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:
May. 14, 2013
Filed:
Sep. 12, 2008
Hitoshi Kihara, Chiba, JP;
Hitoshi Kihara, Chiba, JP;
Taiyo Nippon Sanso Corporation, Tokyo, JP;
Abstract
Method for concentrating nitrogen isotope to obtain a final product nitrogen, in which the stable nitrogen isotope,N, is concentrated, by low-temperature distillation of raw material nitrogen containing trace amounts of oxygen and argon using a plurality of distillation columns in a cascade arrangement. An argon-oxygen mixture is discharged from the bottom of the final column andN-concentrated nitrogen is extracted from a lower intermediate point of the final column. The flow rate of the argon-oxygen mixture discharged from the bottom of the final column is controlled based on the reading of a thermometer installed below the point where the final productN-concentrated nitrogen is extracted, thereby providing a stable nitrogen product.