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:
Jul. 08, 1997
Filed:
Jan. 03, 1996
Thomas Rathbone, Farnham, GB;
The BOC Group plc, Windlesham, GB;
Abstract
A stream of compressed air is purified in a unit by removal of carbon dioxide and water vapour. The air is cooled by passage through a heat exchanger to a temperature suitable for its rectification. The air is separated in a higher pressure rectifier into oxygen-enriched liquid and nitrogen vapour. A stream of the oxygen-enriched liquid is reduced in pressure and introduced into a phase separator provided with a reboiler with the result that further separation takes place and a liquid further enriched in oxygen and an intermediate vapour are formed. A stream of the further-enriched liquid is separated into oxygen and nitrogen in a lower pressure rectifier. A stream of the intermediate vapour is condensed in a condenser and is introduced into the lower pressure rectifier. A part of the liquid nitrogen reflux for the higher and lower pressure rectifiers is formed by condensing nitrogen vapour separated in the higher pressure rectifier by indirect heat exchange with liquid from an intermediate mass transfer region the rectifier. Another part of the liquid nitrogen reflux is formed by vaporising impure oxygen product of the lower pressure rectifier in a condenser-reboiler by indirect heat exchange with nitrogen vapour taken from the lower pressure rectifier.