Agitator Design Calculation Xls Best Jun 2026

The power number is a dimensionless quantity that depends on the impeller type and NRecap N sub cap R e end-sub . The spreadsheet should feature a lookup table for Npcap N sub p based on the selected impeller. C. Power Calculation (P) The power required (in Watts) is calculated as:

To evaluate mixing efficiency, calculate how fast the impeller moves the fluid volume.

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 Wattscap W a t t s Npcap N sub p = Impeller Power Number (dimensionless)

Shaft torque, Bending moments, Stress analysis, Minimum shaft diameter. Static deflection, Critical speed, Modal separation margin. Tab 5: Database / Lookups Npcap N sub p values for flat-blade turbines, hydrofoils, and anchors.

However, the very accessibility of the .xls format breeds significant risk. The most dangerous line in any agitator spreadsheet is the "power number" (Np) input. Np is not a universal constant; it depends on baffle configuration, tank geometry (D/T ratio), impeller clearance, and even viscosity. A spreadsheet that defaults to a standard Np of 5.0 for a Rushton turbine without adjusting for an unbaffled tank will overestimate power by 300-400%. agitator design calculation xls

vt=π⋅N⋅Dv sub t equals pi center dot cap N center dot cap D (e.g., crystallization, blending) Medium Shear: (e.g., heat transfer, gas dispersion) High Shear: (e.g., emulsification) Step 3: Power Consumption Calculation (

Whether the tank is baffled (essential for high-viscosity or turbulent mixing). B. Fluid Properties Density (ρ): Liquid density in

While commercial CFD (Computational Fluid Dynamics) software offers high precision, many engineers rely on a more accessible, transparent, and quick tool: . A well-structured agitator design calculation XLS allows engineers to perform iterative calculations for power number, Reynolds number, pumping rate, and basic shaft sizing in minutes.

For (>10 Pa·s), use anchor or helical ribbon impellers with different Np correlations. The power number is a dimensionless quantity that

( P = 1.37 \times 1000 \times (2.5)^3 \times (0.67)^5 ) → ( P = 1.37 \times 1000 \times 15.625 \times 0.135 ) → ( P ≈ 2,892 , \textW , (2.89 , \textkW) )

The first phase of agitator design focuses on fluid dynamics and power draw. 🔢 Reynolds Number ( NRecap N sub cap R e end-sub

Beyond power, mixing quality depends on flow rate. The spreadsheet calculates: Q = Nq * N * D^3 (where Nq = pumping number, ~0.7 for axial impellers, ~0.3 for radial).

This wasn't just a spreadsheet; it was a repository of fluid dynamics theory condensed into rows and columns. Raj took a deep breath and began entering the data. Power Calculation (P) The power required (in Watts)

Hydraulic forces acting on the impellers create bending stresses on the shaft.

The Power Number is a function of the impeller type and the Reynolds number. The spreadsheet will use IF or VLOOKUP functions to pull the correct Np from a built-in correlation table or chart. For example:

d=(16⋅Ttotalπ⋅τ)1/3d equals open paren the fraction with numerator 16 center dot cap T sub t o t a l end-sub and denominator pi center dot tau end-fraction close paren raised to the 1 / 3 power Ttotalcap T sub t o t a l end-sub

MotorPower(kW)=P⋅Sf1000cap M o t o r cap P o w e r open paren k cap W close paren equals the fraction with numerator cap P center dot cap S sub f and denominator 1000 end-fraction

This is the heart of the spreadsheet. The XLS looks up the based on impeller type and NRe. For a Rushton turbine in turbulent flow, Np ≈ 5–6.