Help for calculating the impeller tip speed to avoid excessive erosion due to suspended particles


Applets are programs based on the java language that are designed to run on your computer using the Java Run Time environment.


The maximum impeller tip speed is based on tests that were done by the Hydraulic Institute www. pumps.org. You can find more information in The Hydraulic Institute's Centrifugal Pumps for Design and Application ANSI/HI 1.3 standard.


This applet is designed to help you calculate the tip velocity of an impeller vane with the simple v = wr formula.


The recommendations on the maximum tip speed are as follows:

- dirty water - 130 ft/s

- medium slurries up to 25% solids and 200 micron solids - 115 ft/s

- higher slurry concentrations and larger solids - 100 ft/s

- pumps with elastomer impeller - 85 ft/s


Tip speeds that are higher than recommended are likely to cause excessive erosion. Elastomer impellers are often used in the mining industry for the transfer of tailings which is a highly abrasive slurry.


The equation used for calculating tip speed is:

where

v: velocity

D: impeller diameter

RPM: revolutions per minute