When people talk about the three types of axial fans in mining and industrial ventilation, they usually mean propeller fans, tube-axial fans and vane-axial fans. All three move air parallel to the shaft of the impeller, but they have different constructions, pressure capabilities and typical applications in underground mines, tunnels and industrial plants.
Propeller axial fans are the simplest. They consist of a set of blades mounted directly on a hub or motor shaft, usually with minimal housing. These fans move a large volume of air at very low static pressure and are often used for general ventilation and cooling in buildings, workshops and on surface around mine plants. In mining, propeller fans are sometimes used for simple intake or exhaust duties where resistance is low, such as ventilating storage sheds or surface conveyor galleries.
Tube-axial fans place the axial impeller inside a cylindrical tube or casing. The tube guides the airflow and allows the fan to develop higher pressure than an open propeller fan. Tube-axial fans are widely used as auxiliary and duct fans in underground mining, blowing or exhausting air through flexible ducts to development headings, stopes and crosscuts. They offer a good balance of airflow, pressure, size and cost, and can be mounted in series or parallel to achieve different ventilation duties.
Vane-axial fans add guide vanes (stators) before and/or after the impeller. These vanes straighten the swirling airflow leaving the rotating blades and recover more static pressure from the dynamic energy in the air stream. As a result, vane-axial fans can achieve higher pressure and efficiency than simple propeller or tube-axial designs. In mining, they are often used as main fans or high-performance auxiliary fans where both high volume and significant pressure are required, for example in deep or high-resistance ventilation circuits.
For mine and industrial designers, understanding the differences between propeller, tube-axial and vane-axial fans helps match each type to the right application. Propeller fans suit low-resistance, general ventilation; tube-axial fans are ideal for ducted auxiliary systems; and vane-axial fans are chosen where higher pressure, better efficiency and more demanding mining ventilation duties must be met.
