Metal Melting Furnaces
Metal melting is done in metallurgy facilities, foundries, steel service centers, metal fabrication factories and metal casters. Metal melting furnaces are used to create molds for metal casting, performs and billets which are pieces of raw metal that require further fabrication to become parts and products, and the molten metal itself is used in metal die casting to produce complex, three dimensional products inside of a mold. They are also commonly found in metal recycling facilities to melt down scrap pieces of metal in order to form new parts. Smelting, the process of extracting ore from melted metal, is also done within metal melting furnaces. These furnaces can be small and portable for short runs or large and permanent processing machines that are fully automated. They are mostly gas powered using propane or natural gas as fuel, while others are electrically powered.
The furnace's chamber where the metal melting occurs must be well insulated to retain the high temperature, and is usually composed of parts made of iron, silicon carbide or a nickel-chromium alloy; all of which are able to function properly under the most extreme heat as well as facilitate the melting process. Most furnaces designed for metal melting are simple in construction. They are composed of an inclined hearth and the molten metal reservoir, which are separated by a wall divide. The wall divide has a passageway for the metal to enter the furnace, as well as an exhaust gas passage to let the gas produced by the melting process out of the chamber. The metal is usually contained in a crucible made of silicon carbide, which is one of the only materials with a heat resistance strong enough to withstand direct contact with molten metal. There are two main types of furnaces used to melt metal-electric arc and
induction furnaces. Electric arc furnaces are popular when recycling metal scrap. They use an arc that creates and electrical breakdown of gas and plasma discharge to generate high heat. The arc is put into direct contact with the metal scrap, and the electric current is conducted onto the metal scrap. This produces high amounts of heat with temperatures up to 1800° C, which is hot enough to melt most metals. Induction furnaces, on the other hand, are able to melt raw ferrous and non ferrous alloys by a helical copper coil and crucible. Iron foundries often use this method of metal melting.
