The water and gas delivery rates are controlled to satisfy the following relations: ##EQU1## wherein Q1 is {HEAD ~ the delivery} of oxygenated gas in {TAIL ~ m3} /hr, 
in
The water and gas delivery rates are controlled to satisfy the following relations : # # EQU1 # # wherein Q1 is { HEAD ~ the delivery } of oxygenated gas in { TAIL ~ m3 } /hr ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH