APPARATUS AND METHOD FOR INCREASING FURNACE LIFE IN AN ELECTRIC FURNACE FOR THERMOPLASTIC MATERIALS

摘要

Electrical erosion of refractory in a tank of a furnace for melting thermoplastic materials is reduced by orienting electrodes employed in Joule effect heating of the thermoplastic to limit the current density in the refractory. High electrical resistivity of certain thermoplastics tends to cause a flow of shunted current in relatively low electrical resistivity refractory of the furnace walls during Joule effect heating. Inter electrode spacing and electrode to furnace wall spacing is arranged according to the relative electrical parameters of the furnace system to achieve sufficient Joule effect heating of the thermoplastic without appreciable electrical corrosion. The effects of three phase power sources with various connections is disclosed.