US3553075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for controlling the hydroxide ion concentration in pulp digestion liquor
Assignee: Calgon Corp
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Filing: 1968-04-01
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Granted: 1971-01-05
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Expires: 1988-04-01
Abstract
Abstract A METHOD IS PROVIDED FORAUTOMATICALLY CONTROLLING THE HYDROXIDE CONCENTRATION OF PULP DIGESTER LIQUOR BY DETERMINING THE DIFFERENTIAL CONDUCTIVITY OF THE LIQUOR AT SPACED STAGES IN THE COOKING PROCESS AND ADJUSTING THE HYDROXIDE CONCENTRATION IN THE BATH FROM A PREVIOUSLY PREPARED CURVE OF C ONDUCTIVITY DIFFERENCES VERSUS HYDROXIDE ION CONCENTRATION.
Inventors
- 👤 Hubert M Rivers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:15
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/22; D21C3/228
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |