Why won’t the submersible pump rotate?
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One of the long-shaft submersible pumps in our facility has experienced problems where it couldn’t be rotated, even after several repairs; repeated attempts at repair have been made yet it still doesn’t work properly. What could be the cause, according to the experts? Help with the diagnosis. The bushings and bearings have been replaced. Working conditions: liquid sulfur, temperature 150°C, drive shaft length of about 2 meters, material 304 stainless steel
There must be a problem with the assembly; the vehicle can’t rotate without being in operation, so there’s probably an issue with the clearance between the components. It’s recommended to check it
Our facility has sulfur submersible pumps, but those manufactured in Dalian often fail to start for the following reasons: 1: Bearings (including contact bearings and plain bearings); it is crucial to control the axial movement of angular contact bearings. 2: All steam pipelines connected to the sulfur pump must be unobstructed; if there are blockages in these pipelines, the sulfur will clump together, preventing the pump from starting. 3: There are standard requirements regarding steam pressure in the processing process; insufficient steam pressure can also cause blockages in the sulfur flow. 4: The sulfur pump has many pipeline connections, and after repairs, pressure tests (using water) must be conducted to check for any leaks in these connections. Any leaks must be fixed, otherwise sulfur will seep in through them
2# zhangya*ong I have the same doubts, but there is one question: Is the gap the same as that of ordinary pumps? Is it still the submersible pump that varies depending on the temperature of the medium?
It’s a submersible pump with an integrated motor; try removing the motor and see.
That’s what happens with sulfur pumps: one reason is a problem with the pump itself, such as jamming of the shaft sleeves, while another reason could be an issue with the steam jacket or incorrect steam pressure. Hehe, just my personal opinion
If there is no solid sulfur blocking it inside, you should first check whether the clearance between the bearing and the sleeve meets the requirements. Also, check whether there is any jamming between the pump head and the pump casing. The axial force of submersible pumps is mainly borne by the rolling bearings and locking nuts in the base; tighten the locking nuts and try lifting the pump shaft as much as possible to see what happens. Check whether the clearance between the bearing and the sleeve is appropriate; if a section of the pump shaft can be installed, rotate the shaft to examine whether there are any signs of wear on the bearing and the sleeve.
I’m not sure what your structure is like; check it section by section. If it can’t be determined, it’s definitely a fitting issue. The key is to see where things stop moving ? ?
Additional information: During several inspections, maintenance tasks, and trial runs, problems were found with the lower two bearings – first it was a cracked mouth ring, then the impeller came loose, and finally the pump shaft broke； The jacket heating issue has been basically resolved, so it can be ignored. Latest update: Yesterday, during the Nth attempt at reinstallation, the pump rotated normally before the reinstallation process began. However, just a few minutes after the pump was placed in the material tank, it stopped rotating again; after about half an hour, it was able to rotate freely and operate normally. ——I’m not sure if it will truly succeed this time
Based on the poster’s final description, the problem is already quite clear. The inability to rotate the machine has nothing to do with the equipment itself; the main reasons are the temperature of the material and uneven heating of the pump. Pump operating environment: (liquid sulfur, temperature 150°C). The pump, once repaired, rotates smoothly without any problems; however, when it is placed in the material tank, heat expansion of the pump body causes uneven heating in the ring gaps. As a result, difficulty in turning the shaft occurs. After some time, the entire pump body becomes relatively evenly heated, so it can be rotated again. As long as the steam pipelines are unobstructed and there are no blockages in the various pipes of the pump, I don’t think there will be any problems this time