Separation of the components of gas mixtures and air

Claim 2

A process as defined in claim 1, including passing a refrigerant from an external source in heat exchange relation through and along an upper fractionating portion of said column for additional removal of heat from said upper portion of said column, and providing refrigeration for said initial fractionation zone.

Claim 3

A process as defined in claim 1 for the separation of oxygen and nitrogen from air, which includes withdrawing cold nitrogen from the top of said initial fractionation zone, introducing said oxygen-rich liquid mixture withdrawn from the bottom of said initial fractionation zone, as feed into said fractionating column intermediate the upper and lower end portions thereof, fractionating said mixture to produce liquid oxygen at the bottom of said column and nitrogen at the upper end of said column, further compressing at least a portion of said nitrogen withdrawn from said initial fractionation zone to a pressure sufficient to evaporate fluid in the lower portion of said fractionating column, said further compressed nitrogen introduced as heat exhange fluid in indirect heat exchange relation through and along substantially the entire lower fractionating portion of said column, withdrawing the resulting sub-cooled liquid nitrogen, further cooling said sub-cooled nitrogen by said throttling same, said further cooled liquid nitrogen then passed in indirect heat exchange relation through and along the upper substantial fractionating portion of said column for said removal of heat therefrom, passing an extraneous refrigerant in heat exchange relation through and along an upper fractionating portion of said column for additional removal of heat therefrom, and providing refrigeration for said initial fractionation zone in indirect heat exchange relation with said column, withdrawing liquid oxygen from the bottom of said fractionating column, and withdrawing a nitrogen overhead from the upper end of said column.

Claim 4

A process for the separation of oxygen and nitrogen from air as defined in claim 4, and including sub-cooling and throttling said liquid oxygen withdrawn from the bottom of said fractionating column to form a further cooled oxygen liquid, passing said further cooled oxygen liquid in indirect heat exchange relation through and along the upper fractionating portion of said column for removal of additional heat therefrom, and withdrawing oxygen vapor as product.

Claim 5

A process for the separation of air into oxygen, nitrogen, and argon, which comprises carrying out the separation in a plurality of fractionation zones, the respective fractionation zones being connected in adjacent side-by-side indirect heat exchange relation with Each other, permitting heat transfer between said fractionation zones through adjacent walls thereof, said plurality of fractionation zones including an initial fractionation zone, a first fractionating column and a second fractionating column, said initial fractionation zone being connected in adjacent side-by-side indirect heat exchange relation with said first fractionating column, and said second fractionating column being connected in adjacent side-by-side indirect heat exchange relation with said first fractionating column, comprising introducing compressed air approximately at its saturation temperature into said initial fractionation zone, withdrawing cold nitrogen as overhead from said initial fractionation zone, withdrawing an oxygen-rich liquid mixture from the bottom of said initial fractionation zone, introducing said oxygen-rich liquid mixture as feed to said first fractionating column, fractionating said feed mixture in said first fractionating column to produce an oxygen-argon liquid at the bottom of said column and nitrogen at the upper end of the column, introducing said oxygen-argon liquid as feed into said second fractionating column and fractionating said last mentioned liquid in said second column to produce liquid oxygen at the bottom of said last mentioned column, and an argon overhead, further compressing at least a portion of said nitrogen overhead from said initial fractionation zone, passing said further compressed nitrogen as heat exchange fluid in indirect heat excange relation through and along a substantial lower fractionating portion of said second fractionating column, withdrawing and further cooling a portion of the resulting liquid nitrogen heat exchange fluid, passing said further cooled portion of liquid nitrogen in indirect heat exchange relation with said argon overhead from said second fractionating column for condensing at least a portion of said argon, and introducing said condensed argon as reflux to said second rractionating column, further cooling the remaining portion of the liquid nitrogen withdrawn from indirect heat exchange relation with the lower portion of said second fractionating column, and introducing at least a portion thereof as reflux to said first fractionating column, and passing an extraneous refrigerant in indirect heat exchange relation through and along a substantial upper fractionating portion of said first fractionating column at a temperature to remove heat therefrom and providing refrigeration for said initial separation zone.

Claim 6

A process as defined in claim 6, which includes sub-cooling the liquid nitrogen withdrawn as heat exchange fluid from heat exchange relation with said second fractionating column, throttling a portion of said sub-cooled liquid nitrogen for passage in indirect heat exchange relation with said argon for condensing at least a portion thereof, separating the remaining portion of said sub-cooled liquid nitrogen into two streams, throttling said first stream of liquid nitrogen to further cool same and introducing said throttled first stream of nitrogen as reflux into said first fractionating column, throttling said second stream of sub-cooled liquid nitrogen for further cooling same, and introducing said throttled second stream as reflux into said initial fractionation zone, and including mixing said nitrogen vapor following indirect heat exchange relation with said argon, with a portion of said nitrogen overhead vapor from said initial fractionation zone, passing the resulting nitrogen vapor in indirect heat exchange relation with liquid nitrogen withdrawn from heat exchange relation with the lower portion of said second fractionating column, for sub-cooling said liquid nitrogen, work expanding the exiting nitrogen vapors to provide energy for compressing said at least a portion of said nitrogen overhead fron said initial fractionation zone, passing the expanded nitrogen vapors in indirect heat exchange relation with compressed air feed for cooling same, passing the nitrogen overheaD from said first fractionating column in indirect heat exchange relation with said liquid oxygen for sub-cooling same, and then passing the exiting nitrogen vapors in indirect heat exchange relation with compressed air feed for cooling same, withdrawing liquid oxygen from the bottom of said second fractionating column, sub-cooling said liquid oxygen and vaporizing said sub-cooled liquid oxygen in indirect heat exchange relation with said initial fractionation zone to remove heat therefrom, and passing oxygen vapors exiting from indirect heat exchange relation with said initial fractionation zone, in indirect heat exchange relation with compressed air feed for cooling same, and compressing the exiting oxygen vapors.

Claim 7

The process as defined in claim 6, said initial fractionation zone being connected in adjacent side-by-side indirect heat exchange relation with the upper portion of said first fractionating column, and the lower portion of said first fractionating column being connected in adjacent side-by-side indirect heat exchange relation with the upper portion of said second fractionating column.