Patent US4072105A successfully refreshed from Google Patents.
US2981671A
Expired / Lapsed
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Method of reducing scale formation in electrodialytic cells
Assignee: Permutit Co Ltd
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Filing: 1958-12-15
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Granted: 1961-04-25
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Expires: 1978-12-15
Abstract
No abstract record available.
Inventors
- 👤 Griffiths Benjamin Kenneth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:08
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/42; B01D61/44; B01D61/52
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
IN A PROCESS FOR REMOVING IONS FROM AQUEOUS SOLUTION BY PASSAGE OF THE SOLUTION THROUGH EVERY ALTERNATE COMPARTMENT OF A MULTI-COMPARTMENT ELECTRODIALYSIS CELL CONTAINING ALTERNATING CATION-SELECTIVE AND ANION-SELECTIVE MEMBRANES, IONS TO BE REMOVED PASSING THROUGH BOTH THE MEMBRANES BOUNDING EACH SUCH COMPARTMENT INTO ANOTHER SOLUTION PASSING THROUGH THE REMAINING COMPARTMENTS, AND THE PROCESS BEING SUCH THAT SCALE FORMS ON SOME BUT NOT ALL OF THE MEMBRANES, THE IMPROVEMENT COMPRISING SUBSTITUTING FOR AT LEAST SOME OF THE SELECTIVE MEMBRANES ON WHICH SCALE FORMS ONLY BY MEMBRANES OF SUFFICIENTLY LOWER SELECTIVITY TO PRODUCE A SUBSTANTIAL DECREASE IN SCALING, NOT MORE THAN ONE MEMBRANE OF ANY COMPARTMENT BEING SUBSTITUTED BY A NON-SELECTIVE MEMBRANE.
Claim 2
Dependent Claim
110 words
IN A PROCESS FOR REMOVING IONS FROM AQUEOUS SOLUTION BY PASSAGE OF THE SOLUTION THROUGH EVERY ALTERNATE COMPARTMENT OF A MULTI-COMPARTMENT ELECTRODIALYSIS CELL CONTAINING ALTERNATING CATION-SELECTIVE AND ANION-SELECTIVE MEMBRANES, IONS TO BE REMOVED PASSING THROUGH BOTH THE MEMBRANES BOUNDING EACH SUCH COMPARTMENT INTO ANOTHER SOLUTION PASSING THROUGH THE REMAINING COMPARTMENTS, AND THE PROCESS BEING SUCH THAT SCALE FORMS ON SOME BUT NOT ALL OF THE MEMBRANES, THE IMPROVEMENT COMPRISING SUBSTITUTING FOR AT LEAST SOME OF THE SELECTIVE MEMBRANES ON WHICH SCALE FORMS ONLY BY MEMBRANES OF SUFFICIENTLY LOWER SELECTIVITY TO PRODUCE A SUBSTANTIAL DECREASE IN SCALING, NOT MORE THAN ONE MEMBRANE OF ANY COMPARTMENT BEING SUBSTITUTED BY A NON-SELECTIVE MEMBRANE.
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) | 1964-04-24 | 1964-10-24 | 1965-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-24 | 1968-10-24 | 1969-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-24 | 1972-10-24 | 1973-04-25 | $7700.00 | Window Closed / Lapsed |