Fundamental Studies on Induction Heating and Stirring of Non-Metallic Molten Fluid

Abstract

Induction heating of non-metallic molten fluid has been investigated, mainly performed on melt glass stirring. Because silicate glass has relatively high viscosity and low electric conductivity for induction stirring, their experiments require very high temperature above 1500°C, and are difficult for observation and measurements. In this report, observation and simulation of heat generation and flow in molten salt are presented. And flow states of molten vanadium oxide glass is observed, both of them have low melting points. It is intended to investigate them from both experimental and theoretical directions, as a fundamental research. It is demonstrated that molten NaCl-KCl possessed the low impedance value in frequency range of hundred kHz to 1MHz, preferable for giving rise to induction current generation. Circulating flow of the fluids from the container wall to the center was observed. Temperature measurement in the melt was also conducted at various positions with respect to the coil configuration. The flow velocity and temperature distribution were analyzed by numerical simulation, and compared with the measurements, taking account of the transparent nature of the molten salts. They are shown to explain the experimental results, mostly. Molten vanadium oxide glass having the similar physical properties exhibited the similar flow characteristics.