Reasons for the detachment of the impeller in axial flow pumps
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In one of our projects involving triple-effect evaporation for the evaporation of sulfuric acid, the axial flow pump in the second effect stopped circulating after a month; it was later found that the impeller of the axial flow pump had fallen off. Could anyone help analyze what caused this? We were unable to determine the cause at the time, so we simply replaced the impeller and welded it in place ! !
Just to add, they are screws that are fixed in place by welding; there’s no rotating impeller, and the impeller needs to be replaced when it becomes heavily worn
I feel like the impeller isn’t fixed properly!
Problems with processing, production, and quality: victory:
Is your pump frequently adjusted to vary its flow rate and operate under varying loads? Did any reversal occur? If there is any, please check it
The impeller should be installed hot; it may have fallen off due to insufficient clamping force or uneven heating.
In forced-circulation evaporation, there is no flow regulation at all. However, there are many start-up and shutdown operations during steel testing – I wonder if this will have an impact?
The pump impeller exerts a very large torque; therefore, a key or pin connection should be designed between the impeller and the shaft. If the key or pin is missing or not installed at all, this can cause the impeller to detach quickly. Inspect it and reinstall the appropriate connection. If the screws are simply welded in place, they will not hold for long either
Do you agree with the above view, or should we disassemble it to find the root cause? Never handle it carelessly.
It should be a clearance fit; is the shaft corroded? Welding? Not recommended. Will it be repaired in the future? Are the threads on the impeller and shaft damaged?
Check the interference amount when you installed it; also upload a picture – how can we analyze it without a picture?
First, check the condition of the check valve at the pump outlet； Also, whether the lock nut thread is right-hand or left-hand (some pump manufacturers use right-hand threads in this case) ； Next, check the fit between the shaft head and the shaft, as well as the issue with the key pins.