US4001384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovery of oxides of sulfur from combustion waste gas
Assignee: AGC Inc
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Filing: 1973-05-29
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Granted: 1977-01-04
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Expires: 1993-05-29
Abstract
Abstract A process for the recovery of oxides of sulfur from combustion waste gases, which comprises cooling said waste gases and forming entrained particles of sodium compounds, consisting essentially of sodium carbonate, by spray contact with sodium hydroxide or sodium carbonate, converting sodium carbonate in the particles to sodium sulfate by passing said oxides of sulphur containing waste gases and said sodium compound particles over plate-like packings, whereby said particles are comminuted to a finer particle size form so as to enhance the reaction of said sulfate particles with the oxides of sulfur in said waste gases, collecting entrained particles of said sodium compounds in a dust collector.
Inventors
- 👤 Junji Iwakura
- 👤 Kimihiko Sato
- 👤 Hisashi Fujii
- 👤 Yoshihiro Hashimoto
- 👤 Shigeo Ono
- 👤 Shozaburo Watanabe
- 👤 Akio Yokoyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:36
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501; B01D53/505
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
144 words
A process for the recovery of oxides of sulfur from oxygen containing combustion waste gases, which comprises: cooling said waste gases having an initial temperature of 400° - 600° C and forming entrained articles of sodium compounds consisting essentially of sodium carbonate, by spray contacting said waste gases with a solution of sodium hydroxide or sodium carbonate, wherein the ratio of said sodium hydroxide or sodium carbonate to said oxides of sulfur is 0.9 to 1.5; converting sodium carbonate in the particles to sodium sulfate by passing said waste gases containing said oxides of sulfur and said sodium compound particles over plate-like packings, whereby said particles are comminuted to a finer particle size form, so as to enhance the reaction of said particles with the oxides of sulfur in said waste gases; and collecting entrained particles after said conversion step in a dust collector.
Claim 2
Dependent Claim
144 words
A process for the recovery of oxides of sulfur from oxygen containing combustion waste gases, which comprises: cooling said waste gases having an initial temperature of 400° - 600° C and forming entrained articles of sodium compounds consisting essentially of sodium carbonate, by spray contacting said waste gases with a solution of sodium hydroxide or sodium carbonate, wherein the ratio of said sodium hydroxide or sodium carbonate to said oxides of sulfur is 0.9 to 1.5; converting sodium carbonate in the particles to sodium sulfate by passing said waste gases containing said oxides of sulfur and said sodium compound particles over plate-like packings, whereby said particles are comminuted to a finer particle size form, so as to enhance the reaction of said particles with the oxides of sulfur in said waste gases; and collecting entrained particles after said conversion step in a dust collector.
Claim 3
Dependent Claim
62 words
The process according to claim 1, wherein in said cooling step the concentration of sodium hydroxide or sodium carbonate in the sprayed solution is in the range of 1 - 20 wt.% which maintains an equivalency of sodium hydroxide or sodium carbonate in the range of 0.9 - 1.5 compared to the content of oxides of sulfur present in the waste gas.
Claim 4
Dependent Claim
21 words
The process according to claim 1, wherein in the cooling step the waste gas is cooled to 200° - 350° C.
Claim 5
Dependent Claim
20 words
The process according to claim 1, wherein the spray nozzle is cooled below the dew point of the surrounding atmosphere.
Claim 6
Dependent Claim
27 words
The process according to claim 1, wherein a plurality of said reaction chamber contains plate-like packings which are slanted with respect to the direction of gas flow.
Claim 7
Dependent Claim
37 words
The process according to claim 5, wherein in the reaction step the sodium compounds particles impinge upon the plate-like packings in the reaction chamber which forms fine particles having an average diameter of 0.5 - 1 μ.
Claim 8
Dependent Claim
24 words
The process according to claim 1, wherein in the reaction step, the waste gas is maintained at a temperature from 200° - 350° C.
Claim 9
Dependent Claim
30 words
The process according to claim 1, wherein in the dust collecting step the mist of sulfuric acid remaining in the reacted waste gas is removed by contact with sodium carbonate.
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) | 1980-01-04 | 1980-07-05 | 1981-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-04 | 1984-07-05 | 1985-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-04 | 1988-07-05 | 1989-01-04 | $7700.00 | Window Closed / Lapsed |