Patent US2715514A successfully refreshed from Google Patents.
US4668489A
Expired / Lapsed
US
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Method for treating gas streams
Assignee: EFB Inc A CORP OF
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Filing: 1985-04-03
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Granted: 1987-05-26
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Expires: 2005-04-03
Abstract
Abstract A gaseous constituent such as SO 2 , HCl, or HF is removed from a gas stream in a granular bed filter containing granules coated with a sorbent material which is reactive with the gaseous constituent. Granules carrying reacted sorbent material are removed from the granular bed filter, cleaned of reacted sorbent material and coated with further sorbent material for reuse in the granular bed filter. Electrification of the filter bed permits simultaneous, highly efficient removal of particulates entrained in the gas stream.
Inventors
- 👤 Jeffrey Alexander
- 👤 Karim Zahedi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:54
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/508; B01D53/68; B01D53/685; B01D2257/00; B01D2257/20; B01D2257/204; B01D2257/2045; B01D2257/2047
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
155 words
A method of treating a gas stream containing a halogenous gaseous constituent to be removed, comprising providing a granular bed filter, supplying to the bed of said filter granules of a gravel having deposited thereon a coating of a sorvent material reactive with said gaseous constituent, passing gas from said gas stream through said bed for contacting said gas with the sorbent material on said granules and for reacting the sorbent material on said granules with the gaseous constituent contained in said gas, removing said granules from the bed of said filter after said gas has been in contact with the sorbent material on said granules, detaching reacted sorbent material from the removed granules, depositing a coating of further sorbent material on said removed granules, resupplying the further coated granules to the bed of said filter, and passing further gas from said gas stream through the bed of said filter with the resupplied granules therein.
Claim 2
Independent Claim
155 words
A method of treating a gas stream containing a halogenous gaseous constituent to be removed, comprising providing a granular bed filter, supplying to the bed of said filter granules of a gravel having deposited thereon a coating of a sorvent material reactive with said gaseous constituent, passing gas from said gas stream through said bed for contacting said gas with the sorbent material on said granules and for reacting the sorbent material on said granules with the gaseous constituent contained in said gas, removing said granules from the bed of said filter after said gas has been in contact with the sorbent material on said granules, detaching reacted sorbent material from the removed granules, depositing a coating of further sorbent material on said removed granules, resupplying the further coated granules to the bed of said filter, and passing further gas from said gas stream through the bed of said filter with the resupplied granules therein.
Claim 3
Dependent Claim
43 words
A method in accordance with claim 1, further comprising electrically charging particulates contained in the gas passed through the bed of said filter before passage thereof through said bed and electrifying said bed for adhering said particulates to the granules within said bed.
Claim 4
Dependent Claim
30 words
A method in accordance with claim 1, wherein said detaching of reacted sorbent material comprises agitating said removed granules, by pneumatically conveying the same, for dislodging reacted sorbent material therefrom.
Claim 5
Dependent Claim
63 words
A method in accordance with claim 1, wherein said sorbent material comprises a material selected from the group consisting of hydrated lime (Ca(OH 2 )), calcined limestone (CaO), sodium carbonate (Na 2 CO 3 ), sodium bicarbonate (NaHCO 3 ), limestone (CaCO 3 ), and mixtures therof, said hydrated lime and calcined limestone being used with or without sodium hydroxide (NaOH) added thereto.
Claim 6
Dependent Claim
21 words
A method in accordance with claim 4, wherein said gaseous constituent is one of hydrogen chloride (HCl) and hydrogen fluoride (HF).
Claim 7
Dependent Claim
34 words
A method in accordance with claim 1, wherein said granules comprise natural gravel having a diameter in the range from about 1/16 inch to about 1 inch (about 16 mm to about 250 mm).
Claim 8
Dependent Claim
27 words
A method in accordance with claim 1, wherein said depositing comprises attaching said coating of further sorbent material on said removed granules in a further granular bed.
Claim 9
Dependent Claim
27 words
A method in accordance with claim 7, wherein said attaching comprises electrostatically adhering particles of said removed sorbent material to said granules in said further granular bed.
Claim 10
Dependent Claim
26 words
A method in accordance with claim 7, wherein said attaching comprises dispersing particles of said sorbent material into an agitated portion of said further granular bed.
Claim 11
Dependent Claim
49 words
A method in accordance with claim 7, wherein said attaching comprises applying a liquid containing said sorbent material to said removed granules in said further granular bed and, prior to applying said liquid, heating those granules to a temperature which will cause said liquid to evaporate upon application thereto.
Claim 12
Dependent Claim
21 words
A method in accordance with claim 10, wherein said liquid is applied in an agitated portion of said further grannular bed.
Claim 13
Dependent Claim
24 words
A method in accordance with claim 10, wherein said sorbent material comprises a first part in solution and a second part in a slurry.
Claim 14
Dependent Claim
64 words
A method in accordance with claim 7, wherein said attaching comprises dispersing electrically charged particles of said sorbent material into said further granular bed, applying a liquid to said removed granules and dispersed particles of sorbent material in said further granular bed and, prior to applying said liquid, heating those granules to a temperature which will cause said liquid to evaporate upon application thereto.
Claim 15
Dependent Claim
23 words
A method in accordance with claim 13, wherein said dispersing and applying are done in an agitated portion of said further granular bed.
Claim 16
Dependent Claim
20 words
A method in accordance with claim 13, wherein said attaching includes electrifying said removed granules of said further granular bed.
Claim 17
Dependent Claim
43 words
A method in accordance with claim 4, further comprising electrically charging particulates contained in the gas passed through the bed of said filter before passage thereof through said bed and electrifying said bed for adhering said particulates to the granules within said bed.
Claim 18
Independent Claim
177 words
A method of treating a gas stream containing a gaseous constituent to be removed, comprising providing a granular bed filter, supplying to the bed of said filter granules of a gravel having deposited thereon a coating of a sorbent material reactive with said gaseous constituent, electrifying said bed, directing gas from said gas stream into said filter, electrically charging particulates contained in said gas, passing said gas through said bed in order to contact said gas with the sorbent material on said granules and thereby react the sorbent material on said granules with the gaseous constituent contained in said gas and in order to adhere the electrically charge particulates to the granules of said bed, removing said granules from said bed after said gas has been in contact with the sorbent material on said granules, detaching reacted sorbent material from the removed granules, depositing a coating of further sorbent material on said removed granules, resupplying the further coated granules to said bed, and passing further gas from said gas stream through said bed containing the resupplied granules.
Claim 19
Independent Claim
177 words
A method of treating a gas stream containing a gaseous constituent to be removed, comprising providing a granular bed filter, supplying to the bed of said filter granules of a gravel having deposited thereon a coating of a sorbent material reactive with said gaseous constituent, electrifying said bed, directing gas from said gas stream into said filter, electrically charging particulates contained in said gas, passing said gas through said bed in order to contact said gas with the sorbent material on said granules and thereby react the sorbent material on said granules with the gaseous constituent contained in said gas and in order to adhere the electrically charge particulates to the granules of said bed, removing said granules from said bed after said gas has been in contact with the sorbent material on said granules, detaching reacted sorbent material from the removed granules, depositing a coating of further sorbent material on said removed granules, resupplying the further coated granules to said bed, and passing further gas from said gas stream through said bed containing the resupplied granules.
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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) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |