🌀 Agitated Stirred Vessel Mixing & Impeller Power

Calculate agitated stirred tank reactor mixing: shaft power (kW / HP), Power number (Np), impeller Reynolds number, primary pumping rate, 95% blend time, and gassed power reduction.

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated

Agitated Stirred Vessel Mixing & Impeller Power

Fluid Mechanics

📊 Solver Telemetry ● ACTIVE

👁️ Views 42

⚡ Solves 36

💾 Downloads 252 📦 Fortran Code 4.5 KB

📅 Released Jun 2026

⏱️ Latency < 1 ms

🌀 Stirred Tank Reactor Hydrodynamics & Impeller Vortex

Real-time visual simulation: Rotating impeller, wall baffles, and circulation mixing streamlines

📝 Configuration & Presets

⚡ Rushton Gas Dispersion (180 rpm) 🧪 Fermenter Pitched Blade (120 rpm) 🍯 High-Viscosity Anchor (8.5 Pa·s) 💧 Water Flash Mixing Propeller

⚙️ Impeller Type & Baffles

Impeller Geometry:

Baffles Configuration:

Impeller Speed N [rpm]:

📐 Geometry (Impeller & Vessel)

Impeller Diameter D [m]:

Tank Diameter T [m]:

Liquid Level Depth H [m]:

🧪 Fluid Properties & Aeration

Fluid Density ρ [kg/m³]:

Dynamic Viscosity μ [Pa·s]:

Gassing Rate Q_g [vvm]: 0.0 for ungassed liquids

Rushton & Nagata Mixing Formulation:
• Impeller Reynolds Number: Re_i = ρ · N · D² / μ
• Shaft Power: P = N_p · ρ · N³ · D⁵ [Watts]
• Pumping Flow Rate: Q_p = N_q · N · D³ [m³/s]
• 95% Blend Time: θ₉₅ = 5.4 / (N · N_p^1/3) · (T/D)².

📊 Mixing Performance Results

📊 Output Summary
💾 Fortran Source

Impeller Shaft Power Demand

0.33 kW (0.45 HP)

Power Number N_p: 1.270 | Re_i: 26250

θ₉₅ = 22.4 s

95% Homogenization Time 22.4 s 0.37 minutes

Primary Pumping Rate (Q_p) 711.0 m³/h 197.5 L/s

Impeller Tip Speed 3.14 m/s Shear intensity index

Flow Regime in Vessel TURBULENT Re = 26250

📈 Shaft Power P (kW) vs Impeller Speed N (rpm)

📉 Blend Time θ_95 (s) vs Impeller Speed N (rpm)

=================================================================
 THERMOFLUIDCALC — AGITATED VESSEL MIXING & POWER REPORT
=================================================================
Case Title                 : Biopharmaceutical Fermenter Pitched Blade Turbine
Impeller Geometry          : Pitched Blade Turbine 45° (Axial-Radial High-Flow)
Vessel & Speed             : Speed N = 120.0 rpm (2.00 rev/s), D = 0.50 m, Tank T = 1.50 m, Depth H = 1.50 m
Fluid & Aeration           : Density = 1050.0 kg/m3, Viscosity = 0.0200 Pa.s, Gassing = 0.00 vvm
-----------------------------------------------------------------
IMPELLER SHAFT POWER       : 0.333 kW (0.45 HP)
Power Number (Np)          : 1.2700
Impeller Reynolds (Re_i)   : 26250.0 (Fully Turbulent regime)
Primary Pumping Rate (Qp)  : 711.00 m3/h (197.50 L/s)
95%% Homogenization Time   : 22.4 seconds (0.37 minutes)
Impeller Tip Speed         : 3.14 m/s (Shear Index)
=================================================================

📘 Calculation Methodology & Industrial Mixing Standards

Power Number $N_p$ & Flow Number $N_q$

Governed by dimensionless numbers $N_p = P / (\rho N^3 D^5)$ and $N_q = Q_p / (N D^3)$. Wall baffles prevent central air vortexing and maximize power draw for rapid blending.

Aeration Gassing Reduction Factor

In aerated fermenters and bioreactors, rising gas cavities behind impeller blades reduce effective fluid density and drag, lowering power demand by up to $50\%$.

Key Engineering Assumptions

Standard cylindrical flat-bottom or dished-bottom stirred tank geometry.
Michel & Miller gassed power correlation for gas-liquid dispersions.
Applicable to chemical reactors, biopharma bioreactors, and polymer mixing.

ThermoFluidCalc Engineering Report