Furnace – An Introduction
The word furnace has been derived from the Latin word ‘fornax’. Fornax in Latin refers to an oven, or kiln. Furnace, therefore, as understood from the word is a source of heat. The use of furnace becomes necessary when the heat required needs to be maintained at a constant temperature, or simply put the heat needs to be fed continuously so that a particular process requiring the heat gets completed.
Difference between Domestic and Industrial Furnaces
The word furnace is often used for heat sources that find applications in both domestic and commercial areas. In a domestic application, furnace refers to the equipment that supplies the heating for a home, or which is used to boil water, or such similar heating applications.
In an industrial scenario, furnace often refers to the heat source that provides heat for the melting of ore during the extraction of metal, and so forth.
Thus, though they are referred to with different names, and are used in various applications, their primary purpose remains the same, provide heat!
How’s the heat in a furnace produced?
Furnaces provide the heat for the various applications they are used in, either by the combustion of a fuel, or through electricity and the use of heating elements, or through the principle of induction, and so forth.
What dictates the size of a furnace?
The size and construction of a furnace varies with the kind of application that particular furnace is intended to be used in. Thus, a furnace providing heating to a home will not be as bulky as a furnace providing heat to smelt ore in a steel making factory.
Industrial Furnaces and Their Names
Industrial furnaces are often known by the exact application they would be used for, and their construction too would be such that they serve only that purpose for which they have been built.
On these lines, the furnaces used in the metal industry itself has so many varieties. Based on the purpose they serve in the industry, they are known by names such as:
- Open Hearth furnace
- Blast furnace
- Electric Arc furnace
- Puddling furnace, and so forth.
Each furnace has a particular function, for instance,
- Open hearth furnace has the function of enabling the burning out of excessive carbon and other such impurities from pig iron during the process of steel making.
- The Electric Arc furnace, as the name signifies uses electric arc to generate the heat required for the process. They find extensive uses in the steel making industry, and they are capable of generating temperatures in the range of 1800º C and beyond.
- Blast furnace is used to reduce iron ore to pig iron
- Puddling furnace is used to make wrought iron from pig iron.
Thus, the output of a particular furnace can also become the input to another furnace. As mentioned previously, each furnace has a purpose, and they are designed in accordance, but, the primary role they play is providing the required heat.
Need for insulating the furnace
Insulation is a critical part of a furnace. Efficient furnaces limit the amount of heat that escapes from it through proper insulation. Ceramic fibre, firebrick, etc are often used as insulation materials to insulate a furnace and make it efficient.
Furnaces are equipment certain industries cannot survive without.