US4657740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of scavenging oxygen from aqueous mediums
Assignee: Veolia WTS USA Inc
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Filing: 1984-11-21
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Granted: 1987-04-14
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Expires: 2004-11-21
Abstract
Abstract Methods for chemically scavenging oxygen from an aqueous medium comprising the addition of linear, water soluble polyethyleneamines, such as tetraethylenepentamine and triethylenetetramine, as the sole oxygen scavenger, to the desired aqueous medium. Suitable environments for use of these amines comprise boiler feedwater and boiler steam condensate systems.
Inventors
- 👤 Nancy A. Feldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:29
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/14; C23F11/141
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
53 words
A method for reducing the amount of oxygen in an oxygen containing aqueous medium comprising adding to said aqueous medium, as the sole oxygen scavenger, an oxygen scavenging amount of a polyethyleneamine solution comprising a member selected from the group consisting of tetraethylenepentamine, and triethylenetetramine or water soluble salt forms or mixtures thereof.
Claim 2
Independent Claim
53 words
A method for reducing the amount of oxygen in an oxygen containing aqueous medium comprising adding to said aqueous medium, as the sole oxygen scavenger, an oxygen scavenging amount of a polyethyleneamine solution comprising a member selected from the group consisting of tetraethylenepentamine, and triethylenetetramine or water soluble salt forms or mixtures thereof.
Claim 3
Dependent Claim
16 words
A method as recited in claim 1 wherein said aqueous medium comprises feedwater to a boiler.
Claim 4
Dependent Claim
19 words
A method as recited in claim 1 wherein said aqueous medium comprises condesnsed steam in a boiler condensate system.
Claim 5
Dependent Claim
12 words
A method as recited in claim 1 wherein said member is tetraethylenepentamine.
Claim 6
Dependent Claim
12 words
A method as recited in claim 1 wherein said member is triethylenetetramine.
Claim 7
Dependent Claim
35 words
A method as recited in claim 1 wherein said polyethyleneamine solution is added in an amount of between 1 to about 2,000 parts of said polyethyleneamine based upon one million parts of said aqueous medium.
Claim 8
Dependent Claim
32 words
A method as recited in claim 6 wherein said polyethyleneamine solution is added in an amount of between 50 to about 1,000 parts based upon one million parts of said aqueous medium.
Claim 9
Dependent Claim
15 words
A method as recited in claim 1 wherein said aqueous medium has a alkaline pH.
Claim 10
Dependent Claim
15 words
A method as recited in claim 8 wherein said pH is about 8 or greater.
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) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |