US3928531A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Black liquor oxidation process
Assignee: Westvaco Corp
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Filing: 1974-03-18
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Granted: 1975-12-23
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Expires: 1994-03-18
Abstract
Abstract Gas-liquid contact reaction efficiency in a two stage heavy black liquor oxidation process is improved by co-current contact in the first stage and countercurrent contact in the second stage or vice versa. Such improved efficiency is sustained by preventing the obstruction of gas discharge nozzles. Gas discharge nozzle flow and distribution is sustained at design levels pursuant to distribution system parameters constructed substantially according to the relation D R A W I N G
Inventors
- 👤 William H Boatwright
- 👤 Thomas C Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:41
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/0057
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
A METHOD OF INTIMATELY CONTACTING A FLOWING QUANTITY OF CELLULOSE PULPING LIQUOR WITH A QUANTITY OF OXIDIZING GAS, SAID METHOD COMPRISING THE STEPS OF: A. PROVIDING A SUBSTANTIALLY UNPRESSURIZED FLUID RETENTION VESSEL HAVING A HORIZONTAL SECTIONAL AREA DIVIDED INTO AT LEAST TWO RETENTION VOLUMES; B. SUPPLYING CONCENTRATED SPENT CELLULOSE PULPING LIQUOR TO A FIRST OF SAID RETENTION VOLUMES; C. DISCHARGING SAID LIQUOR FROM A SECOND OF SAID RETENTION VOLUMES; D. DISTRIBUTING SUBSTANTIALLY ALL OF AN OXIDIZING GAS OVER SUBSTANTIALLY ALL OF SAID HORIZONTAL SECTIONAL AREA AT ONE END OF SAID RETENTION VOLUMES FOR FLOW TRAVERSE ALONG THE LENGTH OF SAID VOLUMES TOWARD THE OTHER END THEREOF IN DIRECT CONTACT WITH SAID LIQUOR; AND,
Claim 2
Independent Claim
113 words
A METHOD OF INTIMATELY CONTACTING A FLOWING QUANTITY OF CELLULOSE PULPING LIQUOR WITH A QUANTITY OF OXIDIZING GAS, SAID METHOD COMPRISING THE STEPS OF: A. PROVIDING A SUBSTANTIALLY UNPRESSURIZED FLUID RETENTION VESSEL HAVING A HORIZONTAL SECTIONAL AREA DIVIDED INTO AT LEAST TWO RETENTION VOLUMES; B. SUPPLYING CONCENTRATED SPENT CELLULOSE PULPING LIQUOR TO A FIRST OF SAID RETENTION VOLUMES; C. DISCHARGING SAID LIQUOR FROM A SECOND OF SAID RETENTION VOLUMES; D. DISTRIBUTING SUBSTANTIALLY ALL OF AN OXIDIZING GAS OVER SUBSTANTIALLY ALL OF SAID HORIZONTAL SECTIONAL AREA AT ONE END OF SAID RETENTION VOLUMES FOR FLOW TRAVERSE ALONG THE LENGTH OF SAID VOLUMES TOWARD THE OTHER END THEREOF IN DIRECT CONTACT WITH SAID LIQUOR; AND,
Claim 3
Dependent Claim
26 words
A method as described by claim 1 wherein said liquor is supplied to said first retention volume at the same end thereof as said oxidizing gas.
Claim 4
Dependent Claim
28 words
A method as described by claim 2 wherein said liquor is removed from said second retention volume at the same end thereof as said oxidizing gas is supplied.
Claim 5
Dependent Claim
30 words
A method as described by claim 1 wherein said liquor flows co-current with said oxidizing gas in said first volume and counter-current of said oxidizing gas in said second volume.
Claim 6
Dependent Claim
58 words
A method as described by claim 1 wherein said oxidizing gas is distributed to all of said horizontal sectional area through a multiple outlet manifold conduit, said method further comprising the step of retaining the velocity of said oxidizing gas from each outlet junction with said manifold at substantially the same quantity as upon entrance to said junction.
Claim 7
Dependent Claim
25 words
A method as described by claim 5 wherein the static pressure of said oxidizing gas within each of said multiple outlets is substantially the same.
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) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |