A gas fired tube and shell heat exchanger directs {HEAD ~ a flame} directly into {TAIL ~ an inlet end} of the tube bundle and the flame and exhaust are drawn through the tube bundle by an induced draft blower located in the exhaust stream outside of the shell 
directly into
A gas fired tube and shell heat exchanger directs { HEAD ~ a flame } directly into { TAIL ~ an inlet end } of the tube bundle and the flame and exhaust are drawn through the tube bundle by an induced draft blower located in the exhaust stream outside of the shell
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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