Causes of Vibration:

1. Too Light or Small Cement Foundation:
   An unstable foundation may lead to fan vibrations.

2. Insufficient Stiffness of the Base and Volute:
   If the base and volute of the centrifugal induced draft fan have insufficient stiffness, it can result in vibration issues.

3. Loose Anchor Bolts or Unstable Connections:
   Loose anchor bolts or weak connections between the base and the foundation can cause unstable operation and vibration.

4. Lack of Support and Flexible Connections in the Inlet and Outlet Pipelines:
   If the inlet and outlet pipelines are not properly supported or have no flexible connections, or if the distances between the equipment foundations are too close, this can lead to vibration problems.

Solutions:

1. Reinforce the Foundation:
   Strengthen or re-grout the foundation to improve its stability.

2. Increase Stiffness:
   Improve the stiffness of the base and volute to ensure they can withstand the vibrations of the fan.

3. Tighten Anchor Bolts and Connections:
   Ensure the anchor bolts are properly tightened and the connections between the base and the foundation are secure.

4. Install Support and Flexible Connections:
   Install appropriate support and flexible connections for the inlet and outlet pipelines to reduce vibration transmission.

5. Increase the Distance Between Equipment Foundations:
   Ensure that the foundations of other equipment are kept at a suitable distance from the centrifugal induced draft fan foundation to avoid interference.