US4012299A
Expired / Lapsed
US
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Metallic descaling system
Assignee: Ruthner Industrieplannungs AG
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Filing: 1976-04-01
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Granted: 1977-03-15
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Expires: 1996-04-01
Abstract
Abstract A process for descaling a metallic body, wherein the body is immersed in a first electrolyte, and subsequently, in a second electrolyte. The first electrolyte is an aqueous solution having, by weight, at least 60% potassium hydroxide, at least 5% water and no more than 30% potassium nitrate, and a total amount of potassium hydroxide and potassium nitrate of at least 80%. The second electrolyte is an aqueous solution of at least one neutral salt from the group consisting of the chloride, sulfate and nitrate of an alkali metal or ammonium.
Inventors
- 👤 Donald R. Zaremski
- 👤 Albert Krepler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:11
CPC Classifications
C; C25; C25F; C25F1/00; C25F1/02; C25F1/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
154 words
A process for descaling a metallic body, which comprises the steps of: immersing said body in a first electrolyte, said electrolyte being an aqueous solution having, by weight, at least 60% potassium hydroxide, at least 5% water and no more than 30% potassium nitrate, and a total amount of potassium hydroxide and potassium nitrate of at least 80%; passing an electric current through said body and first electrolyte for a period of at least 3 seconds; removing said body from said first electrolyte after scale on said body has been conditioned for subsequent removal; subsequently immersing said body in a second electrolyte of an aqueous solution of at least one neutral salt from the group consisting of the chloride, sulfate, and nitrate of an alkali metal or ammonium; passing an electric current through said body and second electrolyte for a period of at least 4 seconds; and removing said body from said second electrolyte.
Claim 2
Dependent Claim
154 words
A process for descaling a metallic body, which comprises the steps of: immersing said body in a first electrolyte, said electrolyte being an aqueous solution having, by weight, at least 60% potassium hydroxide, at least 5% water and no more than 30% potassium nitrate, and a total amount of potassium hydroxide and potassium nitrate of at least 80%; passing an electric current through said body and first electrolyte for a period of at least 3 seconds; removing said body from said first electrolyte after scale on said body has been conditioned for subsequent removal; subsequently immersing said body in a second electrolyte of an aqueous solution of at least one neutral salt from the group consisting of the chloride, sulfate, and nitrate of an alkali metal or ammonium; passing an electric current through said body and second electrolyte for a period of at least 4 seconds; and removing said body from said second electrolyte.
Claim 3
Dependent Claim
33 words
A process according to claim 1, wherein said first electrolyte consists essentially of, by weight, from 65 to 75% potassium hydroxide, from 10 to 20% water and from 10 to 20% potassium nitrate.
Claim 4
Dependent Claim
35 words
A process according to claim 1 wherein said second electrolyte contains from 0.1 to 50 grams per liter of a compound from the group consisting of fluorides, chlorides, perchlorates, chromates, nitrites, sulfites, nitrates and sulfates.
Claim 5
Dependent Claim
13 words
A process according to claim 1, wherein the neutral salt is sodium sulfate.
Claim 6
Dependent Claim
14 words
A process according to claim 1, wherein said metallic body is an alloy steel.
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) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |