Indirect method of measuring glass temperature in a Cold Crucible Induction Melter

Abstract : This study is concerned with the control and optimization of the vitrification process of High-Level-Waste in a Cold Crucible Induction Melter (CCIM). We developed a new method for the control of glass temperature in the crucible, based on the precise measurement of heat flux through a water-cooled stick immersed into the glass melt. The measuring stick is separated from the flowing hot glass by a cold glass skull, ensuring much lower exposure to corrosive conditions than classical thermocouple sensors. This heat flux measurement enables a precise estimate of the glass temperature using a newly designed correlation formula between heat flux and glass temperature. Dimensioning of the measurement stick size and cooling water supply was achieved by running coupled 3D numerical simulations of fluid flow, heat transfers and electromagnetics in the CCIM.