US4067690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Boiler water treatment
Assignee: WR Grace and Co Conn
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Filing: 1977-02-09
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Granted: 1978-01-10
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Expires: 1997-02-09
Abstract
Abstract The invention disclosed provides a method for boiler water treatment to retard corrosion due to dissolved oxygen. Hydroxylamine, certain derivatives thereof and their salts have now been found to be highly effective oxygen scavengers for use in boiler water and thereby effect reduction of corrosion resulting from dissolved oxygen.
Inventors
- 👤 Dionisio G. Cuisia
- 👤 Chih M. Hwa
- 👤 Jose T. Jacob
- 👤 Murrell L. Salutsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:31
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/68; C02F1/683; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/14; C23F11/147; C23F11/18; C23F11/181; C02F2303/00; C02F2303/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
A method for control of corrosion of iron and steel surfaces in boiler apparatus caused by dissolved oxygen, in an aqueous boiler water system which consists essentially of boiler water containing dissolved oxygen, said boiler system being operated at a temperature of 298° to 637° F. and 50 to 2000 psi which comprises adding to the said system an effective amount, 0.001-500 parts per million parts of water, of an oxygen scavenger having the general formula: ##STR2##where R 1 , R 2 , and R 3 are either the same or different and selected from the group consisting of hydrogen, lower alkyl and aryl, and the water-soluble salts thereof.
Claim 2
Independent Claim
109 words
A method for control of corrosion of iron and steel surfaces in boiler apparatus caused by dissolved oxygen, in an aqueous boiler water system which consists essentially of boiler water containing dissolved oxygen, said boiler system being operated at a temperature of 298° to 637° F. and 50 to 2000 psi which comprises adding to the said system an effective amount, 0.001-500 parts per million parts of water, of an oxygen scavenger having the general formula: ##STR2##where R 1 , R 2 , and R 3 are either the same or different and selected from the group consisting of hydrogen, lower alkyl and aryl, and the water-soluble salts thereof.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the oxygen scavenger is present in an amount between 0.01 to about 50 parts per million of water.
Claim 4
Dependent Claim
32 words
The method of claim 1 wherein the lower alkyl group has between 1 and about 8 carbon atoms, and the aryl is selected from the group consisting of phenyl, benzyl and tolyl.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein the oxygen scavenger water-soluble salt is selected from the group consisting of chloride, sulfate, acid sulfate, phosphate and sulfite.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein the oxygen scavenger is hydroxylamine.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein the oxygen scavenger is N,N-diethylhydroxylamine.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |