Production of oxygen
Abstract
Abstract 976,352. Cold separation of air. PETROCARBON DEVELOPMENTS Ltd. March 29, 1961 [April 4, 1960], No. 11892/60. Heading F4P. In a two-stage air rectification process for the production of gaseous oxygen both columns 13, 14 operate at superatmospheric pressure and effluent nitrogen issuing from the head of the low-pressure column 14 through a line 23 is expanded in a turbine 17 and the cold so produced is used to cool exchangers 10, 11 traversed by the compressed feed air freed of water vapour and carbon dioxide; product gaseous oxygen being discharged from the column 14 through a line 22. Prior to expansion, the effluent nitrogen is warmed in an exchanger 12 which serves to cool liquid nitrogen passing from the upper portion of the high-pressure column 13 through a line 24 and expansion valve 16 to the column 14. Product oxygen may be further compressed by the power brake 17<SP>1</SP> of the turbine 17. In a modification the effluent nitrogen also serves to cool the oxygen-rich liquid passing from the base of column 13 to the column 14 through a line 25 and expansion valve 15.
Inventors
- 👤 Martin S W Ruhemann
- 👤 Laurel E Putman
Bibliographic Details
Claims Analysis
Total Claims: 2References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-12-31 | 1966-07-02 | 1967-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-12-31 | 1970-07-02 | 1971-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-12-31 | 1974-07-02 | 1975-01-01 | $7700.00 | Window Closed / Lapsed |