As described above, in {HEAD ~ the procedures} of switching to {TAIL ~ a reductive operation}, after the flow rate of the product gas is reduced by the flow control valve 33 corresponding to the degree of reductive operation, the operational mode of the PSA apparatus 11 is changed corresponding to the reduced flow rate 
As described above , in { HEAD ~ the procedures } of switching to { TAIL ~ a reductive operation } , after the flow rate of the product gas is reduced by the flow control valve 33 corresponding to the degree of reductive operation , the operational mode of the PSA apparatus 11 is changed corresponding to the reduced flow rate
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH