After wiped out dust and mechanical impurity the
feed air went in oil free screw air compressor and pressed to
1.1MPa(G), then cooled to 5~*0? in air pre-cooler, and
at last the water, CO2, hydrocarbon was adsorbed by molecular sieve
in alternative molecular sieve adsorber.
The processed air after purification, except a
small part of air become the bearing gas of gas bearing turbo
expander, the other part divided two groups in main heat exchanger,
most the part is extracted to refrigerate in turbo expander as
cyclic air. The expansion air went back the main heat exchanger
recover the cold flow then send to compressor inlet as cyclic air;
the other air is cooled saturation state by back air in main heat
exchanger, and rectification with small liquid in
column.
Liquid oxygen is extracted
from the main condensation evaporator, out cold box, and send to
use’s storage tank.
Waste nitrogen is extracted
from the top of upper tower of rectifying column, and out cold box
as regeneration gas of molecular sieve adsorber after
reheated.
