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