US3674686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter precoating method
Assignee: Idreco USA Ltd
•
Filing: 1970-02-24
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Granted: 1972-07-04
•
Expires: 1990-02-24
Abstract
Abstract To control the flocculation of a mixture of fine anion and cation ion exchange resins in order to form an even coating on a filter septum, the resins are first mixed in a heavy slurry, and are then added at a controlled rate to the recirculation liquid entering the filter vessel.
Inventors
- 👤 Donald B Brimmer
- 👤 James Stuart Brown
- 👤 Charles H Becker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:31
CPC Classifications
B; B01; B01D; B01D37/00; B01D37/02; B01J; B01J47/00; B01J47/12; B01J47/133
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
23 words
The method according to claim 1 in which said slurry is drawn into the liquid stream through the suction opening of an eductor.
Claim 2
Dependent Claim
23 words
The method according to claim 2 in which said rate of flow of liquid through the eductor is regulated by a control valve.
Claim 3
Dependent Claim
34 words
The method according to claim 2 in which the slurry is passed through a valve which is intermittently opened in a controlled duty cycle before being passed into the suction opening of the eductor.
Claim 4
Dependent Claim
21 words
The method according to claim 1 in which said slurry is pumped by a variable displacement pump into the liquid stream.
Claim 5
Dependent Claim
31 words
The method according to claim 1 in which said slurry is formed in an elevated storage tank and fed from said tank through a controllable throttling valve into said liquid stream.
References Cited (Backward Citations)
US21893A
Cited
US2162074A
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US2367557A
Cited
US3199677A
Cited
US3214369A
Cited
US3250703A
Cited
US3250704A
Cited
US3501060A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |