The fluidized product then passes between contact surfaces 2 following passage through {HEAD ~ a brief clearance} between leftmost weir 13 and the leftmost edge of {TAIL ~ contact surfaces} 2 
The fluidized product then passes between contact surfaces 2 following passage through { HEAD ~ a brief clearance } between leftmost weir 13 and the leftmost edge of { TAIL ~ contact surfaces } 2
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH