1. What is Impeller Diameter?

The impeller diameter is a critical parameter in centrifugal pump design that determines the pump's performance characteristics including flow rate, head, and efficiency. It's the diameter of the rotating component that imparts energy to the fluid.

2. How Does the Calculator Work?

The calculator uses the fundamental impeller diameter equation:

Where:

• \( D \) — Impeller diameter (m)
• \( Q \) — Flow rate (m³/s)
• \( g \) — Acceleration due to gravity (9.81 m/s²)
• \( n \) — Rotational speed (rev/s)
• \( H \) — Head (m)
• \( \pi \) — Pi constant (~3.1416)

Explanation: The equation balances the energy imparted by the impeller (related to diameter and speed) with the energy needed to achieve the required head at the given flow rate.

3. Importance of Impeller Diameter

Details: Proper impeller sizing is crucial for pump efficiency, NPSH requirements, and avoiding cavitation. It affects the pump's performance curve and operating point.

4. Using the Calculator

Tips: Enter flow rate in m³/s, rotational speed in rev/s (not RPM), and head in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How does impeller diameter affect pump performance?
A: Larger diameters generally produce higher heads at the same speed, while smaller diameters produce lower heads but may be more efficient at lower flow rates.

Q2: Can I use RPM instead of rev/s?
A: Yes, but you'll need to convert RPM to rev/s by dividing by 60 before entering the value.

Q3: What's the typical range for impeller diameters?
A: For centrifugal pumps, diameters typically range from 0.05m to over 1m depending on pump size and application.

Q4: Does this work for all pump types?
A: This equation is specifically for centrifugal pumps. Positive displacement pumps use different design principles.

Q5: How accurate is this calculation?
A: This provides a theoretical diameter. Actual designs may vary based on specific efficiency requirements, blade design, and other factors.