| 摘要 |
PURPOSE:To save the quantity of water from the source of water supply and to effectively melt snow by controlling the operation of a water lifting pump based on a detected value of the temperature of water in a medium temperature tank and the operation of a circulating pump based on a detected value of a snow melting pipe embedding body to maintain the temperature of water to be supplied to the snow melting pipe to a predetermined value. CONSTITUTION:In a case where the temperature of water within a medium temperature tank 11 is less than a predetermined value and when a water lifting pump 4 operates, water W from the source of water supply having a temperature which is higher than the temperature of water within the medium temperature tank 11 is pumped up to a high-temperature tank 10. The water level is raised, and water having a high temperature flows into a medium temperature tank 11 through a water passing hole 13 from the high temperature-tank 10. In a case where the geothermic temperature of the snow melting pipe embedding body 2 becomes less than a predetermined value and a circulating pump 5 is actuated, water which has been sucked up from the medium temperature tank N is sent to a snow melting pipe 3 via a circulation pipe arrangement 17, and after melting snow piled up in the snow melting pipe embedding body 2, it is discharged into the upper portion of a low-temperature tank 12. When the liquid level of the low-temperature tank 2 rises up, a water flow passing through a weir 14 is produced in the medium temperature tank 11, and when it exceeds a preset value, water is drained out of the bottom portion of the low-temperature tank 12 via a flow- out pipe 19.
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