When we choose to buy a centrifugal fan, the choice of the centrifugal fan model is very important, and the choice of fan wheel is even more important, so how do we choose the impeller of the centrifugal fan?

In a centrifugal fan, increasing the number of blades of the impeller can increase the theoretical pressure of the impeller, because it can reduce the influence of the relative vortex (that is, increase the K value). However, the increase in the number of blades will increase the friction loss of the impeller channel, which will reduce the actual pressure of the fan and increase the energy consumption.

Therefore, for each type of impeller, there is an optimal number of blades. The specific determination of the number of blades is sometimes based on the designer's experience. According to the current application situation in my country, the selection range of the number of blades is recommended in Table 2.

Centrifugal fan design requirements: the operating point that meets the required flow and pressure should be near the highest efficiency point; the highest efficiency value should be as large as possible, and the efficiency curve should be flat; the stable working range of the pressure curve should be wide; the fan has a simple structure and good manufacturability Convenient selection of materials and accessories; sufficient strength, rigidity, and safe work; stable operation, low noise; good adjustment performance, strong work adaptability; fan size as small as possible, light weight; convenient operation and maintenance, disassembly and assembly Transportation is simple and easy.

There are often contradictions between aerodynamic performance and structure (strength, craftsmanship), and the main contradiction is usually solved through coordination. This requires the designer to choose a reasonable design plan to resolve the main contradiction.

With the different uses of fans, the requirements are different. For example, fans used in public buildings are generally used for ventilation. Generally, the most important requirement is low noise. Multi-blade centrifugal fans have this feature; and require large flow The centrifugal fan is usually a double suction type; for some high-pressure centrifugal fans, the specific speed is low, and the relative proportion of leakage loss is generally larger.

For more product information, please click here: Fan & Impeller Wheels.