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:
May. 14, 1997
Shinji Tomita, Hyogo-ken, JP;
Teisan Kabushiki Kaisha, Tokyo, JP;
Abstract
A high purity nitrogen generator unit which is excellent in the energy efficiency and the recovery of high purity nitrogen gas, is provided. In a rectification column 1, feed air is separated to oxygen-rich liquid air and nitrogen gas. The oxygen-rich liquid air in its bottom is reduced in pressure by a first expansion valve 21 and sent to a composition regulation column 3. The nitrogen gas in its top is condensed in a nitrogen condenser 2, the resulting liquid nitrogen is returned as a reflux liquid to the rectification column 1 and non-condensed gas is released. After oxygen-rich waste gas in the lower part of the composition regulation column 3 is reduced in pressure by an expansion turbine 6, it is released by way of a first heat exchanger 4. Mixed gas in the top of the composition regulation column 3 is introduced for re-circulation into a first compressor 5. Another portion of the mixed gas is returned to the composition regulation column 3 by way of a second compressor 7, second heat exchanger 8 and second expansion valve 22. The second compressor 7 is driven by means of the expansion turbine 6. High purity liquid nitrogen taken out of the vicinity of the top of the rectification column 1 is evaporated for recovery in the second heat exchanger 8.