Centrifugal pump minimum flow protection
Centrifugal pump minimum flow protection
(OP)
Hi everybody,
Can anybody please make me aware the importance of the minimim flow circulation required for the centrifugal pump. In which scenario we go for the minimum flow protection.
Is the minimum flow and the recycle flow is same terms for the pump ?
If we have the process requirement of 100 m3/hr and the pump minimum flow is 20m3/hr, then should the pump be 120m3/hr atleast ?
thanks
Can anybody please make me aware the importance of the minimim flow circulation required for the centrifugal pump. In which scenario we go for the minimum flow protection.
Is the minimum flow and the recycle flow is same terms for the pump ?
If we have the process requirement of 100 m3/hr and the pump minimum flow is 20m3/hr, then should the pump be 120m3/hr atleast ?
thanks





RE: Centrifugal pump minimum flow protection
There are various factors that determine the minimum flow rate (MFR) of a centrifugal pump, among them: fluid temperature rise, NPSH rise due to internal recirculation, and, as well, possible increases in vibration, pressure fluctuations and thrusts.
As a long-time pump user my impression is that the MFR is the lowest pump delivery that can be maintained continuously without sustaining damage. Thus the answer would be no, any flow rate greater than the minimum indicated by the manufacturer, would be admissible.
For a lively discussion on the subject of a spillback line see thread407-195091: Design minimum flow line.
RE: Centrifugal pump minimum flow protection
RE: Centrifugal pump minimum flow protection
Similarly the best way to protect the pump is by means of a digital load monitor to trip the pump when minimum flow is reached (a power curve of such units is crudely speaking a straight line curve )
For further information on such devices see www.cdrpumps.co.uk - we recomend them for ALL pump insallations asminimum flow is a common problem in pump installations.
Ash Fenn
www.cdrpumps.co.uk
RE: Centrifugal pump minimum flow protection
http://virtualpipeline.spaces.msn.com
RE: Centrifugal pump minimum flow protection
In the absence of other data, look at the lowest flow at which the family curves published show an efficiency line.
RE: Centrifugal pump minimum flow protection
http://virtualpipeline.spaces.msn.com