Centrifugal pum and viscous effect 1

[Vic123]

I have 2 centrifugal pumpS having bep at capacities OF 100gpm and 500 gpm respectively. The impellers have the same outer diameter.
My question is in viscous applications(say 500cP) which pump should have the least drop in head and flowrate(when comparing BEP IN OIL to BEP IN WATER).

 

[25362]

The Pump Handbook by Karassik et al, McGraw-Hill, is a good source on this subject and brings an exemplified application of the chart published by the Hydraulic Institute.

However, this chart should be used as a rough indication for radial flow pumps with Newtonian fluids, and not as basis for quantitative predictions of a given pump performance when switching from water to a viscous fluid.

For a wider discussion on the effects of viscosity:

thread407-159572
thread407-70097
thread407-85933

 

[Artisi]

Generated head from a centrifugal pump does not change due to a change of specific gravity - a pump capable of 100 metres head on water at SG 1 will generate a head of 100 metres on a product of S.G 0.9 or 100 metres on a product with an S.G. of 1.2, but, discharge pressure will be effected as will the power input by the change of S.G.

For viscous products - a change of viscosity will effect Head, quantity, efficiency and power input compared to the water curve.

Naresuan University
Phitsanulok
Thailand