Finding the reasons for high vibration in mechanical pumps
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During the water-cooling operation of the methanol plant, it was observed that the pipeline of the bottom reflux pump experienced significant vibration. When testing the pump, we used full reflux, and the pipeline showed some vibration, but the level of vibration during water-cooling operation was surprisingly high. Pump operating conditions: inlet pressure: 0.11 Mpa, outlet pressure: 1.6 Mpa, flow rate: 117 m3/h, shaft power: 400 Kw. Determine whether the problem lies with the pump or the return pipeline
You can try seeing how it works with the motor running idle.
Is it because the minimum backflow rate of the pump is too low, causing the pump to get stuck?
This post was last edited by “Never be mediocre” on May 24, 2017, at 23:00. Turn off the recirculation; what should be the opening degree of the control valve at the outlet leading to the heat exchanger? Try setting it to fully open. If vibration persists, it may be because the pump is designed to handle methanol as the fluid to be transported; its density is 0.791 g/mL at 25 °C, which is lower than that of water. When this pump is used to pump water, more work is required from the pump, resulting in increased stress on the pipes. When backflow occurs, the pump pressure drops, less work is needed from the pump, and thus the stress on the pipelines is reduced.
The impeller is not properly balanced； There is an object blocking the impeller flow channel, causing the impeller to become unbalanced ； Bearing damage ； The pump is loose to the base, and the base is loose to the foundation ； The coupling that connects the motor to the pump is not properly aligned ； The bearing radial clearance is too large ； Low-frequency resonance of the unit.
Is the flow rate too high, causing vibration?
Are you referring to large vibrations in the pipeline, or large vibrations in the pump? It seems to have nothing to do with the pump. It’s just related to the fixed processes and pipelines, as well as whether resonance occurs.
For this matter, it’s not very useful to show flowcharts; it’s better to provide some actual images. I heard it’s fine that you’ve returned everything to normal; there was a lot of vibration during the trial run. One reason is that the load might be relatively high during operation. Then it’s also impossible that it’s caused by vibration of the pipeline itself, right? Upload some photos from the scene.
Check again to see if your pipeline supports and fixations are secure!