US4375426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalytic fibre packs for ammonia oxidation
Assignee: Johnson Matthey PLC
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Filing: 1980-10-16
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Granted: 1983-03-01
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Expires: 2000-10-16
Abstract
Abstract This invention is concerned with the application of fibrous products from platinum group metal or platinum group metal alloys to the oxidation of ammonia in the manufacture, for example, of nitric acid and to the production of hydrogen cyanide in the Andrassow Process. In particular, the invention relates to a catalyst assembly including an agglomeration or assemblage of randomly oriented fibres made from a platinum group metal or an alloy containing at least one platinum group metal, gold or silver. The fibres used in the catalyst assembly are preferably produced by melt extraction or melt spinning processes.
Inventors
- 👤 Arthur G. Knapton
- 👤 Gordon L. Selman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:08
CPC Classifications
B; B01; B01J; B01J12/00; B01J12/007; B01J23/00; B01J23/38; B01J35/00; B01J35/50; B01J35/58; C; C01; C01B; C01B21/00; C01B21/20; C01B21/24; C01B21/26; C01B21/265; C01C; C01C3/00; C01C3/02; C01C3/0208; C01C3/0212; C01C3/0216
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
41 words
A catalyst assembly including an agglomeration or assemblage of randomly oriented melt extracted or melt spun fibres made from a platinum group metal or an alloy containing at least one platinum group metal and supported on at least one metal gauze.
Claim 2
Dependent Claim
41 words
A catalyst assembly including an agglomeration or assemblage of randomly oriented melt extracted or melt spun fibres made from a platinum group metal or an alloy containing at least one platinum group metal and supported on at least one metal gauze.
Claim 3
Dependent Claim
15 words
A catalyst assembly according to claim 1 wherein the fibres are of relatively short length.
Claim 4
Dependent Claim
23 words
A catalyst assembly according to claim 1 wherein the fibres are of generally circular or non-circular cross section and bearing an irregular surface.
Claim 5
Dependent Claim
22 words
A catalyst assembly according to claim 1 wherein the length of the fibres falls within the range of 1/2 to 4 inches.
Claim 6
Dependent Claim
22 words
A catalyst assembly according to claim 4 wherein the length of the fibres falls within the range of 1/2 to 2 inches.
Claim 7
Dependent Claim
41 words
A catalyst assembly according to claim 5 wherein the fibres are of "D"-cross-sectional shape having the major dimension thereof falling within the range 0.004 to 0.006 inch and having the minor dimension therof falling within the range 0.002 to 0.005 inch.
Claim 8
Dependent Claim
12 words
A catalyst assembly according to claim 1 wherein the fibres are crimped.
Claim 9
Dependent Claim
32 words
A catalyst assembly according to claim 1 wherein the agglomeration of fibres is compressed to a density such that the agglomeration contains between 10 and 30 kg per square meter of agglomerate.
Claim 10
Dependent Claim
25 words
A catalyst assembly according to claim 8 wherein the said density falls within the range of 15 to 20 kg per square meter of agglomerate.
Claim 11
Dependent Claim
33 words
A catalyst assembly according to claim 1 wherein the agglomeration of fibres is supported on at least one gauze made from a platinum group metal or alloy thereof or an oxidation-resistant base metal.
Claim 12
Dependent Claim
35 words
A catalyst assembly according to claim 1 wherein the agglomeration of fibres is sandwiched between layers comprising one or more gauzes made from a platinum group metal, or alloy thereof or an oxidation-resistant base metal.
Claim 13
Dependent Claim
17 words
A catalyst assembly according to claim 10 wherein the fibres are made from a 10% Rh/Pt alloy.
References Cited (Backward Citations)
GB889583A
Cited
US3406025A
Cited
US3769240A
Cited
US3838185A
Cited
US3904344A
Cited
US3812901A
Cited
US3931051A
Cited
US4069171A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-28 | 1986-08-30 | 1987-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-28 | 1990-08-30 | 1991-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-28 | 1994-08-30 | 1995-03-01 | $7700.00 | Window Closed / Lapsed |