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. 12, 1998
Filed:
Nov. 25, 1996
Dietrich Rottmann, Munchen, DE;
Linde Aktiengesellschaft, Wiesbaden, DE;
Abstract
The method and the apparatus are used to obtain oxygen and nitrogen at superatmospheric pressure by low-temperature separation of air in a rectification column system. Compressed and purified feed air (1, 3) is introduced into a pressure column (4). Liquids (5, 8) from the lower region and, respectively, from the upper or middle region of the pressure column (4) are fed into the low-pressure column (7). A third liquid fraction (17) from the lower region of the low-pressure column (7) is evaporated in indirect heat exchange (12) with condensing vapour (11) from the upper region of the pressure column (4), at least a portion of the vapour (22, 24, 26, 27) obtained in the process being introduced into the low-pressure column (7). Condensate (13) is fed into the pressure column (4); A pressurized nitrogen fraction (10, 14, 15) is extracted as product from the upper region of the pressure column (4). The pressure of the third liquid fraction (17) from the lower region of the low-pressure column (17) is increased upstream of the indirect heat exchange (12); that portion (24) of the vapor which is obtained during the indirect heat exchange and led back into the low-pressure column is expanded (25) before being introduced (27) into the low-pressure column (7).