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