Reasons for the large vibration in multi-stage centrifuges
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What are the reasons for excessive vibration in multi-stage centrifugal pumps? The centrifugal pump in our unit stopped working right after it was started due to high vibration! Please share your opinions and help solve this!
I think there might be the following reasons, which you can rule out: 1) Misalignment of the coupler: bent pump shaft, worn bearings, misalignment of the unit, impeller hitting the pump casing. 2) Excessive pump shaft runout: Wear of bearings and journal or excessive clearance. 3) Hydraulic imbalance: Imbalance of the impeller, or blockage or damage in certain vanes of the centrifugal pump. 4) Foundation vibration: poor foundation stiffness, loose corner screws, or resonance. Remedial measures: Reinforce the foundation, tighten the foot screws. 5) The efficiency of the centrifugal pump unit drops sharply, or the efficiency of the axial flow pump unit decreases slightly, accompanied by cavitation noise.
I’ve never seen this situation before – the pump is vibrating severely. How can the manufacturer even sell such pumps to you? Could it be due to an overload, a leakage issue, or some electrical problem?
There is no overcurrent, no leakage, and the electrical system is functioning properly
The most common reason for large jumps at a certain point is imbalance and misalignment
Was it operated in accordance with the procedures?
This post was last edited by Kuuki Kyōko on 2010-9-12 at 13:09. Enough has been said above. However, I believe that if vibration is severe right at startup and causes the vehicle to jump out, the shaft is the most likely culprit. The pump’s dynamic balance isn’t properly adjusted; after all, even normal installation errors in alignment wouldn’t cause the machine to stop operating – that would be too careless
Agree with 7 hugs. I think the possible reasons are: unbalanced rotor ； Excessive rotor runout ； The pump is evacuated or cavitation is present ； Low motor power ； The bearing preload clearance is too small ； Too small assembly clearances in various parts of the rotor can all cause the pump to trip during startup.