| 摘要 |
A process and apparatus for separating air in which compressed, purified air is cooled in a heat exchanger 18 and separated in a single rectification column 24 into nitrogen vapour at its top and liquid oxygen at its bottom. A nitrogen stream is withdrawn from the column 24 and is partly condensed in a condenser 32. Fluid from the condenser 32 is passed into a phase separator 36. A stream of the resulting vapour phase is warmed in the heat exchanger 18, and is expanded in a turboexpander 48. The resulting expanded vapour is passed through the heat exchanger 18 from its cold end to its warm end in order to provide refrigeration for the process. A stream of liquid oxygen is withdrawn from the bottom of the column 24, is reduced in pressure by passage through a valve 43, is vaporised by heat exchange with condensing nitrogen in the condenser 32 and is compressed cold in the compressor 54. One part of the compressed oxygen is taken as product, and another part recycled to the column 24. The turboexpander 48 is coupled to and drives the compressor 54. <IMAGE> |
