| 摘要 |
<p>998,751. Cold separation of air. BRITISH OXYGEN CO. Ltd. July 2, 1964 [July 18, 1963; Nov. 14, 1963], Nos. 28470/63 and 45100/63. Heading F4P. Compressed air to be separated into gaseous nitrogen and liquid oxygen in a conventional double column 20, 24, Fig. 1, is washed in a water scrubber 2, precooled and partially dried in an exchanger 4 traversed by reverse flowing separated oxygen and nitrogen a portion of which recooled at 6 and recirculated by a blower 7 through the exchanger 4, partly freed of condensables in a pair of high temperature alternating absorbers 11 (only one of which is shown), further cooled in continuous heat exchangers 12, 13 traversed by reversely flowing nitrogen and oxygen respectively, completely freed of condensibles in a pair of alternating absorbers 14 (only one of which is shown) and the air feed is divided into a minor portion which is liquefied in a liquid oxygen vaporizer 15, and into a major portion which having been cooled in a nitrogen exchanger 16 is in part liquefied in a nitrogen exchanger 18 and is added to the minor portion and is thereafter expanded at a valve 19 after which it is added to the remainder of the feed air having left exchanger 16 and having been liquefied in a turbine 17, the whole of the so liquefied air then being fed to the high-pressure column 20 Reactivation and recooling of low temperature absorber 14 is effected by withdrawing a portion of product nitrogen from outlet 32, forcing it by a blower 33, Fig. 2, through a precooler 34, mixing with liquid nitrogen in a Venturi 35 and passing the mixture reversely through the absorber 14. An argon column 30 is connected to the low pressure column 24 of an intermediate level thereof.</p> |
