Some common faults and solutions of centrifugal fans

Update:05-02-2021
Summary:

Failure phenomenon one Trouble phenomenon: vibration ca […]

Failure phenomenon one
Trouble phenomenon: vibration caused by unbalanced rotor of centrifugal blower fans
the reason:
1. The blades of the centrifugal fan are corroded or worn seriously;
2. The fan blades do not operate after the final assembly, and the shaft is bent due to the weight of the impeller and the main shaft;
3. Uneven attachments on the surface of the impeller, such as rust, dust or asphalt, etc.;
4. The impeller is deformed due to transportation, installation or other reasons, causing the impeller to lose balance;
5. The balance block on the impeller falls off or the balance is not found after overhaul;
Approach:
1. Repair or replace;
2. Re-overhaul, and if it is not used for a long time after final assembly, it should be turned regularly to prevent the shaft from bending;
3. Remove attachments;
4. Repair the impeller and re-do dynamic and static balance tests;
5. Find balance.


Fault phenomenon two
Trouble phenomenon: the fixed parts of the centrifugal fan cause resonance
the reason:
1. The cement foundation is too light or the grouting is poor or the plane size is too small, causing the fan foundation to be disconnected from the foundation, the anchor bolts are loose, and the machine base is not firmly connected, making the foundation rigidity insufficient;
2. The rigidity of the fan base or volute is too low;
3. The inlet and outlet pipes connected to the fan are not supported and softly connected;
4. The adjacent facilities are too close to the foundation of the wind turbine, or the rigidity is too small;
Approach:
1. Reinforce the foundation or re-grouting, and tighten the nuts;
2. Strengthen its rigidity;
3. Add support and soft connection;
4. Increase stiffness.
Fault phenomenon three
Trouble phenomenon: overheating of centrifugal fan bearing
the reason:
1. The centrifugal fan main shaft or parts on the main shaft rub against the bearing box;
2. The motor shaft and the fan shaft are not concentric, so that the inner rolling bearing in the bearing box does not move;
3. Too much grease in the bearing box;
4. There is a gap between the bearing and the bearing box hole and loose, and the bolt of the bearing box is too tight or too loose;
Approach:
1. Check which part is rubbing, and then deal with it;
2. Adjust the concentricity of the two axes;
3. The grease in the box is 1/3~1/2 of the box space;
4. Adjust the bolts.
Fault phenomenon four
Trouble phenomenon: centrifugal fan bearing wear
the reason:
1. There are pitting, spots, rust marks and peeling on the surface of the rolling bearing ball of the centrifugal fan;
2. The clearance between the inner circle of the cylindrical bearing and the outer circle of the rolling bearing exceeds 0.1mm;
Approach:
1. Repair or replace;
2.The bearing should be replaced or the inner circle of the box should be enlarged and inserted into the inner sleeve.

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