Patent US3888968A successfully refreshed from Google Patents.
US3888968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of separating impurities for removal in desulfurization of effluent gas in a wet lime-gypsum process
Assignee: Mitsubishi Heavy Industries Ltd
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Filing: 1972-11-08
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Granted: 1975-06-10
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Expires: 1992-11-08
Abstract
Abstract A method of separating impurities for removal in the desulfurization of effluent gas in a wet lime-gypsum process wherein sulfur oxide is removed from sulfur oxide-containing gas using lime slurry as absorbent, characterized in that, in filtering out from the solution in process such metallic impurities as metallic salts and oxides that come from the dust in the gas and also from material lime, the carbon dust collected from the gas is utilized as nuclei for flocculation of the hydroxides.
Inventors
- 👤 Masumi Atsukawa
- 👤 Naoharu Shinoda
- 👤 Haruo Kuwubara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:42
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/46; C01F11/464; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501; C02; C02F; C02F1/00; C02F1/52
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
144 words
IN A METHOD FOR THE REMOVAL OF SULFUR OXIDE FROM AN EFFLUENT GAS USING A WET LIME-GYPSUM PROCESS WHEREIN SULFUR OXIDE IS REMOVED FROM A SULFUR OXIDE CONTAINING GAS BY PASSING THE GAS THROUGH A COOLING TOWER TO REMOVE CARBON DUST THEREFROM, AND THEN THROUGH A GAS ADSORPTION COLUMN CONTAINING A LIME SLURRY AS AN ABSORBENT TO PRODUCE CALCIUM SULFITE, PASSING THE CALCIUM SULFITE THROUGH AN OXIDIZER TO CONVERT IT TO CALCIUM SULFATE IN THE FORM OF A GYPSUM SLURRY WHICH IS THEN PAPASSED THROUGH A SLURRY CONCENTRATOR WHEREIN THE SUPERNATANT FLUID THEREFROM IS PASSED TO A NEUTRALIZER TO PRECIPITATE THE HYDROXIDES OF THE METALLIC IMPURITIES, AND A FILTER TO SEPARATE THE HYDROXIDE AND TO OBTAIN A PURIFIED FILTRATE, THE IMPROVEMENT WHICH COMPRISES ADDING THE CARBON DUST OBTAINED FROM THE COOLING TOWER TO THE NEUTRALLIZER TO FACILITATE THE PRECIPITATION AND FLOCCULATION OF THE HYDROXIDES.
Claim 2
Dependent Claim
144 words
IN A METHOD FOR THE REMOVAL OF SULFUR OXIDE FROM AN EFFLUENT GAS USING A WET LIME-GYPSUM PROCESS WHEREIN SULFUR OXIDE IS REMOVED FROM A SULFUR OXIDE CONTAINING GAS BY PASSING THE GAS THROUGH A COOLING TOWER TO REMOVE CARBON DUST THEREFROM, AND THEN THROUGH A GAS ADSORPTION COLUMN CONTAINING A LIME SLURRY AS AN ABSORBENT TO PRODUCE CALCIUM SULFITE, PASSING THE CALCIUM SULFITE THROUGH AN OXIDIZER TO CONVERT IT TO CALCIUM SULFATE IN THE FORM OF A GYPSUM SLURRY WHICH IS THEN PAPASSED THROUGH A SLURRY CONCENTRATOR WHEREIN THE SUPERNATANT FLUID THEREFROM IS PASSED TO A NEUTRALIZER TO PRECIPITATE THE HYDROXIDES OF THE METALLIC IMPURITIES, AND A FILTER TO SEPARATE THE HYDROXIDE AND TO OBTAIN A PURIFIED FILTRATE, THE IMPROVEMENT WHICH COMPRISES ADDING THE CARBON DUST OBTAINED FROM THE COOLING TOWER TO THE NEUTRALLIZER TO FACILITATE THE PRECIPITATION AND FLOCCULATION OF THE HYDROXIDES.
Claim 3
Dependent Claim
54 words
The method of claim 1 wherein the carbon dust is contained in a waste liquid from the cooling tower, and a supernatant liquid is obtained from the concentrator and said waste liquid, said supernatant liquid, and a portion of the lime slurry are mixed and the mixture is neutralized to precipitate the impurities therein.
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) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |