US4986913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter pad
Assignee: Individual
•
Filing: 1989-04-04
•
Granted: 1991-01-22
•
Expires: 2009-04-04
Abstract
Abstract Filter pads, which are made inherently stable by binders and by removal of the binders can be converted in packings to be maintained under substantially constant surface pressure between rigid filter brackets, are produced first as molded bodies from a suspension of filter aids in liquid by depositing granular, fibrous, or fiber-containing filter aids or mixtures of those filter aids in a casting mold, there being used high rates of flow while avoiding turbulences, and adding binders to the suspension so that the molded body can be stabilized by activation of the binder while drying. It is possible in this process also to manufacture multi-layered filter pads, it having been surprisingly found in those multi-layered filter pads that the layer assembly is kept intact during the filtration even in the filter packing that no longer contains binders. The filter pads or the filter packings produced therefrom according to the invention can, when used, and after reflushing and regeneration operations, finally be utilized, after being replaced, as filter aids in the deposit filtration process.
Inventors
- 👤 Helmut Schafft
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:42
CPC Classifications
B; B01; B01D; B01D25/00; B01D25/001; B01D25/002; B01D25/22; B01D25/26; B01D29/00; B01D29/11; B01D29/111; B01D29/31; B01D29/50; B01D29/52; B01D29/54; B01D29/62; B01D29/66; B01D29/96; B01D2101/00; B01D2101/005; B01D2101/02; B01D2201/00; B01D2201/08; B01D2201/085; B01D2201/18; B01D2201/182; B01D2201/34; B01D2201/40; Y; Y10; Y10S; Y10S264/00; Y10S264/48
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
118 words
A filter pad comprising a multiplicity of adjacent layers (a to i; j to r; s to z) of different filtration properties ranging from coarse to progressively finer filter layers, wherein the course layer is a base layer and the progressively finer layers are successively deposited thereon whereby each progressively finer layer at least partially penetrates into pores of the immediately adjacent deposited layer thereby improving the surface bonding between adjacent layers, and said filter pad being rendered dimensionally stable by means of a binder material and being convertible to a filter packing by an in-situ removal of said binder material. further comprising at least one layer that contains agents which enzymatically treat the medium to be filtered.
Claim 2
Dependent Claim
118 words
A filter pad comprising a multiplicity of adjacent layers (a to i; j to r; s to z) of different filtration properties ranging from coarse to progressively finer filter layers, wherein the course layer is a base layer and the progressively finer layers are successively deposited thereon whereby each progressively finer layer at least partially penetrates into pores of the immediately adjacent deposited layer thereby improving the surface bonding between adjacent layers, and said filter pad being rendered dimensionally stable by means of a binder material and being convertible to a filter packing by an in-situ removal of said binder material. further comprising at least one layer that contains agents which enzymatically treat the medium to be filtered.
Claim 3
Dependent Claim
26 words
A filter pad according to claim 1, wherein at least one of said adjacent layers (j or r) is predominantly formed from a granular filter aid.
Claim 4
Dependent Claim
26 words
A filter pad according to claim 1, wherein at least one of said adjacent layers (a to i) is predominantly formed from a fibrous filter aid.
Claim 5
Dependent Claim
15 words
A filter pad according to claim 3, wherein said filter aid comprises an organic material.
Claim 6
Dependent Claim
15 words
A filter pad according to claim 3, wherein said filter aid comprises an inorganic material.
Claim 7
Dependent Claim
17 words
A filter pad according to claim 1, and comprising at least one layer of an absorbing agent.
Claim 8
Dependent Claim
36 words
A filter pad according to claim 6, wherein said absorbing agent is selected from the group consisting of kieselguhr, perlite, bentonite, fuller's earth, silicious gel, activated charcoal, cellulose, polyvinylpolypyrrolidone, linter of cotton, aluminum silicate and polyamide.
Claim 9
Dependent Claim
26 words
A filter pad according to claim 1, wherein at least one of said adjacent layers (a to i) is exclusively formed from a fibrous filter aid.
Claim 10
Dependent Claim
15 words
A filter pad according to claim 8, wherein said filter aid comprises an organic material.
Claim 11
Dependent Claim
14 words
A filter pad according to claim 8, wherein said filter aid comprises inorganic material.
Claim 12
Dependent Claim
17 words
A filter pad according to claim 1, and comprising at least one layer of an absorbing agent.
Claim 13
Dependent Claim
116 words
A filter pad comprising a multiplicity of adjacent layers (a to i; j to r; s to z) of different filtration properties ranging from coarse to progressively finer filter layers, wherein the course layer is a base layer and the progressively finer layers are successively deposited thereon whereby each progressively finer layer at least partially penetrates into pores of the immediately adjacent deposited layer thereby improving the surface bonding between adjacent layers, and said filter pad being rendered dimensionally stable by means of a binder material and being convertible to a filter packing an in-situ removal of said binder material, comprising at least one layer that contains agents which fermentatively treat the medium to be filtered.
Claim 14
Dependent Claim
116 words
A filter pad comprising a multiplicity of adjacent layers (a to i; j to r; s to z) of different filtration properties ranging from coarse to progressively finer filter layers, wherein the course layer is a base layer and the progressively finer layers are successively deposited thereon whereby each progressively finer layer at least partially penetrates into pores of the immediately adjacent deposited layer thereby improving the surface bonding between adjacent layers, and said filter pad being rendered dimensionally stable by means of a binder material and being convertible to a filter packing an in-situ removal of said binder material, comprising at least one layer that contains agents which fermentatively treat the medium to be filtered.
References Cited (Backward Citations)
GB483294A
Cited
GB481238A
Cited
US2395301A
Cited
GB600208A
Cited
US2655552A
Cited
GB677515A
Cited
GB656754A
Cited
GB858313A
Cited
GB849821A
Cited
GB834051A
Cited
US3003643A
Cited
US3158532A
Cited
US3238056A
Cited
GB1219144A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-21 | 1994-07-23 | 1995-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-21 | 1998-07-23 | 1999-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-21 | 2002-07-23 | 2003-01-22 | $7700.00 | Window Closed / Lapsed |