Controller 5 with input from flowmeter 6 and output to control valve 7 acts to control the flow of an oxygen reducing agent such as an alkaline sulfite 11, with sodium sulfite being preferred, to maintain {HEAD ~ an operator selectable ratio} of reducing {TAIL ~ agent flow} 11 to flow of stream 1 
of reducing
Controller 5 with input from flowmeter 6 and output to control valve 7 acts to control the flow of an oxygen reducing agent such as an alkaline sulfite 11 , with sodium sulfite being preferred , to maintain { HEAD ~ an operator selectable ratio } of reducing { TAIL ~ agent flow } 11 to flow of stream 1
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH