| 摘要 |
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. |
