Patent US4222877A successfully refreshed from Google Patents.
US4222877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Utilization of non-woven fabrics in water treatment
Assignee: Individual
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Filing: 1978-06-14
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Granted: 1980-09-16
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Expires: 1998-06-14
Abstract
Abstract A filtering method, and a filter, for removing turbidity and color from water, uses as a filtering medium, a blanket of non-woven fabric, particularly a blanket of felted fibers. The blanket is, in use, supported on a gravel bed, slotted ceramic blocks or the like, and can be held and protected by a grating.
Inventors
- 👤 Leziro M. Silva
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:31
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/28; C02F1/288; B; B01; B01D; B01D24/00; B01D24/007; B01D24/02; B01D24/20; B01D24/22; B01D39/00; B01D39/14; B01D2201/00; B01D2201/18; B01D2201/188
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
106 words
A filter for filtering water, comprising a lower horizontal water-pervious supporting means, filtering blanket of uniform thickness lying on and supported by said lower supporting means, said blanket comprising superposed layers of non-woven fabric comprising felted fibers selected from the group consisting of synthetic fibers and inorganic fibers, an upper water-pervious supporting means of overlying said blanket to confine said blanket between said lower supplying means and said upper supporting means, means for supporting raw water under pressure to pass through said blanket in one direction to filter said water and means for passing washwater through said blanket in the opposite direction to back-wash said filter.
Claim 2
Dependent Claim
106 words
A filter for filtering water, comprising a lower horizontal water-pervious supporting means, filtering blanket of uniform thickness lying on and supported by said lower supporting means, said blanket comprising superposed layers of non-woven fabric comprising felted fibers selected from the group consisting of synthetic fibers and inorganic fibers, an upper water-pervious supporting means of overlying said blanket to confine said blanket between said lower supplying means and said upper supporting means, means for supporting raw water under pressure to pass through said blanket in one direction to filter said water and means for passing washwater through said blanket in the opposite direction to back-wash said filter.
Claim 3
Dependent Claim
20 words
A filter according to claim 1, in which said fibers are synthetic fibers having a thickness of about 30 microns.
Claim 4
Dependent Claim
24 words
A filter according to claim 1, in which said fibers are synthetic fibers and have a density of 1 to 2.3 g/cm 3 .
Claim 5
Dependent Claim
23 words
A filter according to claim 1, in which said fibers are fiberglass and have a density of 0.02 to 0.05 g/cm 3 .
Claim 6
Dependent Claim
25 words
A filter according to claim 1, in which said blanket has a porosity of 80 to 96% and a permeability of 0.02 to 0.6 cm/s.
Claim 7
Dependent Claim
17 words
A filter according to claim 1, in which said lower supporting means comprising small, slotted ceramic blocks.
Claim 8
Dependent Claim
46 words
A filter according to claim 1, in which said lower supporting means comprises a layer of gravel below said blanket and said inner supporting means comprises a grating above said blanket, the direction of flow for filtering being down through said grating, blanket and gravel layer.
Claim 9
Dependent Claim
19 words
A filter according to claim 7, in which a grating is interposed between said blanket and said gravel layer.
Claim 10
Dependent Claim
28 words
A filter according to claim 1, in which said upper supporting means comprises a layer of gravel superposed on said blanket with a grating above said gravel layer.
Claim 11
Dependent Claim
19 words
A filter according to claim 9, in which a grating is interposed between said blanket and said gravel 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) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |