US4147755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air pollution control process
Assignee: Combustion Engineering Inc
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Filing: 1977-04-21
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Granted: 1979-04-03
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Expires: 1997-04-21
Abstract
Abstract Gases containing SO 2 from a furnace are contacted in the scrubbing zone of a scrubber with an aqueous scrubbing medium containing Ca(OH) 2 whereby sulfites are formed. The Ca(OH) 2 additive is at least partially the Ca(OH) 2 sludge produced in the manufacture of acetylene from CaC 2 . This sludge contains constituents which retard or inhibit the oxidation of sulfite to sulfate to thereby reduce the possibility of sulfate scaling in the system.
Inventors
- 👤 Madanamohana R. Gogineni
- 👤 Philip C. Rader
- 👤 Wilfred R. Roczniak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:04
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
122 words
A method of removing SO 2 from the flue gases produced in the combustion of sulfur-containing fuels comprising the steps of: a. providing a scrubbing medium, said scrubbing medium comprising a mixture of water and the Ca(OH) 2 sludge from an acetylene manufacturing process, said Ca(OH) 2 sludge containing at least one ingredient which inhibits the oxidation of sulfite to sulfate, b. contacting said flue gas in a scrubbing zone with said scrubbing medium whereby said SO 2 reacts with said scrubbing medium to form sulfite, c. withdrawing said scrubbing medium from said scrubbing zone, d. separating precipitated calcium sulfite from said withdrawn scrubbing medium, and e. recycling said scrubbing medium from step (d.) to step (a.) to form said scrubbing medium.
Claim 2
Independent Claim
122 words
A method of removing SO 2 from the flue gases produced in the combustion of sulfur-containing fuels comprising the steps of: a. providing a scrubbing medium, said scrubbing medium comprising a mixture of water and the Ca(OH) 2 sludge from an acetylene manufacturing process, said Ca(OH) 2 sludge containing at least one ingredient which inhibits the oxidation of sulfite to sulfate, b. contacting said flue gas in a scrubbing zone with said scrubbing medium whereby said SO 2 reacts with said scrubbing medium to form sulfite, c. withdrawing said scrubbing medium from said scrubbing zone, d. separating precipitated calcium sulfite from said withdrawn scrubbing medium, and e. recycling said scrubbing medium from step (d.) to step (a.) to form said scrubbing medium.
Claim 3
Dependent Claim
37 words
A method as recited in claim 1 wherein the pH of said scrubbing medium in step (a.) is maintained in the range of 8.0 to 10.0 by controlling the rate of addition of said Ca(OH) 2 sludge.
Claim 4
Dependent Claim
39 words
A method as recited in claim 1 wherein said scrubbing medium further includes hydrated lime and wherein said Ca(OH) 2 sludge comprises at least about 10 percent of the total of said Ca(OH) 2 sludge and said hydrated lime.
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) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |