| 摘要 |
<p>PURPOSE:To prevent freezing securely by feeding a current to a heater connected closely to a joining pipe at the upper stream of a discharge port, while operating a pump forcibly when the temperature in the pump or the outer air temperature becomes a specific value, in the system in which the pump operation is stopped following the opening and closing of bibcocks. CONSTITUTION:The downstream side of two pumps 2 and 3 is connected to bibcocks 9 through a joining pipe 7, a discharge port 20, and a discharge pipe 8. A thermistor 19 is fixed to the joining pipe 7 to detect the temperature of the water flowing through the joining pipe 7, and when it perceives that the temperature is lower than the freezing temperature, the signal is delivered to a base with microcomputer in a control box 12. In this base with microcomputer, a switch to open and close a heater 10 and a motor circuit is turned on when a freezing protection variable switch is turned on, and the joining pipe 7 at the downstream side from the center of the suction ports 21, and the part near the inlet of a pressure tank 11 are heated by the heater 10 to protect the pump device from freezing. And when it is perceived that the temperature of the water flowing through the joining pipe 7 is at a specific value or higher, the switch to open and close the heater 10 and the motor circuit is turned off.</p> |
