{HEAD ~ An inlet} 26 is provided for the reactant header which introduces reactant thereto which in turn flows within {TAIL ~ the tubes} of the tube bundle 12 
{ HEAD ~ An inlet } 26 is provided for the reactant header which introduces reactant thereto which in turn flows within { TAIL ~ the tubes } of the tube bundle 12
HEAD 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