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US 5,231,837 AGranted
Cryogenic distillation process for the production of oxygen and nitrogen
AssigneeLiquid Air Engineering Corporation
InventorBao Ha
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AssigneeLiquid Air Engineering Corporation
InventorBao Ha
Estimating the term…
A cryogenic distillation process for the production of oxygen and nitrogen is provided, which entails: a) providing a feed stream of clean, dry and compressed air, b) cooling at least a fraction of the compressed air and introducing the same into a high pressure column, and separating the same into nitrogen-rich stream at the top of the column and an oxygen-rich stream at the bottom of the column, wherein the overhead of the high pressure column exchanges heat with both the bottom of the low pressure column and the bottom of an intermediate column, c) introducing at least a fraction of the oxygen-rich stream into the intermediate column to afford a top liquid fraction A and a bottom liquid fraction B, the overhead of the intermediate column exchanging heat with the low pressure column at a location above the bottom reboiler of the low pressure column, wherein the pressure of the intermediate column is lower than the high pressure column but higher than the low pressure column, d) introducing at least a fraction of the liquid fractions A and B into the low pressure column as feed, e) feeding at least a fraction of the nitrogen-rich stream of step b) to the low pressure column as reflux, and f) recovering an oxygen-rich stream product at the bottom of the low pressure column and a low pressure nitrogen- rich stream at the top of the low pressure which further comprises recovering a medium pressure nitrogen stream column.
A cryogenic distillation process for production of oxygen and nitrogen, which comprises:
A cryogenic distillation process for the production of oxygen and nitrogen, which comprises:
An apparatus for producing oxygen and nitrogen having three distillation columns, which comprises a triple rectification column comprising a higher pressure column having feed stream input means, heat exchange means joining an upper end of the higher pressure column and a lower end of both a low pressure and an intermediate column, separate conduit means for feeding nitrogen-rich liquid from the higher pressure column to the lower pressure column and oxygen-rich liquid to the intermediate column, separate conduit means for feeding the products of the intermediate column to the low pressure column as feeds, separate conduit means for discharging nitrogen-rich gas from the low pressure column, separate conduit means for discharging an oxygen-rich stream from the low pressure column, and wherein a top portion of the intermediate column is in heat exchange relation with the low pressure column at a location above a bottom reboiler of the low pressure column.
An apparatus for producing oxygen and nitrogen having three distillation columns, which comprises a triple rectification column comprising a higher pressure column having feed stream input means, heat exchange means joining an upper end of the higher pressure column and a lower end of both a low pressure and an intermediate column, separate conduit means for feeding nitrogen-rich liquid from the higher pressure column to the lower pressure column and oxygen-rich liquid to the intermediate column, separate conduit means for feeding products of the intermediate column to the low pressure column as feeds, separate conduit means for discharging nitrogen-rich gas from the low pressure column, separate conduit means for discharging an oxygen-rich stream from the low pressure column, separate conduit means for transferring liquid produced at a bottom of the intermediate column to an overhead of the intermediate column and separate conduit means for feeding resulting vaporized liquid from an overhead condenser to the low pressure column.
Dependencies are inferred from the claim text.