Side-Entry Impeller Positioning



Side-Entry drawing by Geoff Graham

 How do we achieve maximum mixing in a side-entry application? It's not by chance, or trial and error. Rules definitely apply here. Let's take a look:

The rule of thumb for positioning a side entry impeller is a minimum of 1/3 the impeller diameter off the wall.

• H = Distance off wall

D = Impeller diameter

“Suction” area = pD x H

“Discharge” area = pD²/4


Suction = discharge in order to avoid “starving” impeller flow.

pD x H = pD²/4
H = D/4

So, for a flat wall H is constant.

For a curved wall, H is going to vary. 1/3 D is pretty close to ¼ D, and as it is slightly longer, more forgiving of wall curvature, etc.

Sharpe Mixers has been sizing side-entry mixers for for many years. These industries include asphalt mixing, pulp & paper, waste water, petroleum, storage tanks and more. How can we assist you? Let us know what your needs are and we can size a side-entry mixer for you today!

Submitted by Steven F. Drury, P.E.