Parts of Centrifugal Pump

Centrifugal pumps are a kind of fluid transfer equipment widely used in industrial and civil fields. Understanding the main components of centrifugal pumps and their functions can not only help us better understand their working principles, but also provide the necessary knowledge support for routine maintenance and troubleshooting.

What is a centrifugal pump?

Centrifugal pump is a kind of fluid conveying equipment that utilizes the principle of centrifugal force to convert mechanical energy into fluid kinetic energy. It is widely used in various industrial fields, such as water treatment, chemical, petroleum, pharmaceutical, electric power, etc. Centrifugal pump is especially suitable for conveying clear water or light liquid.

Working Principle of Centrifugal Pumps

Centrifugal pumps propel liquids by means of a rotating impeller. As the liquid enters the pump casing from the suction port of the pump, the impeller accelerates the liquid by rotating it. The liquid flows under centrifugal force to the outside of the pump casing and is discharged through the pump discharge port. In this process, the rotation of the impeller converts the kinetic energy of the liquid into pressure energy, thus propelling the fluid through the piping system.

Components of Centrifugal Pumps

1. Pump Casing

• Function: The pump casing or volute surrounds the impeller and is responsible for directing the fluid from the impeller to the discharge port. It also converts the kinetic energy of the fluid into pressure energy. The volute shape helps guide the fluid efficiently and reduces energy loss.

2. Impeller

• Function: The impeller is the rotating part of the pump that imparts energy to the fluid, increasing its velocity. As the impeller spins, centrifugal force is generated, pushing the fluid outward and into the pump casing. The impeller plays a key role in providing the flow of the fluid.

3. Suction Eye

• Function: The suction eye is the opening where the fluid enters the impeller. Its design ensures smooth entry of the fluid into the impeller, minimizing the impact of turbulence and swirling, which helps maintain the pump’s efficiency.

4. Suction and Discharge Nozzles

• Function: The suction nozzle is the point where fluid enters the pump, while the discharge nozzle is where the fluid exits. These nozzles connect the pump to the rest of the piping system and are essential for the proper flow direction and fluid delivery.

5. Bearings

• Function: Bearings support the rotating pump shaft, ensuring smooth rotation and minimizing friction. They help keep the shaft and impeller aligned and prevent any unwanted movement, thus enabling smooth operation of the pump.

6. Pump Shaft

• Function: The pump shaft connects the motor or driver to the impeller, transmitting rotational power to drive the impeller. The shaft plays a critical role in transferring energy from the motor to the fluid being pumped.

7. Mechanical Seal

• Function: Mechanical seals or packing prevent the fluid from leaking along the shaft. Modern pumps typically use mechanical seals, while older pumps may rely on packing. These seals ensure that the pump operates efficiently without fluid leakage.

8. Impeller Chamber

• Function: The impeller chamber surrounds the impeller and is where the fluid is accelerated and directed towards the discharge nozzle. It is crucial for converting the kinetic energy of the fluid into pressure as it moves through the pump.

9. Diffuser (Optional)

• Function: In certain centrifugal pumps, a diffuser is used to further convert the velocity energy of the fluid into pressure energy. This component is typically used in high-performance pumps to improve efficiency and ensure better flow management.

10. O-Rings and Gaskets

• Function: O-rings and gaskets are used between various parts of the pump to create seals, preventing leakage and ensuring the pump operates efficiently. These seals help maintain pressure inside the pump and ensure no fluid escapes during operation.

11. Motor or Drive Unit

• Function: The motor or drive unit powers the centrifugal pump, driving the pump shaft and impeller. The motor can be electric, diesel, or steam-powered, depending on the specific application and operational requirements.

Features of Centrifugal Pumps

1. High efficiency and stability
2. Wide range of applications
3. Simple structure
4. Suitable for high flow and low head applications

Types of Centrifugal Pump Systems

Single-Stage Centrifugal Pump

Description: The single-stage centrifugal pump is the most common type of centrifugal pump and has only one impeller (i.e., one pump stage). It is suitable for applications with low flow and head requirements.

Features

• Simple construction, lower cost, suitable for low to medium flow applications.
• oSuitable for lower pressure operating conditions.

Multi-stage Centrifugal Pumps

Descriptions:Multi-stage centrifugal pumps have multiple impellers (pump stages), each of which is coupled to the other stages via the pump shaft, increasing the head by raising the pressure stage by stage.

Features

• High head can be achieved within the same pump, suitable for occasions where higher pressure is required.
• Works more efficiently and is suitable for fluid transportation that requires a larger head.

Open Impeller Centrifugal Pump

Description: Open Impeller Centrifugal Pumps have no closed casing for the impeller and the liquid is in direct contact with the front and rear surfaces of the impeller.

Features

• Suitable for handling fluids containing large particles.
• Impeller is easy to clean and maintain, but relatively inefficient.

Closed Centrifugal Pump

Description: Closed Impeller Centrifugal Pumps have a closed front and back cover on the outside of the impeller, with the fluid flowing only through the center of the impeller.

Features

• Suitable for the transportation of clean liquids with high efficiency.
• Due to the closed design, the flow and head of the pump are more stable.

Vertical Centrifugal Pump

Features

• Small footprint, suitable for space-constrained environments.
• Suitable for occasions such as deep well or deep water pumping.

Self-priming Centrifugal Pump

Description: Self-priming centrifugal pumps are able to automatically draw liquid from the suction piping, avoiding the step of externally filling traditional centrifugal pumps with water.

Features

• No need to be filled with liquid beforehand, suitable for environments with discontinuous liquid supply.
• High suction capacity, suitable for liquids containing gas or foam.

Magnetic Drive Centrifugal Pump

Features

• Prevents leakage and is suitable for transferring toxic, hazardous or valuable liquids.
• Simple maintenance and high efficiency.

Summary

Centrifugal pumps, as indispensable equipment for industrial applications, have core components that perform their respective roles to ensure the efficient and reliable operation of the pump. Understanding these components and their roles not only helps us to better grasp the working principle of the pump, but also provides the necessary theoretical support for pump maintenance and optimization.

AOBL is a manufacturer specializing in the research, development, production and sales of pumps, offering a wide range of pumps, which are widely used in industrial wastewater, electroplating, surface treatment and other fields. If you have any questions about centrifugal pumps or need further information, please feel free to contact us, our expert team will provide you with professional support and solutions.