Fractional distillation of argon from air, with increased purity and economy,

摘要

The fractionation system has at least one air fractionation column (9), a raw argon column (17) and an argon purification column (25). A raw argon fraction (24), from the raw argon column (17) is taken to an intermediate location in the argon purification column (25), which has a head cooled by indirect heat exchange (29). A nitrogen rich residual fraction (31) is withdrawn from the upper region of the argon purification column (25); from its base a purified argon stream (26) is extracted. In this column (25) fractionation takes place at least partly in packing (33,34). In addition to the method, plant to carry it out is also claimed.