| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot-water circulation apparatus, in which slime and the like are prevented from sticking to a three-way valve element and the valve element is operated smoothly. SOLUTION: In normal purification operation, warm water in a bathtub Y is sucked through a suction pipe 21 by a pump 13; the sucked warm-water is passed via a purifier 14 and a heat-sterilization tank 15 for carrying out purification, heat insulation, and sterilization, and it is poured again in the bathtub Y through a pouring pipe 26. The thermal sterilization operation for the piping is carried out once every two weeks. That is, hot water is circulated by switching of the three-way valve 16 in a closed circuit composed the pump 13, the purifier 14, and the tank 15, excluding the bathtub Y. The valve element 72 of the valve 16 is rotated backward once a day for the following two weeks from the finish of the last sterilization of the closed circuit to a start of the next sterilization of the circuit. Thus, sticking of slime and the like to the valve element 72 is suppressed, and the valve element 72 is prevented from locking due to slime and the like.
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