Preferably, however, the chamber is slightly leaky in both directions so that {HEAD ~ a pressure barrier}, which builds up within {TAIL ~ the kiln} as it generates reducing gases, prevents an oxidizing atmosphere from entering the kiln chamber or rapid atmosphere exchange 
builds up within
Preferably , however , the chamber is slightly leaky in both directions so that { HEAD ~ a pressure barrier } , which builds up within { TAIL ~ the kiln } as it generates reducing gases , prevents an oxidizing atmosphere from entering the kiln chamber or rapid atmosphere exchange
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH