| 摘要 |
PURPOSE:To measure the impurity density in sodium precisely in a short time even when impurities are at low temperatures by providing a temperature detector in a device which cools and heats Na or near its exit in a device which detects the impurity density in Na from the saturated solution temperature of impurities. CONSTITUTION:The temperature detector 1 is provided in the cooling and heating device 12 for Na sent from main system piping for cooling Na, etc., to a circulating device 3 through a filter 1 and a heat exchanger 2 or near its exit. When the impurity density in Na is low, it takes a long time to deposit the impurities and the temperature is close to the solidification temperature of Na, so the flow rate in an orifice 8 becomes unstable owing to the solidification and deposition of Na. For this purpose, a controller 14 uses signals from the temperature detector 17, orifice flow rate detector 7, and a total-flow-rate detector 6 which receives a signal from the device 12 to control the temperature to the temperature which is a specific temperature higher than the solidification point of Na, measuring even low density impurities precisely in a short time. |
