A 6-stage large-circuit canned pump in our unit often suffers from rear bearing wear, shaft sleeve bearing breakage
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Like the title, it is a reverse circulation pump. When the pump is on and ready, the same problem has occurred on both pumps. We have also roughly deduced that it is caused by unbalanced axial thrust. At first, we thought that the shaft return pipeline was not smooth, and then we changed the stop valve on the shaft return pipeline to a ball valve to try the effect. The result was that the pump was still worn and cracked. No abnormality was found during operation. When we stopped and disassembled it, we found that the bearing was damaged! Sorry for typing on mobile phone!
This kind of phenomenon should be searched first from the aspect of process use. For example, whether the physical indicators of the material are suitable for the use conditions of the pump,,,,. Mechanically, check whether the installation is standardized, such as the installation environment, relevant gaps and others. It's best to send a few more pictures, what the whole device looks like, and what it looks like after disassembly... facilitate discussion. for reference
This situation is often related to changes in process indicators. Check the actual flow rate of the medium and the rated flow rate of the pump, and adjust it according to the actual flow rate. If there is no need for the medium, it is recommended to use graphite bearings that are not fragile.
What about pump and motor channeling? What about the bearing gland and thrust pre-clearance? If it is difficult to judge the working condition problem, you can check the motor running current and whether the suction volume is insufficient, etc.
This damage is not related to the return line.
Impact cracking is caused by the thrust of the shaft backward, and wear and tear is caused by dry grinding. In addition, there are certain skills in on-site assembly. It is recommended to let professionals repair it 15242535301
Huanyou's multi-stage pump has back-to-back impellers. Generally, the axial force is not too large. A broken rear bearing can basically be ruled out as a problem with the axial force. If your machine is fine and the valve opening is fine, consider that the resistance direction of the reverse return line is correct (try changing the stop valve on the shaft return line to a ball valve) ； It is possible that the resistance in your reverse return line can not only be eliminated by the stop valve and ball valve. Generally, the head of the reverse circulation pipe of a Japanese-made (and environmentally friendly Japanese) multi-stage pump is about 10% of the head of the reverse flow pipe. You can check again to see if the liquid in the tail cannot return, which may also cause retention and the temperature of the liquid in the rear bearing is too high.