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#1 Guest_Sam_*

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Posted 26 September 2003 - 03:42 AM

Is there any pump available in the market to acheive reasonable efficiency ( say 50 - 60%) with zero head.

#2 Guest_Guest_guest_*

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Posted 26 September 2003 - 03:52 AM

yes

#3 Art Montemayor

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Posted 26 September 2003 - 06:26 PM

Sam:

What efficiency are you talking about? The pump's mechanical efficiency?

What do you mean by "zero" head? If there is no head for the pump to work against, there is no work done and no pumping taking place. A pump works by overcoming a head - no matter how small.

Do you mean a very small head? What kind of pump do you have in mind, a centrifugal? Or is your question just a general, theoretical question?

#4 Guest_Guest_Luiz_*

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Posted 28 September 2003 - 02:16 PM

Sam is probably talking about the shutoff point (flow = zero) of a centrifugal pump. I think it's impossible. The achievement of 50-60% usually falls on the curved part of the HxQ chart near the optimum and very far from the zero flow. Near the shutoff the best you could get would be something around 10%.
Remember, you must be a cold-blood engineer to put a centrifugal pump working on the 'flat' part of the chart.

#5 benoyjohn

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Posted 01 March 2004 - 03:05 AM

Sam,
Why do you need a pump with zero head? I mean If there is no requirement to generate differential pressure, then why do you need a pump? Will the fluid not flow on its own?

regards
Benoy

#6 djack77494

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Posted 01 September 2004 - 10:42 PM

Whether you are talking about zero head or zero flowrate, it doesn't matter. In either case, the pump will be doing zero useful work. Since no useful work will be done, the pump's efficiency is without meaning. Sounds to me like you should just remove the pump. (grins)
Doug smile.gif




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