US4278635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for deoxygenation of water
Assignee: WR Grace and Co Conn
•
Filing: 1979-12-26
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Granted: 1981-07-14
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Expires: 1999-12-26
Abstract
Abstract A method for boiler water treatment to retard corrosion due to dissolved oxygen. Hydroquinone and certain related compounds are highly effective oxygen scavengers for use in boiler water and thereby effect reduction of corrosion resulting from dissolved oxygen.
Inventors
- 👤 Herman Kerst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:17
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/14; C23F11/141; C23F11/12; C23F11/122; C23F11/16; C23F11/163
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
103 words
A method for control of corrosion of metal surfaces in a boiler system caused by dissolved oxygen in the water, which comprises adding to the said system an effective amount, from 0.1 to 20 parts by weight per part of the oxygen in the water of an oxygen scavenger selected from the group consisting of ##STR2## in which R and R 1 are independently selected from the group consisting of --OH or --NH 2 ; R 2 (when present) is lower alkyl containing 1-8 carbons: M is H, Na, or K: and combinations thereof; said group member being the sole oxygen scavenger present.
Claim 2
Independent Claim
103 words
A method for control of corrosion of metal surfaces in a boiler system caused by dissolved oxygen in the water, which comprises adding to the said system an effective amount, from 0.1 to 20 parts by weight per part of the oxygen in the water of an oxygen scavenger selected from the group consisting of ##STR2## in which R and R 1 are independently selected from the group consisting of --OH or --NH 2 ; R 2 (when present) is lower alkyl containing 1-8 carbons: M is H, Na, or K: and combinations thereof; said group member being the sole oxygen scavenger present.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein the oxygen scavenger is used in an amount between 1 to about 5 times the weight of oxygen in the water.
Claim 4
Dependent Claim
14 words
The method of claim 1 or claim 2 wherein the oxygen scavenger is hydroquinone.
Claim 5
Dependent Claim
21 words
The method according to claim 1 in which the pH of the water in the boiler system is maintained above 8.
Claim 6
Independent Claim
84 words
A method according to any of claims 1, 2, or 4 in which the metal surfaces are iron and/or steel; the scavenger is hydroquinone added to the feed water of the boiler; said feed water containing dissolved oxygen; the amount of hydroquinone as fed being 1-5 times the weight of oxygen in the feed water; the residual hydroquinone in the water in the boiler being maintained at about 0.1-1 ppm; and maintaining the pH of the boiler feed water within the range of 8-11.
References Cited (Backward Citations)
US1988823A
Cited
US2682563A
Cited
US2835715A
Cited
US3551349A
Cited
US3728281A
Cited
US3843547A
Cited
US3983048A
Cited
US4026664A
Cited
US4096090A
Cited
US4022711A
Cited
US4079018A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-07-13 | 1985-01-12 | 1985-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-13 | 1989-01-12 | 1989-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-13 | 1993-01-12 | 1993-07-14 | $7700.00 | Window Closed / Lapsed |