US3764526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamics reverse osmosis membranes of ultrathin discs
Assignee: United States Department of the Interior
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Filing: 1972-03-28
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Granted: 1973-10-09
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Expires: 1992-03-28
Abstract
Abstract Ultrathin membrane discs are prepared by spraying a casting solution of the membrane material onto a surface to form a number of individual discs, allowing the solvent to evaporate from the discs, and removing the discs from the casting surface. Slurries of these discs may be used to form dynamic membranes suitable for use in reverse osmosis applications such as the desalination of water.
Inventors
- 👤 W King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:54
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
16 words
The membrane of claim 1 in which said reverse osmosis separation is the desalination of water.
Claim 2
Dependent Claim
16 words
The membrane of claim 1 in which said ultrathin membrane discs consist of a neutral polymer.
Claim 3
Dependent Claim
13 words
The membrane of claim 3 in which said neutra polymer is cellulose acetate.
Claim 4
Dependent Claim
105 words
A process for the separation of pure solvent from a solution by reverse osmosis comprising the steps of: forming a dispersion of ultrathin membrane discs, passing said dispersion over the feed side of a porous support material in the separation apparatus to deposit a layer of ultrathin discs on said support material, using said layer of ultrathin membrane discs as the active reverse osmosis membrane to effect said separation, and repairing at least a portion of said layer of ultrathin membrane discs when necessary by passing said dispersion of ultrathin membrane discs over the feed side of said porous support material to remake said layer.
Claim 5
Dependent Claim
13 words
The process of claim 5 wherein said separation is the desalination of water.
Claim 6
Dependent Claim
16 words
The process of claim 5 wherein said ultrathin membrane discs are composed of a neutral polymer.
Claim 7
Dependent Claim
12 words
The process of claim 7 wherein said neutral polymer is cellulose acetate.
Claim 8
Dependent Claim
33 words
The process of claim 5 including the step of removing said active layer of ultrathin membrane discs when replacement is required, prior to said repairing of at least a portion of said layer.
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) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |