Verfahren und Vorrichtung zum Erzeugen von Stickstoff aus Luft

摘要

This invention concerns a process and device in which air is first compressed to an initial pressure in a precompressor (1), then is cooled, cleaned and reheated. A heat exchanger (2) is used for simultaneous cooling and reheating. Separation of the nitrogen is done in a separating device (4) which consists of a plurality of membrane separators. The nitrogen-enriched concentrate of the last step is recirculated to the suction side of the precompressor (1). The separated nitrogen is compressed to the desired pressure in a final compressor (6) which is connected to the separation device (4). A pressure switch (8) controls the system so that, upon starting up, the final compressor (6) is connected only when the working pressure of the separation device (4) is reached. Up to this point the gas delivered from the separation device (4) is partially recirculated to the precompressor (1). Leakage nitrogen from the final compressor (6) also recirculates to the precompressor (6).