A furnace is an energy center that drives processes and operations in almost all types of industrial setups. Technically speaking, it is a very essential heat enclosure device employed to process raw materials at high temperatures in a solid as well as a liquid state. They generate heat in a controlled way with help of the combustion of a fuel source. The thermal energy thus created is used in industrial settings for the manufacturing and processing of materials. Furnaces are extensively used in many sectors from metallurgy to chemicals, ceramics, and building materials.
Importance of furnaces:
The rising demand for metals across several industries including automobiles, railroads, metallurgy, and construction to chemicals, is causing more and more industries to be set up. This in turn is propelling the demand for industrial furnaces from businesses all over the globe. Experts predict the global market for Industrial furnaces driven by growing opportunities in metal and steel processing industries is projected to touch 15 billion USD by 2024.
How does a furnace work?
The basic structure of an Industrial furnace consists of a radiant, convection section, coil, burner, flue stack, and insulation. In its simplest structure, a furnace works by allowing materials to heat up to required temperature levels in the radiant section by burning fuel using the burner.
Types of Furnaces:
Designs of furnaces differ based on their functionalities, types of fuel, heating duty, and applications. They are made as per international codes and standards. The most crucial factor that decides the choice for an industrial furnace is generally its operating temperatures. Furnaces that can produce higher temperatures often cost more. A few typical high-temperature-producing furnaces employed in metals and materials production and processing are Bell, Box, and Forging furnaces. But industrial furnace designs are most widespread based on their applications in numerous industries from metal smelting to the food industry, ceramic processing to glass making, and from cement production to manufacturing.
Applications of furnaces:
There are various application of furnaces. No wonder the use of furnaces is quite common. Below the major applications of furnaces are outlined in summary.
Ashing: It is a process of withdrawing organic material from a sample before analysis. It is done by heating a substance and separating non-combustible ash. The process is widely used in the food and petroleum industries.
Calcination: Furnaces are used in the thermal treatment process applied in the case of solid materials like ores in order to cause some change in their physical form or bring about a thermal decomposition, or chemical dissociation of the substance. It takes place in absence of air inside a calciner fitted in a heated furnace without causing the product to melt.
Tempering: A heat treatment process, Tempering alters the mechanical properties like ductility and hardness of a material. It is used to enhance the toughness of certain metals, most commonly iron-based alloys like steel. A tempering furnace works exactly in the same way, treats a ferrous metal product with heat and increases its toughness.
Smelting: It is a method of obtaining refined metal from raw materials called ores by heating in a furnace. It is mostly employed in extractive metallurgy. Smelting uses heat and chemical reductants to decompose the ore, driving off other by-products before leaving just the metal behind.
Sintering: A major thermal process of fusing a large number of loose materials together into one solid mass by employing pressure, and sufficient high temperature below the melting point of the materials. It is generally used in the manufacturing process for materials including ceramics, metals, and plastics.
Annealing: Annealing furnaces heat a material to a certain temperature for a specific amount of time, and then cool it at a suitable rate to alter its chemical or physical characteristics. The chief aim of Annealing is to reduce the brittleness and hardness of metal and make it easier to work with. This process is generally used for metals in the construction and automotive sector.
Furnaces are also used in applications like brazing – joining two or more materials together with a filler. This apart, processes like baking, curing drying, quenching, and preheating as well are some of the extensive applications of industrial furnaces.