| 摘要 |
1,069,866. Purification of oxygen. AIR REDUCTION CO. Inc. May 25, 1965 [June 2, 1964], No. 22105/65. Heading F4P. Commercially pure oxygen is freed of low boiling impurities by compressing at (106), Fig. 1 (not shown), cooling to saturation temperature in a pass (110c) of a heat exchanger (110), condensing at (115) at the base of a rectification column (113), withdrawing hydrogen, helium and nitrogen impurities from the condenser (113) through a duct (116), expanding the partly purified liquid oxygen through a valve (120) into the upper end of column (113), withdrawing argon and nitrogen gas from the head of the column through a duct (126) and after passage through a pass (110a) of exchanger (110), returning at least a portion to the inlet of the compressor (106) and withdrawing product gas from above the pool of liquid oxygen collecting at the base of the column (113) and serving to cool condenser (115) through a duct (122) provided with a motor operated valve (134), and leading to a liquid nitrogen cooled condenser (128) from which product liquid oxygen is withdrawn through a valve (130). Nitrogen for cooling condenser (128) and a condenser (118) at the head of column (113) is supplied from a reservoir (124) and the resulting nitrogen vapour traverses a pass (110b) of exchanger (110). The valve (134) is controlled by a servo device (107) responsive to the argon content of a sample withdrawn from the column (113) at a point (114a), to the flow of saturated feed oxygen entering the column through a duct (112) and to the composition of product gas in duet (122). The methane content of the feed gas is removed by a conventional catalyst chamber (103). In a modification methane is removed from feed liquid oxygen in a preliminary rectification column (351), Fig. 3 (not shown). In a further modification the gaseous oxygen leaving the base of the column (413), Fig. 4 (not shown) through valve (434) is freed of methane in a catalyst chamber (426) prior to liquefaction in a condenser 428.
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