P = Kp * μ * N² * D³ (where Kp is the laminar power constant).
P=Np⋅ρ⋅N3⋅D5cap P equals cap N sub p center dot rho center dot cap N cubed center dot cap D to the fifth power = Power (Watts) = Rotational speed (revolutions per second) = Impeller diameter (meters) agitator design calculation xls repack
Next comes the core: hydrodynamic sizing. The repack lays out familiar correlations—power number (Np) tied to impeller type, Reynolds number to determine flow regime, and impeller diameter as a fraction of tank diameter. Behind the scenes, formulas dynamically switch between laminar and turbulent regimes, swapping in the correct Np and flow coefficient. Conditional formatting highlights when an assumed regime changes, nudging you to review assumptions. P = Kp * μ * N² *
Several industrial incidents (reported in CFM magazine) traced miscalculated agitator shafts to pirated spreadsheets. Once power is determined, the shaft must be
Once power is determined, the shaft must be sized to withstand both torque and bending moments to prevent mechanical failure. : Calculated as is power in kW and Shaft Sizing : The equivalent bending moment ( Mecap M sub e
The XLS repack tool provides calculations for:
In the world of chemical engineering, pharmaceutical manufacturing, and wastewater treatment, the agitator (or mixer) is the unsung hero. It ensures homogeneity, suspends solids, disperses gases, and enhances heat transfer. However, designing an agitator is not a matter of guesswork. It requires rigorous calculations involving power numbers, Reynolds numbers, impeller selection, and baffle configurations.