| 摘要 |
PURPOSE:To prevent exactly a communicating pipe from being broken even in case of dry heating by providing a heater on the lower part of a tank for containing liquid, providing roughly vertically a transparent communicating pipe communicating with the tank, on the side part of the heater, and positioning the lower end of this communicating pipe at the upper part of the heater. CONSTITUTION:A liquid L in a tank 3 is heated by a heater 13, its temperature rises, and its temperature is kept constant by intermitting electric conduction using a thermostat 13a. When a pushing body 28 is pressed downward in this state, first of all, an abutting plate 36 abuts on a packing 33, a leading-in hole 32 is blocked airtightly, and also when a movable plate 26 is pressed downward, a bellows 25 is compressed together with air of its inside, and the compressed air is exhausted into the tank 3 through through-holes 42, 43. The inside of the tank 3 is communicating with the inside of a communicating pipe 15 through each bush 15a, 15b, therefore, a liquid surface of the same level as a liquid surface in the tank 3 is formed in the communicating pipe 15. |
