Patent US4929363A successfully refreshed from Google Patents.
US4929363A
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Method for filtering a fluid
Assignee: Filtration Ltd
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Filing: 1988-02-19
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Granted: 1990-05-29
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Expires: 2008-02-19
Abstract
Abstract A method for filtering a fluid in a filter system, including a filter housing and a filter element, which method comprises modifying filter throughput in such a way that differential pressure across the filter system caused by build-up of filter cake is substantially maintained at a predeterminable level for at least part of filter-operation time between flushings. A filter system for a fluid for operation by the method is also described.
Inventors
- 👤 Ytzhak Barzuza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:37
CPC Classifications
B; B01; B01D; B01D37/00; B01D37/04; B01D29/00; B01D29/60; B01D29/606; B01D29/62; B01D29/66
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
58 words
A method for filtering a fluid in a filter system, including a filter housing and a filter element, comprising the step of: modifying filter throughput in such a way that differential pressure across said filter system caused by build-up of filter cake is substantially maintained at a predeterminable level for at least part of filter-operation time between flushings.
Claim 2
Independent Claim
58 words
A method for filtering a fluid in a filter system, including a filter housing and a filter element, comprising the step of: modifying filter throughput in such a way that differential pressure across said filter system caused by build-up of filter cake is substantially maintained at a predeterminable level for at least part of filter-operation time between flushings.
Claim 3
Dependent Claim
17 words
The method as claimed in claim 1, wherein modifying said filter throughput consists in a reduction thereof.
Claim 4
Dependent Claim
25 words
The method as claimed in claim 1, wherein said predeterminable level of said differential pressure is higher than 0.02 bar and lower than 0.4 bar.
Claim 5
Dependent Claim
22 words
The method as claimed in claim 1, wherein said differential pressure is maintained constant for at least 30% of said filter-operation time.
Claim 6
Dependent Claim
19 words
The method as claimed in claim 1, comprising the further step of indicating the need for, or initiating, flushing.
Claim 7
Independent Claim
89 words
A method for filtering a fluid in a filter system that includes a filter housing containing a filter element through which fluid is pumped, and throughput control means for controlling filter throughput, said method comprising the steps of: (a) detecting the differential pressure across said filter housing as a consequence of buildup of filter cake on said filter element; and (b) operating on said control means as a function of said differential pressure such that, after the differential pressure reaches a threshold, the differential pressure is maintained substantially constant.
Claim 8
Independent Claim
89 words
A method for filtering a fluid in a filter system that includes a filter housing containing a filter element through which fluid is pumped, and throughput control means for controlling filter throughput, said method comprising the steps of: (a) detecting the differential pressure across said filter housing as a consequence of buildup of filter cake on said filter element; and (b) operating on said control means as a function of said differential pressure such that, after the differential pressure reaches a threshold, the differential pressure is maintained substantially constant.
Claim 9
Dependent Claim
33 words
A method according to claim 6 wherein said throughput control means includes valve means, and wherein the step of operating on said control means serves to change the setting of said valve means.
Claim 10
Dependent Claim
22 words
A method according to claim 7 including the step of gradually closing said valve means as the thickness of filter cake increases.
Claim 11
Dependent Claim
22 words
A method according to claim 7 including the step of gradually opening said valve means as the thickness of filter cake increases.
Claim 12
Dependent Claim
21 words
A method according to claim 6 wherein said differential pressure threshold is in the range of about 0.02 to 0.4 bar.
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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) | 1993-05-28 | 1993-11-27 | 1994-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-28 | 2001-11-27 | 2002-05-29 | $7700.00 | Window Closed / Lapsed |