There are many kinds of centrifugal fans
, among which, according to the different blades assembled on the fan, it can be divided into two kinds of forward-leaning and back-leaning. Many customers are not clear about the two kinds of procurement. Here are the three differences between the two.
First of all, we need to have a general understanding of the concept of these two kinds of fans.
Forward-leaning fans are usually blowers whose impeller hubs and impeller edges are parallel and whose exit Angle is greater than 90 degrees. Generally use high quality steel plate for production.
Its advantage is to be able to choose small size shaft and bearing, so it has a wider range of operation, and lower cost. The disadvantage is that its performance curve shape and resistance curve is parallel, the blade strength is relatively low, the speed is also relatively low, the static pressure reduction of the system may lead to motor overload.
Backward fan is usually induced draft fan, its impeller hub and impeller are not parallel, impeller outlet Angle is less than 90 degrees, so its impeller is inclined. It is manufactured using glass fiber reinforced PA66 or galvanized steel.
Its advantage is that the impeller structure is high strength, more suitable for high static pressure system, no overload power curve, so the operation noise is relatively low, the air volume is relatively large, its effective area is also relatively wide. Its disadvantage is that the running speed is fast, resulting in higher requirements for dynamic balance, the need to use larger shafts and bearings.
The difference between the two is mainly reflected in three aspects:
1, efficiency: with a static pressure head to overcome the system resistance, the forward tilt fan is smaller than the backward tilt fan. Because of the increasing of the wind trough, the wind loss of the backward fan is smaller than that of the forward fan. As a result, forward leaning is often less efficient than backward leaning.
2. Energy consumption: The efficiency of the fan often affects the actual shaft power of the fan. Because the efficiency of the forward fan is lower than that of the backward fan, the power consumption of the forward fan is often larger than that of the backward fan.
3. Noise: The speed between the airflow of the forward fan and the housing collision is relatively large, and the curvature of the rear blade groove is gentle, so the noise of the forward fan is larger than that of the backward fan in the process of operation.
After reading the above introduction, I believe you should know where the difference between forward and backward tilt centrifugal fans is. When choosing, we should know the difference between the two, so that we will not buy the wrong.