Multistage centrifugal pump is a common industrial equipment, widely used in water treatment, chemical industry, petroleum, energy and other fields. It accelerates and transports the liquid by the centrifugal force of the rotating impeller, and has the characteristics of high efficiency and reliability. The multi-stage centrifugal pump consists of multiple levels of centrifugal pumps, each with an independent impeller. When the liquid passes through one level, its pressure will increase and continue to increase at the next level to reach the required working pressure. The structural design of the multistage centrifugal pump is exquisite, which optimizes the efficiency of fluid transfer. A plurality of impellers are arranged on the pump body, and the function of each impeller is similar to an independent centrifugal pump, which can increase the pressure step by step. This structure makes the multistage centrifugal pump able to cope with high lift, large flow conditions.

As a common type of pump, multistage centrifugal pump has the characteristics of high head, stable flow and high operating efficiency, and has been widely used in many industrial fields. When using multistage centrifugal pump, attention should be paid to the installation environment, inspection before operation, maintenance and safe operation to ensure its performance and service life.

In the pump industry, multi-stage centrifugal pump is a common pump type. Its biggest feature is that the impeller is combined in series and installed in a shell. In this way, the lift of the pump can be improved. In many industrial fields, such as electric power, steel, chemical industry, etc., multistage centrifugal pump has been widely used. Below Hunan Sanchang Pump Co., Ltd. will introduce the working principle, characteristics, selection and use of multi-stage centrifugal pumps.

1. features

1. High head: Since the impellers of the multi-stage centrifugal pump are connected in series, its head can be greatly improved. In general, the head of a single-stage centrifugal pump is about 100 meters, while the head of a multi-stage centrifugal pump can reach hundreds of meters or even kilometers.

2. Flow stability: The flow of multi-stage centrifugal pumps is generally stable and will not be affected by many factors like single-stage centrifugal pumps, such as pump speed, medium temperature, etc.

3. High operating efficiency: Due to the complex structure of the multi-stage centrifugal pump, its operating efficiency is relatively high. In many industrial fields, the operating efficiency of multi-stage centrifugal pumps can reach more than 80%.

Convenient maintenance: Although the structure of the multi-stage centrifugal pump is more complicated, its maintenance is relatively convenient. Generally speaking, it is only necessary to regularly check and replace the bearings, seals and other components.

2. selection

When choosing a multistage centrifugal pump, it needs to be selected according to actual needs. In general, the following aspects need to be considered:

1. Brand and price: brand and price need to be considered. Generally speaking, the price of well-known brands is relatively high, but the quality and after-sales service are also better.

2. Operating environment: It is necessary to consider the operating environment of the pump, such as temperature, humidity, dust, etc. These factors will affect the performance and service life of the pump.

3. Power supply and voltage: The power supply and voltage need to be considered. Generally speaking, single-phase power supply can drive motors below 220V, while three-phase power supply can drive motors above 380V.

4. Flow and head: The flow and head need to be determined according to actual demand. Generally speaking, the flow rate refers to the volume of fluid per unit time, and the head refers to the height of the fluid in the pump.

5. Medium characteristics: need to consider the characteristics of the fluid, such as density, viscosity, corrosion and so on. These factors will affect the performance and service life of the pump.

3. working principle

The working principle of multi-stage centrifugal pump is similar to that of single-stage centrifugal pump, but the difference is that the number of impellers is large. When the motor drives the pump shaft to rotate, the blades in the impeller are subjected to centrifugal force during the rotation, and the liquid is thrown out from the center of the impeller and enters the pump housing. A low pressure area is formed in the central part of the impeller, and the fluid is sucked into the pump under the action of pressure. After the action of multiple impellers, the fluid is discharged under the action of pressure.

Application field of 4. multistage centrifugal pump

Multi-stage centrifugal pumps are suitable for conveying high-pressure and large-flow liquids, and are usually used in the following fields:

Power industry: used to transport cooling water, circulating water and other media.

Construction industry: used to transport water supply, drainage and other media.

Petroleum industry: used to transport crude oil, natural gas and other media.

Chemical industry: used to transport various chemical media.

Agricultural industry: used for irrigation, farmland drainage, etc.

Precautions for 5. use

In the use of multi-stage centrifugal pump, need to pay attention to the following matters:

1. Installation environment: The multi-stage centrifugal pump needs to be installed on a flat and solid horizontal ground to avoid vibration and noise caused by uneven ground. In addition, it is necessary to ensure that there are no debris and flammable materials around the pump to ensure safety.

2. Maintenance: Multi-stage centrifugal pumps require regular maintenance, including cleaning impellers, bearings, seals and other components, as well as the replacement of damaged parts. In addition, the motor needs to be inspected and maintained regularly to avoid malfunctions caused by motor failures.

3. Pre-operation inspection: The pump needs to be inspected before operation, including whether the fasteners are loose, whether the bearings are lubricated, and whether the sealing ring is intact. In addition, it is also necessary to check whether the motor is running normally to avoid malfunctions caused by motor failures.

4. Safe operation: Pay attention to safe operation when using multi-stage centrifugal pumps, especially when dealing with flammable, explosive or toxic media. It is necessary to ensure that the skills and knowledge of the operators meet the requirements and comply with the relevant safety operating procedures.