Ultra-high purity oxygen production
AssigneeLiquid Air Engineering Corporation
InventorsJames T. Shelton, deceased, Bao Ha
Life of this patent
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Abstract
A process for producing an ultra-high purity fluid product comprising the steps of collecting in the lower portion of a cryogenic fractionation zone an ultra-high purity fluid product; providing reboil to said fractionation zone by condensing a portion of a lesser purity composition of the same fluid product by indirect heat exchange in a first reboiler; and vaporizing said portion of said lesser purity composition by indirect heat exchange with a warmer stream of an impure fluid.
Claims16
A process for producing an ultra-high purity fluid product comprising the steps of:
- (a) collecting in the lower portion of a cryogenic fractionation zone an ultra-high purity fluid product;
- (b) providing reboil to said fractionation zone by condensing a portion of a lesser purity composition of the same fluid product by indirect heat exchange in a first reboiler;
- and
- (c) vaporizing said portion of said lesser purity composition by indirect heat exchange with a warmer stream of an impure fluid.
A process for producing an ultra-high purity oxygen product comprising the steps of:
- (a) feeding liquid oxygen comprising impurities to a first fractional distillation column;
- (b) separating impurities which are higher boiling than oxygen by fractionation in said first column to form an oxygen overhead stream substantially free of heavy impurities;
- (c) feeding at least a portion of said oxygen overhead stream to a second cryogenic distillation column;
- (d) providing reboil to said second distillation column by condensing a portion of a lesser purity grade of oxygen by indirect heat exchange in a first reboiler in the bottom of said second distillation column;
- and
- (e) vaporizing said portion of said lesser purity fluid by indirect heat exchange with a warmer stream of an impure fluid.
A system for producing ultra-high purity fluid by cryogenic distillation comprising:
- (a) a fractional distillation column having a first reboiler in the bottom portion thereof;
- (b) a second reboiler to vaporize a portion of a fluid by indirect heat exchange;
- (c) conduit means to convey said portion of vaporized fluid to said first reboiler for condensing at least a portion of said fluid in said first reboiler;
- and
- (d) means to convey a impure fluid to said second reboiler to provide heat for vaporizing said portion of said intermediate fluid.
In a process for producing an ultra-high purity fluid collected in the bottom of a cryogenic distillation column having first a reboiler therein the improvement comprising:
- (a) conveying a warm impure stream to a second reboiler to vaporize a portion of a lesser purity fluid and condensing a portion of said vaporized lesser purity fluid in said first reboiler to provide reboil for said distillation column and producing an ultra-high purity fluid from the said distillation column comprising less than 10 part per billion impurities.
Dependencies are inferred from the claim text.