What Is The Essential Difference Between Mixed Flow Pump And Centrifugal Pump?
Nov 13, 2025
In the field of fluid machinery, mixed flow pumps and centrifugal pumps are two common pump types. They play important roles in many industrial and civilian fields. Understanding their essential differences is crucial for selecting and using these devices correctly.
1, Structural differences
(1) Impeller structure
Mixed flow pump
The impeller shape of a mixed flow pump is between that of a centrifugal pump and an axial flow pump. Its blades are twisted, with both the radial extension of centrifugal pump blades and the axial extension of axial flow pump blades. This blade shape causes the fluid of the mixed flow pump to be subjected to both centrifugal and axial forces during operation. For example, some common mixed flow pump impellers have blade outlet placement angles generally between 20 ° and 60 °, which can affect the performance characteristics of the mixed flow pump.
The impeller blades of centrifugal pumps are usually radial or curved backwards. The blades mainly generate centrifugal force, which throws the fluid from the center of the impeller towards the edge of the impeller. The placement angle of the blade outlet of the centrifugal pump impeller is generally greater than 90 °, and some even close to 180 °, which allows the fluid to obtain a large centrifugal force in the impeller.
(2) Pump body structure
Mixed flow pump
The pump body of mixed flow pumps is mostly a volute structure, but compared with the volute of centrifugal pumps, its throat area is larger. This structure helps to better balance radial and axial forces during fluid flow, while also adapting to the characteristics of both radial and axial fluid flow in mixed flow pumps. In addition, the inlet and outlet of mixed flow pumps are usually on the same axis or have a certain angle to adapt to different installation and operation requirements.
The pump body of centrifugal pumps is also mostly a volute structure, but the throat area is relatively small. The inlet of a centrifugal pump is usually located on the side of the pump body, and the outlet is located on the top or side of the pump body, which is different from the layout of the inlet and outlet pipelines of a mixed flow pump.
2, Differences in Working Principles
(1) Working principle of mixed flow pump
Energy conversion
When a mixed flow pump is in operation, the impeller rotates to drive fluid motion. Due to the twisted shape of the blades, the fluid experiences a combined effect of centrifugal and axial forces in the impeller. Centrifugal force causes the fluid to move towards the edge of the impeller, while axial force pushes the fluid to flow in the axial direction. During this process, both the kinetic energy and pressure energy of the fluid are increased. As the fluid flows from the center to the edge of the impeller, its velocity gradually increases and the pressure also gradually increases.
Flow trajectory
The fluid flow trajectory in a mixed flow pump is an oblique flow between the radial and axial directions. After entering the impeller from the inlet, the fluid flows along the inclined channel of the blade. When flowing out of the impeller, there are both radial and axial velocity components.
(2) Working principle of centrifugal pump
Energy conversion
Centrifugal pumps mainly rely on the centrifugal force generated by the rotation of the impeller to operate. When the impeller rotates at high speed, the fluid is thrown towards the edge of the impeller under the action of centrifugal force. During this process, the velocity of the fluid increases, and the pressure also rises accordingly. Centrifugal pumps mainly convert the mechanical energy input by the impeller into the kinetic energy and pressure energy of the fluid, with the increase in kinetic energy accounting for a large proportion, and then convert the kinetic energy into pressure energy through components such as the volute.
Flow trajectory
The fluid flow trajectory inside a centrifugal pump is radial. The fluid is thrown from the center of the impeller towards the edge of the impeller, and then gradually changes direction along the volute channel of the pump body, flowing out from the outlet.
3, Differences in Performance Characteristics
(1) Flow and head characteristics
Mixed flow pump
The flow rate of mixed flow pumps is relatively large, generally between 100-10000 cubic meters per hour, depending on the pump model and specifications. Its head range is relatively narrow, usually between 10-100 meters. The flow head curve of a mixed flow pump is relatively flat, and within a certain range of head, the impact of flow changes on head is relatively small.
The flow range of centrifugal pumps is also very wide, ranging from a few cubic meters per hour to thousands of cubic meters per hour. The head range of centrifugal pumps is wide, ranging from a few meters to several hundred meters. The flow head curve of a centrifugal pump generally shows a hump shape, with high efficiency near the excellent operating point. After deviating from the excellent operating point, the efficiency will rapidly decrease.
(2) Efficiency
Mixed flow pump
Mixed flow pumps have higher efficiency under medium flow and high head conditions. Due to the characteristics of its structure and working principle, mixed flow pumps can effectively convert the input energy into the effective energy of the fluid when dealing with high flow rates and certain head requirements, with an efficiency generally reaching around 70% -85%.
The efficiency of centrifugal pumps in the high-efficiency zone is also relatively high, usually reaching around 80% -90%. But when the flow rate and head deviate from the optimal operating point, the efficiency decreases rapidly. For example, when the flow rate is below 50% of the optimal operating point, the efficiency of the centrifugal pump may decrease to below 50%.
(3) Cavitation performance
Mixed flow pump
The cavitation performance of mixed flow pumps is relatively poor. Due to the high inlet flow rate and large blade inlet angle of mixed flow pumps, cavitation is prone to occur at the blade inlet. Especially under low head and high flow conditions, cavitation problems are more severe.
The cavitation performance of centrifugal pumps is relatively good. The inlet angle of the centrifugal pump blades is relatively small, and the inlet flow rate is relatively slow, which can reduce the occurrence of cavitation to a certain extent. However, centrifugal pumps may also experience cavitation problems in high altitude, high temperature, or poor suction conditions.
4, Difference in application scope
(1) Application scope of mixed flow pump
Hydraulic engineering
Mixed flow pumps are widely used in irrigation and drainage engineering. For example, in large-scale agricultural irrigation systems, mixed flow pumps can lift water from the source to a higher position and then transport it to various farmland through channels. In terms of drainage, mixed flow pumps can be used to remove waterlogging, especially in areas with relatively flat terrain. Mixed flow pumps can effectively discharge accumulated water.
Urban water supply
In some cities' raw water intake and diversion projects, mixed flow pumps can also be used to transport water from the water source to water treatment plants or urban water supply networks. Especially when a large flow rate and moderate head are required, a mixed flow pump is a more economical choice.
(2) Application scope of centrifugal pump
Industrial sector
Centrifugal pumps are widely used in industries such as chemical, petroleum, and power. In the chemical industry, centrifugal pumps can be used to transport various chemical media such as acids, bases, salt solutions, etc. In the petroleum industry, centrifugal pumps can be used for processes such as crude oil transportation and water injection. In the power industry, centrifugal pumps can be used for supplying circulating cooling water, etc.
Construction field
Centrifugal pumps play an important role in building water supply and drainage systems. For example, in the water supply system of high-rise buildings, centrifugal pumps can lift water from the bottom level pool to the high-rise water tank to meet the water needs of users. In the fire protection system, centrifugal pumps are also important water supply equipment that can provide sufficient water volume and pressure in the event of a fire.
In summary, there are essential differences between mixed flow pumps and centrifugal pumps in terms of structure, working principle, performance characteristics, and application scope. In practical applications, it is necessary to choose a mixed flow pump or centrifugal pump reasonably based on specific operating conditions such as flow rate, head, liquid properties, and other factors. For situations with high flow rates, medium head, and not particularly high requirements for cavitation performance, mixed flow pumps are a good choice; For working conditions with a wide range of flow and head, high efficiency requirements, and sensitivity to cavitation performance, centrifugal pumps have more advantages.