1. The main differences between chemical axial flow pumps and mixed flow pumps
1). Impeller structure and working principle
The axial flow pump uses a propeller impeller. The liquid mainly flows along the pump axis and relies on the lift generated by the blades to transport the liquid. It is suitable for large flow and low head conditions.
The mixed flow pump uses an oblique flow impeller. The liquid has both axial and radial velocity components at the impeller outlet, and has the hydraulic characteristics of an axial flow pump and a radial flow centrifugal pump.
The main difference between the two lies in the flow direction of the impeller outlet and the matching relationship between flow rate and head.
2). Comparison of main technical parameters
Comparative projects | Chemical axial flow pump | Chemical mixed flow pump |
|---|---|---|
Impeller type | Propeller type | Oblique flow type |
Liquid flow direction | Mainly along the axial direction | Axial and radial combination |
Flow characteristics | Particularly suitable for extremely large flow rates | Suitable for large flow rates |
Head characteristics | Low lift | Low to medium lift |
Typical single-stage lift | Usually about 1–15 m | Can cover about 5–60 m |
Performance characteristics | Obvious advantages in low-lift conditions | Both flow and lift |
Common applications | Evaporation crystallization, forced circulation | Cooling circulation, process transportation |
Note: The above lift is the technical reference range of the pump type and is not a guaranteed parameter for Leap's specific products. The actual performance should be based on the model curve, rotation speed and working conditions.
2. How to choose a pump type based on flow rate and lift?
1). Large flow rate and low head give priority to axial flow pumps
For systems such as evaporator forced circulation and crystallizer circulation, the process requirement is often to maintain a large circulation flow rate rather than transporting liquid to a higher position.
If the total head of the system is low, it is usually easier for an axial flow pump to match such working conditions.
For example, if the design flow of a chemical circulation system is 3000 m³/h and the head is 4 m, the axial flow pump can be evaluated first, but the medium density, cavitation conditions and performance curves still need to be checked.
2). Consider a mixed-flow pump when the flow is large and the pipeline resistance is high
When the system has long delivery pipelines, heat exchangers, filtration equipment or a certain static head, a mixed-flow pump may be more suitable.
For example, for a circulation system with a design flow of 2000 m³/h and a head of 20 m, a mixed-flow pump can be listed as a candidate.
The above two working conditions are only examples of selection and do not represent the rated parameters of specific product models.
3. What chemical applications are axial flow pumps and mixed flow pumps suitable for?
1). Typical applications of chemical axial flow pumps
Forced liquid circulation in evaporation and crystallization devices
Large flow process circulation in salt chemical industry and fertilizer production
Suitable When crystal-containing suspension circulation under structural configuration
Other large-flow, low-lift chemical circulation systems
For media containing solid particles, additional confirmation of the allowable particle size, concentration and wear resistance requirements is required.
2). Typical applications of chemical mixed flow pumps
Chemical plant circulating cooling water system
Large-scale process water delivery system
Circulating system with a certain static head
Industrial devices that require both large flow rate and certain pipeline resistance
If the working conditions require higher head, the radial centrifugal pump should also be included in the selection comparison.
4. Frequently Asked Questions about Purchasing Axial Flow Pumps and Mixed Flow Pumps
1). Is a mixed flow pump necessarily more efficient than an axial flow pump?
Not necessarily. Efficiency mainly depends on how well the pump type matches the actual operating point.
Axial flow pumps may have better operating efficiency under suitable low head and large flow conditions; mixed flow pumps may have more advantages under higher head conditions.
2). Can axial flow pumps replace mixed flow pumps?
Substitution can only be considered when the flow, head, NPSH and operating range all meet the requirements. Direct replacement cannot be made simply because the inlet and outlet sizes are the same.
3). What parameters need to be provided when purchasing?
It is recommended to provide flow rate, head, medium name, temperature, density, viscosity, corrosiveness, solid content, inlet liquid level, installation method, power frequency and continuous operation requirements.
For special media, material compatibility and sealing requirements should also be provided.
5. How to reduce the risks of chemical pump procurement and operation?
Purchasers should require suppliers to provide complete performance curves, efficiency data, shaft power, NPSHr and material configuration instructions.
For continuous operation devices, emphasis should also be placed on evaluating the pump's allowable operating range, ease of maintenance, shaft seal scheme and spare parts supply.
In particular, it should be noted that the power and operating stability of axial flow pumps in low flow areas cannot be simply applied to the judgment methods of ordinary centrifugal pumps. Start-up and adjustment programs should be developed according to specific performance curves.
6. Feiyue Pump Industry’s Chemical Pump Selection Solution
Jiangsu Feiyue Pump Industry provides pump product selection support for chemical, petrochemical and industrial fluid transportation projects.
For large flow circulation conditions, buyers can submit flow rate, head, medium composition, operating temperature and installation requirements to Feiyue Pump Industry, and technical personnel will evaluate the applicable pump type and material plan.
