US4451441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for exhaust gas treatment
Assignee: WR Grace and Co Conn
•
Filing: 1983-09-09
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Granted: 1984-05-29
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Expires: 2003-09-09
Abstract
Abstract Suspended particles in exhaust gases, such as carbon and lead particles in internal combustion engine exhaust gases, are removed by passing the gases through a coarse filter and then through a fine filter. The filters may comprise a ceramic foam material and a catalyst material effective for the conversion of the carbon particles and/or gaseous pollutants in the exhaust gases to innocuous entities may be deposited on the filters.
Inventors
- 👤 Michael V. Ernest
- 👤 James M. Maselli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:57
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N3/2825; B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; F01N13/00; F01N13/009; F01N3/02; F01N3/021; F01N3/033; F01N3/035; F01N2330/00; F01N2330/06; F01N2570/00; F01N2570/02; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y10; Y10S; Y10S55/00; Y10S55/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
66 words
A method for removing carbon and lead particles from internal combustion engine exhaust gases comprising passing the gases through a coarse ceramic foam filter having a pore size of from about 2 to about 20 pores per 25 millimeters in length and then through a fine ceramic foam filter having a pore size of from about 15 to about 50 pores per 25 millimeters in length.
Claim 2
Independent Claim
66 words
A method for removing carbon and lead particles from internal combustion engine exhaust gases comprising passing the gases through a coarse ceramic foam filter having a pore size of from about 2 to about 20 pores per 25 millimeters in length and then through a fine ceramic foam filter having a pore size of from about 15 to about 50 pores per 25 millimeters in length.
Claim 3
Dependent Claim
48 words
The method of claim 1 in which the coarse filter has a pore size off from about 6 to about 20 pores per 25 millimeters in length and the fine filter has a pore size of from about 17 to about 30 pores per 25 millimeters in length.
Claim 4
Dependent Claim
20 words
The method of claim 1 in which the filters further comprise a carbon combustion catalyst material deposited on the filters.
Claim 5
Dependent Claim
25 words
The method of claim 3 in which the catalyst material comprises a noble metal, an element of the first transition series, hafnium, or mixtures thereof.
Claim 6
Dependent Claim
70 words
The method of claim 3 in which the catalyst material comprises a mixture of catalytically-effective amounts of at least one supported material selected from the group consisting of a noble metal, chromium, and catalytically-active compounds thereof, said material supported on a porous refractory inorganic oxide, and at least one bulk material selected from the group consisting of an element of the first transition series, silver, hafnium, and catalytically-active compounds thereof.
References Cited (Backward Citations)
GB641399A
Cited
GB808806A
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GB1014498A
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GB1412142A
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GB1450389A
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GB1462993A
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US4032124A
Cited
GB2035835A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |