Patent US3121749A successfully refreshed from Google Patents.
US5089237A
Expired / Lapsed
US
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Gas filter with catalytic coating and a gastight downstream region
Assignee: Daimler Benz AG
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Filing: 1990-06-29
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Granted: 1992-02-18
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Expires: 2010-06-29
Abstract
Abstract A soot burn-off filter including a monolithic filter block made of porous ceramic with a multiplicity of channels which extend in the direction of flow of the exhaust gases of a combustion engine. The channels are sealed alternately at the ends by plugs and are separated from one another by porous partition walls. The partition walls are provided with a catalytic coating and have an increased flow resistance in a region at the downstream end of the filter, the partition walls in this region being of gastight design and the catalytic coating of the partition walls ending in a region upstream of the gastight region of the partition walls.
Inventors
- 👤 Hans-Dieter Schuster
- 👤 Friedhelm Nunnemann
- 👤 Hans-Joachim Langer
- 👤 Erwin Strohmer
- 👤 Gerd Tiefenbacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:46
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/02; F01N3/021; F01N3/022; F01N3/0222; F01N3/033; F01N3/035; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N3/2825; F01N3/2828; F01N3/2882; B; B01; B01J; B01J35/00; B01J35/50; B01J35/56; F01N2330/00; F01N2330/06; F01N2510/00; F01N2510/06; Y; Y10; Y10S; Y10S430/00; Y10S430/165
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
132 words
Soot burn-off filter comprising a monolithic filter block made of porous ceramic with a multiplicity of channels which extend in the direction of flow of the exhaust gases of a combustion engine, are sealed alternately at the ends by plugs and are separated from one another by partition walls that have an upstream region and a downstream region, the upstream region of the partition walls being porous, the partition walls being provided with a catalytic coating, wherein the downstream region of the partition walls at the downstream end of the filter are gastight such that neither a flow of exhaust gas nor abrasive particles carried along in the flow of exhaust gas occurs in the downstream region, and wherein the downstream region of the partition walls is free of the catalytic coating.
Claim 2
Dependent Claim
132 words
Soot burn-off filter comprising a monolithic filter block made of porous ceramic with a multiplicity of channels which extend in the direction of flow of the exhaust gases of a combustion engine, are sealed alternately at the ends by plugs and are separated from one another by partition walls that have an upstream region and a downstream region, the upstream region of the partition walls being porous, the partition walls being provided with a catalytic coating, wherein the downstream region of the partition walls at the downstream end of the filter are gastight such that neither a flow of exhaust gas nor abrasive particles carried along in the flow of exhaust gas occurs in the downstream region, and wherein the downstream region of the partition walls is free of the catalytic coating.
Claim 3
Dependent Claim
25 words
Soot burn-off filter according to claim 1, wherein fibrous materials of ceramic material are placed in the partition walls, extending in the longitudinal direction thereof.
Claim 4
Dependent Claim
32 words
Soot burn-off filter according to claim 1, wherein the downstream region of the partition walls are produced by impregnating the latter with a material which seals the pores of the filter material.
Claim 5
Dependent Claim
32 words
Soot burn-off filter according to claim 2, wherein the downstream region of the partition walls are produced by impregnating the latter with a material which seals the pores of the filter material.
Claim 6
Dependent Claim
205 words
Method of making a monolithic filter block made of porous ceramic with a multiplicity of channels which extend in the direction of flow of the exhaust gases of a combustion engine, are sealed alternately at the ends by plugs and are separated from one another by porous partition walls, the partition walls being provided with a catalytic coating and being gastight in a region at the downstream end of the filter, said method comprising: forming a monolithic filter block of porous ceramic with a multiplicity of channels which extend in the direction for flow of the exhaust gases of a combustion engine, sealing the channels alternately at the ends by plugs with separation of the channels from one another by partition walls that have an upstream region and a downstream region, the upstream region of the partition walls being porous, the partition walls being provided with a catalytic coating, wherein the downstream region of the partition walls at the downstream end of the filter are gastight such that neither a flow of exhaust gas nor abrasive particles carried along in the flow of exhaust gas occurs in the downstream region, and wherein the downstream region of the partition walls is free of the catalytic coating.
Claim 7
Dependent Claim
205 words
Method of making a monolithic filter block made of porous ceramic with a multiplicity of channels which extend in the direction of flow of the exhaust gases of a combustion engine, are sealed alternately at the ends by plugs and are separated from one another by porous partition walls, the partition walls being provided with a catalytic coating and being gastight in a region at the downstream end of the filter, said method comprising: forming a monolithic filter block of porous ceramic with a multiplicity of channels which extend in the direction for flow of the exhaust gases of a combustion engine, sealing the channels alternately at the ends by plugs with separation of the channels from one another by partition walls that have an upstream region and a downstream region, the upstream region of the partition walls being porous, the partition walls being provided with a catalytic coating, wherein the downstream region of the partition walls at the downstream end of the filter are gastight such that neither a flow of exhaust gas nor abrasive particles carried along in the flow of exhaust gas occurs in the downstream region, and wherein the downstream region of the partition walls is free of the catalytic coating.
Claim 8
Dependent Claim
23 words
Method according to claim 5, wherein fibrous materials of ceramic material are placed in the partition walls, extending in the longitudinal direction thereof.
Claim 9
Dependent Claim
30 words
Method according to claim 5, wherein the downstream region of the partition walls are produced by impregnating the latter with a material which seals the pores of the filter material.
Claim 10
Dependent Claim
30 words
Method according to claim 6, wherein the downstream region of the partition walls are produced by impregnating the latter with a material which seals the pores of the filter material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-17 | 1995-08-19 | 1996-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-17 | 1999-08-19 | 2000-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-17 | 2003-08-19 | 2004-02-18 | $7700.00 | Window Closed / Lapsed |