US3240627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of calcium sulfate deposits
Assignee: Dow Chemical Co
•
Filing: 1964-07-06
•
Granted: 1966-03-15
•
Expires: 1984-07-06
Abstract
No abstract record available.
Inventors
- 👤 William S White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:09
CPC Classifications
F; F28; F28G; F28G9/00; C; C02; C02F; C02F5/00; C02F5/08; C09; C09K; C09K8/00; C09K8/52; C09K8/528; Y; Y10; Y10S; Y10S159/00; Y10S159/13; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
THE METHOD OF REMOVING AN ANHYDRITE DEPOSIT FROM CONFINED SURFACES WHICH COMPRISES SUBJECTING SAID DEPOSIT TO THE COOLING ACTION OF A CHILLED FLUID, REMOVING SAID CHILLED FLUID FROM THE DEPOSIT, CONTACTING THE SO COOLED DEPOSIT WITH AN AQUEOUS SOLUTION CONTAINING BETWEEN ABOUT 10% AND 20% SODIUM HYDROXIDE BY WEIGHT AT A TEMPERATURE OF BETWEEN ABOUT 30*F. AND 50*F. FOR A SUFFICIENT TIME TO CONVERT AT LEAST A PORTION OF THE ANHYDRITE TO A SLUDGE, REMOVING THE RESULTING SPENT SODIUM HYDROXIDE SOLUTION FROM THE CONFINED SURFACE SO TREATED, DISSOLVING ANY SLUDGE NOT REMOVED DURING THE REMOVAL OF THE SODIUM HYDROXIDE SOLUTION BY TREATMENT WITH AN ACID SOLUTION, AND REMOVING THE RESULTING SPENT AID SOLUTION FROM SAID CONFINED SURFACE.
Claim 2
Independent Claim
117 words
THE METHOD OF REMOVING AN ANHYDRITE DEPOSIT FROM CONFINED SURFACES WHICH COMPRISES SUBJECTING SAID DEPOSIT TO THE COOLING ACTION OF A CHILLED FLUID, REMOVING SAID CHILLED FLUID FROM THE DEPOSIT, CONTACTING THE SO COOLED DEPOSIT WITH AN AQUEOUS SOLUTION CONTAINING BETWEEN ABOUT 10% AND 20% SODIUM HYDROXIDE BY WEIGHT AT A TEMPERATURE OF BETWEEN ABOUT 30*F. AND 50*F. FOR A SUFFICIENT TIME TO CONVERT AT LEAST A PORTION OF THE ANHYDRITE TO A SLUDGE, REMOVING THE RESULTING SPENT SODIUM HYDROXIDE SOLUTION FROM THE CONFINED SURFACE SO TREATED, DISSOLVING ANY SLUDGE NOT REMOVED DURING THE REMOVAL OF THE SODIUM HYDROXIDE SOLUTION BY TREATMENT WITH AN ACID SOLUTION, AND REMOVING THE RESULTING SPENT AID SOLUTION FROM SAID CONFINED SURFACE.
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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) | 1969-03-14 | 1969-09-13 | 1970-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-14 | 1973-09-13 | 1974-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-14 | 1977-09-13 | 1978-03-15 | $7700.00 | Window Closed / Lapsed |