Electrical Properties and Melting Treatment Rate of a Continuous Induction Waste Melter

Abstract

The continuous induction melter with a graphite-packed bed heat generator has a possible application to a waste melter because of its flexibility regarding waste contents, large treatment rate, and safe performance. This study proposed an analysis scheme for locally matching conditions between a melter and a high frequency electric power generator, and for fluctuation ranges of the frequency and input electric power in the melter. This scheme consisted of estimations of the melter coil inductance and resistance by eddy current loss from analytical solutions of Maxwell equations, which are linked to the locally matching conditions about capacitance and transformer turn number ratio. The measured results in a 100 kW pilot melter were compared to experimental ones. Energy use efficiency of the melter was also obtained by carrying out melting treatment rate measurements regarding two major components included in the wastes, iron and calcium silicate.
Numerical results agreed well with the measured ones regarding the local matching conditions (capacitance: 10.4 μF, transformer turn number ratio: 7/15), and the fluctuation widths of the frequency (0.3 kHz) and input power (7 %). The measured melting treatment rates were 135 kg/h for iron and 40 kg/h for calcium silicate, when the respective values of input electric power were 92 and 85 kW. Based on these results, the energy use efficiency of the pilot melter was about 40 %.