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Calculating the Effect of Baffles on Power Calculations

Q: Agitator power calculation formula does not include Baffle's size or width, but it definately affects. How to calculate the effect of Baffles on Power Calculations?

A:

The effect of baffles on power is much less than the effect of impeller type and size.  Standard baffles are 4 baffles, 1/12 of the tank diameter.  If the factor for 4 standard baffles is 1.0, then the power factor for 3 baffles is 0.90, 2 baffles is 0.77, 1 baffle is 0.6, and no baffles is about 0.3.  With no baffles in low viscosity, the factor changes with rotational speed because of swirling or solid body rotation.  Higher viscosity, especially over 10,000 cp, without baffles probably has the same effect as full baffles.  The effect of baffle width is similar to the effect of number of baffles. 

The best estimate of baffle effect is in proportion to the baffle area. Shortened baffles will have some combined effect, depending on where they are with respect to the impeller.

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