U.S. patent application number 12/298356 was filed with the patent office on 2009-07-09 for substrate having corrugated sheet(s) and channel(s) for treating exhaust gases of combustion engines.
This patent application is currently assigned to ECOCAT OY. Invention is credited to Juha Laiho, Juhani Makela, Pekka Matilainen, Aulis Vakkilainen.
Application Number | 20090175768 12/298356 |
Document ID | / |
Family ID | 38624583 |
Filed Date | 2009-07-09 |
United States Patent
Application |
20090175768 |
Kind Code |
A1 |
Vakkilainen; Aulis ; et
al. |
July 9, 2009 |
SUBSTRATE HAVING CORRUGATED SHEET(S) AND CHANNEL(S) FOR TREATING
EXHAUST GASES OF COMBUSTION ENGINES
Abstract
The present invention relates a substrate having corrugated
sheet(s) and channel(s) for treating exhaust gases of combustion
engines. The present invention also relates to methods for
manufacturing and using said substrate having said open channel(s).
The substrate (1) comprises at least one corrugated sheet (3)
having depressions (3d) and one flat wire mesh sheet (2) having
depressions (2d) which is connected to said corrugated sheet (3)
and between said flat wire mesh sheet (2) and said corrugated sheet
(3) there are at least partially open channels (POC) for exhaust
gas (EG) flow, and the depth of depression (2d) of said flat wire
mesh sheet (2) is 0.05-0.5 mm smaller than the height of the
corrugation (3c) of said corrugated sheet (3).
Inventors: |
Vakkilainen; Aulis;
(Vihtavuori, FI) ; Laiho; Juha; (Kuusa, FI)
; Makela; Juhani; (Laukaa, FI) ; Matilainen;
Pekka; (Jyvaskyla, FI) |
Correspondence
Address: |
YOUNG & THOMPSON
209 Madison Street, Suite 500
ALEXANDRIA
VA
22314
US
|
Assignee: |
ECOCAT OY
VIHTAVUORI
FI
|
Family ID: |
38624583 |
Appl. No.: |
12/298356 |
Filed: |
April 24, 2006 |
PCT Filed: |
April 24, 2006 |
PCT NO: |
PCT/FI06/00129 |
371 Date: |
October 24, 2008 |
Current U.S.
Class: |
422/180 ; 29/890;
60/299; 60/311 |
Current CPC
Class: |
B01D 46/10 20130101;
F01N 2330/323 20130101; B01D 39/12 20130101; B01D 2275/105
20130101; B01D 2239/065 20130101; Y10T 29/49345 20150115; B01D
2275/20 20130101; Y10S 55/30 20130101; Y10T 29/49826 20150115; F01N
3/035 20130101; F01N 2330/02 20130101; F01N 2330/322 20130101; B01D
2279/30 20130101; F01N 3/2821 20130101; B01D 46/521 20130101; Y10S
55/10 20130101; B01D 2265/04 20130101; F01N 2330/12 20130101; F01N
2330/38 20130101; B01D 2275/10 20130101; F01N 3/0222 20130101; B01D
2239/0668 20130101; F01N 2330/321 20130101 |
Class at
Publication: |
422/180 ; 60/299;
60/311; 29/890 |
International
Class: |
F01N 3/022 20060101
F01N003/022; B01J 19/00 20060101 B01J019/00; F01N 3/035 20060101
F01N003/035; B21D 51/16 20060101 B21D051/16 |
Claims
1. A substrate having corrugated sheet(s) and channel(s) for
treating exhaust gases of combustion engines, characterized in that
the substrate (1) comprises at least one corrugated sheet (3)
having depressions (3d) and one flat wire mesh sheet (2) having
depressions (2d) which is connected to said corrugated sheet (3)
and between said flat wire mesh sheet (2) and said corrugated sheet
(3) there are at least partially open channels (POC) for exhaust
gas (EG) flow, and that the depth of depression (2d) of said flat
wire mesh sheet (2) is 0.05-0.5 mm smaller than the height of the
corrugation (3c) of said corrugated sheet (3).
2. A substrate according to claim 1, characterized in that said
corrugated sheet (3) is a corrugated wire mesh sheet.
3. A substrate according to claim 1, characterized in that said
depressions (3d) of the corrugated sheet (3) has been matched to
the depressions (2d) of the flat wire mesh sheet (2).
4. A substrate according to claim 1, characterized in that the
depth of the depression (2d, 3d) is 0.5-1.5 mm.
5. A substrate according to claim 1, characterized in that the
height of the corrugation (3c) is 1.0-3.0 mm.
6. A substrate according to claim 1, characterized in that mesh
number of the mesh sheet is from 30 to 300.
7. A substrate according to claim 1, characterized in that said
flat wire mesh sheet (2) and said corrugated sheet (3) have been
attached to each other by welding or by brazing.
8. A substrate according to claim 1, characterized in that said
sheets (2, 3) have been at least partially covered by support
and/or catalytic material.
9. A method for using a substrate according to claim 1 for
purifying exhaust gases (EG).
10. A method for manufacturing a substrate having corrugated
sheet(s) for treating exhaust gases of combustion engines,
characterized in that a flat wire mesh sheet (2) having depressions
(2d) is connected to a corrugated sheet (3) having depressions (3d)
so that between said flat wire mesh sheet (2) and said corrugated
sheet (3) there are at least partially open channels (POC) for
exhaust gas (EG) flow, and that the depth of depression (3d) being
smaller than the height of the corrugation (3c).
11. A method according to claim 9, characterized in that said flat
wire mesh sheet (2) is connected to said corrugated sheet (3) by
rolling.
12. A method according to claim 9, characterized in that said flat
wire mesh sheet (2) is connected to said corrugated sheet (3) by
stacking or folding.
13. A method according to claim 9, characterized in that a flat
wire mesh sheet (2) is connected to a corrugated sheet (3) by
making depressions (2d, 3d) to said flat wire mesh sheet (2) and
corrugated sheet (3) and matching these depressions (2d, 3d) to
each other.
14. A method according to claim 9, characterized in that said flat
wire mesh sheet (2) and said corrugated sheet (3) are attached to
each other by welding or by brazing.
15. A substrate according to claim 2, characterized in that said
depressions (3d) of the corrugated sheet (3) has been matched to
the depressions (2d) of the flat wire mesh sheet (2).
16. A substrate according to claim 2, characterized in that the
depth of the depression (2d, 3d) is mm.
17. A substrate according to claim 3, characterized in that the
depth of the depression (2d, 3d) is mm.
18. A substrate according to claim 2, characterized in that the
height of the corrugation (3c) is mm.
19. A substrate according to claim 3, characterized in that the
height of the corrugation (3c) is mm.
20. A substrate according to claim 4, characterized in that the
height of the corrugation (3c) is mm.
Description
[0001] The present invention relates a substrate having corrugated
sheet(s) and channel(s) for treating exhaust gases of combustion
engines. The present invention also relates to methods for
manufacturing said substrate having said open channel(s).
BACKGROUND OF THE INVENTION
[0002] For the treatment of exhaust gases of combustion engines
substrates having open or closed channels or combinations of those
is used. In open channels the exhaust gas is directly flowing
through the substrate. In substrate having closed channels exhaust
gas is forced to flow through walls, e.g. through ceramic or
metallic porous walls. In open channels the reduction of gaseous
impurities is often high but the reduction of impurity particles is
low, e.g. from 10 to 15%. In closed channels/wall flow filters the
reduction of gaseous impurities is high and also the reduction of
impurity particles is high, e.g. from 70 to 99%. The problem in
closed channels is the clogging of walls. Closed channels/wall flow
filters will gradually wholly clog if they are not cleaned.
Pressure loss will also increase. One way to keep the channels open
is to clean them continuously or periodically.
DISCLOSURE OF THE INVENTION
[0003] A substrate that efficiently reduces particles and gas
impurities of exhaust gas in open channels has now been invented.
Accordingly a method for manufacturing said substrate has also been
invented.
[0004] For this purpose, the invention is characterized in facts
presented in the independent claims. Some preferable embodiments of
the invention are disclosed in other claims.
[0005] Constructional embodiments of the invention are not limited
in any way. According to an embodiment of the invention, the
catalyst of the invention can be present in several structures
assembled parallel or in series with respect to the flow direction
or cascade with POC/DPF-structure/substrates.
[0006] According to an embodiment of the invention the substrate
comprises corrugated sheet(s) having depressions connected to flat
wire mesh sheet(s) and between said flat wire mesh sheet and said
corrugated sheet there are at least partially channel(s) for
exhaust gas flow and the depth of depression is 0.05-0.5 mm smaller
than the height of the corrugation.
[0007] It has been surprisingly discovered that the reduction of
particles flowing in open channels is essentially improved. Also
the reduction of impurity gases in at least partially open channels
is improved.
[0008] Preferably the depth of the depression is 0.5-1.5 mm and the
height of the corrugation is 1.0-3.0 mm. This combination is very
effective both in reduction of particles and in the reduction of
impurity gases. The depressions can be e.g. 10-40 mm, such as 20-30
mm, from each other.
[0009] Exhaust gas can freely flow through partially open channels
but on the surfaces of sheet the gas flow rate is reduced due to
irregular surface of wire mesh sheet(s) and due to depressions of
sheets. These irregular surfaces and depressions also mix the gas
thus minimizing standard deviation of gas retention time. The
surfaces of wire mesh sheet(s) also act as an effect open particle
trap for exhaust gas particles. This combination adds contacts of
impurity of gases and particles thus adding retention time and
reduction of impurities and particles. Impurity particles are more
often attached to mesh sheet compared to smooth sheet. Especially
heavy and large particles are attached on the surfaces of wire mesh
sheet(s).
[0010] The reduction of particles is very much depending on the
particle source and composition of particles. Particles can include
various amount Volatile Organic Compounds (VOF's), solid carbon,
sulphur, water and metal oxides. A standard oxidation catalyst can
oxidize majority VOF's and reduce this way 10 to 60% of particle
mass. With the new invention it is possible to improve particle
reduction even up to 80%. With the new invention it is possible to
improve reduction of gas impurities >90%.
[0011] An important character of new partially open channel is that
it is not clogging at all or the clogging is minimal compared to
closed channels or filters, which will gradually wholly clog if
they are not cleaned. This is very important and the substrate
having at least partially open channels according to the invention
can be used in most demanding conditions and they are useful in
many applications.
[0012] The particles attached to the surfaces of at least partially
open channel(s) break down to gaseous impurities, which further
decompose to harmless compounds. Part of gas can flow through
openings of mesh sheet(s) and particles attach on surfaces of
sheet(s). Also this leads to better reduction of particles. On the
other hand partially open channels do not clog or the clogging is
minimal and pressure loss and flow rate of gas are not reduced near
the sheet(s). This reduces failure in operation thus adding
efficiency of the partially open channel.
[0013] The shape of openings of mesh sheet(s) can vary. It can be
canal-like, square-like, diamond-like or hole-like. E.g. in
diamond-like mesh sheet the wires can be at one level or they can
be crosswise.
[0014] Pressure difference between sides of the mesh sheet(s) adds
flowing of exhaust gas through pores of the mesh sheet. This
phenomenon leads to attachments of particles on support and better
reduction of particles from exhaust gas.
[0015] According to an embodiment of the invention said corrugated
sheet is a corrugated wire mesh sheet. This adds contacts of
impurity gases and particles thus adding retention time and
reduction of impurities. This leads to better reduction values of
impurity particles of exhaust gas. Collision of gas also leads to
better contact of gas with catalytically active material thus
improving reduction of gaseous impurities and adding retention time
of particles in said substrate.
[0016] Preferably, there are open channels with both sizes of said
mesh sheet. The structure of wire mesh sheet is simply, they are
easy to manufacture and the reduction of particles is high compared
e.g. smooth sheet used in open channels.
[0017] According to an embodiment of the invention said flat wire
mesh sheet has depressions. Also this adds reduction of impurity
gases particles by reducing flow rate of impurity gases and adding
attachment of particles on support.
[0018] According to an embodiment of the invention depressions of
the corrugated sheet have been matched to the depressions of the
flat wire mesh sheet. This leads to better strength of the
substrate because its locking layers to each other.
[0019] According to an embodiment of the invention the median
opening size of mesh sheet is from 0.01 to 0.5 mm, preferably from
0.05 to 0.3 mm, such as from 0.08 to 0.2 mm.
[0020] According to an embodiment of the invention the mesh
diameter is 0.08-0.24 mm. The mesh diameter is preferably 0.1-0.15
mm. Then the mechanical strength is high and pressure loss of gas
flow is low.
[0021] According to an embodiment of the invention mesh number of
the mesh sheet is from 30 to 300. At least part of exhaust gas can
flow through the openings of mesh sheets. This leads to attachment
of particles of exhaust gas to the surfaces of support giving
essentially better reduction of particles.
[0022] According to an embodiment of the invention said flat wire
mesh sheet and said corrugated sheet have been attached to each
other by welding/brazing. This leads to better strength of the
substrate.
[0023] According to an embodiment of the invention said sheet(s)
have been at least partially covered by support and/or catalytic
material. Preferable median pore size of said support is over 5 nm,
preferably from 10 to 50 nm, such as from 15 to 20 nm. Optimal pore
size of the support also depends on exhaust gases and circumstances
of gas flow near mesh sheet(s). Exhaust gases can have e.g. median
particle size from 5 to 200 nm and median pore size can e.g. be
from 5 to 20 nm.
[0024] Preferable support comprises coarse particles and/or fibres,
which are projecting out from the plane of said support. Preferably
the support has the median particle size over 0.4 .mu.m, such as
from 1.5 to 3.5 .mu.m. This essentially adds the adhesion of
particles thus improving the reduction of particles in said
substrate
[0025] According to an embodiment of the invention sheet(s) has
(have) been essentially covered with a support having the median
particle size over 1.4 .mu.m and/or having pores over 10 nm. This
also improves reduction of impurity particles by adding attachment
of particles to sheets.
[0026] Particles of exhaust gas of combustion engines can be
efficiently treated with substrate having mesh sheet(s) partially
open channels according to the invention. The reduction of impurity
particles is surprisingly high compared to traditional substrates.
Also the reduction of gaseous impurities is high. The mesh sheet(s)
according to the invention does not clog or the clogging is minimal
so that it does not have effect s on flowing rate of exhaust gas in
substrate. Also pressure loss in substrate is minimal.
[0027] The substrate can e.g. be a particle oxidation catalyst
(POC) or SCR catalyst. It can also be a hydrolysis catalyst. The
substrate can be preferably used to purify impurity particles of
exhaust gases of combustion engines. The structure of substrate can
vary. It can be e.g. wound or stacked or folded.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Now some embodiments of the present invention will be
described in more detail with reference to the appended
drawings.
[0029] FIG. 1 shows a substrate having corrugated sheet having
depressions and a flat wire mesh sheet.
[0030] In FIG. 1 substrate 1 comprises corrugated smooth sheets 3
having depressions 3d and flat wire mesh sheets 2 having
depressions 2d. These sheets are connected to each other and
between said sheets 2, 3 there are partially open channels POC for
exhaust gas EG flow. The depressions 3d of the corrugated sheet 3
has been matched to the depressions 2d of the flat wire mesh sheet
2. The depth of depression 2d of said flat wire mesh sheet 2 is
smaller than the height of the corrugation 3c of said corrugated
sheet 3. In this embodiment the depth of the depression 2d, 3d is
about 1 mm and the height of the corrugation 3c is about 2 mm.
* * * * *