Mixing Power Number: Keep Speed and Diameter Exponents Visible

Define the Process Model

Holding the model coefficients and fluid basis fixed, impeller power scales with N³D⁵. ProQuip’s impeller-power explanation identifies these dependencies and the geometry, viscosity and baffling effects behind its coefficients. A sensitivity calculation deliberately freezes those coefficients; it does not prove they stay fixed after a real layout change.

Compare a Hypothetical Case

In a hypothetical model comparison, a 10% speed increase gives 1.1³ = 1.331, a 33.1% increase in calculated impeller power. A separate 10% diameter increase at the same speed gives 1.1⁵ = 1.611, about 61.1% more. Applying both changes gives a factor of 1.1⁸, approximately 2.144. These are ratios, with no claimed installed kilowatt rating.

Complete the Engineering Review

Ask the supplier to distinguish calculated power at the impeller from drive nameplate capacity. Record which coefficient and fluid conditions were held fixed. If a dimension changes, check whether the impeller-to-tank relationship and Reynolds number still support that coefficient. Keep a spreadsheet sensitivity case separate from the final mechanical sizing case.

For a processing-tank enquiry, attach the actual geometry and required task. The ratios do not establish an acceptable speed increase or motor replacement. They explain why an apparently small geometry change deserves a renewed engineering calculation.

How does a specified power-number model respond to a changed impeller geometry or speed?

This blank worksheet is for your own project. It contains no H M machine trial result.

Customer Questions

Related Equipment References

Review the actual offered equipment and application separately from this educational example.

• processing-tank enquiry

Primary References

These references support the technical principles discussed in this guide. The worked examples and review questions are educational.

• ProQuip’s impeller-power explanation
• processing-tank enquiry