Numerical Analysis of Historical Change of the Electric Resistance in the TVF Glass Melter

Kawamura, Takumi*; Sakai, Takaaki

Concerning to the TVF glass melter in the Tokai reprocessing center, it is being planned to detect the deposition of the platinoid elements in a glass melter and remove them periodically to extend the melter lifetime. Numerical analysis has been performed for the electric resistance evaluation in order to estimate the sedimentation situation and current density distribution from the melter resistance. Electric field analysis was carried out by using MAGNA-FIM code and the influence factors to melter resistance was evaluated concerning to the sedimentation situation and glass temperature. In addition, transition of the sedimentation and melter resistance was estimated from the operation history of the TVF-1 melter. As a result, the followings were obtained. From the evaluation of the influence factors to melter resistance, it turns out that the volume and the platinoid elements concentration of a sediment influence notably to melter resistance when the sediment contacts to electrodes. The sediment temperature at the melter bottom has small sensitivity in case of the contact situation. the glass temperature in the melter upper part, however, has big sensitivity in melter resistance irrespective of the existence of contact. Based on the above sensitivity evaluation, numerical analysis was carried out supposing the sedimentation process which suits to a melter resistance fall during the operation history of the TVF-1 melter. As input conditions, the voltage between electrodes and the temperature in the melter were referred from the operation history data. It was assumed that the platinoid elements concentration in a sediment increased constantly for every operation batch. As a result, the characteristics of melter resistance history was reproduced successfully in general. Thereby, it became prospective to predict the sedimentation situation by using the new resistance analysis model for the glass melter.