Abnormal noise in water ring vacuum pump
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We use water ring vacuum pumps here; when the liquid level in the water tank is raised to 60%, that is, above the water filling port of the vacuum pump’s pump head, unusual noises occur – very harsh noises – but the motor current remains relatively stable. The water level in the tank can be lowered to just below the filling port on the vacuum pump head, and then the problem will go away; however, the motor current will fluctuate significantly and remain at a relatively high level. Experts, please help answer. Thank you
There is a strange noise, it’s harsh. This indicates friction between the impeller and the pump casing, as well as wear on the bearings, shaft sleeves, and shaft inside; as a result, the dynamic balance is poor. Another reason for poor dynamic balance is the presence of air in the circulating fluid that enters the vacuum pump; this air is brought in when the return water enters the water tank, and it doesn’t have time to rise to the surface and separate. If the liquid level is below the water inlet of the pump head, and it is not in a powered circulation mode, the pump may not receive any water and thus run idle, leading to instability.
Based on your description, the abnormal noise emitted by the water ring pump is likely cavitation noise caused by an excessively low vacuum level. A simple way to check this is to slightly open the inlet of the water ring pump and see if the noise persists. If there are any more, we should consider whether it’s a mechanical failure. But you said that the abnormal noise disappeared when the liquid level was below the return water inlet of the gas-liquid separator; it must have been cavitation noise. I guess this situation only occurs when the pump is not connected to the system; it should work fine when it is in operation with the system connected. Also, the liquid level must not be below the return water inlet, as this can cause severe damage to the pump.
Our water ring pump is connected to the system for vacuuming, and the make-up air valve is fully open.
There is probably too much water in the liquid ring, which increases the work required by the pump. Adding an overflow port will solve the problem
Is the rotor worn and cavitating? It has affected the balance.
It was just bought and used for the first time; once the vacuum level was reduced to a very low level, that’s exactly what happened
When there is too little water, the motor current fluctuates significantly and remains high
The whistling sound is caused by a high vacuum level; the vacuum pump chosen is too powerful.
Increasing the water supply a bit would help… It’s hot like this
Cavitation occurs due to the high vacuum; when the liquid level in the tank is raised to 60%, that is, above the water filling port of the vacuum pump, a seal is formed, resulting in a high vacuum inside the pump and thus cavitation. The water level in the tank can be lowered below the filling port of the vacuum pump head; the other components inside the tank then maintain the desired vacuum level, using the same principle as when the gas relief valve is opened. The current changes at this time due to fluctuations in the vacuum level.