METHOD AND APPARATUS FOR HEATING MATERIALS

The present invention pertains to a direct current electric arc furnace for melting or heating raw materials or molten material. The furnace comprises a refractory lined vessel for holding raw or molten metal material. The furnace also comprises a first top electrode and at least a second top electrode. Each of the top electrodes enters the vessel above the raw or molten material and has a position in the vessel. The furnace comprises at least one bottom electrode mounted in the bottom of the vessel and in electrical contact with the raw or molten material in the vessel. Additionally, the furnace comprises an electrical power supply mechanism with conductors to electrically connect to the top electrodes and the bottom electrode in order to input electrical energy into the material through the top and bottom electrodes in the form of arcs which deflect toward each other and define a hot area. The first and second top electrodes have the same electrical polarity while the bottom electrode has an opposite electrical polarity to the electrical polarity of the top electrodes. The present invention pertains to a method for heating raw material. The method comprises the steps of providing direct current to a first top electrode and a second top electrode having the same electrical polarity, and to a bottom electrode having opposite polarity to the top electrodes in a vessel. Next, there is the step of creating a first electric arc in the vessel from the first top electrode which contacts the material. Then, there is the step of creating a second electrical arc in the vessel from the second top electrode which contacts the material and is deflected toward the first electric arc to create a hot area.