US4968438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gallic acid as an oxygen scavenger
Assignee: Ecolab USA Inc
•
Filing: 1988-11-17
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Granted: 1990-11-06
•
Expires: 2008-11-17
Abstract
Abstract An improved method for scavenging dissolved oxygen from waters used to generate steam which comprises treating said waters with at least 0.3 mole of gallic acid per mole of oxygen contained in said bioler waters. An aqueous concentrate useful for treating boiler waters to scavenge oxygen therefrom which contains at least 0.3% by weight of gallic acid. This aqueous concentrate has a pH adjusted to at least 8.5.
Inventors
- 👤 Cynthia A. Soderquist
- 👤 John A. Kelly
- 👤 Frederick S. Mandel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:12
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/12; C23F11/124; C02; C02F; C02F1/00; C02F1/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
43 words
An improved method for scavenging dissolved oxygen from waters used to generate steam having a temperature of at least 185° F. which comprises treating said waters with at least 0.3 mole of gallic acid per mole of oxygen contained in said boiler waters.
Claim 2
Dependent Claim
43 words
An improved method for scavenging dissolved oxygen from waters used to generate steam having a temperature of at least 185° F. which comprises treating said waters with at least 0.3 mole of gallic acid per mole of oxygen contained in said boiler waters.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein at least 1 mole gallic acid per mole of oxygen is used.
Claim 4
Independent Claim
64 words
A method for scavenging dissolved oxygen from waters having a temperature of at least 185° F. used to generate steam which comprises treating said waters with sufficient aqueous concentrate which contains at least 0.3% by weight gallic acid, said aqueous concentrate having a pH of at least 8.5% said pH having been adjusted by a base of the type used to treat boilers waters.
Claim 5
Independent Claim
64 words
A method for scavenging dissolved oxygen from waters having a temperature of at least 185° F. used to generate steam which comprises treating said waters with sufficient aqueous concentrate which contains at least 0.3% by weight gallic acid, said aqueous concentrate having a pH of at least 8.5% said pH having been adjusted by a base of the type used to treat boilers waters.
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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) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |