U.S. patent application number 13/174075 was filed with the patent office on 2012-06-14 for dosing module for exhaust post treatment system of vehicle.
This patent application is currently assigned to Kia Motors Corporation. Invention is credited to Gisoo Hyun.
Application Number | 20120144812 13/174075 |
Document ID | / |
Family ID | 46144726 |
Filed Date | 2012-06-14 |
United States Patent
Application |
20120144812 |
Kind Code |
A1 |
Hyun; Gisoo |
June 14, 2012 |
DOSING MODULE FOR EXHAUST POST TREATMENT SYSTEM OF VEHICLE
Abstract
A dosing module for an exhaust gas post treatment system of a
vehicle, which may be used to inject a reducing agent along a flow
direction of exhaust gas at a front side of a selective catalyst
reduction (SCR) unit, may include a dosing main body having a
connection portion that may be connected to the SCR unit and an
inflow portion into which the exhaust gas flows, an injector that
may be disposed at a boss portion that may be mounted on the dosing
main body to inject the reducing agent into the dosing main body,
and a guide member that may be disposed inside the dosing main body
to guide the exhaust gas flowing into the dosing main body along a
predetermined route.
Inventors: |
Hyun; Gisoo; (Hwaseong-city,
KR) |
Assignee: |
Kia Motors Corporation
Seoul
KR
Hyundai Motor Company
Seoul
KR
|
Family ID: |
46144726 |
Appl. No.: |
13/174075 |
Filed: |
June 30, 2011 |
Current U.S.
Class: |
60/301 |
Current CPC
Class: |
F01N 2610/02 20130101;
F01N 3/2892 20130101; B01F 3/04049 20130101; F01N 2610/1453
20130101; Y02A 50/20 20180101; F01N 13/009 20140601; Y02T 10/24
20130101; Y02A 50/2325 20180101; B01F 5/0268 20130101; F01N 3/2066
20130101; Y02T 10/12 20130101; F01N 3/035 20130101; F01N 3/106
20130101; B01F 5/0606 20130101 |
Class at
Publication: |
60/301 |
International
Class: |
F01N 3/10 20060101
F01N003/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 2010 |
KR |
10-2010-0125531 |
Claims
1. A dosing module for an exhaust gas post treatment system of a
vehicle, which is used to inject a reducing agent along a flow
direction of exhaust gas at a front side of a selective catalyst
reduction (SCR) unit, comprising: a dosing main body having a
connection portion that is connected to the SCR unit and an inflow
portion into which the exhaust gas flows; an injector that is
disposed at a boss portion that is mounted on the dosing main body
to inject the reducing agent into the dosing main body; and a guide
member that is disposed inside the dosing main body to guide the
exhaust gas flowing into the dosing main body along a predetermined
route.
2. The dosing module for the exhaust gas post treatment system of
claim 1, wherein the guide member has a plate shape to separate the
connection portion from the inflow portion in the dosing main
body.
3. The dosing module for the exhaust gas post treatment system of
claim 2, wherein one end of the guide member is fixed to an inside
wall of the dosing main body and the other end thereof is bent from
the inside wall to have a curved shape.
4. The dosing module for the exhaust gas post treatment system of
claim 3, wherein the curved shape is bent toward the injector with
a predetermined curvature to enclose the inflow portion
therein.
5. The dosing module for the exhaust gas post treatment system of
claim 1, wherein the guide member has a plurality of holes.
6. The dosing module for the exhaust gas post treatment system of
claim 5, wherein a baffle member is mounted in the dosing main body
to be engaged with the guide member and an inside wall of the
dosing main body to form the inflow portion.
7. The dosing module for the exhaust gas post treatment system of
claim 6, wherein the baffle member has a plate shape except at the
inflow portion in the dosing main body.
8. The dosing module for the exhaust gas post treatment system of
claim 7, wherein the baffle member forms a flow passage between the
guide member and an inside wall of the dosing main body.
9. The dosing module for the exhaust gas post treatment system of
claim 7, wherein the baffle member is disposed on a slant toward
the inflow portion in the dosing main body.
10. The dosing module for the exhaust gas post treatment system of
claim 3, wherein the injector is disposed on a slant along the flow
direction of the exhaust gas on the boss member.
11. The dosing module for the exhaust gas post treatment system of
claim 10, wherein the injector injects the reducing agent toward
the curved portion of the guide member.
12. The dosing module for the exhaust gas post treatment system of
claim 1, wherein the connecting portion forms a connecting passage
that is connected to the SCR unit at a lower portion of the dosing
main body.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Korean Patent
Application No. 10-2010-0125531 filed in the Korean Intellectual
Property Office on Dec. 9, 2010, the entire contents of which is
incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] An exemplary embodiment of the present invention relates to
an exhaust system of a vehicle. More particularly, the present
invention relates to a dosing module of a selective catalyst
reduction (SCR) unit for exhaust gas post treatment.
[0004] 2. Description of Related Art
[0005] Generally, an exhaust system of an engine is provided with
exhaust gas post treatment such as with a diesel oxidation catalyst
(DOC), a diesel particulate filter (DPF), a selective catalyst
reduction (SCR) unit, etc., so as to reduce diesel particulate
matter (PM) and nitrogen oxide (NO.sub.x).
[0006] Of these, a reducing agent (for example, a urea solution) is
injected into the exhaust gas by an injector, the reducing agent
(urea) is hydrolyzed to ammonia (NH.sub.3) by the heat of the
exhaust gas, and nitrogen oxide (NO.sub.x) of the exhaust gas
reacts with the ammonia (NH.sub.3) through a catalyst of the SCR
unit to be transformed into nitrogen (N.sub.2) gas and water
(H.sub.2O).
[0007] In the conventional exhaust gas post treatment device such
as one using the DOC, the DPF, and the SCR unit, as an example, the
DOC and the DPF are disposed in a flowing direction of the exhaust
gas, and the SCR unit is disposed at a downstream side of the DPF.
Further, a dosing module having an injector is disposed between the
DPF and the SCR unit to inject the reducing agent.
[0008] In a conventional dosing module, the injection speed of the
reducing agent is increased by raising the injection pressure
according to EM (emission) standards.
[0009] However, the spray depth of the reducing agent from the
injector is increased in the conventional art such that the
injected reducing agent is accumulated on the interior wall of the
exhaust gas line, i.e., there is a problem that a wall wetting
phenomenon is generated.
[0010] That is, the wall wetting phenomenon of the reducing agent
that is injected is a cause of deterioration of purification
efficiency of nitrogen oxide and activation of the SCR, and in a
case that the liquid element of the reducing agent evaporates on
the interior wall of the exhaust gas line, a solid residue thereof
remains, and resultantly it becomes difficult to control the
injection amount.
[0011] Meanwhile, in another conventional art, a mixer is disposed
in the exhaust gas line so as to mix the reducing agent that is
injected by the injector with the exhaust gas and so as to prevent
the wall wetting.
[0012] However, since the mixer is disposed in the exhaust gas
line, material cost is increased thereby and there is a problem
that the durability thereof is reduced.
[0013] On the other hand, in another conventional art, the injector
is disposed at a curved pipe portion of the exhaust gas line so as
to prevent the wall wetting phenomenon such that the reducing agent
is injected into the exhaust gas passing the curved pipe
portion.
[0014] However, since the injector is disposed at the curved
portion of the exhaust gas line, it is necessary to secure
appropriate positioning such that the reducing agent may be
hydrolyzed to ammonia (NH.sub.3) by the heat of the exhaust gas.
Accordingly, it is necessary to secure the shape of the exhaust
pipe to provide the appropriate positioning, the entire post
treatment layout becomes complicated thereby, and there is a
problem that it is difficult to dispose the injector on the
layout.
[0015] The information disclosed in this Background of the
Invention section is only for enhancement of understanding of the
general background of the invention and should not be taken as an
acknowledgement or any form of suggestion that this information
forms the prior art already known to a person skilled in the
art.
BRIEF SUMMARY
[0016] Various aspects of the present invention are directed to
providing a dosing module for an exhaust gas post treatment system
of a vehicle having advantages of substantially preventing a wall
wetting phenomenon of a reducing agent and improving efficiency of
a selective catalyst reduction (SCR) unit without injecting the
reducing agent into a curved pipe and without disposing a mixer in
the exhaust pipe.
[0017] A dosing module for an exhaust gas post treatment system of
a vehicle, which may be used to inject a reducing agent along a
flow direction of exhaust gas at a front side of a selective
catalyst reduction (SCR) unit, may include a dosing main body
having a connection portion that may be connected to the SCR unit
and an inflow portion into which the exhaust gas flows, an injector
that may be disposed at a boss portion that may be mounted on the
dosing main body to inject the reducing agent into the dosing main
body, and a guide member that may be disposed inside the dosing
main body to guide the exhaust gas flowing into the dosing main
body along a predetermined route.
[0018] The guide member may have a plate shape to separate the
connection portion from the inflow portion in the dosing main
body.
[0019] One end of the guide member may be fixed to an inside wall
of the dosing main body and the other end thereof may be bent from
the inside wall to may have a curved shape, wherein the curved
shape may be bent toward the injector with a predetermined
curvature to enclose the inflow portion therein.
[0020] The guide member may have a plurality of holes, wherein a
baffle member may be mounted in the dosing main body to be engaged
with the guide member and an inside wall of the dosing main body to
form the inflow portion.
[0021] The baffle member may have a plate shape except at the
inflow portion in the dosing main body, wherein the baffle member
forms a flow passage between the guide member and an inside wall of
the dosing main body.
[0022] The baffle member may be disposed on a slant toward the
inflow portion in the dosing main body.
[0023] The injector may be disposed on a slant along the flow
direction of the exhaust gas on the boss member, wherein the
injector injects the reducing agent toward the curved portion of
the guide member.
[0024] The connecting portion forms a connecting passage that may
be connected to the SCR unit at a lower portion of the dosing main
body.
[0025] The dosing module for an exhaust gas post treatment system
of a vehicle prevents the wall wetting phenomenon in an exemplary
embodiment of the present invention without injecting the reducing
agent to the curved pipe and without disposing the mixer in the
exhaust pipe, and the mixture of the exhaust gas and the reducing
agent and the uniformity and the reaction activity thereof are
improve regardless of the layout of the vehicle such that the
efficiency of the SCR unit is increased.
[0026] The methods and apparatuses of the present invention have
other features and advantages which will be apparent from or are
set forth in more detail in the accompanying drawings, which are
incorporated herein, and the following Detailed Description, which
together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a schematic block diagram showing an exhaust gas
post treatment system of a vehicle according to an exemplary
embodiment of the present invention.
[0028] FIG. 2 is an exploded perspective view showing a dosing
module for an exhaust gas post treatment system of a vehicle
according to an exemplary embodiment of the present invention.
[0029] FIG. 3 is a schematic diagram of an assembled front view of
FIG. 2.
[0030] FIG. 4A and FIG. 4B show operational states of a dosing
module for an exhaust gas post treatment system of a vehicle
according to an exemplary embodiment of the present invention.
[0031] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various features illustrative of the basic
principles of the invention. The specific design features of the
present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0032] In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0033] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that the present description is
not intended to limit the invention(s) to those exemplary
embodiments. On the contrary, the invention(s) is/are intended to
cover not only the exemplary embodiments, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
[0034] Portions having no relation with the description will be
omitted in order to explicitly explain an exemplary embodiment of
the present invention, and the same reference numerals will be used
for the same or similar elements throughout the specification.
[0035] In the drawings, size and thickness of each element is
approximately shown for better understanding and ease of
description. Therefore, the present invention is not limited to the
drawings, and the thicknesses of layers, films, panels, regions,
etc., are exaggerated for clarity.
[0036] FIG. 1 is a schematic block diagram showing an exhaust gas
post treatment system of a vehicle according to an exemplary
embodiment of the present invention.
[0037] Referring to the drawings, an exemplary embodiment of the
present invention can be applied to an exhaust gas post treatment
system 200 that purifies exhaust gas generated from a diesel engine
for a commercial vehicle.
[0038] Here, the exhaust gas post treatment system 200, for
example, includes a diesel oxidation catalyst (DOC) 1 that is
disposed on the exhaust line, a diesel particulate filter (DPF) 3
that is disposed at a downstream side of the DOC 1, and a selective
catalyst reduction (SCR) unit 5 that is disposed at a downstream
side of the DPF 3.
[0039] In this case, the DOC 1 oxidizes all hydrocarbons and carbon
monoxide of the exhaust gas and oxidizes nitrogen monoxide to
nitrogen dioxide.
[0040] The DPF 3 includes a catalyst support for trapping
particulate matter (PM) included in the exhaust gas, and the
catalyst support eliminates the PM through a chemical reaction.
[0041] Further, the SCR unit 5 chemically reduces nitrogen oxide
passing the DOC 1 and the DPF 3 to N.sub.2 gas by using a reducing
agent such as a urea solution.
[0042] That is, the reducing agent is transformed to ammonia by the
oxidation heat, and the nitrogen oxide reacts with the ammonia
through the catalyst of the SCR 5 to be transformed into N.sub.2
gas and water.
[0043] Meanwhile, the exhaust gas post treatment system 200
includes a dosing module 100 that is disposed between the DPF 3 and
the SCR 5 according to the present exemplary embodiment, which is
used to inject the reducing agent along a flowing direction of the
exhaust gas.
[0044] The dosing module 100 according to the present exemplary
embodiment is not limited by a layout of a vehicle, and it enhances
mixing of the exhaust gas and the reducing agent and improves
efficiency of the SCR unit 5 by reaction activation and improved
uniformity.
[0045] FIG. 2 is an exploded perspective view showing a dosing
module for an exhaust gas post treatment system of a vehicle
according to an exemplary embodiment of the present invention, and
FIG. 3 is a schematic diagram of an assembled front view of FIG.
2.
[0046] Referring to the drawing, according to an exemplary
embodiment of the present invention, the dosing module 100 for an
exhaust gas post treatment system of a vehicle basically includes a
dosing main body 10, an injector 30, a guide member 50, and a
baffle member 70, and these are described as follows.
[0047] As shown in FIG. 1, the dosing main body 10 can connects the
DPF 3 and the SCR unit 5 of the exhaust gas post treatment system
200 in the present exemplary embodiment.
[0048] One side of the dosing main body 10 is closed and the other
side thereof is opened to have a cylinder shape, and the dosing
main body 10 has an inflow portion 11 into which the exhaust gas
flows and a connecting portion 13 that is connected to the SCR unit
5.
[0049] The inflow portion 11 is an inlet into which the exhaust gas
flows, and can be formed in another side of the dosing main body 10
through the guide member 50 that is to be described hereafter and
the baffle member 70.
[0050] The combination structure of the guide member 50 that forms
the inflow portion 11 and the baffle member 70 will be described
hereafter.
[0051] The connecting portion 13 is connected to the SCR unit 5
through a pipe to form a connecting passage 12 that is connected to
the SCR unit 5.
[0052] Here, the connecting passage 12 has a narrower cross-section
than that of the dosing main body 10, and can be formed at a lower
side of the dosing main body 10.
[0053] The injector 30 that is to be described hereafter is
disposed at a boss member of an upper side of the dosing main body
10.
[0054] An opening is formed to be connected to an interior space of
the dosing main body 10, and the boss member 15 is disposed around
the opening to be welded on the exterior circumference of the
dosing main body 10.
[0055] In this case, the boss member 15 is biased from the upper
center of the exterior circumference of the dosing main body 10 in
one direction by a predetermined distance, and a mounting bracket
17 for mounting the injector 30 is disposed on the boss member
15.
[0056] In the above, the injector 30 is used to inject the reducing
agent into the dosing main body 10, and is mounted on the opening
of the boss member 15 through the mounting bracket 17. The injector
30 is mounted at the boss member on a slant along the flowing
direction of the exhaust gas.
[0057] The injector 30 is a secondary injection device of a
conventional art that is used in an exhaust system of this field,
and a detailed description thereof will be omitted in this
specification.
[0058] The guide member 50 guides the exhaust gas flowing into the
dosing main body 10 through the inflow portion 11 along a
predetermined line in the present exemplary embodiment.
[0059] Also, the guide member 50 promotes mixing of the reducing
agent injected by the injector 30 with the exhaust gas and
atomizing of the reducing agent to improve mixture uniformity of
the exhaust gas and the reducing agent.
[0060] The guide member 50 is disposed inside the dosing main body
10 to have a plate shape that separates the inflow portion 11 from
the connecting portion 13 in the dosing main body 10.
[0061] Here, the guide member 50 is welded on the interior wall of
the dosing main body 10, wherein one end thereof is fixed on the
interior wall corresponding to the inflow portion 11 and the other
end thereof is extended from the fixed portion.
[0062] In this case, the other end portion of the guide member 50
is bent to have a semi-circular shape, and one end portion thereof
has a softly curved shape to be fixed on the interior wall of the
dosing main body 10.
[0063] A round portion 51 of the other end portion of the guide
member 50 generates a strong turning flow in the exhaust gas
flowing into the dosing main body 10 to improve the mixture
uniformity of the exhaust gas and the reducing agent.
[0064] A plurality of holes 53 are formed on all areas of the guide
member 50 and the holes 53 promotes mixing of the exhaust gas and
the reducing agent, wherein the reducing agent is injected by the
injector 30 and the exhaust gas is guided by the guide member
50.
[0065] Meanwhile, the injector 30 is biased toward one side
direction from the upper center of the dosing main body 10 by the
boss member 15 that is described above such that the injector 30
injects the reducing agent toward the round portion 51 of the guide
member 50.
[0066] That is, since the reducing agent of the injector 30 is
injected toward the round portion 51 of the guide member 50 in
which the holes 53 are formed, the reducing agent does not collide
with the interior wall of the dosing main body 10 at an early
injection stage.
[0067] The baffle member 70 forms the inflow portion 11 into which
the exhaust gas flows, induces the exhaust gas to the inflow
portion 11, and improves the straightness of the reducing agent by
preventing axial movement of the exhaust gas in the present
exemplary embodiment.
[0068] The baffle member 70 is fixed on the interior wall and the
guide member 50 to have a plate shape covering a part except the
inflow portion 11 in the dosing main body 10.
[0069] That is, the baffle member 70 contacts the guide member 50
to be fixed on the interior wall of the dosing main body 10, and
the inflow portion 11 corresponding to the shape of the guide
member 50 is formed.
[0070] The baffle member 70 covers between the guide member 50 and
the dosing main body 10 except at the inflow portion 11 to form a
flow passage 71 of the exhaust gas, and an inlet of the exhaust gas
is formed by the inner side of the guide member 50 and the interior
wall of the dosing main body 10.
[0071] Here, it is desirable for the baffle member 70 to be slanted
toward the inflow portion 11 on the interior surface of the dosing
main body 10 so as to induce the exhaust gas toward the inflow
portion 11.
[0072] Accordingly, in a dosing module 100 for an exhaust gas post
treatment system of a vehicle according to an exemplary embodiment
of the present invention, the exhaust gas that has passed the DOC 1
and the DPF 3 is induced to the inflow portion 11 by the baffle
member 70 of the dosing main body 10 to flow through the inflow
portion 11.
[0073] Referring to FIG. 4A and FIG. 4B, operation of the dosing
module 100 will be described hereafter according to the present
exemplary embodiment. The exhaust gas collides with the round
portion 51 of the guide member 50 to form a strong turning flow and
flows through the flow passage 71 between the guide member 50 and
the dosing main body 10.
[0074] In this process, the injector 30 injects the reducing agent
and is disposed on the slant toward one side direction from the
upper center of the dosing main body 10 such that the reducing
agent is injected toward the round portion 51 of the member 50.
[0075] The baffle member 70 prevents axial direction flowing of the
exhaust gas to improve the straightness of the reducing agent that
is injected from the injector 30.
[0076] Because the reducing agent that is injected from the
injector 30 is injected toward the round portion 51 of the guide
member 50 where the holes 53 are formed in the present exemplary
embodiment, the reducing agent is prevented from being attached to
the interior wall of the dosing main body 10 at an early stage
thereof.
[0077] Meanwhile, the reducing agent injected by the injector 30
collides with the guide member 50 of a high temperature in the
present exemplary embodiment and the atomization thereof is
improved thereby, and the mixing time of the exhaust gas and the
reducing agent is secured.
[0078] The reducing agent collides with the exhaust gas flowing
through the holes 53 of the guide member 50 to be mixed therewith
and the atomization thereof is promoted. The reducing agent is
uniformly mixed by the strong turning flow of the exhaust gas that
is formed by the flow passage 71.
[0079] Accordingly, the reducing agent is transformed to ammonia
(NH.sub.3) by the heat of the exhaust gas in the dosing main body
10 in the present exemplary embodiment, and the NH.sub.3 flows into
the SCR unit (5 of FIG. 1) through the connecting portion 13 to
react with nitrogen oxide in all areas of the SCR 5 by an venturi
effect.
[0080] As described, a dosing module 100 for an exhaust gas post
treatment system of a vehicle prevents the wall wetting phenomenon
in an exemplary embodiment of the present invention without
injecting the reducing agent into a curved pipe and without
disposing the mixer in the exhaust pipe.
[0081] With this, the mixture of the exhaust gas and the reducing
agent and the uniformity and the reaction activity thereof are
improved regardless of the layout of the vehicle in the present
exemplary embodiment such that the efficiency of the SCR unit 5 is
increased.
[0082] For convenience in explanation and accurate definition in
the appended claims, the terms "upper", "lower", "inner" and
"outer" are used to describe features of the exemplary embodiments
with reference to the positions of such features as displayed in
the figures.
[0083] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
* * * * *