| 摘要 |
PURPOSE: To detect the presence of solid phase within liquid phase, by providing means which turns on a refrigerant system when electric potential of a first control probe is higher than that of a reference probe, while turning off the same when a second control probe is higher than that of the reference probe. CONSTITUTION: A current from an AC power supply 12 flows from probes 5, 7, 8 to a ground probe 6. Resistance between the ground probe 6 and the probe 5 is reference one. When an ice bank 99 is advanced, the resistance between the probe 7 and the ground probe 6 exceeds the reference resistance. Comparators 34, 35 transmit a high signal to a logic/control unit 36 which unit 36 then transmits an electric signal to a compressor 101 whereby cooling operation is interrupted, and the ice bank 99 is prevented from greatly growing. When the ice bank 99 is released from the surroundings of the probe 8, the logic/control unit 36 detects a fact that the resistance between the probe 8 and the ground probe 6 becomes equal to the reference resistance, and transmits an electric signal for restarting the operation of the compressor 101 to control the size of the ice bank 99. |
