Controller 5 with input from flowmeter 6 and output to control {HEAD ~ 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 an operator selectable ratio of reducing {TAIL ~ agent flow} 11 to flow of stream 1 
Controller 5 with input from flowmeter 6 and output to control { HEAD ~ 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 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 HEAD HEAD HEAD HEAD HEAD 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 TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH