| 摘要 |
PURPOSE:To control safely the pressure rise in a piping with a solidified UF6 at the reheating time, by switching the control target value of a temperature controller to a normal control target value when the temperature of the piping at the temperature control time rises to reach a value where a flowing gas is not solidified. CONSTITUTION:A heating heater 2 attached to a piping 1 through which a sublimable gas such as gaseous UF6 flows, a thermometer 3 which measures the temperature of the piping, and a temperature controller 4 are provided. The controller 4 consists of a temperature rise rate detecting circuit 5, a temperature detecting circuit 6, two target value setting circuits 8 and 9, etc. If the temperature of the piping is lowered because of power failure and the sublimable UF6 is solidified and is stuck to the inside of the pipe and power failure is released thereafter, the temperature of the piping is controlled to a prescribed temperature lower than the normal control target temperature by a control circuit 7. Then, the solidified UF6 starts sublimating, and complete sublimation is detected by the temperature rise rate detecting circuit 5, and the measured temperature is detected by the temperature detecting circuit 6, and the control temperature is switched to the normal control target value in accordance with a command of the control circuit 7 by a switch 10. |
