US3433670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pickling bath control apparatus and method
Assignee: Inland Steel Co
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Filing: 1965-10-21
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Granted: 1969-03-18
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Expires: 1985-10-21
Abstract
No abstract record available.
Inventors
- 👤 Uno T Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:52
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23G1/08; G; G01; G01N; G01N21/00; G01N21/75; G01N21/77; G01N21/78
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
174 words
IN A FERROUS METAL TREATING PROCESSUSING A PICKLING SOLUTION CONTAINING AN ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC, HYDROFLUORIC, NITRIC, PHOSPHORIC, AND PERCHLORIC ACIDS AND WHEREIN THE SAID ACID IS CONSUMED BY REACTION WITH THE METAL IN AQUEOUS SOLUTION, AND WHEREIN MAKEUP PICKLING ACID IS ADDED TO SAID SOLUTION DURING THE PICKLING PROCESS, AN IMPROVED METHOD OF CONTROLLING THE ADDITION OF PICKLING ACID TO SAID PICKLING SOLUTION WHICH COMPRISES; PHOTOMETRICALLY MEASURING THE CONCENTRATION OF THE FERROUS ION CONCENTRATION IN SAID PICKLING SOLUTION CONTAINING SAID PICKLING ACID TO OBTAIN A FIRST SIGNAL WHICH IS A MEASURE OF THE CONCENTRATION OF SAID FERROUS ION OF SAID PICKLING SOLUTION, MEASURING THE SPECIFIC GRAVITY OF SAID PICKLING SOLUTION TO OBTAIN A SECOND SIGNAL, COMBINING THE SAID FIRST AND SECOND SIGNALS TO OBTAIN A CORRECTED SIGNAL WHICH IS A MEASURE OF ONLY THE ACID CONCENTRATION OF THE SAID SOLUTION, AND FEEDING SAID CORRETED SIGNAL TO AN ACID VALVE FLOW CONTROL MEANS WHICH EFFECTS ADDITION OF ACID TO SAID SOLUTION WHEN THE ACID CONCENTRATION DROPS TO A PREDETERMINED VALUE.
Claim 2
Dependent Claim
174 words
IN A FERROUS METAL TREATING PROCESSUSING A PICKLING SOLUTION CONTAINING AN ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC, HYDROFLUORIC, NITRIC, PHOSPHORIC, AND PERCHLORIC ACIDS AND WHEREIN THE SAID ACID IS CONSUMED BY REACTION WITH THE METAL IN AQUEOUS SOLUTION, AND WHEREIN MAKEUP PICKLING ACID IS ADDED TO SAID SOLUTION DURING THE PICKLING PROCESS, AN IMPROVED METHOD OF CONTROLLING THE ADDITION OF PICKLING ACID TO SAID PICKLING SOLUTION WHICH COMPRISES; PHOTOMETRICALLY MEASURING THE CONCENTRATION OF THE FERROUS ION CONCENTRATION IN SAID PICKLING SOLUTION CONTAINING SAID PICKLING ACID TO OBTAIN A FIRST SIGNAL WHICH IS A MEASURE OF THE CONCENTRATION OF SAID FERROUS ION OF SAID PICKLING SOLUTION, MEASURING THE SPECIFIC GRAVITY OF SAID PICKLING SOLUTION TO OBTAIN A SECOND SIGNAL, COMBINING THE SAID FIRST AND SECOND SIGNALS TO OBTAIN A CORRECTED SIGNAL WHICH IS A MEASURE OF ONLY THE ACID CONCENTRATION OF THE SAID SOLUTION, AND FEEDING SAID CORRETED SIGNAL TO AN ACID VALVE FLOW CONTROL MEANS WHICH EFFECTS ADDITION OF ACID TO SAID SOLUTION WHEN THE ACID CONCENTRATION DROPS TO A PREDETERMINED VALUE.
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) | 1972-03-17 | 1972-09-16 | 1973-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-03-17 | 1976-09-16 | 1977-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-03-17 | 1980-09-16 | 1981-03-18 | $7700.00 | Window Closed / Lapsed |