Open hearth furnace:
Open hearth process is also called a Siemens-martin process i.e. steel making technique for most of the applications in the 20th century. This process seeks a means to increase the temperature in a metallurgical furnace that uses the waste heat given out from the furnace that directs the fumes from the furnace through a brick checker work. A brick is heated to a high temperature, and then it is introduced into the furnace. The device is first used to produce steel that is charged with pig iron and wrought iron along with their scrap. In the US and Britain are best suited to the open hearth process.
Natural gas or atomized heavy oils are used as fuel. The air and fuel are heated before combustion. The furnace gets charged with blast furnace iron in liquid form, steel crap that is combined with ore, limestone, dolomite, and fluxes. The roofs and body of the durance are made of highly refractory materials as magnetic bricks. 600 tons is the capacity of the open hearth furnaces that are installed in groups for massive auxiliary equipment, that is needed to charge up the furnaces and to handle the liquid steel that can be employed efficiently. It is most commonly used in industrial applications as electric arc furnace and oxygen process based furnaces.