The fluid product flows through zone III while in {HEAD ~ thermal contact} with {TAIL ~ the right half} of contact surfaces 2, passes through a brief clearance between the rightmost end of the contact surfaces 2 and the rightmost weir 13, over the upper edge of the rightmost weir 13 and eventually into collection conduit 16 provided at the bottom of zone IV 
with
The fluid product flows through zone III while in { HEAD ~ thermal contact } with { TAIL ~ the right half } of contact surfaces 2 , passes through a brief clearance between the rightmost end of the contact surfaces 2 and the rightmost weir 13 , over the upper edge of the rightmost weir 13 and eventually into collection conduit 16 provided at the bottom of zone IV
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH OTH OTH OTH