| 摘要 |
A cryogenic air separation process and apparatus in which air is cooled in heat exchanger 16 after compression in compressor 10 and purification in a purifier 12. The air is rectified in a rectification column 26 to produce an oxygen rich liquid. An argon-oxygen stream containing liquid lean in nitrogen is separated in column 50 to form oxygen and argon streams. Argon vapour is condensed in condenser 59 to supply reflux to the argon column 50. An oxygen rich liquid stream is expanded through valve 64 to a pressure at which the oxygen rich liquid is below the condensation temperature of the argon vapour and is then vaporized against the condensing argon vapour. The vaporized oxygen rich liquid is then introduced into a nitrogen stripper column 42 and nitrogen is stripped therefrom by a stripper gas to produce the argon-oxygen liquid which is introduced into the argon column 50. The nitrogen stripper column 42 is regulated to operate in a predetermined pressure range so that the entry level at which oxygen enters the nitrogen stripper column 42 is at a pressure no greater than the pressure of the oxygen rich liquid after expansion. Argon is removed from the top of the argon column 50 as a product. The process and apparatus can be operated to produce high purity argon vapour or liquid very lean in nitrogen and oxygen with the use of trays and/or structured packing as liquid contacting mass transfer elements in the columns. Additionally, high purity oxygen and nitrogen products can also be produced by such process and apparatus. <IMAGE> |
