US4336140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water purification process
Assignee: Permutit Boby Ltd
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Filing: 1980-09-12
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Granted: 1982-06-22
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Expires: 2000-09-12
Abstract
Abstract Water of low solids content is purified by ion exchange treatment in separate beds with anion and cation exchange resins, the rate of flow of water through the last bed at least being fast. The beds are usually shallow and the flow rate through the last bed at least, and generally through all the beds, is at least 100 meters per hour. Apparatus suitable for use in such a process comprises a tower including supports for holding the beds one above the other and means for passing the water to be treated vertically through the tower.
Inventors
- 👤 Joseph H. Smith
- 👤 Trevor A. Peploe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:47
CPC Classifications
B; B01; B01J; B01J47/00; B01J47/02; B01J47/022; B01J39/00; B01J39/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
113 words
A process of purifying water including sulfates and chlorides having a solids content below 10 mg/l by ion exchange comprising passing the water through a bed of cation exchange resin and then through a bed of anion exchange resin and then through a final bed of cation exchange resin, the particle size of the resin in each bed being between 0.5 and 1.2 mm, in which process each bed is less than 75 cm deep, the flow rate through each bed is above 120 meters per hour, and the cation and anion exchange resins are regenerated separate from each other, thereby producing purified water having a dissolved solids content of below 5 μg/l.
Claim 2
Dependent Claim
113 words
A process of purifying water including sulfates and chlorides having a solids content below 10 mg/l by ion exchange comprising passing the water through a bed of cation exchange resin and then through a bed of anion exchange resin and then through a final bed of cation exchange resin, the particle size of the resin in each bed being between 0.5 and 1.2 mm, in which process each bed is less than 75 cm deep, the flow rate through each bed is above 120 meters per hour, and the cation and anion exchange resins are regenerated separate from each other, thereby producing purified water having a dissolved solids content of below 5 μg/l.
Claim 3
Dependent Claim
21 words
A process according to claim 1 in which the dissolved solids content of the treated water is less than 1 μg/l.
Claim 4
Dependent Claim
47 words
A process according to claim 1 in which the first bed of cation exchange resin is 25 to 40 cm deep, the bed of anion exchange resin is 50 to 75 cm deep and the final bed of cation exchange resin is 25 to 40 cm deep.
Claim 5
Dependent Claim
22 words
A process according to claim 1 in which the flow rate through each bed is from 120 to 240 meters per hour.
Claim 6
Dependent Claim
22 words
A process according to claim 1 in which the particle size of the resin in each bed is 0.7 to 1.0 mm.
Claim 7
Dependent Claim
25 words
A process according to claim 1 in which the water contains a sufficient amount of a volatile nitrogenous base that its pH is above 8.
Claim 8
Dependent Claim
80 words
A process according to claim 1 in which the beds of resin are arranged one above the other in a vertical tower on substantially horizontal supports with the final cation bed being below the anion bed and the anion bed being below the first cation bed, and the water to be treated as passed down through the tower at a flow rate of above 120 meters per hour while migration of resin from one bed to the next is prevented.
Claim 9
Dependent Claim
37 words
A process according to claim 1 in which the anion resin and the cation resin are regenerated separately and, after regeneration, are individually air mixed in the bed through which the water to be purified will flow.
Claim 10
Dependent Claim
44 words
A process according to claim 1 in which the cation exchange resin is regenerated by contact with sulphuric acid and the anion exchange resin is regenerated by contact with the used regenerant from the cation exchange resin and then by contact with sodium hydroxide.
Claim 11
Dependent Claim
27 words
A process according to claim 1 in which the anion resin is regenerated by contact with sodium carbonate or bicarbonate and then by contact with sodium hydroxide.
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) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |