Principles to be followed in designing industrial large fan blades

Industrial large fans have been imported into China from abroad, and batches of industrial fan manufacturers have been continuously researching, developing, and producing a full range of large industrial fan series products suitable for various environmental improvements in China. High-quality large fans are often built on good materials and unique advanced designs. The fan blades of industrial large fans are made of 5052 aviation aluminum, and unique blade designs can maximize the advantages of large fans and meet the needs of different users. When designing fan blades, industrial fan manufacturers need to follow certain principles.

1. Control the spacing between the fan blades If the spacing between the blades is too small, it will cause airflow disturbance, add conflicts on the blade surface, and reduce fan efficiency. If the spacing is too large, it will cause increased pressure loss and insufficient wind pressure.

2. It is better to design an odd number of fan blades Odd-numbered blades have better dynamic balance, avoiding resonance of the fan blades, thus reducing bearing wear, extending the service life, and reducing maintenance costs. If an even number of symmetrically shaped blades are used, it is difficult to achieve good balance adjustment, which may lead to system resonance, fatigue of the blades, and risks such as deformation or fracture of the blades or shaft over long-term operation.

3. Control the noise of the fan during the blade design The interaction and friction between the flowing air and surrounding objects, the separation effect of the blades on the airflow, and the periodic pulsating force of the cyclic blowing will all produce noise. The faster the airflow speed and the more turbulence, the greater the wind noise tends to be, and it will increase with the acceleration of the wind speed. The main impact of noise lies in the health and safety of the users. The vibration accompanying the noise may cause phenomena such as clicking wear, loose interfaces, and disc scratches, which can affect the usage.

4. Adopt a variable cross-sectional streamlined design for the fan blades The fan blades of industrial fans usually have an equal cross-section. Based on the angle between the root and end of the blades and the rotating axis, as well as the width of the root and end, the three-dimensional blade surface is formed by stacking, and then curve fitting is performed. This allows for a variable cross-sectional streamlined blade design that incorporates aerodynamic principles.

5. Control the curvature of the blade Within a certain range, the larger the curvature of the blades, the greater the gas kinetic energy and the larger the air volume and wind pressure under the same speed. At the same time, the resistance to which the blades are subjected also requires a larger torque from the motor. Therefore, controlling the curvature of the blades can increase the airflow of the fan blades while reducing motor losses.

6. The blade design should have a suitable inclination angle The larger the inclination angle, the greater the pressure difference between the upper and lower surfaces of the blades, and the greater the wind pressure disadvantage at the same speed. However, if the pressure on the upper surface of the blade is too high, it may cause backflow, which will reduce the effectiveness of the fan. Therefore, the inclination angle of the blades of industrial large fans should be controlled within 3° to 6°, which can allow the fan to generate maximum upward lift and reduce the torque borne by the decelerating motor during operation.