How to Calculate Lobe Pump Head

You need to refer to any hydraulic handbook to see how the prssure loss is calculated.

However, the equations refer to Newtonian liquids only.Sauce is thixotropic in nature and the laws of Newtonian liquids should not be applied directly.

I have calculated the pr drop based on the data you have submitted.

For a 1-1/2 " pipe dia the loss is 38 MWC or 3.8 bar,while for a 2" line it will be approx 17 MWC or 1.7 bar.

For accurate determination,you need to test run the pump in known straight length of pipe for a known flow rate.It is then possible to extrapolate the results for other dia pipes and flow rates.

You could use the following formula:

1) friction loss (m) = flow rate USPM x equivalent length of pipe(m) x viscosity in cP/1587 x d^4

where d is inches

conversion of 500 lph to USPRM is 2.2

2) To the result (1) add 6 metres of vertical run.

3)multiply the result in (20 by sp.gravity to obtain MWC equivalent

4) divide result (3) by 10 to get pressure drop in bar.

Chuck Cowlagi