US5098455A
Expired / Lapsed
US
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Regenerable exhaust gas filter element for diesel engines
Assignee: Dow Chemical Co
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Filing: 1990-12-21
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Granted: 1992-03-24
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Expires: 2010-12-21
Abstract
Abstract A regenerable exhaust gas filter element for diesel engines includes an interlaced network of mullite crystals grown together forming a rigid porous body. Soot carried by exhaust gas from a diesel engine flowing through the filter is trapped in the porous body and thereafter burned off to regenerate the element. A network of mullite crystals in accordance with the invention is automatically interlaced and fused with one another to form the porous body of the filter element.
Inventors
- 👤 Peter A. Doty
- 👤 John R. Moyer
- 👤 Neal N. Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:33
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/02; F01N3/021; F01N3/022; F01N3/0222; B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2072; B01D39/2075; C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/185; C04B38/00; C04B2111/00; C04B2111/00474; C04B2111/00793; F01N2330/00; F01N2330/06; F02; F02B; F02B3/00; F02B3/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10S; Y10S55/00; Y10S55/10; Y10S55/30; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149; Y10T428/24744
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
62 words
A regenerable exhaust gas filter element for diesel engines, comprising: an interlaced network of mullite crystals grown together to form a rigid porous body such that the soot carried by exhaust gas from a diesel engine flowing therethrough is trapped in the porous body, said network of mullite crystals being automatically interlaced and fused with one another to form the porous body.
Claim 2
Dependent Claim
62 words
A regenerable exhaust gas filter element for diesel engines, comprising: an interlaced network of mullite crystals grown together to form a rigid porous body such that the soot carried by exhaust gas from a diesel engine flowing therethrough is trapped in the porous body, said network of mullite crystals being automatically interlaced and fused with one another to form the porous body.
Claim 3
Dependent Claim
17 words
The element of claim 1, wherein said interlaced network of mullite crystals includes randomly oriented mullite crystals.
Claim 4
Dependent Claim
12 words
The element of claim 1, wherein said crystals are substantially single crystals.
Claim 5
Dependent Claim
17 words
The element of claim 1, wherein said crystals are grown and fused together by pyrolysis of fluorotopaz.
Claim 6
Dependent Claim
18 words
The element of claim wherein said mullite crystals have diameters of between about 4 and about 30 micrometers.
Claim 7
Dependent Claim
72 words
A regenerable exhaust gas filter element for diesel engines, comprising: an interlaced network of mullite crystals grown together to form a rigid porous body such that the soot carried by exhaust gas from a diesel engine flowing therethrough is trapped in the porous body, said network of mullite crystals being formed from alumina and silica by pyrolysis of fluorotopaz to automatically interlace and fuse with one another to form the porous body.
Claim 8
Dependent Claim
72 words
A regenerable exhaust gas filter element for diesel engines, comprising: an interlaced network of mullite crystals grown together to form a rigid porous body such that the soot carried by exhaust gas from a diesel engine flowing therethrough is trapped in the porous body, said network of mullite crystals being formed from alumina and silica by pyrolysis of fluorotopaz to automatically interlace and fuse with one another to form the porous body.
Claim 9
Dependent Claim
17 words
The element of claim 6, wherein said interlaced network of mullite crystals includes randomly oriented mullite crystals.
Claim 10
Dependent Claim
12 words
The element of claim 6, wherein said crystals are substantially single crystals.
Claim 11
Dependent Claim
19 words
The element of claim 6, wherein said mullite crystals have diameters of between about 4 and about 30 micrometers.
Claim 12
Dependent Claim
75 words
A regenerable exhaust gas filter element for diesel engines, comprising: an interlaced network of mullite crystals grown together to form a rigid porous body such that the soot carried by exhaust gas from a diesel engine flowing therethrough is trapped in the porous body, said network of mullite crystals including non-stoichiometric crystals of alumina and silica, and said network of mullite crystals being automatically interlaced and fused with one another to form the porous body.
Claim 13
Dependent Claim
75 words
A regenerable exhaust gas filter element for diesel engines, comprising: an interlaced network of mullite crystals grown together to form a rigid porous body such that the soot carried by exhaust gas from a diesel engine flowing therethrough is trapped in the porous body, said network of mullite crystals including non-stoichiometric crystals of alumina and silica, and said network of mullite crystals being automatically interlaced and fused with one another to form the porous body.
Claim 14
Dependent Claim
17 words
The element of claim 10, wherein said interlaced network of mullite crystals includes randomly oriented mullite crystals.
Claim 15
Dependent Claim
12 words
The element of claim 10, wherein said crystals are substantially single crystals.
Claim 16
Dependent Claim
17 words
The element of claim 10, wherein said crystals are grown and fused together by pyrolysis of fluorotopaz.
Claim 17
Dependent Claim
19 words
The element of claim 10, wherein said mullite crystals have diameters of between about 4 and about 30 micrometers.
Claim 18
Dependent Claim
20 words
The element of claim 10, wherein said non-stoichiometric crystals are crystals of about 2:1 molar ratio of alumina to silica.
Claim 19
Dependent Claim
70 words
A regenerable exhaust gas filter element for diesel engines, comprising: a randomly oriented interlaced network of substantially single crystal mullite whiskers grown together to form a rigid porous body, said mullite whiskers individually having diameters of between about 4 and about 30 micrometers, and aspect ratios of between about 10 and about 50, said mullite whisker network being fabricated from alumina and silica by pyrolyzing fluorotopaz to form mullite crystals.
Claim 20
Dependent Claim
70 words
A regenerable exhaust gas filter element for diesel engines, comprising: a randomly oriented interlaced network of substantially single crystal mullite whiskers grown together to form a rigid porous body, said mullite whiskers individually having diameters of between about 4 and about 30 micrometers, and aspect ratios of between about 10 and about 50, said mullite whisker network being fabricated from alumina and silica by pyrolyzing fluorotopaz to form mullite crystals.
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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) | 1995-03-24 | 1995-09-23 | 1996-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-24 | 1999-09-23 | 2000-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-24 | 2003-09-23 | 2004-03-24 | $7700.00 | Window Closed / Lapsed |