Patent US3577706A successfully refreshed from Google Patents.
US3577706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sulfur dioxide drying
Assignee: IMP SMELTING CORP M S C Ltd
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Filing: 1968-08-30
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Granted: 1971-05-04
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Expires: 1988-08-30
Abstract
Abstract In the production of sulfuric acid, a two-stage drying process for drying gas which contains SO2, organic material and water by contact with weak sulfuric acid of less than 70 percent strength to absorb a major proportion of the water but little of the organic material and then by contact with strong sulfuric acid to absorb the remaining water and the organic material.
Inventors
- 👤 Leopold Moller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:21
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/48; C01B17/50; C01B17/56; B; B01; B01D; B01D53/00; B01D53/26
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
19 words
A process according to claim 1 wherein the strong acid in the second stage is of 90-99.5 percent strength.
Claim 2
Dependent Claim
19 words
A process according to claim 1 wherein the weak acid in the first stage is of 62-68 percent strength.
Claim 3
Dependent Claim
16 words
A process according to claim 3 wherein the weak acid is of approximately 65 percent strength.
References Cited (Backward Citations)
GB852073A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |