A GLASS MELTING BY USE OF A HIGH-FREQUENCY INDUCTION SKULL MELTING METHOD WITH SUBMERGED HEATING ELEMENTS AND ITS HEAT-CONDUCTION ANALYSIS

A new method of melting and holding of a material with low thermal and electrical conductivities is proposed to overcome the problems of lon g heating period and localized overheat in a charge. In this method, a water cooled induction coil is directly used as a crucible, and the e lements heated by a high frequency magnetic field are submerged into t he charge. Experiments have been conducted on glass under various oper ating conditions, i.e. the coil current, the frequency and the radius of the heating elements. A mathematical model is developed to calculat e the process variables such as the heat generation rates in the coil and the heating elements, and the temperature distribution in the char ge. The calculated process variables are compared with the observed on es. The considerably good agreement between the theoretical and experi mental results indicates the validity of the model. The heat generatio n rate in the heating elements is determined by the ratio of the radiu s of the heating element to the electromagnetic penetration depth and has the maximum value at the ratio of 1.8.