The metal made Raschig rings used as {HEAD ~ an auxiliary packing material} in {TAIL ~ 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 
in
The metal made Raschig rings used as { HEAD ~ an auxiliary packing material } in { TAIL ~ 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 OTH OTH OTH OTH HEAD HEAD 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 OTH OTH OTH OTH OTH OTH OTH OTH