Axial fan was invented in Britain in the first half of XVIII century. The first prototype of the fan was created by John Baron in 1830.
Axial fans are divided by purpose and designs on several types:
The video at the end shows the operation of a ceiling fan with retractable blades.
– roof fan;
– window fan;
– desktop fan;
– tower fan;
– other (cooler, cooling in cars etc.).
Axial fans are characterized by the following parameters: p>
– rotation direction (left or right);
– number of blades (from 3 to 7);
– blade shape (flat or curved in two directions);
– engine power;
– impeller diameter; p>
– case type.
Operating temperature range is from + 40 to -40 degrees.
The models are divided into the intake and exhaust fans. Radial (centrifugal) fan is more effective for blowing air, but it worse sucks air. Using the both types of fan provides the active air circulation. Many models have a reverse mode. But the efficiency in this mode is reduced by about 30-40%.
The air flow direction coincides with the impeller axis. The wheel is rotated by a motor. Axial fans are divided into domestic and industrial with a flow of up to 50 Pa. They are well suited for supplying large volumes of air at a low aerodynamic resistance of the system. Therefore, axial fans are often used in channel-free ventilation systems. They also are often used in systems with a small length of air duct, for example, in bathrooms, shower rooms, in offices, on car washes etc.
The design of the axial fan comprises housing, an axial impeller with blades and the engine. The impeller closes by the cylindrical housing.
Rotating blades direct air axially. Airflow almost not spreads in the radial direction. The blades most often are mounted directly on the motor shaft. Some models are equipped with a collector before the impeller that focuses the airflow for improving the fan aerodynamics. Airflow direction is easy adjusted with the help of blades tilt angle.
– compact size;
– rotation control;
– low power consumption;
– low noise level;
– easy to use;
– high efficiency compared to other types;
– low cost and ease of design;
– long service life.
– reliable protection of the motor against overload, sparks and moisture.
Of course, these factors should be taken into account when choosing the optimal fan.
In-line axial fans are often used for air supply and extraction ventilation in the industrial and administrative buildings. Many models additionally cooled further the air.