Agitator Power Calculation Formula

Agitator Power Formula:

\[ P = \rho \times N^3 \times D^5 \times K \]

Density (ρ):

kg/m³

Rotational Speed (N):

rev/s

Impeller Diameter (D):

Impeller Constant (K):

unitless

Power (P):

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1. What is the Agitator Power Calculation Formula?

The Agitator Power Calculation Formula estimates the power required to operate an agitator or mixer in fluid systems. It is widely used in chemical engineering, pharmaceutical manufacturing, and food processing industries for designing and optimizing mixing equipment.

2. How Does the Calculator Work?

The calculator uses the agitator power formula:

\[ P = \rho \times N^3 \times D^5 \times K \]

Where:

\( P \) — Power (Watts)
\( \rho \) — Fluid density (kg/m³)
\( N \) — Rotational speed (revolutions per second)
\( D \) — Impeller diameter (meters)
\( K \) — Impeller constant (unitless)

Explanation: The formula demonstrates that power consumption is highly dependent on rotational speed (cubed relationship) and impeller diameter (fifth power relationship), making these the most critical factors in agitator design.

3. Importance of Agitator Power Calculation

Details: Accurate power calculation is essential for proper motor selection, energy efficiency optimization, process design, and ensuring adequate mixing performance in industrial applications.

4. Using the Calculator

Tips: Enter fluid density in kg/m³, rotational speed in revolutions per second, impeller diameter in meters, and the appropriate impeller constant. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for the impeller constant K?
A: Impeller constants vary by design: Propeller (0.32-1.0), Turbine (2.5-5.0), Paddle (1.5-2.5). Consult manufacturer specifications for exact values.

Q2: Why is rotational speed raised to the third power?
A: The cubic relationship reflects that power increases dramatically with speed due to increased fluid resistance and energy dissipation.

Q3: How does fluid viscosity affect power requirements?
A: Higher viscosity fluids require more power for the same mixing intensity. The formula assumes Newtonian fluids; non-Newtonian fluids require additional corrections.

Q4: Can this formula be used for all impeller types?
A: Yes, but the impeller constant K must be appropriate for the specific impeller geometry and flow regime (laminar or turbulent).

Q5: What are common applications of agitator power calculations?
A: Chemical reactors, bioreactors, wastewater treatment, food mixing, pharmaceutical production, and paint manufacturing.