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How do I determine the mixer design size of the impeller, the baffle plates and motor?

Q: I have a formalin flat-bottom tank made of stainless steel and the size of 8m (height) and 4.570 diameter wide. The formalin viscosity is very low -- close to water. How do I determine the size of the impeller, the baffle plates and motor?

A:

A satisfactory mixer design for this application would be two (2), four-blade, pitched-blade turbine impellers, mounted at reasonable vertical locations for your normal operating liquid levels.  The impellers should be 1.4 meters in diameter and rotate at 45 rpm.  The motor should be 11 KW.  Because of the low viscosity, the tank must have baffles.  Four baffles approximately 0.38 meters wide should work well.  The shaft design must be of sufficient strength to handle torsional and bending loads associated with the mixer operation and the support structure for the mixer needs to be rigid enough to prevent excessive motion of the mixer.

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N = impeller speed
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The divisor is known as Kmix

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