Agitator Design Calculation: Xls

Selection menu for impeller type (Rushton, PBT, hydrofoil) and diameter ratio ( Calculation Module: Reynolds number, Power number ( Npcap N sub p ), Torque, and Power ( ) calculation. Results & Validation: Checks if the power-per-volume (

In RPM or RPS (revolutions per second).

kgm3the fraction with numerator k g and denominator m cubed end-fraction

Fh=2⋅TD⋅Fmcap F sub h equals the fraction with numerator 2 center dot cap T and denominator cap D end-fraction center dot cap F sub m M=Fh⋅Lcap M equals cap F sub h center dot cap L Fhcap F sub h : Hydraulic force ( Fmcap F sub m : Hydraulic baffle factor (typically : Shaft length from the lowest bearing to the impeller ( 🪚 Shaft Diameter (

: Type of agitator (e.g., Rushton Turbine , Marine Propeller , or Anchor ) and its diameter ( 2. Process Calculations (Automated Formulas) agitator design calculation xls

=IF(Re_Cell > 10000, "Turbulent", IF(Re_Cell < 10, "Laminar", "Transitional"))

) is at least 20% away from the natural resonant frequency of the shaft to prevent catastrophic vibration. 4. Standard Geometric Ratios for Industrial Mixers

Generate consistent datasheets for procurement. 2. Key Input Parameters for the XLS Tool

An file is a powerful tool that streamlines complex engineering work. By integrating key parameters, correlations, and mechanical checks into a single spreadsheet, you can quickly and confidently move from process requirements to a reliable agitator design. Selection menu for impeller type (Rushton, PBT, hydrofoil)

First, —determining power number (Np), Reynolds number (NRe), and pumping number (Nq). The spreadsheet calculates whether the flow is laminar, transitional, or turbulent based on impeller diameter (D), rotational speed (N), fluid viscosity (μ), and density (ρ). It then computes the theoretical power draw (P = Np * ρ * N³ * D⁵). Second, mechanical design —shaft diameter calculation based on combined torsion (from motor torque) and bending (from hydraulic drag). Third, impeller selection —lookup tables for standard geometries (Rushton turbines, pitched-blade, hydrofoils) with corresponding Np values.

This equation reveals a crucial insight: the impeller diameter ($D$) has an enormous influence, being raised to the fifth power. A spreadsheet will automatically perform this complex calculation, often with an additional (e.g., 20% or 80% loading) to account for unforeseen losses or variations in process conditions.

Whether your application involves ? I can provide the exact dimensionless constants ( Npcap N sub p Nqcap N sub q ) or specialized scaling formulas for your sheet. Share public link

A template usually includes a table to match the calculated power to the next standard motor size (HP or kW). 4. Structuring the Agitator Design XLS The general formula for agitator power

"Great," Miller grunted. "Call the vendor. They'll send a proposal in... three weeks."

The is the central output of the design calculation, as it directly influences the motor size and operating costs. The general formula for agitator power, applicable primarily in the turbulent regime, is:

The Reynolds number is critical because it dictates which power number correlation should be used. Many agitator design spreadsheets will automatically determine the regime and adjust the calculation methodology accordingly.

= (Density_Cell * Speed_Cell * (Impeller_Dia_Cell^2)) / Viscosity_Cell

This article is for educational purposes. Always consult with mixing equipment manufacturers and perform detailed mechanical engineering analysis for final design and safety-critical applications.