US3627705A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Countercurrent ion exchange regeneration with sulfuric acid
Assignee: Sybron Transition Corp
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Filing: 1970-01-16
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Granted: 1971-12-14
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Expires: 1990-01-16
Abstract
Abstract A method and apparatus for regenerating cation exchange resin which is partially in the calcium form wherein dilution water is injected to prevent the precipitation of calcium sulfate in the column when sulfuric acid is used as the regenerant.
Inventors
- 👤 Albert William Kingsbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:05
CPC Classifications
B; B01; B01J; B01J49/00; B01J49/05; B01J49/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
64 words
A method of treating cation exchange resin with sulfuric acid in accordance with claim 1 wherein sulfuric acid regenerant having a concentration of at least about 1 percent by weight injected into the column is diluted to a concentration of less than about 1 percent by weight by injecting dilution water into the column at a point downstream from the injected sulfuric acid regenerant.
Claim 2
Independent Claim
125 words
A method of regenerating cation exchange resin in the calcium form with sulfuric acid in an ion exchange column comprising: a. moving said resin through the column; b. injecting sulfuric acid regenerant into said moving resin; c. causing said sulfuric acid regenerant to move countercurrent to said resin; d. injecting water at a point downstream from said sulfuric acid regenerant to dilute said sulfuric acid; and e. causing said diluted sulfuric acid to move countercurrent to said resin whereby said resin is first treated with said dilute sulfuric acid to prevent precipitation of calcium sulfate by removal of a major amount of calcium ion in the form of soluble calcium sulfate from said resin, and said resin is subsequently treated with said sulfuric acid regenerant.
Claim 3
Dependent Claim
47 words
A method of regenerating cation exchange resin with sulfuric acid in accordance with claim 3 wherein the sulfuric acid regenerant has a concentration of at least about 1 percent by weight and the diluted sulfuric acid has a concentration of less than about 1 percent by weight.
Claim 4
Independent Claim
86 words
A method of preventing precipitation of calcium sulfate during countercurrent regeneration of a cation exchange resin in the calcium form with sulfuric acid comprising diluting said acid to a concentration less than about 2 percent by weight with water at a point downstream from the point of acid introduction so that said moving resin first contacts said dilute acid and then contacts the more concentrated sulfuric acid, said dilute acid removing calcium in a soluble form prior to contacting said resin with said more concentrated acid.
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) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |