When people ask how many types of fans there are in industry, they are usually surprised to learn that, although there are hundreds of models and sizes, almost all industrial and mining fans belong to a few aerodynamic families. The three core families are axial fans, centrifugal fans and mixed-flow fans. Within these, manufacturers offer many subtypes, and engineers also classify fans by function, such as main ventilation fans, booster fans, auxiliary fans and process exhaust fans.
Axial fans move air parallel to the shaft. In industry and mining, common axial types include propeller fans, tube-axial fans and vane-axial fans. Propeller fans are used for low-pressure general ventilation in workshops and buildings. Tube-axial fans are installed in ducts and auxiliary ventilation systems, for example to ventilate headings and tunnels. Vane-axial fans, which add guide vanes for better pressure and efficiency, are used as powerful main mine fans, tunnel fans and high-performance industrial ventilation fans.
Centrifugal fans, often called blowers, draw air in along the shaft and discharge it radially. They are used where higher static pressure is required, such as dust collection, boiler draft, fume extraction and high-resistance mine ventilation circuits. Subtypes include forward-curved, backward-curved, backward-inclined, radial-blade and airfoil-blade designs. Each subtype is optimised for a different mix of pressure, efficiency, dust handling and noise, giving designers a wide choice within the centrifugal family.
Mixed-flow fans sit between axial and centrifugal designs. Air enters axially and leaves at an intermediate angle. These fans are used in space-constrained tunnels, underground facilities and industrial plants where medium pressure, compact size and good efficiency are required. They are less common than pure axial or centrifugal fans, but play an important role in specialised ventilation projects.
From a system point of view, industrial fans are also categorised by their role in the ventilation scheme. In mines and tunnels there are main surface fans, booster fans in long airways, and auxiliary duct fans serving faces and blind headings. In plants there are supply fans, exhaust fans, ID and FD fans around boilers, cooling tower fans and process fans directly connected to kilns and dryers. All of these are built from axial, centrifugal or mixed-flow principles.
In summary, industry does not use an infinite number of unrelated fan types. Instead, most industrial and mining applications rely on axial, centrifugal and mixed-flow fans, combined into main, booster, auxiliary and process configurations to satisfy specific ventilation and process requirements.
