Theoretical examination of temperature distribution in an electrical furnace by the study of transient heat conduction effects

Abstract: The company Kanthal produces electric heating elements that require high temperature treatment in one production step. In this process step, called sintering, the amount of heat received by the sintered material is in direct correlation to the product’s outcome.  It is therefore of interest for the company to gather information about how heat transfer happens in an electrical furnace. This study examines two different possible scenarios of how the heat transfer in the furnace could look like and which amount of heat the sintered material would receive. The relation between a gaseous ambience at a certain temperature and the temperature an object submerged into this ambience is assuming is studied in the process called "transient heat conduction".  Two models were built in Matlab, representing transient heat conduction effects on two different geometries: a plane wall and a short cylinder.  It could be shown that transient heat conduction effects turned out differently for the two models. The conclusion drawn from the results was that the wall model was susceptible to horizontal heat transfer effects, whereas the cylinder model was affected from all directions equally. Further, an analysis of the heat transfer channels within the furnace revealed that the heat leakage through the furnace muffle edges, which are in contact with air, causes a multiple in heat loss compared to the overall heat leakage.