Patent US3780497A successfully refreshed from Google Patents.
US3780497A
Expired / Lapsed
US
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Adsorption of fluorine and fluorine compounds on alumina
Assignee: AIR INDUSTRIE ENVIRONMENT A Co
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Filing: 1971-08-20
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Granted: 1973-12-25
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Expires: 1991-08-20
Abstract
Abstract The invention relates to a method for adsorbing gaseous fluorine on alumina particles. The alumina particles are introduced at the base of an adsorption column through which the stream of gas to be scrubbed flows, the column terminating in a separator where the particles charged with fluorine are recovered. The method is particularly suitable for scrubbing of gas from electrolytic baths in an aluminium-producing plant.
Inventors
- 👤 W Muhlrad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:24
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/68; C; C25; C25C; C25C3/00; C25C3/06; C25C3/22
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
33 words
A method as claimed in claim 1, in which the alumina particles leaving the adsorption column and recovered in the separator are not saturated with fluorine and are recycled to the adsorption column.
Claim 2
Dependent Claim
22 words
A method as claimed in claim 1, in which the concentration of alumina in the adsorption column is above about 150 g/m3.
Claim 3
Dependent Claim
29 words
A method according to claim 1, in which the speed at which the stream of gas rises in the adsorption column is between about 10 and about 20 m/sec.
Claim 4
Dependent Claim
63 words
A method according to claim 1, in which the separation of the solid particles in suspension in the stream of gas from the adsorption column is performed in two successive stages, the first corresponding to the collection of relatively large alumina particles and the second corresponding to the collection of fine dust remaining suspended in the stream of gas leaving the first stage.
Claim 5
Dependent Claim
28 words
A method according to claim 1, wherein the pressure drop in the adsorption column is only of the order of about 30 to 50 mm of water column.
Claim 6
Dependent Claim
16 words
A method according to claim 1, including replenishing a fraction of fresh alumina into the column.
Claim 7
Dependent Claim
31 words
A method according to claim 7, wherein said fraction of fresh alumina is at least of the order of 2 percent of the quantity of alumina in service in the column.
Claim 8
Dependent Claim
31 words
A method according to claim 7, wherein said fraction of fresh alumina is of the order of 2 to 5 percent of the quantity of alumina in service in the column.
Claim 9
Dependent Claim
20 words
A method according to claim 1, wherein said distributing of alumina particles is in an at least partially downward direction.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |