Heat Conduction Analysis and In-furnace Combustion Test of Exothermic Mold Materials

Abstract

  In this study, a method of analyzing heat conduction in exothermic mold materials was proposed, and a analytical solution for moving steady state heat conduction in a plate of semi-infinite thickness was obtained. In addition a numerical solution was developed for non-steady heat conduction in exothermic materials of different geometries. Satisfactory agreement between the analytical and numerical solutions was confirmed in a range of conditions where an essentially steady state prevails. For verification, small spheres of exothermic materials were ignited in an electric furnace and the temperature at the sphere center was recorded. The basic thermal behavior was found to qualitatively agree with the theoretical predictions, including the overheating phenomenon, whereas some behaviors more complicated than those predicted by simple theory were also observed. The in-furnace combustion test was found to be useful for determining the ignition temperature of exothermic materials and also for the qualitative comparison of the thermal characteristics of different exothermic materials. On the other hand, the test was found not fit for the quantitative determination of combustion heat and other characteristics.