That is, as effluent is admitted to the vessel {TAIL ~ the rate} at which {HEAD ~ liquid} is withdrawn from the vessel is determined by the rate at which a liquid constituent of the effluent enters the vessel so as to maintain the preselected level of liquid, or liquid bed 
at is withdrawn
That is , as effluent is admitted to the vessel { TAIL ~ the rate } at which { HEAD ~ liquid } is withdrawn from the vessel is determined by the rate at which a liquid constituent of the effluent enters the vessel so as to maintain the preselected level of liquid , or liquid bed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL REL OTH HEAD HEAD HEAD HEAD HEAD REL REL 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