The air curtain or {HEAD ~ barrier} is generated by {TAIL ~ a ported manifold} and supply located either on the oven housing exterior adjacent the opening or inside the oven housing adjacent the opening 
is generated by
The air curtain or { HEAD ~ barrier } is generated by { TAIL ~ a ported manifold } and supply located either on the oven housing exterior adjacent the opening or inside the oven housing adjacent the opening
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL 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 OTH