I would like to ask: when using a centrifugal pump to empty a tank, air may get mixed in as the tank is nearly drained (forming an air-water mixture). Can the centrifugal pump still be used in such a situation?
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I would like to ask: when using a centrifugal pump to empty a tank, air may get mixed in as the tank is nearly drained (forming an air-water mixture). Can the centrifugal pump still be used in such a situation? Because the chief engineer said cavitation would occur, that centrifugal pumps cannot be used and diaphragm pumps should be used instead? Does it make sense?
If a centrifugal pump is used, is there any way to avoid the so-called cavitation? ?
If air enters the suction inlet of a centrifugal pump, it can no longer operate, resulting in an empty-pump condition. Diaphragm pumps can be used, with flow rates that can be high or low.
Centrifugal pumps are sensitive to vacuum conditions; add a level interlock
Centrifugal pumps are still the better choice. Can diaphragm pumps prevent cavitation?
Centrifugal pumps cannot be operated in a vacuum for long periods of time. When you notice fluctuations in the pressure at the pump outlet that drop to zero, stop the pump for a while before trying to start it again. Diaphragm pumps can prevent cavitation, but their flow rate is low
If air enters the inlet of the diaphragm pump, it won’t be able to deliver fluid properly~; nothing else seems to be an issue. Centrifugal pumps cannot operate for long periods in a vacuum condition~
Is there no breathing valve or vent valve, or nitrogen seal on the tank? That is, the pipes that are connected to the outside world. If not, during extraction, as the liquid level drops, the volume of space at the top of the tank increases, the pressure decreases, and the amount of gas phase inside the tank rises. The pump’s flow rate and head decrease, the feed pipe provides insufficient feed, and the centrifugal pump impeller is prone to cavitation. Although diaphragm pumps have slightly better resistance to cavitation, they still experience a reduction in flow rate and head pressure. So it is best to install a breather valve or a vent valve. If it is a hazardous liquid or cannot be discharged directly into the air, a nitrogen seal valve can be installed to introduce nitrogen.
If not, during extraction, as the liquid level drops, the volume of space at the top of the tank increases, the pressure decreases, and the amount of gas phase inside the tank rises. What does it mean when the pump’s flow rate and head decrease, there is insufficient feed in the feed pipe, and the centrifugal pump impeller is prone to cavitation? ? Is it the negative pressure created at the top of the tank that results in insufficient suction capacity of the pump (the allowable vacuum level), preventing the liquid from entering the pump inlet smoothly? ? Looking forward to your advice!
Why doesn’t a diaphragm pump feed material when air gets mixed in? ? Will a screw pump also fail to feed if air gets in? ? ?