{HEAD ~ A compartment} is provided within {TAIL ~ the kiln} for selectively introducing a reducing agent into the chamber 
is provided within
{ HEAD ~ A compartment } is provided within { TAIL ~ the kiln } for selectively introducing a reducing agent into the chamber
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH