Centrifugal pump vibration and noise causes and solutions

The principle of the centrifugal pump is simply that when the impeller rotates at a high speed, it drives the rotation of the liquid between the blades. Due to the centrifugal force, the liquid is thrown from the center of the impeller to the outer edge of the impeller, and the kinetic energy increases. When the liquid enters the pump casing, as the flow passage in the volute casing gradually expands, the flow velocity of the liquid gradually decreases, and part of the kinetic energy is converted into static pressure energy, so that the liquid flows out of the discharge outlet with higher pressure. Centrifugal pumps are known as centrifugal pumps because of their centrifugal force. If handled improperly, the centrifugal force generated by the impeller can cause vibration and abnormal noise in the pump.

When the centrifugal pump is used, it is found that the pump vibration and noise are abnormal and should be shut down immediately for inspection.

1. Is the pump foundation secure?

When vibration occurs, first check that the anchor bolts of the centrifugal pump are tight. If it is not tightened, the centrifugal pump will vibrate. It is also necessary to consider whether the foundation strength of the footing is sufficient, and sometimes due to design reasons, the foundation may be soft and can also cause vibration.

2, coupling alignment

Many centrifugal pumps are driven by couplings, and there are many types of couplings. The quality of conventional three-jaw couplings directly affects the normal operation and service life of couplings, shafts, bearings, and mechanical seals.

3, find the center

The fact that the center is not correct is also a common cause of vibration. The center must be adjusted within the specified scope in strict accordance with the standards.

4. Bearing inspection.

Bearing installation problems or damage.

5. The center position of the rotor is adjusted.

The rotor of the water pump should be concentric with the stator, otherwise it will generate friction and vibration when the pump is running.

6, shaft bending and rotor measurement

If you cannot find the cause of the vibration on the outside, you can only disassemble the pump. First, measure and correct the shaft bending, install the rotor with no problem, measure the overall sloshing, scooping, and if it exceeds the standard, correct it.

7, dynamic and static balance detection.

After disassembling the centrifugal pump, in order to avoid vibration when starting the pump, the impeller should also be tested for static balance.

External conditions affect the pump.

When all the possible problems of the water pump itself are eliminated, if the problem of vibration cannot be solved yet, the influence of the external conditions on the water pump must also be considered. Such as: the resonance frequency caused by the natural frequency and vibration frequency of the pump foundation, the vibration of the pump caused by the failure of the prime mover, and the connection between the pipeline and the water pump can also cause the abnormal vibration of the pump due to strong reasons. Generally taking appropriate measures can solve the problem.