) combines the torque and the lateral force (jamming force) applied to the impeller . : Shaft diameter ( FScap F cap S : Factor of Safety. σysigma sub y : Yield stress of the shaft material . 3. Scale of Agitation
Bending Force (Fb)=Hydraulic Force Factor⋅TqD/2Bending Force open paren cap F sub b close paren equals Hydraulic Force Factor center dot the fraction with numerator cap T sub q and denominator cap D / 2 end-fraction Critical Speed Verification
[ P = Po \cdot \rho \cdot N^3 \cdot D^5 ] Where ( Po ) = Power number (depends on impeller type & Re).
The primary calculation determines the motor power needed based on the fluid's physical properties and the chosen impeller. : : Power consumption (Watts). Npcap N sub p
What are you using (e.g., pitched blade, hydrofoil, anchor)? agitator design calculation xls repack
[ t_blend = k_t \cdot \left(\fracTD\right)^2 \cdot \frac1N ]
A reliable calculation spreadsheet uses a sequential workflow. Each step feeds data into the next mechanical or process formula. Step 1: Define Input Parameters
Use the Excel solver tool to maximize D or adjust N to meet process requirements (e.g., pumping rate ) without exceeding the constraints in Step 1. 4. Key Components of a Robust Agitator Calculation Sheet
), a dimensionless constant unique to each impeller geometry (e.g., for a Rushton turbine, ) combines the torque and the lateral force
: For laminar flow (low Reynolds numbers), the Power Number is adjusted using the formula 2. Torque and Shaft Diameter
: Standard practice is to add 10% for gland losses and 20% for transmission losses to select the final motor horsepower (HP). 4. Shaft Mechanical Design
Once the spreadsheet calculates the raw power, use these three metrics to verify that the mixing intensity matches your process goals: Measures mixing intensity. Mild blending: Intense chemical reactions / Gas dispersion: Pumping Rate (
An agitator design calculation XLS tool is a specialized spreadsheet designed to automate the complex mechanical and process engineering required for industrial mixing systems : : Power consumption (Watts)
. The operating speed should typically be at least 20% away from the shaft's natural frequency to avoid catastrophic vibrations. Impeller Tip Speed: Calculated as
G=PV⋅μcap G equals the square root of the fraction with numerator cap P and denominator cap V center dot mu end-fraction end-root is the liquid volume. 3. Mechanical Design and Safety Factors Once the process requirements dictate the impeller size ( ) and speed (
Shaft diameter, critical speed analysis, deflection checks.
Quickly change D (diameter), N (speed), or ρ (density) to see real-time changes in power and torque.