3 replies to this topic

[USR]

what is the relevance of specific speed of centrifugal pumps????

[kkala]

what is the relevance of specific speed of centrifugal pumps????

Centrifugal pump specific speed Ns characterizes the pump type, e.g. Ns=2000-5000 for turbine pumps, Ns=4000-10000 for mixed flow pumps, etc. Its mathematical expression is Ns=NQ^0.5/H^0.75, N=rpm, Q=gpm, H=ft of head.
Perry in the Chapter of 'Transport and storage of Fluids' (p. 10-25 in 7th ed) and Wikipedia (at "specific speed") give explanations of Ns.
According to them, pumps of same Ns have geometrically similar performance curves, that is only scale is different is their Q-H diagrams.

[truckcarrier]

Hi..Specific speed of Centrifugal pumps is defined as "the speed of an ideal pump geometrically similar to the actual pump, which when running at this speed will raise a unit of volume, in a unit of time through a unit of head".The performance of a centrifugal pump is expressed in terms of pump speed, total head, and required flow. This information is available from the pump manufacturer's published curves.

Truckload carriers

[breizh]

Hi USR ,
Take a look at this page :
http://www.gouldspum...m/cpf_0008.html

Hope it supports your query ,
Breizh