{HEAD ~ The heated air} then passes through {TAIL ~ the flow} of grain in each of the columns 26 so as to heat and remove moisture from the grain 
passes through
{ HEAD ~ The heated air } then passes through { TAIL ~ the flow } of grain in each of the columns 26 so as to heat and remove moisture from the grain
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH 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