Pipe/filler unit, internal heat exchanging type distillation column and production method thereof

A pipe/filler unit comprising:

• a pipe where heat is exchanged between an inside and an outside of a pipe wall;
• an inside regular filler layer disposed inside the pipe so as to abut an inner peripheral surface of the pipe, and
• an outside regular filler layer disposed outside the pipe so as to surround the pipe and closely contact an outer peripheral surface of the pipe
• wherein the outside regular filler layer is formed from a plurality of split tubular regular fillers which is split into a plurality of pieces in a peripheral direction. the plurality of split tubular regular fillers has a tubular structure disposed so as to cover an outer peripheral surface of the pipe, and the outside regular filler layer that is the tubular structure formed of the plurality of split tubular regular fillers is fastened by a fastening member so as to closely contact the outer peripheral surface of the pipe.