Method for cryogenic separation of air, air separation device and composite of at least two air separation devices

The invention relates to a method for the cryogenic separation of air using an air separation plant (100-400) with a rectification column system (10) having a pressure column (11) operating at a pressure level of 9 bar to 14.5 bar, a low-pressure column (12) operating at a pressure level of 2 bar to 5 bar, and an argon column (13). According to the invention, the second overhead gas or part thereof is used to form a circulation stream, and the overhead gas or the circulation stream is heated, compressed, recooled and fed into the first rectifying column (11) and/or the second rectifying column (12) partially or wholly or proportionally after being partially or wholly liquefied or in the non-liquefied state. The subject matter of the invention also relates to a corresponding device (100-400). 本发明涉及一种使用带精馏塔系统(10)的空气分离设备(100-400)来低温分离空气的方法，该精馏塔系统具有在9bar至14.5bar的压力水平上运行的压力塔(11)、在2bar至5bar的压力水平上运行的低压塔(12)和氩塔(13)。根据本发明，使用第二顶部气体或其部分来形成循环流，对顶部气体或循环流进行加热、压缩、重新冷却并在部分或全部液化后或者在非液化状态下将其部分或全部或者按比例地馈入第一精馏塔(11)和/或第二精馏塔(12)。本