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