The vertical vibration of the non-coupling end of the centrifugal pump seriously exceeds the standard
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Pump model 250ays200×2, motor 355kw 10kv, inlet 0.68MPa, outlet 2.77MPa, lift 411m, medium propane density 520. The new pump is not very useful. The vibrations of the motors are around 3mm/s. The vibration of the pump is as follows: The horizontal vibration at all positions does not exceed 2.5mm/s, the axial vibration is 4.5mm/s, but the vibration in the vertical direction, the coupling side bearing is 2.5mm/s, the pump inlet and outlet flange vibrations are 4.5mm/s, 8.9mm/s respectively, and the non-coupling side bearing is up to 11.8mm/s. It has been re-centered and controlled within 5 steps, and the anchor screws have not been loose after inspection. The inlet and outlet pipe supports, after adjustment, loosening and padding, have little impact. However, the vibration of the pipe is also relatively large, and the vibration through the insulation is also about 8mm/s. At present, manufacturers believe that there is no problem with the bearings and that it is the pump vibration driven by the pipeline. However, due to process reasons, the pipeline cannot be loosened to check the stress, so we can only think of other reasons and try our best to deal with them. I also hope that experts can help analyze
The components are lighter, check whether there is cavitation
BB2 pump, double suction? The vibration of the non-driving end bearing is too high and it can no longer operate. If it continues to operate, a shaft holding accident may occur at any time. It is not fun if a large amount of propane leaks out. It is recommended to stop the pump immediately and check and replace the bearings. This problem of excessive axial vibration and excessive vibration at the non-drive end is basically caused by poor stress relief in the inlet and outlet pipes. Or create conditions to stop the pump and check the pipe stress. In addition, the bearing lubrication should be carefully checked and it is best to replace all lubricants.
Because it is a new pump and there is basically no abnormal noise from the bearing, the possibility of the bearing being damaged is basically ruled out. Even if the material is light, it should not cause cavitation. There is an identical pump running normally. Moreover, the inlet filter has been checked and there is no clogging. The sound of the pump is normal and there is no sound of cavitation. Cavitation has basically been ruled out. The current idea is that I plan to turn the car and run a meter to check whether the shaft runout at both ends is normal. If it is normal, I will then disassemble the inlet and outlet to check the stress. If you have any opinions, please leave your comments.
1. Is the non-drive end a bearing bush or a bearing? 2. The axial vibration is not small. If there is a problem with the positioning bearing, it is recommended to check the lubricating oil. 3. Check whether the process is running normally by adjusting the outlet valve opening and pressure gauge changes. 4. Whether the filter at the inlet and outlet of the new pump is used during the start-up stage and whether it should be removed during normal operation. It would be better to have a vibration spectrum diagram
It is definitely not an alignment problem. There should be obvious abnormal noise due to cavitation. If not, check the flange connecting the inlet and outlet pipelines to the pump to see if they are tightened properly.
1. The non-driving end is the bearing. 2. The axial vibration is now 3.6mm/s after adjustment and alignment. I think it is basically normal considering that the vertical vibration aggravates this vibration. 3. Because there is no pressure behind all the pumps during the test run, I can only control the pump flow to the rated flow through the outlet valve by observing the flow meter, which should be the rated working condition of the pump at this time. This is the time to measure all the data. 4. The inlet filter is indeed used for construction. It has been dismantled and inspected, and the fine filter has been removed, leaving only the coarse filter. 5. I don’t have the conditions for the spectrogram at the moment.
1. The non-driving end is the bearing. 2. The axial vibration is now 3.6mm/s after adjustment and alignment. I think it is basically normal considering that the vertical vibration aggravates this vibration. 3. Because there is no pressure behind all the pumps during the test run, I can only control the pump flow to the rated flow through the outlet valve by observing the flow meter, which should be the rated working condition of the pump at this time. This is the time to measure all the data. 4. The inlet filter is indeed used for construction. It has been dismantled and inspected, and the fine filter has been removed, leaving only the coarse filter. 5. I don’t have the conditions for the spectrogram at the moment.
1. The non-driving end is the bearing. 2. The axial vibration is now 3.6mm/s after adjustment and alignment. I think it is basically normal considering that the vertical vibration aggravates this vibration. 3. Because there is no pressure behind all the pumps during the test run, I can only control the pump flow to the rated flow through the outlet valve by observing the flow meter, which should be the rated working condition of the pump at this time. This is the time to measure all the data. 4. The inlet filter is indeed used for construction. It has been dismantled and inspected, and the fine filter has been removed, leaving only the coarse filter. 5. I don’t have the conditions for the spectrogram at the moment.
If there is cavitation, the pressure cannot be increased.