Views: 12 Author: jason Publish Time: 2023-04-04 Origin: www.belmont-tech.com
They can be divided into 3 categories according to the input power and control signal, AC, EC, DC
AC means AC fan - Alternating Current
EC means Electronically Commutation fan - Electrical Commutation (also belongs to DC fan)
DC means direct current fan - Direct Current
Generally speaking, the number of blades of a forward-facing fan is >10.
Centrifugal fans are divided into: front inclined centrifugal fans and back inclined centrifugal fans by the different blades of the assembled fans.
Front inclined fan: generally for the blower, impeller hub and and impeller edge parallel, impeller exit angle greater than 90 degrees for the front inclined impeller also known as forward impeller.
Advantages: smaller shafts and bearings can be used, with a wider operating range, low cost.
Disadvantages: performance curve shape and resistance curve may be parallel, blade structure strength is low, low speed, when the system static pressure is reduced is likely to lead to motor overload.
Backward inclined fan: generally for the induced draft fan, impeller hub and impeller is not parallel, impeller exit angle is less than 90 degrees for the backward inclined impeller also known as backward impeller.
Advantages: the impeller has high structural strength, can be used for higher static pressure systems, and power curve without overload, low noise, high air volume, wide efficiency zone, high efficiency and no overload.
Disadvantages: Due to the high speed of operation, the requirements for dynamic balancing are relatively high, so larger shafts and bearings are required.