Patent US3880754A successfully refreshed from Google Patents.
US3880754A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtering with polyacrylonitrile or polyamide fibers as filter aid
Assignee: Bayer AG
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Filing: 1974-04-12
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Granted: 1975-04-29
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Expires: 1994-04-12
Abstract
Abstract The invention is related to the field of settling filtration and claims a method of filtering a liquid suspension wherein ground polyacrylonitrile or polyamide fibres having a fibrous structure are added to the suspension before filtration and wherein settling filtration is carried out by a method known per se.
Inventors
- 👤 Hans R Brost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:37
CPC Classifications
B; B01; B01D; B01D37/00; B01D37/02; B01D39/00; B01D39/02; B01D39/04; B01J; B01J20/00; B01J20/22; B01J20/26; B01J20/261; B01J20/262; B01J20/28; B01J20/28014; B01J20/28023; B01J47/00; B01J47/12; B01J47/133
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
84 words
IN THE PROCESS FO DESALTING OR DECOLORING AN AQUEOUS SOLUTION WITH A FILTER AID BY FORMING A SUSPENSION OF THE FILTERING MEDIUM, INCLUDING A FILTERING AID, HOMOGENIZING SAID SUSPENSION, APPLYING THE SOLIDS CONTENT OF THE SUSPENSION AS A HOMOGENEOUS LAYER AND PASSING THE AQUEOUS SOLUTION TO BE FILTERED THERETHROUGH, THE IMPROVEMENT WHICH COMPRISES EMPLOYING AS SAID HOMOGENEOUS LAYER A MIXTURE OF A CATION AND AN ANION EXCHANGE RESIN TOGETHER WITH A FILTER AID COMPRISING GROUND FIBERS OF POLYACRYLONITRILE, A POLYAMIDE OR A MIXTURE THEREOF.
Claim 2
Dependent Claim
84 words
IN THE PROCESS FO DESALTING OR DECOLORING AN AQUEOUS SOLUTION WITH A FILTER AID BY FORMING A SUSPENSION OF THE FILTERING MEDIUM, INCLUDING A FILTERING AID, HOMOGENIZING SAID SUSPENSION, APPLYING THE SOLIDS CONTENT OF THE SUSPENSION AS A HOMOGENEOUS LAYER AND PASSING THE AQUEOUS SOLUTION TO BE FILTERED THERETHROUGH, THE IMPROVEMENT WHICH COMPRISES EMPLOYING AS SAID HOMOGENEOUS LAYER A MIXTURE OF A CATION AND AN ANION EXCHANGE RESIN TOGETHER WITH A FILTER AID COMPRISING GROUND FIBERS OF POLYACRYLONITRILE, A POLYAMIDE OR A MIXTURE THEREOF.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the ground fibers having a denier range of 1 to 50 dtex.
References Cited (Backward Citations)
US2301430A
Cited
US3252270A
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US3368678A
Cited
US3716483A
Cited
US3618766A
Cited
US3707398A
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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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |