Combination triple duty compressor for prodn. of nitrogen@ and oxygen@ - has multiple shaft machine providing compression for feed air, first main stage, and coolant nitrogen streams

摘要

In the low temp. sepn. of air the feed air (1) is compressed (2), purified (3) and finally cooled (5, 42) before passing to a rectifying column (9) by which it is sepd. into O2 (10) and N2 (19). A recirculant N2 cooling system is maintained by a compressor (27) and a pressure let-down device (30), with a N2 fraction (19, 20, 22) discharging from the column (9) into the first stage compressor (23) which is upstream of the cooling circuit nitrogen recycle compressor (27). The novelty is the use of a single machine to fulfil the duties of the feed air compressor (2), cooling circuit N2 compressor (27) and the first stage compressor (23). USE/ADVANTAGE - Prodn. of O2 and N2 from air using a plant which is more compact and of approximately 50% the capital cost of previous similar plants by virtue of the combination triple duty compressor.