Industrial Heating Furnaces and their Types...

Industrial Heating Furnaces and their Types A furnace is equipment which is used as a reactor, or for melting of metals for casting, or to heat materials to change their shape (e.g. rolling, forging etc.) or properties (heat treatment). Industrial furnaces are mainly used for carrying out the process or for the purpose of heating. Furnaces which are used for carrying out the processes are sometimes known as reactors. Industrial furnaces which do not ‘show colour’, that is, in which the temperature is below 650 deg C are sometimes called ‘ovens’. However, the dividing line between ovens and furnaces is not very sharp. As an example, coke ovens operate at temperatures above 1400 deg C. In the ceramic industry, furnaces are called ‘kilns’. In the petrochemical and chemical process industries, furnaces are termed ‘heaters’, ‘kilns’, ‘afterburners’, ‘incinerators’, or ‘destructors’. The furnace of a boiler is known as its ‘firebox’ or ‘combustion chamber. Industrial heating furnaces are insulated enclosures designed to deliver heat to loads for many forms of heat processing. Furnaces used as reactors, and melting furnaces require very high temperatures and can involve erosive and corrosive conditions. Shaping operations need high temperatures to soften materials for processes such as forging, swaging, rolling, pressing, bending, and extruding etc. Heat treating operations need midrange temperatures to physically change crystalline structures or chemically (metallurgically) alter surface compounds, including hardening or relieving strains in metals, or modifying their ductility. These include aging, annealing, normalizing, tempering, austenitizing, carburizing, hardening, malleabilizing, nitriding, sintering, spheroidizing, and stress relieving etc. Industrial processes which use low temperatures include drying, coating, polymerizing, and chemical changes etc. Industrial heating operations encompass a wide range of temperatures, which depend partly on the material being heated and partly on the purpose of the heating process and...