Design of centrifugal pump outlet pipeline
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This post was last edited by Catalyzing a Grain on 2018-5-2 at 11:28. A centrifugal pump in the facility experiences high vibration levels during operation, yet no issues are found upon inspection. The final conclusion is that the design is not standard; there is a elbow about half a meter away from the outlet. I’m a bit confused. Why does having elbows too close to each other cause pump vibration?
There are many reasons for vibration: 1. Large alignment errors; 2. Unbalanced impeller; 3. Worn or damaged bearings or excessive clearance; 4. Excessive axial movement; 5. Damaged coupling; 6. Bent shaft; 7. Foreign objects in the impeller’s flow channels; 8. Cavitation or gas entrapment
It is recommended to calculate the resonance length of the outlet pipe based on the sound speed of the medium; if it is close to that value, the pipe should be made longer.
Try adding support or weight to the outlet pipeline; if it’s resonance, this method can help alleviate it.
This post was last edited by qun123321 on 2018-4-24 08:17. Excessive vibration in centrifugal pumps is harmful to the pump shaft and seals; pumps with high power levels require flexible connections at their inlet and outlet ends to prevent resonance caused by rigid connections to the pipelines. This problem of yours can be solved by using inlet and outlet soft connectors such as metal hoses; it has nothing to do with elbows
The straight section at the pump outlet is too short; as a result, the higher the outlet pressure, the greater the flow resistance of the material in the pipeline and the self-excitation, which leads to pressure fluctuations inside the pump and thus increased vibration. The first issue to address is how the length of the straight section at the pump outlet should meet the regulatory requirements.
I’m not quite sure why the outlet elbow can cause self-excitation in the pump.