US4576803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing calcium sulfate dihydrate in connection with the desulfurization of flue gases
Assignee: Gottfried Bischoff Bau Kompl Gasreinigungs und Wasserrueckkehlanlagen GmbH and Co KG
•
Filing: 1983-12-09
•
Granted: 1986-03-18
•
Expires: 2003-12-09
Abstract
Abstract A scrubber for flue gases from a fossil-fired power plant in which calcium sulfate dihydrate is produced by recirculating the scrubbing water suspension containing lime and introducing oxygen into the sump collection, has a discontinuously operated pump which withdraws the suspension for recovering of the solid product only discontinuously so as to maintain the solids concentration between 40 and 130 g/l.
Inventors
- 👤 Karl-Rudolf Hegemann
- 👤 Helmut Weissert
- 👤 Jurgen Laimkuhler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:49
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501; C; C01; C01F; C01F11/00; C01F11/46; C01F11/464
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
192 words
A method of operating a scrubbing column for the scrubbing and desulfurizing of flue gas from a fossil-fired power plant, comprising the steps of: (a) preparing a scrubbing liquid by introducing lime and water into the sump of a scrubbing column containing a suspension of calcium sulfate dihydrate in the scrubbing water; (b) scrubbing and desulfurizing said flue gas by passing it through a portion of said column above said sump in counterflow to scrubbing liquid which collects in this sump while introducing oxygen into the liquid in the sump; (c) continuously recirculating the scrubbing liquid from this sump to the scrubbing of flue gas above said sump; (d) detecting the solids concentration of said suspension; (e) commencing at intervals a withdrawal of said suspension from said sump upon the detection of a solids concentration of said suspension at a maximum value in the range of 40 to 130 g/l; (f) terminating the withdrawal upon the the solids concentration in said suspension falling to a minimum value in said range; (g) adding make-up water to the suspension of said sump; and (h) processing the withdrawn suspension to recover calcium sulfate dihydrate therefrom.
Claim 2
Independent Claim
192 words
A method of operating a scrubbing column for the scrubbing and desulfurizing of flue gas from a fossil-fired power plant, comprising the steps of: (a) preparing a scrubbing liquid by introducing lime and water into the sump of a scrubbing column containing a suspension of calcium sulfate dihydrate in the scrubbing water; (b) scrubbing and desulfurizing said flue gas by passing it through a portion of said column above said sump in counterflow to scrubbing liquid which collects in this sump while introducing oxygen into the liquid in the sump; (c) continuously recirculating the scrubbing liquid from this sump to the scrubbing of flue gas above said sump; (d) detecting the solids concentration of said suspension; (e) commencing at intervals a withdrawal of said suspension from said sump upon the detection of a solids concentration of said suspension at a maximum value in the range of 40 to 130 g/l; (f) terminating the withdrawal upon the the solids concentration in said suspension falling to a minimum value in said range; (g) adding make-up water to the suspension of said sump; and (h) processing the withdrawn suspension to recover calcium sulfate dihydrate therefrom.
Claim 3
Dependent Claim
13 words
The method defined in claim 1 wherein said maximum value is 100 g/l.
Claim 4
Dependent Claim
13 words
The method defined in claim 1 wherein said minimum value is 60 g/l.
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) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |