centrifugal pump efficiency
centrifugal pump efficiency
(OP)
I need to estimate an efficiency of a centrifugal pump, but do not have any specifications. This is what I know:
Single stage centrifugal pump
Static head: 100m
Motor power: 200 kW
Water quality: Poor. Water is pumped from the bottom of a gold mine. It is not slurry, but it does contain rock particles.
Given the limited information above, what efficiency can I expect? Rough figure such as 30%, or 50% will be sufficient.
Thanks
Single stage centrifugal pump
Static head: 100m
Motor power: 200 kW
Water quality: Poor. Water is pumped from the bottom of a gold mine. It is not slurry, but it does contain rock particles.
Given the limited information above, what efficiency can I expect? Rough figure such as 30%, or 50% will be sufficient.
Thanks





RE: centrifugal pump efficiency
H = 100 meters = 328 ft. head.
assume water is 62.4 lb/ft^3
ft.lb/min (power)= 8850.7 = ft^3/min (flow) x 62.4 x 328 ft/E (efficiency)
8850.7 = 62.4 x flow x 328/E
E = 62.4 x flow x 328/8850.7 = 2.312 x flow
Sorry. You have 1 equation, 2 unknows. No unique solution.
RE: centrifugal pump efficiency
RE: centrifugal pump efficiency
RE: centrifugal pump efficiency
If you really want to do some calcs and "play around" (that's what I call it) with some numbers go look at the pump name plate.
You can measure motor amps to give you and idea where you're at on % load relative to motor FLA. In pump applications typically motors are sized so the max BHP (and FLA) coincides with ~120% of rated flow. If you're just under motor FLA then you can assume you're at or near rated flow (name plate flow). Use that flow and head to calculate a Specific Speed (not pump RPM... Google it if you don't understand) for that impeller. Use that specific speed number to search online for a pump OEM's sales curve for a similar pump design and application. Compare the head/flow they give for your impeller diameter (also on the name plate) to your "assumed" head/flow.
RE: centrifugal pump efficiency
units:ft, gpm, Hp
You should measure the flow rate, and the BHp at this flow (by measuring the amper)and specific gravity of pumped fluid and then simply use above equation.
Reza
RE: centrifugal pump efficiency
In this case I think he would get a divide by zero error.
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