On-Line Measurement of Liquid Metal Level by Change of Static Gas Pressure

Abstract

On-line measurement of liquid metal level is an essential technique for the coolant systems of fusion reactors to keep their safety operation and to recognize accidents such as a coolant leakage and a coolant blockage. The purpose of the present study is to propose a static gas type level meter which is widely applicable in various coolant systems. This level meter consists of a differential pressure meter and a measurement compartment which is inserted into fluids. The change of the liquid level is measured on-line by the change of the differential pressure between the filler gas in the level meter and the cover gas. The experiments were performed with three fluids: water, viscous fluid (PVA starch) and liquid metal PbBi. The output of the level meter indicated good linearity and reproducibility. The meter output obtained in the experiments was slightly larger than that estimated by theory since the meter output was influenced by surplus gas which was unintentionally involved in the insertion procedure of the level meter. This technical issue was improved by the use of the measurement compartment with several slits, which can release the surplus gas through the slits.