Baosteel's No.8 air separation unit and the practice of its system commissioning

This paper introduces the process flow,technical parameters and relevant features of Baosteel’s No.8 air separation unit(ASU) with a capacity of 60 000m3/h.It summarizes the commissioning work,which includes the adjustment of the air compressor,the system’s naked cooling,the precooling system and the operation adjustment.It also provides detailed analyses on some failures which occurred in the commissioning.Through the modification of the design and the interlocks,the tripping probability of the air compressor was greatly reduced.Through the heating of the system and the control of the water cooler’s nitrogen flow,the overproof content of carbon dioxide and fluctuation of oxygen flow were avoided.Nitrogen-block in the argon system was eliminated by the precise control of the argon rectification flow and argon content.All these solutions have been proved to be effective by practice.