US3816304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtering method
Assignee: Unifrax I LLC
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Filing: 1971-10-27
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Granted: 1974-06-11
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Expires: 1991-10-27
Abstract
Abstract An annular filter element includes a contiguous layer of gel impregnated filter media substantially concentric with a center passage. To remove viruses from a liquid, the liquid is passed through the layer of gel which is formed by the method of contacting the filter media with an aqueous solution containing colloidal particles of a polyvalent metal.
Inventors
- 👤 C Wallis
- 👤 J Melnick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:32
CPC Classifications
C; C12; C12N; C12N7/00; B; B01; B01D; B01D29/00; B01D29/11; B01D29/13; B01D29/15; B01D29/21; B01D29/216; B01D29/50; B01D29/56; B01D29/58; C12N2770/00; C12N2770/00011; C12N2770/32011; C12N2770/32611; C12N2770/32651
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
21 words
A method according to claim 1 wherein said layer is located upstream of at least a portion of said filter media.
Claim 2
Dependent Claim
16 words
A method according to claim 1 wherein said filter media comprises an overlapping winding of yarn.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein said filter media comprises glass fiber.
Claim 4
Dependent Claim
36 words
A method according to claim 1 wherein said ferric chloride is present in a concentration of about 0.002 moles per liter and said sodium carbonate is present in a concentration of about 0.01 moles per liter.
Claim 5
Independent Claim
44 words
A method for the preparation of gel impregnated annular filter media for the removal of viruses from fluids, said method comprising contacting said filter media with an aqueous colloidal suspension formed by mixing equal volumes of aqueous solutions of ferric chloride and sodium carbonate.
Claim 6
Dependent Claim
15 words
A method as set forth in claim 6 wherein said filter media comprises glass fibers.
Claim 7
Dependent Claim
23 words
A method as set forth in claim 7 wherein said ferric chloride is present in a concentration of about 0.002 moles per liter.
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) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |