Working Principle of Vertical Multistage Centrifugal Pumps

Working Principle of Vertical Multistage Centrifugal Pumps

Summary

A vertical multistage centrifugal pump is a specialized variant of centrifugal pumps, characterized by its vertical axial layout.

It is primarily designed for conveying clean water and liquids with physical and chemical properties analogous to clean water.

What you can do with it?
A vertical multistage centrifugal pump is a specialized variant of centrifugal pumps, characterized by its vertical axial layout. It is primarily designed for conveying clean water and liquids with physical and chemical properties analogous to clean water (e.g., low-viscosity, non-corrosive, and non-abrasive fluids). With an operating temperature range of T < 80℃, it is widely applied in scenarios including:
1. Industrial and municipal water supply & drainage systems;
2. Pressurized water supply for high-rise buildings (to address insufficient municipal water pressure);
3. Long-distance water transportation projects (e.g., water transfer between reservoirs);
4. HVAC (Heating, Ventilation, and Air Conditioning) refrigeration cycles;
5. Pressurization of cold/hot water circulation systems (e.g., in bathrooms, industrial process pipelines);
6. Matching with auxiliary equipment (e.g., water treatment units, boiler feed systems).

Below is a detailed breakdown of its working principle, structural components, and core design features.
Working Principle
The core mechanism relies on energy conversion driven by centrifugal force, with the following step-by-step process:

1. Energy Input: The mechanical energy of the prime mover (typically an electric motor) is transmitted to the pump shaft, driving the multi-stage impellers (a key distinction from single-stage pumps) to rotate at high speed.

2. Liquid Acceleration: As the impellers rotate, the liquid entering the impeller flow channels (from the pump inlet) is subjected to centrifugal force. This force pushes the liquid outward along the impeller blades, increasing the liquid's velocity energy and static pressure energy simultaneously.

3. Energy Conversion: After being discharged from the impeller, the high-velocity liquid enters the spiral pressure chamber (volute) or diffuser (a component unique to multistage pumps). In this chamber, most of the liquid's velocity energy is converted into static pressure energy (via gradual expansion of the flow channel), further boosting the liquid's pressure.

4. Continuous Circulation: For multistage designs, the pressurized liquid from the first-stage impeller flows into the next-stage impeller inlet, repeating the acceleration and pressure-boosting process—this is how the pump achieves high outlet pressure. Meanwhile, the discharge of liquid from the first-stage impeller creates a vacuum (low-pressure zone) at the pump inlet. Under the action of atmospheric pressure (or the static pressure of the suction tank), the liquid in the suction pool is continuously pressed into the impeller inlet, forming a stable, continuous liquid conveying cycle.