Industrial fans are an invaluable part of many processes, from providing ventilation and cooling for production plants to conveying tonnes of powders in various industries. With a variety of types, sizes, and designs available, industrial fans can help you create the exact airflow needed for your application. In this blog, we will explore the different types of industrial fans, the criteria to consider when selecting one, how to operate and install them, and the benefits they provide. With this knowledge, you can make sure you choose the right fan to meet your needs.
An industrial fan is a heavy-duty air flow device that is constructed from highly durable materials and components to withstand stringent environments and operate longer to provide constant air flow and pressure. Components of industrial fans which include special types of bearings, enclosed motor housing, continuous welds, precisely machined impellers, and housings made of mild steel, cast aluminium and stainless steel.
Types of Fans
Fans are classified in two types – axial and centrifugal, based on the nature of flow of air through passage of impeller of fan.
Axial Flow Fan: An axial fan pulls and blows air parallel to its shaft axis, which causes the air to transfer axially outward. There are three different types of axial flow fan as follows:
| Axial Flow Fans | |||
|---|---|---|---|
| Propeller Fans | Tube axial Fans | Vane axial Fans | |
| Blade Type | Narrow or propeller blade types | Narrow or propeller blade types | Air foil blades |
| Impeller |  |  | |
| Application | Used to move air against low resistances (less than 1″wg pressure) | Used to move air against moderate pressures (less than 2″wg pressure) | Compared to other axial flow fans, vane axial fans are more efficient and generally will develop higher pressures (up to 8″wg) |
| Feature | Performance is sensitive to added resistance, and a small increase will cause a marked reduction in flow rate | Cylindrical housing normally without straightening vanes | Impeller mounted in cylindrical housings which incorporate straightening vanes on the discharge side of the impeller |
Centrifugal Fans: They displace air radially, changing the direction of the airflow (by 90°). Centrifugal fans can generate relatively high pressures. They are suitable for high pressure applications as compared with axial flow fans. These fans have three basic impeller designs: forward curved, radial, and backward inclined/backward curved.
| Centrifugal Fans | |||
|---|---|---|---|
| Type | Forward curved | Radial Impellers | Backward Curved |
| Blades | Blades are curved towards the direction of rotation | Blades are straight or radial from the hub | Impeller blades are inclined opposite to the direction of fan rotation |
| Impeller |  |  |  |
| Features | Low space requirements | Resist material build-up | Higher tip speeds |
| Low tip speeds | Medium tip speeds | High fan efficiency | |
| Low noise levels | Medium noise levels | Low noise levels | |
| Not recommended for dusts that would adhere to the short- curved blades and cause unbalance | The housings are designed with inlets and outlets sized to produce material conveying velocities | In a non-overloading fan, the maximum horsepower occurs near the optimum operating point so any variation from that point due to a change in system resistance results in a reduction in operating horsepower | |
| Application | It is used against low to moderate static pressures such as those encountered in heating and air conditioning work and replacement air systems | Used for a variety of exhaust systems which handle either clean or dirty air | Single-Thickness Blades – Solid blades allow the unit to handle light dust loading or moisture. Airfoil Blades – They offer higher efficiencies and lower noise characteristics. Hollow blades erode more quickly with material and can fill with liquid in high humidity applications |
Special Type Fans: They include in-line Centrifugal Fans that have backward inclined blades with special housings which permit a straight-line duct installation. Pressure versus flow rate versus horsepower performance curves are similar to a scroll-type centrifugal fan of the same blade type while space requirements are similar to vane axial fans.
To conclude, industrial fans are an essential part of many industries due to their ability to help regulate air flow, air circulation, and air temperature. They come in a variety of shapes, sizes, and power levels to suit any industrial application. Whether you need a large axial fan to move a large volume of air, a powerful centrifugal fan to move air over long distances, or a small inline fan to provide localized air circulation, there is an industrial fan that can meet your needs. With the right fan, you can ensure that your workers, equipment, and materials stay safe and productive. Read the next blogs of the series on links- All you need to know about Industrial Fans: Crucial Factors while choosing an Industrial Fan (rieco.com) and All you need to know about Industrial Fans: Crucial Factors while choosing an Industrial Fan (rieco.com) Visit us at www.rieco.com to know more about Industrial Fans & other Equipment.