The fuel is passed over the cores and {HEAD ~ metal particles} in {TAIL ~ passing} between the inlet and outlet 
The fuel is passed over the cores and { HEAD ~ metal particles } in { TAIL ~ passing } between the inlet and outlet
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH