PURPOSE: To provide a freezing preventive structure for a service water pipe at its rising part to over the ground when it is used in a cold district, with which the freezing preventing effect is high, the equipment cost and/or running cost are low, and the safety is high.
CONSTITUTION: One end of a heat pipe 18 is buried underground, and part at the other end is put alongside the outside surface of a rising part 2 of a service water pipe, and this part 2 and the heat pipe 18 are in a lump covered with a heat insulation 20. The heat pipe 18 is embodied in a double structure consisting of an inner and an outer tube, and the rising part of the service water pipe is inserted through its inside. The heat pipe structure should be split into two longitudinally. The rising part is enwrapped with a corrugated heat pipe having flexibility.
NISHIYAMA SADAYOSHI
YUITSUKA YOICHIRO
TONO TAKASHI
JINNO TAKEO
ZOJIRUSHI CORP