1. What is the Agitator Power Equation?

The Agitator Power Equation calculates the power required to operate an agitator or mixer in fluid systems. It relates power consumption to fluid properties and agitator geometry, providing essential data for equipment selection and energy optimization.

2. How Does the Calculator Work?

The calculator uses the agitator power equation:

Where:

• \( P \) — Power required (W)
• \( N_p \) — Power number (unitless)
• \( \rho \) — Fluid density (kg/m³)
• \( N \) — Rotational speed (s⁻¹)
• \( D \) — Impeller diameter (m)

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

3. Importance of Power Calculation

Details: Accurate power calculation is essential for proper motor selection, energy efficiency optimization, process design, and ensuring adequate mixing performance without equipment overload.

4. Using the Calculator

Tips: Enter power number based on impeller type and flow regime, fluid density in kg/m³, rotational speed in revolutions per second, and impeller diameter in meters. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What are typical power number values?
A: Power numbers range from 0.2-5.0 depending on impeller type. Radial flow impellers typically have higher power numbers than axial flow impellers.

Q2: How does viscosity affect power requirements?
A: Higher viscosity fluids require more power for equivalent mixing. The power number may change with Reynolds number in transitional and laminar flow regimes.

Q3: What is the significance of the speed cubed relationship?
A: The cubic relationship means that doubling the rotational speed increases power consumption by a factor of eight, highlighting the importance of speed control for energy efficiency.

Q4: When is this equation most accurate?
A: The equation is most accurate in fully turbulent flow conditions (Re > 10,000) where power number becomes constant and independent of Reynolds number.

Q5: How do baffles affect power consumption?
A: Baffles typically increase power consumption by preventing vortex formation and ensuring effective energy transfer to the fluid, increasing power number by 20-50%.