Patent US5340548A successfully refreshed from Google Patents.
US5340548A
Expired / Lapsed
US
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Exhaust gas cleaner and method of cleaning exhaust gas
Assignee: Riken Corp
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Filing: 1993-02-11
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Granted: 1994-08-23
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Expires: 2013-02-11
Abstract
Abstract An exhaust gas cleaner comprising a heat-resistant, porous filter, a porous ceramic layer formed on the filter, and a catalyst supported by the ceramic layer, the catalyst consisting essentially of: (a) at least one of alkali metal elements; (b) copper and vanadium; and (c) at least one of rare earth elements. By using this exhaust gas cleaner, particulate matter in the exhaust gas is oxidized by the catalyst supported by the filter, and nitrogen oxides are reduced by the particulate matter serving as a reducing agent.
Inventors
- 👤 Akira Abe
- 👤 Satoshi Sumiya
- 👤 Yoshikazu Takahashi
- 👤 Kiyohide Yoshida
- 👤 Gyo Muramatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:03
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01J; B01J23/00; B01J23/70; B01J23/76; B01J23/84; B01J23/847; B01J23/8472; B01D2255/00; B01D2255/20; B01D2255/202; B01D2255/2022; B01D2255/206; B01D2255/2063; B01D2255/2065; B01D2255/207; B01D2255/20723; B01D2255/20761; B01D2255/90; B01D2255/915; F; F02; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
An exhaust gas cleaner comprising a heat-resistant, porous filter and a catalytic layer consisting of a uniform mixture of a catalyst and a ceramic carrier powder, said catalytic layer being formed on said filter from a solution consisting of an organic salt of ceramic carrier-constituting metal and a solution of a catalytic component metal salt by a sol-gel method, said catalyst consisting essentially of: (a) at least one of alkali metal elements; (b) copper and vanadium; and (c) at least one rare earth element, wherein the amount of said catalyst is 1-20 parts by weight and the amount of said ceramic carrier powder is 1-10 parts by weight, based on 100 parts by weight of said filter.
Claim 2
Dependent Claim
117 words
An exhaust gas cleaner comprising a heat-resistant, porous filter and a catalytic layer consisting of a uniform mixture of a catalyst and a ceramic carrier powder, said catalytic layer being formed on said filter from a solution consisting of an organic salt of ceramic carrier-constituting metal and a solution of a catalytic component metal salt by a sol-gel method, said catalyst consisting essentially of: (a) at least one of alkali metal elements; (b) copper and vanadium; and (c) at least one rare earth element, wherein the amount of said catalyst is 1-20 parts by weight and the amount of said ceramic carrier powder is 1-10 parts by weight, based on 100 parts by weight of said filter.
Claim 3
Dependent Claim
18 words
The exhaust gas cleaner according to claim 1, wherein the ceramic layer is made of TiO 2 .
Claim 4
Dependent Claim
19 words
The exhaust gas cleaner according to claim 1, wherein the amount of said catalyst is 5-15 parts by weight.
Claim 5
Dependent Claim
21 words
The exhaust gas cleaner according to claim 1, wherein the amount of said ceramic carrier powder is 2-6 parts by weight.
References Cited (Backward Citations)
US5141714A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-08-22 | 1998-02-21 | 1998-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-22 | 2002-02-21 | 2002-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-22 | 2006-02-21 | 2006-08-23 | $7700.00 | Window Closed / Lapsed |