Performance Evaluation of Graphite Thin Slabs for Induction Heating Domestic Applications

Suitable utensils for induction heating appliances are mainly made of good conductor ferromagnetic materials. In this paper, the use of alternative materials is investigated by means of an analytical model of the impedance of the induction system. The results reveal that the electromagnetic properties of graphite are appropriate to design convenient loads for this application. The performance of both bulk graphite and slabs of finite thickness is evaluated and compared with the conventional ferromagnetic materials by means of a figure of merit, consisting of the induction efficiency of the power transference. The comparison shows that the induction efficiency of a graphite slab of appropriate thickness is similar to the efficiency of conventional ferromagnetic materials. Results are experimentally validated by measuring the equivalent resistance of a spiral inductor loaded with graphite slabs of different thicknesses.