Air is forced through the tube bundle by either a draft induction blower located at the outlet end of the tube bundle or {HEAD ~ a forced draft blower} located at {TAIL ~ the inlet} 
located at
Air is forced through the tube bundle by either a draft induction blower located at the outlet end of the tube bundle or { HEAD ~ a forced draft blower } located at { TAIL ~ the inlet }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL