A gas fired tube and {HEAD ~ shell heat exchanger} directs a flame directly into 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 {TAIL ~ the shell} 
A gas fired tube and { HEAD ~ shell heat exchanger } directs a flame directly into 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 { TAIL ~ the shell }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL