Solving for pump evacuation with a centrifugal pump
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A centrifugal pump is used to transport fuel oil; this pump has a NPSH of 3.5 meters, a flow rate of 3.6 cubic meters per second, and a head of 140 meters. Both the fuel oil tank and the pump are placed directly on the ground. The temperature of the fuel oil is around 110°C, so vaporization is unlikely. Additionally, the oil level in the pipes is above the pump inlet, which causes the pump to experience intermittent vacuum conditions during operation, affecting its performance. If clogged inlet pipes are ruled out, what other reasons could possibly cause the pump to experience cavitation?
Then it’s possible that the inlet pipeline is blocked or not flowing properly, or the filter is too dirty
I’m not sure about the properties of your fuel oil; I believe it won’t vaporize at 110 degrees. However, the fact that it doesn’t vaporize doesn’t mean there’s no vacuum present. The vapor pressure data at 110 degrees is useful for diagnosing problems. Also, make sure the liquid level in the tank isn’t too low； --Is the inlet diameter of the pump appropriate?
Check whether the pump body and pipelines are vibrating, whether the pump and motor are overheating, and whether the oil pump’s discharge valve is open. If blockages in the inlet pipelines and filter have been ruled out, it may be that the coupling between the pump’s impeller and the motor is loose.
1. It could be that the inlet pipe is blocked or not flowing properly, or the inlet filter is clogged. 2. It might also be that the liquid level in the container is too low. Try reducing the outlet valve – will that help?
It’s possible that the pump model together with the motor it’s paired with is not suitable for transporting this type of fuel, or there might be leaks in the pump’s pipes, which causes vacuum to form
The preliminary assessment is that it is a design issue; the pressure cannot reach the 0.5 kilograms required by the pump, resulting in cavitation. The pump was not selected correctly. Thank you all.