NPSH of submersible pumps and bag pumps
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Dear experts, what is the situation regarding the net positive suction head required for submersible pumps and bag pumps? In theory, cavitation can occur in any pump, but since the impeller is always submerged in the liquid, what are the effects of cavitation? Can bag pumps theoretically transport gas-liquid mixtures with a negligible net positive suction head value? Thank you.
Submersible pumps and bag pumps are similar to ordinary pumps; the only difference is that their inlets are located at a lower level, which effectively increases the net positive suction head available for the device
A gas-liquid two-phase mixture is not acceptable; the gas content in the fluid transported by ordinary centrifugal pumps must be less than 5%
Who says a cartridge pump can transfer two boxes? That’s complete nonsense! It is precisely the fear of cavitation that leads to lowering the impeller; therefore, cavitation cannot be ignored. It’s just that this situation will change as a result of structural modifications
The net positive suction head is generally satisfactory, and no action is required under normal conditions
It seems that cavitation will still occur at the center of the impeller