Recirculation - Centrifugal Pump
Recirculation - Centrifugal Pump
(OP)
Hi everybody
I have a pump (manufacturing yet) that in its alternative condition shall handle only 90 m3/h, but its minimum continuous stable flow is 110 m3/h.
Shall I consider a recirculation of 20 m3/h, right?
But my question is: can I consider a recirculation to suction line or must I consider a recirculation to suction tank?
I'm asking this because the suction tank has a high elevation, then I need to increase diameter rotor to meet this alternative condition.
If you need any information to answer me plase let me know.
Regards
I have a pump (manufacturing yet) that in its alternative condition shall handle only 90 m3/h, but its minimum continuous stable flow is 110 m3/h.
Shall I consider a recirculation of 20 m3/h, right?
But my question is: can I consider a recirculation to suction line or must I consider a recirculation to suction tank?
I'm asking this because the suction tank has a high elevation, then I need to increase diameter rotor to meet this alternative condition.
If you need any information to answer me plase let me know.
Regards





RE: Recirculation - Centrifugal Pump
Yes 20m3 is all you need to recirculate.
Look up ARV - automatic re-circualtion valves on this site and you'll get some good information.
I don't understand why you would need to increase the rotor diameter though- the inlet pressure at the pump plus discharge should be more than inlet pressure, unless you have some big losses in the suction line and only a small differential head pump...
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Recirculation - Centrifugal Pump
Considering 340 m3/h (rated flow), the head rated is 24m.
But considering recirculation to suction tank, due to high elevation of this tank, the head is 30m, it's the reason I need to increase rotor diameter.
RE: Recirculation - Centrifugal Pump
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Recirculation - Centrifugal Pump
Pressure loss at suction considering flow 340 m3/h is only 1m, then I won't reduce enough head even considering losses in suction at minimum flow.
My client have suggested this solution with recirculation line to suction tank in discharge line (with control valve), but I think that the solution with automatic re-circualtion valve will be cheaper, right? ARC valve could be cheaper than control valve, and we will have less piping too.
RE: Recirculation - Centrifugal Pump
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Recirculation - Centrifugal Pump
There is no need to have a larger impeller when spill-back to the supply tank, even if the tank is at a higher elevation. The pump differential head will always be added to suction head. You could easily spill-back to the supply tank with the installed impeller as long as the piping losses are not outrageously high.
Johnny Pellin
RE: Recirculation - Centrifugal Pump
RE: Recirculation - Centrifugal Pump
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way