U.S. patent application number 12/295949 was filed with the patent office on 2009-02-26 for assembly for mixing a medium with the exhaust gas flow of a motor vehicle exhaust system.
This patent application is currently assigned to EMCON TECHNOLOGIES GERMANY (AUGSBURG) GMBH. Invention is credited to Rolf Kaiser, Klaus Rusch.
Application Number | 20090049829 12/295949 |
Document ID | / |
Family ID | 38190593 |
Filed Date | 2009-02-26 |
United States Patent
Application |
20090049829 |
Kind Code |
A1 |
Kaiser; Rolf ; et
al. |
February 26, 2009 |
Assembly for Mixing a Medium with the Exhaust Gas Flow of a Motor
Vehicle Exhaust System
Abstract
An assembly for mixing a medium with an exhaust gas flow of a
motor vehicle exhaust system has a first exhaust pipe and a second
exhaust pipe. The first exhaust pipe comprises a device for
introducing the medium and opens axially into a connecting member
that is widened with respect to the first exhaust pipe. The second
exhaust pipe opens laterally into the connecting member. The
connecting member is configured to impart an angular momentum to
the exhaust gas flow.
Inventors: |
Kaiser; Rolf; (Augsburg,
DE) ; Rusch; Klaus; (Gersthofen, DE) |
Correspondence
Address: |
PAMELA A. KACHUR
950 W 450 S, BLDG. 4
COLUMBUS
IN
47201
US
|
Assignee: |
EMCON TECHNOLOGIES GERMANY
(AUGSBURG) GMBH
Ausburg
DE
|
Family ID: |
38190593 |
Appl. No.: |
12/295949 |
Filed: |
April 3, 2007 |
PCT Filed: |
April 3, 2007 |
PCT NO: |
PCT/EP2007/003004 |
371 Date: |
October 3, 2008 |
Current U.S.
Class: |
60/295 |
Current CPC
Class: |
Y02T 10/12 20130101;
F01N 2470/24 20130101; Y02A 50/20 20180101; Y02T 10/24 20130101;
F01N 3/2066 20130101; Y02A 50/2325 20180101; B01F 5/0618 20130101;
F01N 2240/20 20130101; F01N 2610/02 20130101; F01N 13/08 20130101;
B01F 5/0473 20130101 |
Class at
Publication: |
60/295 |
International
Class: |
F01N 3/00 20060101
F01N003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 5, 2006 |
DE |
10 2006 015 964.0 |
Claims
1. An assembly for mixing a medium with an exhaust gas flow of a
motor vehicle exhaust system, comprising: a first exhaust pipe
comprising a device for introducing a medium into an exhaust gas
flow, the first exhaust pipe opening axially into a connecting
member that is widened with respect to the first exhaust pipe; and
a second exhaust pipe that opens laterally into the connecting
member, wherein connecting member is configured to impart an
angular momentum to the exhaust gas flow.
2. The assembly according to claim 1, wherein the first exhaust
pipe extends beyond an opening region of the second exhaust pipe
into an interior of the connecting member.
3. The assembly according to claim 1, wherein the connecting member
has a cone shape.
4. The assembly according to claim 1, wherein the second exhaust
pipe opens tangentially into the connecting member.
5. The assembly according to claim 1, wherein an inner side of the
connecting member has a guiding face for the exhaust gas flow.
6. The assembly according to claim 1, wherein the device is
arranged downstream of a directing member in the first exhaust
pipe.
7. The assembly according to claim 1, wherein the second exhaust
pipe is formed in one piece with the connecting member.
8. The assembly according to claim 1, wherein the device is a urea
injection device.
Description
RELATED APPLICATIONS
[0001] The application is the U.S. National Phase of
PCT/EP2007/003004 filed Apr. 3, 2007, which claimed priority to
German Application 10 2006 015 964.0 filed Apr. 5, 2006.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an assembly for mixing a medium
with the exhaust gas flow of a motor vehicle exhaust system.
[0003] In modern exhaust systems, it is sometimes necessary to
introduce a medium into the exhaust gas flow to generate specific
reactions. For example, it is possible to inject urea in a
dissolved form upstream of a selective catalytic reduction (SCR)
catalytic converter to provide ammonia as a reducing agent for the
nitrogen oxides present in the exhaust gas. It is also possible to
supply a reducing agent, such as fuel, upstream of a particulate
filter to burn off the particulates retained in the filter in a
controlled way. Generally, it has to be taken into consideration
that the medium which is to be introduced has to be distributed as
homogeneously as possible in the exhaust gas flow to generate a
uniform effect.
[0004] This also particularly applies to two-branch exhaust
systems, such as those for a 6 or 8-cylinder engine for example,
where only one urea injection device is typically provided for SCR
applications in order to reduce costs. The injection device is then
usually arranged downstream of a connecting member which merges the
exhaust gas flows from the two exhaust pipes. The problem of
obtaining an intensive mixing of the exhaust gas with the
introduced medium also arises with this configuration.
[0005] It is therefore the object of the invention to obtain a
uniform distribution of an introduced medium in the exhaust gas
flow, in particular in the exhaust gas flow of a two-branch exhaust
system, with a low effort and a high reliability.
SUMMARY OF THE INVENTION
[0006] The invention provides an assembly of the type initially
mentioned, which has a first exhaust pipe and a second exhaust
pipe. The first exhaust pipe comprises a device for introducing the
medium and opens axially into a connecting member that is widened
with respect to the first exhaust pipe. The second exhaust pipe
opens laterally into the connecting member. The connecting member
is configured to impart an angular momentum to the exhaust gas
flow. The medium is thus first supplied to the exhaust gas flow in
the first exhaust pipe and enters, along with this exhaust gas
flow, the connecting member in which a mixing with an exhaust gas
flow from the second exhaust pipe is produced. A spin leading to a
good swirl, and therefore to a good distribution of the medium, is
imparted to the entire exhaust gas flow inside the connecting
member. Furthermore, soiling of pipe walls by the medium, for
example by a settling of the medium at the pipe walls, is avoided.
The configuration according to the invention is particularly
suitable for a two-branch exhaust system, with only a single device
for introducing the medium being necessary, but the configuration
can be used in any exhaust system where the exhaust gas flow is
distributed at least partially to two pipes.
[0007] The first exhaust pipe extends beyond an opening region of
the second exhaust pipe into an interior of the connecting member.
The exhaust gas flow from the second exhaust pipe thus first
strikes a wall of the first exhaust pipe and is then forced into a
rotary movement about an end of the first exhaust pipe.
[0008] The connecting member has a cone shape with the first
exhaust pipe opening into a larger end face of the connecting
member. A particularly good swirl of the exhaust gas flow is
obtained due to the obliquely tapering lateral walls of the
connecting member.
[0009] Advantageously, the second exhaust pipe opens tangentially
into the connecting member. The exhaust gas flow from the second
exhaust pipe is therefore forced in a simple way to a helical path
along the inner wall of the connecting member.
[0010] To support the swirl of the exhaust gas flow, the connecting
member may have on an inner side a guiding face for the exhaust gas
flow.
[0011] To facilitate the mixing of the introduced medium with the
exhaust gas flow in the first exhaust pipe, the device may be
arranged downstream of a directing member in the first exhaust
pipe.
[0012] According to a one example embodiment, the second exhaust
pipe is formed in one piece with the connecting member.
[0013] As already mentioned initially, the device may be a urea
injection device. However, the device could also be a device for
introducing a reducing agent such as fuel for the regeneration of a
particulate filter, for example.
[0014] These and other features of the present invention can be
best understood from the following specification and drawings, the
following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Further features and advantages of the invention will be
apparent from the description below of a preferred embodiment with
reference to the enclosed drawings.
[0016] FIG. 1 shows a longitudinal section through an assembly
according to the invention; and
[0017] FIG. 2 shows a cross-section through the assembly along the
line II-II.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIG. 1 shows an assembly 10 which is arranged in an exhaust
system of a motor vehicle (not shown) and has a first exhaust pipe
12 and a second exhaust pipe 14, with exhaust gas flowing through
each exhaust pipe in the direction of the arrows P.sub.1. The
exhaust gases flow from the first and second exhaust pipes 12, 14
and are merged in a connecting member 16. The second exhaust pipe
14 opens laterally, in particular tangentially (cf. FIG. 2), into
the connecting member 16 and is formed in one piece with the
connecting member 16 in the example shown.
[0019] The first exhaust pipe 12 opens axially into the connecting
member 16 and has a device 18 for introducing a medium, which in
the present case comprises a urea injection device that is arranged
downstream of a directing member 20. The connecting member 16 has
the shape of a cone and is widened with respect to the first
exhaust pipe 12 which extends beyond the opening region of the
second exhaust pipe 14 into the interior of the connecting member
16.
[0020] Due to the tangential introduction of the exhaust gas flow
from the second exhaust pipe 14 into the cone-shaped connecting
member 16, a swirl of the united exhaust gas flow is obtained. This
swirl is also referred to as a Vortex and leads to a particularly
good mixing with the introduced medium (in the present case
dissolved urea). In the figures, the swirl is indicated by the
helically extending arrow P.sub.2.
[0021] Unlike the embodiment illustrated, the connecting member 16
may have on its inner side a guiding face for the exhaust gas flow,
which is formed by a guide plate or by plastically deformed wall
portions of the connecting member, for example.
[0022] Although an embodiment of this invention has been disclosed,
a worker of ordinary skill in this art would recognize that certain
modifications would come within the scope of this invention. For
that reason, the following claims should be studied to determine
the true scope and content of this invention.
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