Characteristics and differences between axial flow fan and centrifugal fan
The characteristic of axial flow fan is that the fluid flows along the axial direction of fan blade. Such as electric fans and home exhaust fans. The centrifugal type sucks the fluid from the axial direction of the fan and uses the centrifugal force to throw the fluid out from the circumferential direction, such as blower and range hood
Axial flow fan: large flow and small pressure head.
Centrifugal fan: large pressure head and small flow.
The air flow direction of axial flow fan is perpendicular to the rotation direction of blade, and the air flow direction of centrifugal fan is tangent to the rotation direction of blade.
What type of fan is selected? The most important thing is to consider the flow and system resistance loss
Compared with axial flow fans, the biggest disadvantage of centrifugal fans is their large volume. Precisely because of their different structures, under the same air volume and pressure, the power consumption of centrifugal fans is much larger than that of axial flow fans, but the noise will be relatively small. Therefore, axial flow fans are mostly used in fire prevention and ventilation, and centrifugal fans are mostly used in peacetime. In high-end hotel buildings, many require the priority of using centrifugal fans
Axial flow is the air flow in the same direction as the axis of the wind blade. Centrifugation, the air flow is thrown out by centrifugal force.
If the flow direction of air is parallel to the axis, it is called axial flow fan (such as smoke exhaust fan for fire fighting) and vice versa is centrifugal fan (such as fan coil fan)
The fundamental difference between axial flow fan and cabinet centrifugal fan lies in the mechanical structure of fan:
The blade diameter of axial flow fan is limited to the diameter of shell, while centrifugal fan does not have this limitation. Forward inclined or backward inclined blades can be used to meet the requirements of air volume and pressure. Moreover, noise elimination treatment can be done in the cabinet, which has obvious advantages in noise index.
Generally, the rotation number of the motor is low, the motor power is high, and the power consumption phase is more. If the ventilation system is commonly used at ordinary times, try to use cabinet centrifugal fan. For the system not commonly used for fire control and smoke exhaust, it is more economical and reasonable to use high-temperature axial fan!
Centrifugal fan has more advantages than axial fan in the combination selection of large air volume and large air pressure (mainly referring to fan efficiency and noise index)!
The difference between centrifugal fan and axial fan lies in:
1. The centrifugal fan changes the flow direction of the medium in the air duct, while the axial fan does not change the flow direction of the medium in the air duct;
2. The former has high air volume and pressure, while the latter has low air volume and pressure;
3. The former is more complex and the latter is simpler;
4. The former motor is generally connected with the fan through the shaft, while the latter motor is generally in the fan;
5. The former is often installed at the inlet and outlet of the air conditioning unit, boiler drum, induced draft fan, etc., while the latter is often installed in the middle of the air duct or at the front end of the air duct outlet.