In fan applications, axial flow and centrifugal are the two most widely used types. We need to understand his similarities and differences in order to make the correct choice in fan selection according to our own use environment. Here is a brief introduction to these two types of fans.
The characteristic of the axial flow fan is that the fluid flows along the axial direction of the fan blade. Such as electric fans and exhaust fans in the home. The centrifugal type uses centrifugal force to draw fluid from the axial direction of the fan and then uses centrifugal force to throw the fluid out of the circumferential direction, such as blowers and range hoods.
Axial fan: large flow and small pressure head.
Centrifugal fan: large pressure head, small flow.
The airflow direction of the axial fan is perpendicular to the rotation direction of the blades, and the airflow direction of the centrifugal fan is tangent to the rotation direction of the blades.
What type of fan to choose is the most important consideration of flow and system resistance loss.
Compared with the axial flow fan, the centrifugal fan has the biggest disadvantage of its large size. Because of the different structures of the two, the power consumption of the centrifugal fan is much larger than that of the axial flow fan under the same air volume and pressure, but the noise Will be relatively small, so axial fans are mostly used for fire-fighting ventilation, and centrifugal fans are often used for fans. In high-end hotel-like buildings, centrifugal fans are required to be used first.
Axial flow is the air flow in the same direction as the axis of the blade. Centrifugal, which relies on centrifugal force to throw out the airflow. The flow direction of the wind and the axis are parallel, it is called an axial fan, (such as a fire exhaust fan), on the contrary, it is a centrifugal fan (such as a fan with a fan coil).
The fundamental difference between axial fan and cabinet centrifugal fan lies in the mechanical structure of the fan:
The blade diameter of the axial fan is limited to the diameter of the shell, while the centrifugal fan has no limitation in this respect. It can adopt the blades of forward or backward leaning, and the requirements for air volume and pressure are more suitable. Moreover, the cabinet can be muffled, which has obvious advantages in noise indicators.
Generally, the number of revolutions of the motor is lower, the motor power is large, and the power consumption is more. If the ventilation system is usually used, try to use cabinet-type centrifugal fans. For systems that are not commonly used for fire-fighting smoke exhaust, it is more economical and reasonable to use high-temperature axial fans!
Centrifugal fans are more advantageous than axial fans in the combination of large air volume and large air pressure (mainly refer to fan efficiency and noise indicators)!
The difference between centrifugal fan and axial fan is:
1. The centrifugal fan changes the flow direction of the medium in the duct, while the axial flow fan does not change the flow direction of the medium in the duct;
2. The former has high air volume and pressure, while the latter has low air volume and pressure;
3. The former is more complicated to install, while the latter is simpler;
4. The former motor and the fan are generally connected by a shaft, and the latter motor is generally in the fan;
5. The former is often installed at the inlet and outlet of air conditioning units, boiler drums, induced draft fans, etc., while the latter is often installed in the middle of the duct or in front of the duct outlet.