Pump sizing spreadsheet for two simultaneous destinations 2

[drakkkko]

Hi,

I need to sizes a pump with two different simultaneous impultions (i.e. both different tanks elevations and flow rates in one original discharge ).

Unfortunately the company I work for does not have a license for software like fhatom, I can only use excel spreadsheets.

Can someone please be kind to provide me with an excel spreadsheet that can perform this calculation?

Thanks in advance

Regards

 

[1503-44]

You must volumetrically size the pump for the sum of both flows.
Pump Differential Head required is the largest Head of the two destinations.

All you need to do is make one system diagram and plot the curves of both delivery points.

If you have a spreadsheet that will do one destination. Use the combined flow rate. Then do one destination. Save that answer and do the other destination. Save that. The one with the highest Head requirement is what you need to order..

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[pierreick]

Hi,
Download from Internet PSIM2 for this kind of calculation (free): pump system improvement modeling tool .
A bunch of examples are available to start.
Good luck
Pierre

 

[katmar]

If you have a spreadsheet that will do one destination. Use the combined flow rate. Then do one destination. Save that answer and do the other destination. Save that. The one with the highest Head requirement is what you need to order..

This wording is confusing. It could easily be taken to mean that you should calculate the pressure drop for each destination at the combined flow, which would horribly overestimate the pressure drop. What you need to do is to calculate the pressure drop through each line individually, using just the required flow rate for that line. It is correct that you would then select a pump that can deliver the highest head requirement, but at the combined flow.

You would of course have to install a valve in the line with the lower pressure drop to dissipate the additional head since the pump is providing more head than is required to provide the necessary flow. Without this valve the line with the lower pressure drop will deliver too much flow and the other line will be starved.

Katmar Software - AioFlo Pipe Hydraulics

http://katmarsoftware.com

"An undefined problem has an infinite number of solutions"