US5075274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas cleaner
Assignee: Riken Corp
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Filing: 1990-03-15
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Granted: 1991-12-24
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Expires: 2010-03-15
Abstract
Abstract An exhaust gas cleaner having a heat-resistant, porous foam-type filter as a carrier, the filter being constituted by two portions consisting of a portion having a relatively low density and a high-density, thin layer portion formed on one side of the low density portion, the low-density portion supporting a base metal catalyst consisting essentially of (a) at least one of alkali metal elements, and (b) one or more elements selected from the group consisting of transition elements (excluding platinum-group elements) and Sn, and the high-density, thin layer portion supporting a platinum-group element catalyst. The base metal catalyst may further contain at least one of rare earth elements. The exhaust gas cleaning method is conducted by using this cleaner with its low-density portion on the exhaust gas inlet or outlet side.
Inventors
- 👤 Yoshida Kiyohide
- 👤 Sumiya Satoshi
- 👤 Muramatsu Gyo
- 👤 Sato Shinri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:16
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/54; B01J23/56; B01J23/64; B01J23/648; B01J23/6482; B01J23/652; B01J23/6522; B01J23/656; B01J23/6562; B01J23/70; B01J23/76; B01J23/83; B01J23/89; B01J23/8933; B01J23/8946; B01J35/00; B01J35/19; B01J37/00; B01J37/02; B01J37/024; B01J37/0244; F; F01; F01N; F01N13/00; F01N13/009; F01N13/0097; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N3/2825; F01N2250/00; F01N2250/02; F01N2510/00; F01N2510/06; F01N2570/00; F01N2570/04; F02; F02B; F02B1/00; F02B1/02; F02B1/04; F02B3/00; F02B3/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
92 words
An exhaust gas cleaner having a heat-resistant, porous ceramic foam filter as a carrier, said filter being constituted by two portions consisting of a portion having a relatively low density and a high-density, thin layer portion formed on one side of said low density portion, said low-density portion supporting a catalyst consisting essentially of (a) at least one of alkali metal elements, and (b) one or more elements selected from the group consisting of transition elements (excluding platinum-group elements) and Sn, and said high-density, thin layer portion supporting a platinum-group element catalyst.
Claim 2
Dependent Claim
92 words
An exhaust gas cleaner having a heat-resistant, porous ceramic foam filter as a carrier, said filter being constituted by two portions consisting of a portion having a relatively low density and a high-density, thin layer portion formed on one side of said low density portion, said low-density portion supporting a catalyst consisting essentially of (a) at least one of alkali metal elements, and (b) one or more elements selected from the group consisting of transition elements (excluding platinum-group elements) and Sn, and said high-density, thin layer portion supporting a platinum-group element catalyst.
Claim 3
Dependent Claim
40 words
The exhaust gas cleaner according to claim 1, wherein said low-density portion is located on the exhaust gas inlet side of said filter, and said high-density, thin layer portion is located on the exhaust gas outlet side of said filter.
Claim 4
Dependent Claim
40 words
The exhaust gas cleaner according to claim 1, wherein said high-density, thin layer portion is located on the exhaust gas inlet side of said filter, and said low-density portion is located on the exhaust gas outlet side of said filter.
Claim 5
Dependent Claim
19 words
The exhaust gas cleaner according to claim 1, wherein said high-density, thin layer portion further supports gold or silver.
Claim 6
Dependent Claim
107 words
An exhaust gas cleaner having a heat-resistant, porous ceramic foam filter as a carrier, said filter being constituted by portions consisting of a portion having a relatively low density and a high-density, thin layer portion formed on one side of said low density portion, said low-density portion supporting a catalyst consisting essentially of (a) at least one of alkali metal elements, (b) one or more elements selected from the group consisting of elements in IIA group of the Periodic Table, transition elements (excluding platinum-group elements) and Sn, and (c) at least one of rare earth elements; and said high-density, thin layer portion supporting a platinum-group element catalyst.
Claim 7
Dependent Claim
107 words
An exhaust gas cleaner having a heat-resistant, porous ceramic foam filter as a carrier, said filter being constituted by portions consisting of a portion having a relatively low density and a high-density, thin layer portion formed on one side of said low density portion, said low-density portion supporting a catalyst consisting essentially of (a) at least one of alkali metal elements, (b) one or more elements selected from the group consisting of elements in IIA group of the Periodic Table, transition elements (excluding platinum-group elements) and Sn, and (c) at least one of rare earth elements; and said high-density, thin layer portion supporting a platinum-group element catalyst.
Claim 8
Dependent Claim
40 words
The exhaust gas cleaner according to claim 5, wherein said low-density portion is located on the exhaust gas inlet side of said filter, and said high-density, thin layer portion is located on the exhaust gas outlet side of said filter.
Claim 9
Dependent Claim
40 words
The exhaust gas cleaner according to claim 5, wherein said high-density, thin layer portion is located on the exhaust gas inlet side of said filter, and said low-density portion is located on the exhaust gas outlet side of said filter.
Claim 10
Dependent Claim
19 words
The exhaust gas cleaner according to claim 5, wherein said high-density, thin layer portion further supports gold or silver.
Claim 11
Dependent Claim
38 words
The exhaust gas cleaner according to claim 5, wherein Cs, Cu and at least one of Ce and La are supported by said low-density portion, and the platinum-group element catalyst is supported by said high-density, thin layer portion.
Claim 12
Dependent Claim
17 words
The exhaust gas cleaner according to claim 5, wherein silver is further supported by said low-density portion.
Claim 13
Dependent Claim
101 words
An exhaust gas cleaner having a heat-resistant, porous ceramic foam filter as a carrier, said filter being constituted by two portions consisting of a portion having a relatively low density and a high-density, thin layer portion formed on one side of said low density portion, wherein said low-density portion is located on the exhaust gas inlet side of said filter, and said high-density, thin layer portion is located on the exhaust gas outlet side of said filter, a catalyst consisting essentially of Cs, Cu and at least one of Ce and La being supported by the overall body of said filter.
Claim 14
Dependent Claim
101 words
An exhaust gas cleaner having a heat-resistant, porous ceramic foam filter as a carrier, said filter being constituted by two portions consisting of a portion having a relatively low density and a high-density, thin layer portion formed on one side of said low density portion, wherein said low-density portion is located on the exhaust gas inlet side of said filter, and said high-density, thin layer portion is located on the exhaust gas outlet side of said filter, a catalyst consisting essentially of Cs, Cu and at least one of Ce and La being supported by the overall body of said filter.
Claim 15
Dependent Claim
14 words
The exhaust gas cleaner according to claim 11, wherein said filter further supports silver.
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) | 1994-12-23 | 1995-06-24 | 1995-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-23 | 1999-06-24 | 1999-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-23 | 2003-06-24 | 2003-12-24 | $7700.00 | Window Closed / Lapsed |