1. What is a Centrifugal Pump?
A centrifugal pump is a hydraulic machine that converts mechanical energy into hydraulic energy using the principle of centrifugal force. It is widely used to transport liquids such as water, oil, and chemicals.
👉 In simple words:
Mechanical Energy → Kinetic Energy → Pressure Energy
Table of Contents
2. Basic Working Principle
A centrifugal pump works on the principle of centrifugal action.
- When the impeller rotates, fluid enters at the center (eye of the impeller)
- Due to centrifugal force, the fluid is thrown outward toward the casing
- The velocity of fluid increases
- The casing converts this kinetic energy into pressure energy
3. Main Components of Centrifugal Pump
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(a) Impeller
- Rotating part of the pump
- Consists of curved vanes
- Increases velocity of fluid
(b) Casing
- Outer cover of the pump
- Types: Volute casing and Diffuser casing
- Converts velocity into pressure
(c) Suction Pipe
- Connects water source to pump
- Includes foot valve and strainer
(d) Delivery Pipe
- Carries fluid to required height
(e) Shaft
- Connects impeller to motor
- Transmits mechanical energy
(f) Bearings and Seals
- Support shaft
- Prevent leakage
4. Working of Centrifugal Pump
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Step-by-step working:
- Priming: Pump casing is filled with liquid
- Start: Impeller begins rotating
- Suction: Low pressure created at impeller eye
- Acceleration: Fluid moves radially outward
- Energy Conversion: Velocity energy → pressure energy
- Delivery: Fluid discharged through delivery pipe
5. Types of Centrifugal Pumps
(1) Based on Number of Stages
- Single-stage pump
- Multi-stage pump
(2) Based on Impeller Type
- Closed impeller
- Semi-open impeller
- Open impeller
(3) Based on Casing
- Volute pump
- Diffuser pump
6. Important Terms
- Priming: Filling pump with liquid before operation
- Cavitation: Formation of vapor bubbles due to low pressure
- Manometric Head: Actual head developed by pump
- Efficiency: Ratio of output hydraulic power to input power
7. Advantages
- Simple construction
- Low maintenance
- Smooth and continuous flow
- Suitable for large discharge
8. Disadvantages
- Requires priming
- Not suitable for very high head (single stage)
- Efficiency decreases with viscous fluids
- Cavitation may occur
9. Applications
- Water supply systems
- Irrigation
- Firefighting systems
- Chemical industries
- Power plants