Multiple pumps in a system, trying to determine individual flows

[birkATO]

I have an interesting problem here:

I am working dewatering pumps. There are three 9 stage pumps pumping water into a 30" pipe. This 30" pipe goes about 6000 ft, then has a 12" line tapped into it, which splits again into a 5" and 1.5" pipe. The remainder of this water continues up the 30" pipe until it gets to a "Y" conenction where it joins the flow from another set of pumps. The combined flow continues up another length of 20" pipe, goes through a section of 30" pipe, then back to 20", where it finally exits and we know an approximate flow rate. The other set of pumps that combines at the "Y" are from three 4 stage pumps, which pump into a 20" line for about 5000 feet where it joins up with the other flow at the "Y". I do have pump curves for both types of pumps. I know approximate flow out of the system. Is there a way to figure out which percentange of water is flowing from each set of pumps? I need to know how much water is being pumped by the 9 stage pumps versus the 4 stage pumps. I haven't worked on pump systems with that many variables. I especially don't know how to figure the flow out of the two smaller taps into the main line since the system has discharges at different elevations.

 

[Artisi]

You seems you are clouding the issue with all this information. The simple solution is to measure the flow at each pump at the operating conditions -- simple, direct and accurate.

Contact a flow measuring equipment manufacturer / supplier for ways of measuring the flow or find a company that offers this service of measuring onsite flows.

Naresuan University
Phitsanulok
Thailand

 

[katmar]

If you have pump curves available, surely all you need is to know the differential pressure across each pump and you have your answers? If you can get the power / current for each pump motor from your control system that would give you a corroborating value. It all depends how accurate you want to be.


Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com