Industrial furnaces are enclosed structures that contain high heat chambers. Compared to industrial ovens, they provide much higher temperatures and therefore are mostly used on materials with high melting points. They are found in glass fabrication, steel service centers, foundries, forgeries, metal recycling plants and any metallurgy application involving the use of heat to alter, improve, fabricate or form metals like steel, titanium and aluminum, alloys, glass, composite materials and some plastics.
Furnaces meant for small runs are usually of single chamber design and are manually loaded and unloaded with various tools to lift crucibles full of molten metal or heat treated products. Larger volume furnaces have automated conveyor systems that allow many parts or products to be treated at a time. Their controlled atmospheres can be oxidizing, inert, salt bath or vacuum. Their most common use is for heat treating glass and metal, which alters or improves the material's properties by exposing it to high temperatures, then rapid cooling. Furnaces are also capable of aging, annealing, sterilizing and sintering materials, as well as melting raw substances for molding or casting purposes. Furnace specifications include temperature requirements, pressure, internal width, length and height, as well as heat source.There are many different furnace heat sources available today. They include radiant, natural gas, induction, conduction, electrical and dielectric. Each method has specialized benefits, limitations and applications. Radiant heat furnaces are similar to wood stoves and portable heaters. They use a flame to heat an object, commonly a ceramic plate. This object gives off heat that transfers throughout the area. Natural gas furnaces are very common. Compared to electric furnaces, they are an economical method of creating a high heat environment. They burn natural gas or propane in order to generate heat, and are used for their high temperature abilities. Induction furnaces use a combination of electrical resistance and hysteresis losses to heat metal parts. They are exposed to a magnetic field around a coil-carrying alternating current. Induction furnaces are the first choice in metal melting applications and are often used by iron foundries. Electric furnaces are also popular for melting metal. The most common type is an electrical arc furnace, which uses high amounts of electrical current, which travels through a metal arc and is conducted onto large amounts of scrap metal. The current heats the scrap metal to a high enough degree to melt it completely. These furnaces are mostly used for recycling metal parts to be formed into new products.