an inner cylinder supported by and sealingly attached to the main plate such that the inner cylinder at least partially surrounds the stack to define a cathode air stream plenum in fluid communication with the cathodes, wherein the exhaust plenum is in {HEAD ~ fluid communication} with {TAIL ~ the anode air stream plenum and cathode air stream plenum} 
with
an inner cylinder supported by and sealingly attached to the main plate such that the inner cylinder at least partially surrounds the stack to define a cathode air stream plenum in fluid communication with the cathodes , wherein the exhaust plenum is in { HEAD ~ fluid communication } with { TAIL ~ the anode air stream plenum and cathode air stream plenum }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL