1995 Volume 81 Issue 2 Pages 111-116
This paper presented experimental and theoretical study on heat transfer in a high-frequency induction furnace for scrap melting. Single cylinder located on the central axis and a packed bed of carbonaceous materials were heated to assess influence of kind and size of the samples, and induction current on both heating rate and distribution of temperature. A mathematical model based on electromagnetic theory was developed for predicting temperature, current density and electromagnetic fields, and was experimentally validated. The model included multi-layered thermal insulator as a computational area.
During induction heating, a single graphite cylinder was heated uniformly, while a single coke cylinder showed significant temperature gradient and minimum temperature at the center. Larger size, smaller electric resistivity and larger induction current enhanced the heating rate of the cylinder. Distribution of current density was almost concentric, and current gradient was more steep in a graphite than in a coke. A packed bed of spherical graphite was heated up to the melting point of scrap under 2.95kHz and 1330A. The temperature difference within the packed bed was less than 100K with the maximum temperature at the center point.
