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Pump behavior analysis

A 150mm model pump rotating at 1750 rpm has the following characteristic...

A geometrically similar 200 pump having a similar efficiency curve is used to pump water through...

Also answer this question after you solve the attachment question.

If the size of the pump were 275 mm , then what would its maximum efficiency be?

Please refer to attachment for full problem description.


Solution Preview

Please see the attached files.

Coulson and Richardson, Chemical Engineering, Vol 1

To do this problem, you need to know well the affinity laws, which enables calculation of flow, head, total power and NPSH when changes are made to both impeller diameter and pump speed the equations can be combined to:

where D= impeller diameter and N=impeller speed

Most of the solution comes from graphical determination so you will see minor variation of the results. This does not mean they are inaccurate!

I have plotted the graph in the attached Excel file.

1. Flow, head and power required to drive the 200mm pump
First you plot the pump ...

Solution Summary

The solution provides detailed and step-by-step explanation and answer (including graphs) for the problem.