US4147647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scale converters
Assignee: Baker Petrolite LLC
•
Filing: 1973-10-15
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Granted: 1979-04-03
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Expires: 1993-10-15
Abstract
Abstract This invention relates to the use of a water soluble maleate salt, preferably disodium maleate, as a scale converter. Such salts convert scale into a water soluble compound which is capable of aqueous removal without the conventional step of employing either (1) an acid wash or (2) a sequestering agent.
Inventors
- 👤 Richard L. Rybacki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:48
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; Y; Y10; Y10S; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
35 words
A process for dissolving gypsum containing scale which comprises contacting the scale with a water soluble alkali metal maleate salt as a scale converter in an aqueous system having a pH of 7.5 to 12.0.
Claim 2
Dependent Claim
35 words
A process for dissolving gypsum containing scale which comprises contacting the scale with a water soluble alkali metal maleate salt as a scale converter in an aqueous system having a pH of 7.5 to 12.0.
Claim 3
Dependent Claim
14 words
The process of claim 1 where the maleate salt is a dialkali metal maleate.
Claim 4
Dependent Claim
12 words
The process of claim 2 where the maleate salt is disodium maleate.
Claim 5
Dependent Claim
43 words
A solution for converting gypsum containing scale to a soluble form comprising an aqueous solution of a water soluble alkali metal maleate salt scale converter and a wetting agent which assists in wetting the scale and having a pH of 7.5 to 12.0.
Claim 6
Dependent Claim
43 words
A solution for converting gypsum containing scale to a soluble form comprising an aqueous solution of a water soluble alkali metal maleate salt scale converter and a wetting agent which assists in wetting the scale and having a pH of 7.5 to 12.0.
Claim 7
Dependent Claim
18 words
A process of dissolving gypsum containing scale which comprises contacting the scale with the solution of claim 4.
Claim 8
Dependent Claim
14 words
The solution of claim 4 where the maleate salt is a dialkali metal maleate.
Claim 9
Dependent Claim
18 words
A process of dissolving gypsum containing scale which comprises contacting the scale with the solution of claim 6.
Claim 10
Dependent Claim
11 words
The solution of claim 5 where the maleate is disodium maleate.
Claim 11
Dependent Claim
18 words
A process of dissolving gypsum containing scale which comprises contacting the scale with the solution of claim 8.
Claim 12
Dependent Claim
24 words
A process of dissolving gypsum scale comprising contacting the scale with disodium maleate in an aqueous system having a pH of 7.5 to 12.0.
Claim 13
Dependent Claim
24 words
A process of dissolving gypsum scale comprising contacting the scale with disodium maleate in an aqueous system having a pH of 7.5 to 12.0.
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) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |