During {TAIL ~ its passage} through the direct heating zones 30, {HEAD ~ the emulsion} is further heated by direct contact with the heating tubes 34 
During { TAIL ~ its passage } through the direct heating zones 30 , { HEAD ~ the emulsion } is further heated by direct contact with the heating tubes 34
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH