Induction furnace

There are three types of induction furnaces: direct core type induction furnace, vertical core type induction furnace and indirect core type induction furnace. In a direct core type induction furnace, charge is the short circuited secondary of the transformer. Due to the heavy current induced, charge gets melted. For the flow of current in the secondary, molten metal is required. Therefore to begin with in a direct core type induction furnace, molten metal has to be poured in the annular hearth. Here magnetic coupling between the two coils is very weak. The leakage resistance is very high and power factor is very low. This can be avoided by operating the furnace at lower frequencies. In a vertical core type induction furnace (also known as ajax wyatt vertical core type furnace), a vertical crucible is used for the charge. Since the furnace is narrow and v-shaped, molten metal gets accumulated at the bottom. In an indirect core type induction furnace, principle of induction is utilized for providing heat treatment to metal. This is similar to that of a resistance oven but differing in power factor.