Vibration in the screw pump outlet pipeline
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On site, two Netchi screw pumps are used to feed the plate and frame filter press; they have a power rating of 30 kW, a head of 100, and a flow rate of 60. The filter press operates at a constant pressure of 0.8 MPa during feeding. When the pressure drops to around 0.5 MPa, severe vibration occurs in the outlet pipeline, and the discharge is uneven; the gauge pointer fluctuates between 0 and 0.5. Inspection of the stator sleeve revealed severe internal wear. Could everyone please help analyze whether it is severe stator wear that leads to uneven discharge volume, thereby causing vibration in the outlet pipeline.
This post was last edited by 3983596_FPPZ on 2019-5-10 13:32. If the output pressure is set at 0.8 MPa, how can it still drop to 0.5 MPa? Is the pump feeding normally? Is the motor overloaded? It is recommended to contact the pump manufacturer to resolve this issue
The filter press uses a constant pressure of 0.8 MPa for feeding; is it abnormal if the pressure is below 0.8 at the beginning of pump operation?
The cranking is fine; the pump is operating with normal vibration and temperature levels
When this situation occurs, the first thing to check is the process – why isn’t there continuous operation? “The outlet pipeline vibrates severely, the discharge is uneven, and the pressure gauge pointer fluctuates between 0 and 0.5. ” ； “Inspection of the stator sleeve revealed severe internal wear. ”What is the reason for this? Are the material particles too large? Is there a foreign object? It is recommended to look for the issue in the process before the materials enter the pump.
The question now is whether uneven discharge, resulting from excessive stator wear, is causing the pipeline vibration. The cause of stator wear is wear resulting from dry grinding without feeding.
This post was last edited by CHANGBAISHI on 2019-5-10 at 17:38. In other words, the lack of liquid involved prevents the screw pump from operating continuously; given the current level of wear, it should still be possible to keep using the pump. The key issue remains the high solid content of the material, which needs to be addressed. It is best to refer to the instructions to check whether the relevant technical requirements and the current status of the materials meet the specifications. Whether the suction pressure of the pump meets the operating conditions of the pump (liquid level height).
To use an analogy: if the material contains sediment and has a high solid content, then when the filter chamber of the filter press is filled to capacity, too much sediment accumulates inside the pump. This sediment can cause wear on the stator side. We have encountered similar situations in the past; after replacing the pump with another one, this problem no longer occurred.