Process Analysis Air Separation Units

Nj or Oj in case of leakage however, additional monitoring of the indoor air for Oj is customary. In contrast to process analytics, the product control during the tanking is carried out at another place with different instruments, i.e. directly at the tanks. Table 2.11 sets out important measuring points in air separation units together with the applied analytics. 

In addition, the water content of the regeneration gas entering the molectdar sieve adsorber is analyzed. Due to this dew point analysis the leak-proofness of the pressurized tubes of the regeneration gas heat exchanger conducting superheated steam is guaranteed. In normal operation, a dew point of-70 °C is indicated. 

All process analyzer were periodically calibrated with certified calibration gases, commonly stored in 10 L steel or aluminium cylinders. 

in addition, krypton, xenon or neon are produced, analytics will extend considerably (see Section 3.5). Due to the presently increasing size ofOj-produdng air separation units a krypton/xenon recovery is more and more of economical interest. Actually many Linde plants are equipped with such krypton/xenon-enrichment columns which are integrated in the main cold box and thus belonging to the main air separation unit. The enriched noble gas containing liquid is continuously directed to a tank and from there often shipped by road tank cars to a Kr/Xe-purification unit for further refurbishment 

In this sump a 4000fold enrichment pertaining to the outside air concentrations of Kr and Xe is realized. Subsequently aU heavy air impurities which are able to pass the air purification accumulate at this location. Common sump concentrations are 4000 vppm Kr, 350 vppm Xe, 2000 vppm CH4, 10-150 vppm N2O, 

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