Melting of bulk non-ferrous metallic materials by microwave hybrid heating (MHH) and conventional heating: a comparative study on energy consumption

Foundry industries aim at reducing energy consumption in processing of materials. Continuous efforts are ongoing to exploit unconventional energy sources such as microwave energy to overcome drawbacks of conventional sources. In the present work, a comparative study of electrical energy consumption during melting of known quantity of metallic material in microwave oven and in conventional muffle electric furnace is carried out. The non-ferrous bulk metallic materials such as tin, zinc, aluminum and brass are used as candidate materials. A 900-W modified domestic microwave oven, operating at 2.45 GHz and a conventional muffle furnace are used for the study. The electrical energy consumed for melting of known quantity of metallic materials is presented along with the observed material wastage during melting process. The study shows that microwave oven consumes significantly lesser time than the conventional muffle electric furnace for the melting of known quantity of candidate materials. It is found that melting bulk metallic materials by microwave irradiation reduces electrical energy consumption than that of conventional melting process. In addition, material wastage is around twofold lesser by microwave melting process than the conventional melting process for the known quantity of candidate materials.