US3835622A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of nitrogen oxides from carbon black pellet dryer purge gas
Assignee: Phillips Petroleum Co
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Filing: 1973-04-27
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Granted: 1974-09-17
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Expires: 1993-04-27
Abstract
Abstract A combination of steps for removing nitrogen oxides from carbon black pellet dryer purge gas which, upon filtration, is scrubbed first with aqueous nitric acid solution and then with process water, the liquids being admixed, preferably, with aid of a jet venturi mixer and also in one modification the purge gas being heat interchanged with vent gas from at least one of the scrubbers to cool the purge gas before it is contacted with the scrubbing medium.
Inventors
- 👤 E Henderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:56
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/44; C09C1/48; C09C1/56; C09C1/58; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56; C01; C01P; C01P2004/00; C01P2004/50
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
36 words
A process according to claim 1 wherein at least one of the process water and the aqueous nitric acid used to contact the purge gas is admixed therewith with the aid of a jet venturi mixer.
Claim 2
Dependent Claim
29 words
A process according to claim 1 wherein the hot purge gas is heat interchanged with cooler scrubbed purge gas before the purge gas is passed to the scrubbing step.
Claim 3
Dependent Claim
91 words
A process according to claim 1 wherein process water is circulated through a last scrubbing zone to scrub nitrogen oxides from the purge gas which has been once treated with a scrubbing medium until a sufficient concentration of nitric acid has been attained and then passing at least a portion of the thus acidified process water to a first scrubbing zone wherein it is contacted with the purge gas and there used until its concentration has reached a level at which it is advantageously used for wet pelleting of carbon black.
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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |