Patents by Inventor David M. Stuart

David M. Stuart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5533339
    Abstract: Air is compressed in compressors, cooled in a main heat exchanger, and separated into oxygen and nitrogen products in a double rectification column comprising a higher pressure rectification column and a lower pressure rectification column. A liquid oxygen product is withdrawn from the lower pressure column via a conduit. A liquid nitrogen product is also formed. An argon-enriched oxygen vapour stream is withdrawn from the lower pressure column through an outlet and has argon separated from it in an argon column. In order to help meet the requirements of the higher pressure column for reflux, a nitrogen vapour stream is withdrawn from the top of the lower pressure column, is warmed by passage through the heat exchanger, is recompressed in a compressor, and is liquefied by passage back through the heat exchanger from its warm end to its cold end and passage through a valve. A high liquid make and a high argon recovery can both be achieved.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 9, 1996
    Assignee: The BOC Group plc
    Inventors: Stephen R. Clare, Paul Higginbotham, David M. Stuart