
[0019] The machine 100 also includes a plurality of ground-engaging
elements 106, in this case being wheels. As should be appreciated
by one of ordinary skill in the art, an engine 108 (see FIG. 2) of
the engine system 104 may provide propulsion power for the
ground-engaging elements 106 and may power a variety of other
machine systems, including various mechanical, electrical, and
hydraulic systems and/or components. Further, the machine 100 may
also include an operator control station 110, including a variety
of operator controls and displays useful for operating the machine
100 and/or a dump body 112 which may be pivotal relative to the
machine frame 102.
[0020] Referring to FIG. 2, a schematic diagram of the engine
system 104 is illustrated, according to one embodiment of the
present disclosure. The engine system 104 includes the engine 108,
which may be an internal combustion engine, such as, a
reciprocating piston engine or a gas turbine engine. The engine 108
may be a spark ignition engine or a compression ignition engine,
such as, a diesel engine, a homogeneous charge compression ignition
engine, or a reactivity controlled compression ignition engine, or
other compression ignition engines known in the art. The engine 108
may be fueled by gasoline, diesel fuel, biodiesel, dimethyl ether,
alcohol, natural gas, propane, hydrogen, combinations thereof, or
any other combustion fuel known in the art.
[0021] The engine 108 may include other components (not shown),
such as, a fuel system, an intake system, a drivetrain including a
transmission system, and so on. The engine 108 may be used to
provide power to any machine including, but not limited to, an
on-highway truck, an off-highway truck, an earth moving machine, an
electric generator, and so on. Accordingly, the engine system 104
may be associated with an industry including, but not limited to,
transportation, construction, agriculture, forestry, power
generation, and material handling.
[0022] Referring to FIG. 2, the engine system 104 includes an
aftertreatment system 114 fluidly connected to an exhaust manifold
of the engine 108. The aftertreatment system 114 is configured to
treat an exhaust gas flow exiting the exhaust manifold of the
engine 108. The exhaust gas flow contains emission compounds that
may include oxides of nitrogen (NOx), unburned hydrocarbons,
particulate matter, and/or other combustion products known in the
art. The aftertreatment system 114 may be configured to trap or
convert NOx, unburned hydrocarbons, particulate matter,
combinations thereof, or other combustion products present in the
exhaust gas flow, before exiting the engine system 104.
[0023] In the illustrated embodiment, the aftertreatment system 114
includes a first module 116 that is fluidly connected to an exhaust
conduit 118 of the engine 108. During engine operation, the first
module 116 is arranged to internally receive engine exhaust gas
from the exhaust conduit 118. The first module 116 may contain
various exhaust gas treatment devices, such as, a Diesel Oxidation
Catalyst (DOC) 120 and a Diesel Particulate Filter (DPF) 122, but
other devices may be used. The first module 116 and the components
found therein are optional and may be omitted for various engine
applications in which the exhaust treatment function provided by
the first module 116 is not required.
[0024] In the illustrated embodiment, the exhaust gas flow provided
to the first module 116 by the engine 108 may first pass through
the DOC 120 and then through the DPF 122 before entering a conduit
123. The conduit 123 includes a mixing tube 124. Further, the
aftertreatment system 114 includes a reductant supply system 126. A
reductant is injected into the mixing tube 124 by a reductant
injector assembly 127. The reductant injector assembly 127 may
include one or more reductant injectors 128 (see FIG. 3). The
reductant may be a fluid, such as, Diesel Exhaust Fluid (DEF). The
reductant may include urea, ammonia, or other reducing agent known
in the art.
[0025] The reductant supply system 126 includes a reductant tank
130. The reductant is contained within the reductant tank 130.
Parameters related to the reductant tank 130 such as size, shape,
location, and material used may vary according to system design and
requirements. Further, the reductant injector 128 may be
communicably coupled to a controller (not shown). Based on control
signals received from the controller, the reductant from the
reductant tank 130 is provided to the reductant injector 128 by a
pump assembly 132. As the reductant is injected into the mixing
tube 124, the reductant mixes with the exhaust gas flow passing
therethrough, and is carried to a second module 134. Further, the
conduit 123 is configured to fluidly interconnect the first module
116 with the second module 134, such that, the exhaust gas flow
from the engine 108 may pass through the first and second modules
116, 134 in series before being released at a stack 136 connected
downstream of the second module 134.
[0026] The second module 134 encloses a Selective Catalytic
Reduction (SCR) module 138 and an Ammonia Oxidation Catalyst (AMOX)
140. The SCR module 138 operates to treat exhaust gases exiting the
engine 108 in the presence of ammonia, which is provided after
degradation of a urea-containing solution injected into the exhaust
gas flow in the mixing tube 124. The AMOX 140 is used to convert
any ammonia slip from the downstream flow of the SCR module 138
before exiting the stack 136.
[0027] FIG. 3 illustrates a partial cutaway perspective view of a
portion of the conduit 123 shown in FIG. 2, depicting the mixing
tube 124 and the SCR module 138 located downstream of the conduit
123, according to one embodiment of the present disclosure. In
order to promote mixing of the reductant with the exhaust gas flow,
a mixing system 142 may be associated with the aftertreatment
system 114. The mixing system 142 is provided within the portion of
the mixing tube 124. The mixing system 142 may be positioned
downstream of the reductant injector assembly 127 and upstream of
the SCR module 138. The mixing system 142 includes a plurality of
mixing elements 144. The mixing elements 144 may include same or
different type of mixing elements. For example, the mixing elements
144 may include flapper mixers, swirl mixers, impingement mixers,
and the like. The amount of the reductant that may be injected into
the mixing tube 124 may be appropriately metered based on engine
operating conditions.
[0028] The aftertreatment system 114 disclosed herein is provided
as a non-limiting example. It will be appreciated that the
aftertreatment system 114 may be disposed in various arrangements
and/or combinations relative to the exhaust manifold. These and
other variations in aftertreatment system design are possible
without deviating from the scope of the disclosure.
[0029] Reductant injector mounts 200, 202 are associated with the
aftertreatment system 114. The reductant injector mounts 200, 202
are positioned upstream of the SCR module 138 with respect to an
exhaust gas flow direction "F". Further, the reductant injector
mounts 200, 202 are attached to a top portion 146 of the mixing
tube 124. The reductant injector mounts 200, 202 may be attached to
the mixing tube 124 using a joining process, such as welding.
Alternatively, any joining process, such as brazing, soldering, may
be used. Further, mechanical fasteners or an adhesive may also be
used for attaching the reductant injector mounts 200, 202 to the
mixing tube 124. As shown in the accompanying figures, the
reductant injector mounts 200 are disposed in a direction parallel
to the exhaust gas flow direction "F". Whereas, the reductant
injector mounts 202 are disposed in an angular orientation with
respect to the exhaust gas flow direction "F". The reductant
injector mount 200, 202 is configured to mount the reductant
injector 128 onto the mixing tube 124. A number of the reductant
injector mounts 200, 202 may depend on a number of the reductant
injectors 128 associated with the aftertreatment system 114, and
may vary based on system requirements.
[0030] The mixing tube 124 of the present disclosure includes two
reductant injectors 128 associated therewith. Therefore, the mixing
tube 124 includes two reductant injector mounts 200, 202 mounted to
the top portion 146 of the mixing tube 124. It should be noted that
the number of reductant injectors and the reductant injector mounts
may vary. In one example, four reductant injectors and the
corresponding reductant injector mounts may be provided on the
mixing tube 124. The design of the reductant injector mount 200
will now be explained with reference to FIGS. 4-6.
[0031] Referring to FIGS. 3, 4, and 5, the reductant injector mount
200 has a substantially rectangular shape. The reductant injector
mount 200 defines an axis A-A'. The axis A-A' is parallel to the
exhaust gas flow direction "F". Alternatively, the reductant
injector mount 200 may be square, circular, or elliptical in shape.
The reductant injector mount 200 includes a stepped design. When
mounted on the mixing tube 124, a first portion 404 of the
reductant injector mount 200 may project from the top portion 146
of the mixing tube 124. Whereas a second portion 406 (see FIG. 4)
of the reductant injector mount 200 may project into an interior
space 409 the mixing tube 124. Further, the top portion 146 of the
mixing tube 124 includes a cut out region 413 (see FIG. 3). The cut
out region 413 is configured to receive the second portion 406 of
the reductant injector mount 200, in order to attach the reductant
injector mount 200 with the mixing tube 124. The cut out region 413
has a rectangular shape with rounded edges. It should be noted that
the shape of the cut out region 413 may vary based on the shape of
the reductant injector mount 200.
[0032] The reductant injector mount 200 includes a mounting region
402. The mounting region 402 is configured to be connected to and
in contact with the mixing tube 124. The mounting region 402
referred to herein collectively refers to the top surface 405 of
the first portion 404 and the second portion 406 facing the exhaust
gas flow.
[0033] The mounting region 402 of the reductant injector mount 200
may include a plurality of receiving elements 408. In the
illustrated embodiment, the reductant injector mount 200 includes
three receiving elements 408. However, a number of the receiving
elements 408 may vary as per system requirements. The receiving
elements 408 project from the mounting region 402 of the reductant
injector mount 200.
[0034] In one example, the receiving elements 408 are configured to
receive mechanical fasteners (not shown) of the reductant injector
128, in order to couple the reductant injector 128 to the reductant
injector mount 200. The receiving elements 408 include apertures
411 (see FIG. 6). In the illustrated embodiment, the apertures 411
are embodied as blind holes. Alternatively, the apertures 411 may
be embodied as through-holes. In one embodiment, the receiving
elements 408 may be integral with the reductant injector mount 200.
Alternatively, the receiving elements 408 may be formed as a
separate component and later assembled with the reductant injector
mount 200. When the reductant injector mount 200 is coupled to the
mixing tube 124, the receiving elements 408 may project into the
interior space 409 of the mixing tube 124.
[0035] The reductant injector mount 200 includes a contoured region
410. The contoured region 410 is formed in the mounting region 402.
The contoured region 410 is configured to provide a flow field for
the exhaust gases flowing therethrough. The contoured region 410 is
designed such that the contoured region 410 may increase a velocity
of the exhaust gas flow through the contoured region 410. The
contoured region 410 may also be configured to reduce a
recirculation of the exhaust gases flowing therethrough. The
direction of the exhaust gas flow through the contoured region 410
is marked by arrows "F" in FIG. 5.
[0036] The reductant injector mount 200 includes a cut out portion
412. The cut out portion 412 is provided on the contoured region
410 of the reductant injector mount 200. More particularly, the cut
out portion 412 is positioned in a throat portion 414 of the
contoured region 410. The cut out portion 412 is configured to
receive a reductant injector tip 416 of the reductant injector 128
therethrough. As shown in FIG. 4, the cut out portion 412 is
positioned closer to a downstream end 417 of the contoured region
410 with respect to the exhaust gas flow direction "F" as compared
to an upstream end 418 of the contoured region 410. A diameter "D"
of the cut out portion 412 corresponds to a diameter of the
reductant injector tip 416 of the reductant injector 128.
[0037] As illustrated in FIG. 6, the cut out portion 412 of the
contoured region 410 is configured to receive the reductant
injector tip 416. The reductant injector 128 may be provided with a
gasket 420. The gasket 420 may embody a metal clip gasket and may
be configured to hold the reductant injector tip 416 in place. The
gasket 422 may flush or protrude into the mixing tube 124. An
excessive protrusion of the gasket 422 and thereby the reductant
injector tip 416 may lead to an improper injection and distribution
of the reductant within the mixing tube 124. Therefore, a depth to
which the gasket 420 protrudes within the mixing tube 124 is
decided optimally, based on system requirements. In some
embodiments, a second gasket 422 may also be provided in contact
with the gasket 420. The gaskets 420, 422 may be together
configured to adjust the depth of protrusion of the reductant
injector tip 416 into the mixing tube 124.
[0038] Referring to FIG. 4, the contoured region 410 includes a
first lobe 424 and a second lobe 426. The first and second lobes
424, 426 are provided on either sides of the cut out portion 412.
The first and second lobes 424, 426 are connected at the throat
portion 414 of the contoured region 410. The first lobe 424 is
positioned at a location upstream of the cut out portion 412 with
respect to the exhaust gas flow direction "F" (see FIG. 5). More
particularly, the first lobe 424 is positioned at the upstream end
418 of the contoured region 410 with respect to the exhaust gas
flow direction "F". Whereas, the second lobe 426 is positioned
downstream of the cut out portion 412 with respect to the exhaust
gas flow direction "F" (see FIG. 5). More particularly, the second
lobe 426 is positioned at the downstream end 417 of the contoured
region 410 with respect to the exhaust gas flow direction "F".
[0039] Referring to FIG. 4, the first lobe 424 of the contoured
region 410. The width "W1" is measured along an axis X-X' of the
reductant injector mount 200, wherein the axis X-X' is
perpendicular to the axis A-A'. Further, the second lobe 426 of the
contoured region 410 has a width "W2". The width "W2" is measured
along the axis X-X' of the reductant injector mount 200. A ratio
"R1" of the width "W1" to the diameter "D" of the cut out portion
412 and a ratio "R2" of the width "W2" to the diameter "D" of the
cut out portion 412 are decided such that the velocity of the
exhaust gas flow is increased through the contoured region 410 and
recirculation of the exhaust gas flow therethrough is reduced. In
one embodiment, the ratio "R1" of the width "W1" of the first lobe
424 to the diameter "D" of the cut out portion 412 is approximately
from 0.75 to 5. In some embodiments, the ratio "R1" is
approximately from 0.75 to 2.5 or 2.5 to 5. In one example, the
ratio "R1" may be approximately equal to 2.5.
[0040] In one embodiment of the present disclosure, the width "W1"
of the first lobe 424 may be equal to the width "W2" of the second
lobe 426. Therefore, the ratio "R1" may be equal to the ratio "R2".
Accordingly, the ratio "R2" of the width "W2" of the second lobe
426 to the diameter "D" of the cut out portion 412 is approximately
from 0.75 to 5. In some embodiments, the ratio "R2" is
approximately from 0.75 to 2.5 or 2.5 to 5. In one example, the
ratio "R2" may be approximately equal to 2.5. Alternatively, the
width "W1" of the first lobe 424 may be different than the width
"W2" of the second lobe 426. In such an example, the ratio "R1" may
be different than the ratio "R2".
[0041] When the reductant injector mount 200 is mounted on the
mixing tube 124, a curved surface of the contoured region 410 of
the reductant injector mount 200 faces the exhaust gas flow. The
curvature of the contoured region 410 varies along a cross section
of the reductant injector mount 200. Referring to FIG. 5, the first
and second lobes 424, 426 are provided at an angle with respect to
the mounting region 402. An angle of incidence ".alpha.1",
".alpha.2" of the first and second lobes 424, 426 respectively are
decided such that the exhaust gas flow adapts a streamlined flow in
the contoured region 410. The angle of incidence ".alpha.1"
hereinafter is interchangeably referred to as receiving angle
".alpha.1", and is defined at the upstream end 418 of the contoured
region 410 of the reductant injector mount 200, with respect to the
exhaust gas flow direction "F".
[0042] More particularly, the receiving angle ".alpha.1" is formed
by an upstream end 436 of the first lobe 424 with respect to the
mounting region 402 of the reductant injector mount 200. The
exhaust gas flow is received on the contoured region 410 of the
reductant injector mount 200 at the receiving angle ".alpha.1". In
one embodiment, the angle of incidence ".alpha.1" of the contoured
region 410 at the first lobe 424 is approximately from 3.degree. to
45.degree.. In one example, the angle of incidence ".alpha.1" may
be approximately 6.degree.. Further, the angle of incidence
".alpha.2" of the contoured region 410 at the second lobe 426 is
approximately from 10.degree. to 45.degree.. For example, the angle
of incidence ".alpha.2" may be approximately 17.degree..
[0043] Referring to FIG. 6, the reductant injector mount 200 has a
thickness "D1" at a downstream end 432 of the first lobe 424. The
thickness "D1" may be measured from a distance "A" from an axis
Y-Y' of the cut out portion 412. Further, the reductant injector
mount 200 has a thickness "D2" at a downstream end 434 of the
second lobe 426. The depth "D2" may be measured from a distance "B"
from the axis Y-Y' of the cut out portion 412. It should be noted
that the distance "A" referred to herein is equal to the distance
"B". Further, a ratio "R3" of the thickness "D1" to the thickness
"D2" is approximately from 0.4 to 0.9. In some embodiments, the
ratio "R3" is approximately from 0.4 to 0.6 or 0.6 to 0.9. In one
example, the ratio "R3" may be approximately equal to 0.7.
[0044] Referring now to FIG. 7, a perspective view of an alternate
embodiment of the reductant injector mount 700 is shown. In this
embodiment, a circumference of the cut out portion 702 of the
contoured region 704 disposed on the mounting region 710 is defined
by a tapered region 708. The tapered region 708 tapers along a
thickness "T" of the reductant injector mount 700 towards the outer
surface 706 of the reductant injector mount 700. More particularly,
a diameter of the cut out portion 702 decreases along the thickness
"T" towards the outer surface 706 of the reductant injector mount
700, such that a diameter "D" of the cut out portion 702 at the
contoured region 704 is greater than a diameter "d" at the outer
surface 706 of the reductant injector mount 700. It should be noted
that the design and shape of the contoured region 410, 704 and thus
the reductant injector mount 200, 700 is not limited to the
exemplary illustrations in FIGS. 4-7 and may vary therefrom.
[0045] FIG. 8 illustrates another reductant injector mount 800,
according to one embodiment of the present disclosure. As
illustrated, the contoured region 802 is formed in the mounting
region 810 of the reductant injector mount 800 may have an
approximately oblong shape, with curved sections 814, 816 provided
at either ends along the axis Z-Z'. In this embodiment, a width
"W3" of the contoured region 802 is uniform along the axis Z-Z' of
the reductant injector mount 800.
[0046] As discussed earlier, based on system requirements, the
reductant injector mounts 202 may be positioned angularly on the
mixing tube 124 with respect to the exhaust gas flow direction "F"
(see FIG. 3). Referring to FIG. 9, accordingly the contoured region
902 is formed in the mounting region 904 of such reductant injector
mounts 202 are oriented so that the contoured region 902 is aligned
with respect to the exhaust gas flow direction "F", when the
reductant injector mount 202 is fitted onto the mixing tube 124. An
axis F-F' defined by the contoured region 902 is parallel to the
exhaust gas flow direction "F". More particularly, the axis F-F' of
the contoured region 902 is angled with respect to the axis Z-Z',
so that the contoured region 902 is aligned with the exhaust gas
flow direction "F". It should be noted that the design of the
contoured region 902 shown in FIG. 9 is exemplary, and may include
any other design, such as that explained in FIGS. 4-7, without
limiting the scope of the present disclosure.
INDUSTRIAL APPLICABILITY
[0047] Flow field around an injection location of the reductant
injector mounted on the mixing tube may have unfavorable
recirculating and/or low velocity patterns of the exhaust gas flow.
This may create/increase formation of urea deposits that may be
present in the reductant. Such urea deposition can prevent/hinder
the reductant spray pattern/interaction with the exhaust gas flow
and further cause deposition issues and reduce NOx conversion in
the aftertreatment system.
[0048] FIG. 10 is a flowchart for a method 1000 for controlling
exhaust gas flow in the conduit 123. At step 1002, the reductant
injector 128 is received through the mounting region 402, 710, 810,
904 of the reductant injector mount 200, 202, 700, 800. At step
1004, the exhaust gas flows over the contoured region 410, 704,
802, 902 of the reductant injector mount 200, 202, 700, 800. At
step 1006, based on the flow, the velocity of the exhaust gas flow
increases through the contoured region 410, 704, 802, 902. Further,
the exhaust gas flow is received at the receiving angle
".alpha.1".
[0049] At step 1008, based on the flow, the recirculation of the
exhaust gas flow flowing through the contoured region 410, 704,
802, 902 is reduced. The exhaust gas flow is then discharged
towards the SCR module 138 provided downstream of the conduit 123.
The flow field provided by the contoured region 410, 704, 802, 902
of the reductant injector mount 200, 202, 700, 800 has reduced or
no recirculation around the reductant injector tip 416 and also
increases the velocity near the injection location.
[0050] Accordingly, the deposit formation of the reductant around
the reductant injector tip 416 may reduce or be eliminated because
of reduced recirculation and increased velocity of the exhaust gas
flow through the reductant injector mount 200, 202, 700, 800.
Further, the reductant may uniformly mix with the exhaust gas flow
and an improved NOx conversion may take place in the aftertreatment
system 114. Also, servicing and maintenance associated with removal
of the reductant deposits close to the reductant injector 128 may
be reduced, thereby decreasing cost associated with servicing and
maintenance cost of the aftertreatment system 114.
[0051] While aspects of the present disclosure have been
particularly shown and described with reference to the embodiments
above, it will be understood by those skilled in the art that
various additional embodiments may be contemplated by the
modification of the disclosed machines, systems and methods without
departing from the spirit and scope of what is disclosed. Such
embodiments should be understood to fall within the scope of the
present disclosure as determined based upon the claims and any
equivalents thereof.
* * * * *