US3827976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for cleaning reverse osmosis membranes
Assignee: Graftech Technology LLC
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Filing: 1972-07-11
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Granted: 1974-08-06
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Expires: 1992-07-11
Abstract
Abstract A PROCESS FOR CLEANING REVERSE OSMOSIS MEMBRANES WHICH HAVE BEEN CONTAMINED WITH WATER INSOLUBLE FOULANTS COMPRISES THE STEPS OF (A) CONTACTING THE REVERSE OSMOSIS MEMBRANE, UNDER PRESSURE, WITH A CLEANING SOLUTION CONTAINING, PER LITER OR WATER, ABOUT 0.25-2.5 ML. OF AN ORGANIC NON-IONIC SURFACTANT, ABOUT 20-75 GRAMS OF AT LEAST ONE SALT SELECTED FROM NA2SO4, K2SO4 AND NACL, AND AT LEAST ONE MINERAL ACID SELECTED FROM HYDROCHLORIC AND SULFUIC ACID IN AN AMOUNT EFFECTIVE TO PROVIDE A CLEANING SOLUTION HAVING A PH BETWEEN ABOUT 1.54.0 (B) RELEASING THE PRESSURE ON THE REVERSE OSMOSIS MEMBRANE, AND (C) FLUSHING THE SOLUTION FROM THE MEMBRANE.
Inventors
- 👤 R Stana
- 👤 J Markind
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:46
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/02; B01D61/10; B01D63/00; B01D63/06; B01D63/062; B01D65/00; B01D65/02; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/16; B01D2321/00; B01D2321/16; B01D2321/162; B01D2321/168
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |