US3684094A
Expired / Lapsed
US
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LIQUID TREATMENT SYSTEM FOR HIGH pH WATER
Assignee: Graftech Technology LLC
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Filing: 1970-07-28
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Granted: 1972-08-15
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Expires: 1990-07-28
Abstract
Abstract A packing composition effective to reduce the pH of alkaline liquids, used as a pretreatment, in association with a reverse osmosis membrane and support in a liquid treatment system, is made of an encapsulating matrix of polymeric material that is essentially water impermeable at a pH between about 4.5 and 8 and which becomes significantly water permeable at a pH above about 9, and an acidulous material which is encapsulated by the matrix at a pH between about 4.5 and 8, and released progressively from the matrix at a pH above about 9.
Inventors
- 👤 Richard M Chamberlin
- 👤 Regis R Stana
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:01
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/02; B01D61/04; B01D61/025; C; C02; C02F; C02F1/00; C02F1/66; B01D2311/00; B01D2311/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
38 words
The liquid treatment system of claim 1 wherein the acidulous material is uniformly distributed throughout the matrix of polymeric material and constitutes from about 1 to 60 weight percent of the packing composition of the liquid pretreatment system.
Claim 2
Dependent Claim
35 words
The liquid treatment system of claim 2 wherein the polymeric material constituting the matrix comprises a cellulose compound containing a chemical group which is appreciably hydrolyzable in water at a pH greater then about 9.
Claim 3
Dependent Claim
36 words
The liquid treatment system of claim 3 wherein the polymeric material constituting the matrix is selected from the grOup consisting of cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate-butyrate, cellulose acetate-propionate, methyl cellulose and ethyl cellulose.
Claim 4
Dependent Claim
53 words
The liquid treatment system of claim 4 wherein the acidulous material is alumina, the polymeric material constituting the matrix is cellulose acetate, the reverse osmosis membrane of the liquid purification system is selected from the group consisting of cellulose esters and cellulose ethers and the support for the membrane is a porous support.
Claim 5
Dependent Claim
26 words
The liquid treatment system of claim 5 wherein the reverse osmosis membrane is a tubular membrane and the support for the membrane is a tubular support.
Claim 6
Dependent Claim
56 words
The liquid treatment system of claim 1 wherein the acidulous material is selected from the group consisting of alumina, magnesium nitrate, magnesium chloride, magnesium sulfate, ammonium nitrate, silver chloride, silver sulfate, lead nitrate, silver chloride, silver sulfate, lead nitrate, lead chloride, lead sulfate, iron nitrate, iron chloride, iron sulfate, aluminum nitrate, aluminum chloride and aluminum sulfate.
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) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |