The burner is a gas fired burner whose flame is encapsulated in a layer of cool air due to the effect of {HEAD ~ the induction blower} drawing {TAIL ~ air} through the tube bundle from the exhaust outlet, so that the flame does not melt or burn through the tubes 
drawing
The burner is a gas fired burner whose flame is encapsulated in a layer of cool air due to the effect of { HEAD ~ the induction blower } drawing { TAIL ~ air } through the tube bundle from the exhaust outlet , so that the flame does not melt or burn through the tubes
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 REL 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