The metal made {HEAD ~ Raschig rings} used as {TAIL ~ an auxiliary packing material} in the present invention has a bulk volume of preferably 0.3 3.5 times that of the shaped catalyst and a packed density of preferably 0.5 1.5 kg/l 
used as
The metal made { HEAD ~ Raschig rings } used as { TAIL ~ an auxiliary packing material } in the present invention has a bulk volume of preferably 0.3 3.5 times that of the shaped catalyst and a packed density of preferably 0.5 1.5 kg / l
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL 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