US3679543A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlling the cooking process in pulp digestion by differential conductivity measurements
Assignee: Calgon Corp
•
Filing: 1970-08-18
•
Granted: 1972-07-25
•
Expires: 1990-08-18
Abstract
Abstract A METHOD IS PROVIDED FOR AUTOMATICALLY CONTROLLING THE COOKING PROCESS IN A PULP DIGESTER BY DETERMINING THE DIFFERENTIAL CONDUCTIVITY OF THE LIQUOR IN SAID DIGESTER AT SPACED STAGES IN THE COOKING PROCESS AND ADJUSTING ONE OF THE CONTROL VARIABLES TEMPERATURE, TIME OF PROCESSING AND LIQUOR STRENGTH INCLUDING THE HYDROXIDE CONCENTRATION IN THE BATH FROM A CURVE OF CONDUCTIVITY DIFFERENCES VERSUS CONCENTRATION PREVIOUSLY PREPARED.
Inventors
- 👤 Hubert M Rivers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:54
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/22; D21C3/228
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |