There is air in the centrifugal pump
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The company’s cooling tower has two circulation water pumps; there is air in it, and it cannot be removed even after several attempts. The cooling tower tank is not very deep; there is approximately 20 cm of liquid above the inlet pipe of the centrifugal pump. Could it be that the low liquid level is the reason why gas keeps getting into the centrifugal pump?
How did you fill this pump with water? Is the water level higher than the highest point of the pump body? Otherwise, it won’t be possible to fill it completely. Also, check if there are any swirls at the water outlet of the tank – is the water temperature high?
The liquid level should be above the highest point of the pump body, not above the inlet pipe. If the liquid level cannot exceed the highest point of the pump body, a vacuum pump must be used to remove air.
The centrifugal pump is vertical, and when starting the pump, the operator generally does not fill it with water; there is a slight height difference between the water surface and the pump. Additionally, there is a cooling fan on top of the cooling tower, and the water flows from top to bottom. Could this result in a large number of bubbles being formed, which enter the pump before they have time to burst?
It is because the distance from the suction inlet to the water surface is too small; the vortices generated during operation allow air to enter, resulting in air entrainment (unless there is a leak in the water inlet pipe or the pump body). Consider lengthening the water intake pipe or installing an anti-vortex device.
Most centrifugal pumps can exhaust air automatically once they are in operation. If air remains present, it is necessary to carefully check for leaks in the suction pipeline, as well as to determine whether vortices are forming at the beginning of the pump’s suction pipeline, or whether air is mixed in with the liquid being drawn in.
This post was last edited by qiyuchun on 2016-4-23 at 10:20. It is obvious that the inlet liquid level is too low.
First, try reducing the flow rate of the centrifugal pump and see.
1. Water temperature. 2. Location (height) of the exhaust point