Top 5 Industrial Processes That Use Centrifugal Fans

March 27, 2017 | by Neel Rao

Centrifugal / Radial fans offer regulated high pressure airflow that is required for several industrial applications and air pollution systems. Centrifugal fans are constant volume devices and can operate under high sensitive conditions such as high or low temperatures, corrosive gases, acidic fumes etc. There are several ways how a centrifugal fan can be used as a process fan in industries, such as in transporting air/gas, drying, cooling, material handling, air re-circulation etc.

Dust collection / De-dusting
From small factories to heavy duty industrial applications, centrifugal fans have wide usage in dust collection and de-dusting process. De-dusting requires broad variety of centrifugal fan types which work on the principles of pressure type system and depression type system. For example, in wood industry where pressure type systems are required, centrifugal fans with radial blade types are often used to move the dust particles directly through the fan. De-dusting process can also be of depression type system where backward inclined, airfoil or flat blade centrifugal fans are mounted on the top of cyclone in the kiln or within the filtering system to remove the airborne particles.

Conveying of materials
The type of the centrifugal fan required for conveying depends on the density of the material to be conveyed in industrial process. Since industrial processes require variety of materials to be handled through different operational procedures, the fan should produce enough air velocity to move the material and convey it to the destination point. The typical centrifugal fans used in material handling are high pressure radial fans or industrial exhauster paddle wheel fans. If material to be handled or conveyed is light and dry such as wood dust, flour etc, they can be conveyed directly through the fan system. However, if bulk powders and other materials such as plastic pellets, wood chips, grain, saw dust etc are to be handled and conveyed, it is done indirectly where centrifugal fans with desired airflow are used to blow the material in the needed direction.

Cooling
Centrifugal fans of various types are used in heat reduction applications in industries, where cold air is blown to cool the industrial material. For example, cooling fans are used in cement industry to blow cool air to reduce the temperature of clinker from high to low temperatures (typically from 1500oC to 100oC). Similarly, heavy duty centrifugal fans find wide range applications in glass industry to cool the oven walls and reduce the temperature of glass material. When liquid glass is distributed from the ovens into different moulds, such as in bottle production, high pressure fans are installed for mould cooling. Likewise, in case of preparation of flat glass (used in windows), high volume centrifugal fans with medium pressure are often used for cooling. The common centrifugal fans used as cooling fans are airfoil, backward inclined or high pressure radial fans.

Drying
Industrial processes use forced or induced draft centrifugal fans such as airfoil, backward curved, backward inclined, or radial fans to circulate the air needed for controlling the temperature and moisture of materials. When moisture content is to be removed from the material, hot air is forced across it through a fan system. In cement industry centrifugal fans are used to dry the clinker in a kiln system. Similarly in food processing industry, centrifugal dryer fans are usually needed to dry and exhaust the moisture content from the food material before it is sent for packing. These fans find wide usage in wood and paper industry for drying the material in their manufacturing units. In paper industry, these fans are used to dry the paper along the process either by exhausting air by creating a depression under paper pulp/paste or by passing the material through a heated oven making it exposed to high temperatures for drying.

Air re-circulation
Boilers & burners are used in variety of industries for producing heat and energy. The process requires a stable and consistent airflow to maintain proper fuel combustion. Fans in industrial boilers allow fresh air to flow into the system to maintain sufficient oxygen levels for proper fuel combustion. Particularly in glass and steel industry, centrifugal fans with typically high pressure are used as air recirculating fans to maintain a homogeneous temperatures inside the ovens. In power plant boilers, forced and induced draft centrifugal fans play important roles where they supply required air for fuel combustion and in the maintenance of furnace temperature.