Patent ID: 9291389
Filing Date: 2016-03-22
CPC Classification: F25J

Claim Text:
1. A method for producing argon by cryogenic rectification of feed air comprising: (a) directing feed air into a higher pressure column configured to produce oxygen-enriched liquid and a nitrogen-rich stream by cryogenic rectification within the higher pressure column; (b) withdrawing the nitrogen rich stream from the higher pressure column and directing the nitrogen rich stream from the higher pressure column to a lower pressure column configured to produce an oxygen product stream and a nitrogen-rich product stream or waste stream by cryogenic rectification within the lower pressure column; (c) withdrawing an argon-oxygen-containing side stream from the lower pressure column and directing the argon-oxygen-containing side stream from the lower pressure column to an argon column configured to produce an argon-rich vapor stream and a bottoms liquid by cryogenic rectification within the argon column; (d) directing the bottoms liquid from the argon column to the lower pressure column; (e) directing the argon rich vapor stream to an argon condensing assembly disposed within the lower pressure column; (f) withdrawing the oxygen-enriched liquid from the higher pressure column and directing the oxygen-enriched liquid from the higher pressure column to the argon condensing assembly, the argon condensing assembly configured to condense the argon rich vapor stream against the oxygen-enriched liquid from the higher pressure column to produce an argon-rich liquid stream and a partially vaporized oxygen-rich stream; and (g) releasing the partially vaporized oxygen-rich stream into the lower pressure column; (h) removing the argon-rich liquid stream from the argon condensing assembly; wherein any of the oxygen-enriched liquid from the higher pressure column is directed to lower pressure column via the argon condensing assembly; and wherein a portion of the argon-rich liquid stream is removed from the argon condensing assembly as an argon product.