Patent US4519816A successfully refreshed from Google Patents.
US4519816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the recovery of solvent vapors
Assignee: Dow Chemical Co
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Filing: 1980-10-01
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Granted: 1985-05-28
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Expires: 2000-10-01
Abstract
Abstract Polyurethane foams are employed to separate vapor of a volatile, organic liquid such as perchloroethylene from air or other gas containing the organic vapor. The absorbed, organic vapor can subsequently be recovered in liquid form by desorbing the vapor from the vapor laden foam and subsequently condensing the desorbed vapors.
Inventors
- 👤 Donald H. Clarke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:27
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; B01D53/1493; B01D53/1418; B01D53/1487; Y; Y10; Y10S; Y10S55/00; Y10S55/13; Y10S55/42
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
68 words
A method for recovering vapor of a volatile, organic liquid in a liquid form from a gas containing the organic vapor, said method comprising the steps of (a) contacting the gas containing the organic vapor with a gas permeable polyurethane foam at conditions sufficient to reduce the concentration of the vapor in the gas; (b) desorbing the organic vapor from the foam; and (c) condensing the desorbed vapor.
Claim 2
Independent Claim
68 words
A method for recovering vapor of a volatile, organic liquid in a liquid form from a gas containing the organic vapor, said method comprising the steps of (a) contacting the gas containing the organic vapor with a gas permeable polyurethane foam at conditions sufficient to reduce the concentration of the vapor in the gas; (b) desorbing the organic vapor from the foam; and (c) condensing the desorbed vapor.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the gas containing the organic vapor is air and the organic vapor is a halogenated hydrocarbon, an aromatic hydrocarbon or an aliphatic ketone.
Claim 4
Dependent Claim
33 words
The method of claim 2 wherein the polyurethane foam is the reaction product of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate or a mixture thereof with a hydroxyl-containing compound of a monomeric polyhydroxyl compound or a polyoxyalkylene polyol.
Claim 5
Dependent Claim
24 words
The method of claim 3 wherein the hydroxyl-containing compound is a polyoxyalkylene polyol derived from ethylene or propylene glycol or ethylene or propylene oxide.
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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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |