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:
Sep. 15, 1998
Filed:
Jul. 31, 1996
Thomas Rathbone, Farnham, GB;
The BOC Group plc, Windlesham, GB;
Abstract
Air is compressed in an arrangement of compressors. A first flow of the thus compressed air flows through a main heat exchanger from its warm end to its cold end and is liquefied by passage through a valve. Two second stream of compressed air are taken. One is expanded in one expansion turbine and the other in another expansion turbine. The streams leaving the valve and the one expansion turbine are separated in a double rectification column. Liquid oxygen product is extracted from outlet thereof. Part is taken as liquid product and the rest is vaporized by passage through the heat exchanger from its cold end to its warm end and taken as gaseous oxygen product. The ratio of liquid oxygen product to total oxygen product is capable of being varied. Accordingly a chosen but variable proportion of the two second air streams flows to the double rectification column and a chosen but variable proportion of the two second air streams is returned to the arrangement of compressors to an intermediate compressor.