US2824800A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of cooking sulphite pulp
Assignee: Rosenblads Patenter AB
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Filing: 1955-07-06
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Granted: 1958-02-25
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Expires: 1975-07-06
Abstract
No abstract record available.
Inventors
- 👤 Rosenblad Curt Fredrik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:16
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/22; D21C7/00; D21C7/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
184 words
IN A METHOD OF DIGESTING OR COOKING SULPHITE PULP, THE PROCESS OF PREHEATING THE DIGESTION ACID WHEN CHARGING A DIGESTER AND RECOVERING HEAT FROM WASTE LIQUOR COPMPRISING IN COMBINATION THE STEPS OF BLOWING A DIGESTER TO AN ATMOSPHERIC PRESSURE BLOW PIT, WHILE FLUSHING AND COOLING THE DIGESTER CONTENT WITH LOW TEMPERATURE WASTE LIQUOR, WITHDRAWING THE HOT WASTE LIQUOR FROM THE BLOW PIT AND STORING SAID WASTE LIQUOR SUBSTANTIALLY AT ITS BLOW PIT TEMPERATURE, PASSING, IN INDIRECT HEAT EXCHANGE RELATION TO EACH OTHER, DIGESTION ACID WHICH IS BEING CHARGED TO A DIGESTER AND STORED HOT WASTE LIQUOR, SO AS IN A FIRST STAGE TO HEAT THE DIGESTION ACID AND TO COOL THE LIQUOR, STORING THE COOLED WASTE LIQUOR SEPARATELY FROM THE HOT WASTE LIQUOR, PASSING THE HEATED DIGESTION ACID AND STREAM IN INDIRECT HEAT EXCHANGER RELATION TO EACH OTHER, SO AS TO INCREASE IN A SECOND STAGE THE TEMPERATURE OF THE DIGESTION ACID TO THE DESIRED PREHEATING TEMPERATURE, PASSING THE DIGESTION ACID TO THE DIGESTER AT SAID PREHEATING TEMPERATURE AND UTILIZING STORED COOLED SPENT LIQUOR AS FLUSHING AND COOLING AGENT IN A DIGESTOR BLOWING PROCESS.
Claim 2
Dependent Claim
184 words
IN A METHOD OF DIGESTING OR COOKING SULPHITE PULP, THE PROCESS OF PREHEATING THE DIGESTION ACID WHEN CHARGING A DIGESTER AND RECOVERING HEAT FROM WASTE LIQUOR COPMPRISING IN COMBINATION THE STEPS OF BLOWING A DIGESTER TO AN ATMOSPHERIC PRESSURE BLOW PIT, WHILE FLUSHING AND COOLING THE DIGESTER CONTENT WITH LOW TEMPERATURE WASTE LIQUOR, WITHDRAWING THE HOT WASTE LIQUOR FROM THE BLOW PIT AND STORING SAID WASTE LIQUOR SUBSTANTIALLY AT ITS BLOW PIT TEMPERATURE, PASSING, IN INDIRECT HEAT EXCHANGE RELATION TO EACH OTHER, DIGESTION ACID WHICH IS BEING CHARGED TO A DIGESTER AND STORED HOT WASTE LIQUOR, SO AS IN A FIRST STAGE TO HEAT THE DIGESTION ACID AND TO COOL THE LIQUOR, STORING THE COOLED WASTE LIQUOR SEPARATELY FROM THE HOT WASTE LIQUOR, PASSING THE HEATED DIGESTION ACID AND STREAM IN INDIRECT HEAT EXCHANGER RELATION TO EACH OTHER, SO AS TO INCREASE IN A SECOND STAGE THE TEMPERATURE OF THE DIGESTION ACID TO THE DESIRED PREHEATING TEMPERATURE, PASSING THE DIGESTION ACID TO THE DIGESTER AT SAID PREHEATING TEMPERATURE AND UTILIZING STORED COOLED SPENT LIQUOR AS FLUSHING AND COOLING AGENT IN A DIGESTOR BLOWING PROCESS.
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) | 1961-02-24 | 1961-08-26 | 1962-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-24 | 1965-08-26 | 1966-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-24 | 1969-08-26 | 1970-02-25 | $7700.00 | Window Closed / Lapsed |