The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 25, 1997
Filed:
Oct. 09, 1996
John Douglas Oakey, Godalming, GB;
Paul Higginbotham, Guildford, GB;
The BOC Group plc, Windlesham, GB;
Abstract
A stream of precooled and purified air is introduced into a double rectification column comprising a higher pressure rectification column and a lower pressure rectification column and is separated therein into an oxygen-rich fraction and a nitrogen-rich fraction. A stream of argon-enriched oxygen vapor flows from an outlet of the lower pressure rectification column into a side column in which argon is separated therefrom. An oxygen-enriched liquid air stream is taken from an outlet at the bottom of the higher pressure rectification column. A vaporous oxygen-enriched air stream is introduced into the lower pressure rectification column through an inlet above the outlet. At least part of the oxygen-enriched liquid is separated in a further or intermediate pressure rectification column provided with a reboiler, thereby forming a vapor depleted of oxygen and a liquid air stream further enriched in oxygen. At least one stream of the further-enriched liquid is vaporised to form the oxygen-enriched vapor that is introduced into the lower pressure rectification column. A part of the oxygen-depleted vapor is condensed in a condenser and is taken as product or reintroduced into the lower pressure rectification column. The partial reboiling in the reboiler is effected by indirect heat exchange with a vapor stream withdrawn from an intermediate region of the side column. The condenser is cooled by a stream of liquid withdrawn from the further rectification column.