Causes of Abnormal Operation in Forward-Curved Double-Inlet Centrifugal Fans

Causes of Abnormal Operation in Forward-Curved Double-Inlet Centrifugal Fans

Three common abnormal phenomena occur during the operation of forward-curved double-inlet centrifugal fans: severe vibration, excessive bearing temperature rise, and excessive motor current or temperature rise. So, why does this happen? Let me explain below. First, the primary causes of severe vibration in forward-curved double-inlet centrifugal fan units are as follows: 1. Misalignment between the fan shaft and motor shaft. 2. Insufficient foundation or overall support for the forward-curved double-inlet centrifugal fan assembly. 3. Loose propeller bolts or rivets, propeller deformation, or loosening of the propeller shaft's flange hole and shaft. 4. Loose connecting bolts between the casing, bearing housing and bracket, or bearing housing and bearing cover. 5. Dust or debris on blades, blade wear, impeller deformation, or shaft bending disrupts rotor balance. 6. Resonance may occur when inlet/outlet ducts or discharge pipes are improperly installed.