{HEAD ~ A part} of {TAIL ~ the heated air} is used as the heated air for drying and the other is exhausted to the open air 
{ HEAD ~ A part } of { TAIL ~ the heated air } is used as the heated air for drying and the other is exhausted to the open air
HEAD HEAD HEAD HEAD HEAD HEAD 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