Brief Introduction to Axial Flow Pumps.

1. How The Axial Flow Pumps Work? 

Firstly, the fluid enters the pump through its suction nozzle and reaches the pump body, then comes into contact with the blades of the propeller. The rotation of the propeller causes the fluid to move axially. The key parameters such as the diameter of the propeller, the rotation direction and the blade angle jointly determine the flow rate, the direction of the fluid and the outlet pressure of the pump. As the propeller rotates, the kinetic energy of the fluid is instantaneously converted into pressure energy, and thus the fluid pressure increases proportionally with the increase in rotational speed. Once the fluid reaches the required pressure level, it will be discharged through the propeller of the axial flow pump.

Overall, the axial propeller pump accelerates the fluid from the suction nozzle to the discharge nozzle by rotating its propeller blades. Because of this feature, the axial flow pump is widely used in applications where require big flow rates and relatively low head.

2. Typical Structure of Axial Flow Pumps

The axial flow pump is mainly composed of the pump body, the propeller, the pump shaft and the mechanical seal. The propeller is installed at the suction of the pump, while the pump elbow works as the casing to contain all the internal components. These components work together to guide the fluid flow and generate pressure within the pump.

2.1  Suction & Discharge 

The suction and discharge directions of the axial flow elbow pump can be tailered made and can be interchanged by changing the direction of propeller. In most of the cases, the axial propeller pumps adopts a structure with end suction and top discharge, but other configurations are also available for selection to meet specific application needs.

2.2 Propeller

The propeller is the essential component of the axial-flow propeller pump, which features the multiple inclined blades installing on the propeller hub. The propeller blades interact with the fluid during the rotation of shaft, creating a flow long the shaft to the discharge of pump.

2.3 Pump Bearings 

The pump shaft is another core component of the entire rotating system, which supporting the propeller as well as the mechanical seal, the shaft of such elbow propeller pumps requires the precise finish-machining to bear the stresses created by the rotation. The bearings of axial flow pumps function as the holder of rotating components including the propeller, mechancial seals, shaft...

2.4 Shaft Sealing 

There are several types of shaft sealing for an axial flow pumps, mainly include the packing seal, mechanical seal and dynamic seal. However, due to the restrictions of environment-protection regulations, packing seal is not allowed to be used, as the axial flow pumps mainly handle the corrosive and harsh fluids which may lead severe pollution to the environment once leakage happens. On the other hand, the mechanical seals are the proven sealing method for most of the applications of axial flow propeller pumps.

2.5 Bearing Frame & Base Plate 

The bearing frame of an axial flow pump serves as the fixed structure for the pump bearings and the pump shaft, and it is also connected to the pump elbow. The base plate acts as the installation platform for the pump and the motor, integrating all the main pump components (such as the pump body, bearing frame, and motor) into a complete pump equipment.

2.6 Shaft Sealing,  Flushing System & Bearing Lubrication 

The proper flush plan to the mechanical seal of an axial flow pump must be adopted to avoid the leakage of mechanical seal caused by the high temperature accumulated during the operation. Furthermore, the bearings of axial elbow pump can generate high friction heat after long time and continuous operation, thus, the sufficient lubrication is important to avoid damage to the bearings.

2.7 Driving Part 

The propeller of an axial flow pump is powered by the driving part which mainly is an electric motor, but there are options include a diesel engine or a turbine according to the needs of customers.

3. Features of Axial Flow Pumps 

With optimized design and hydraulic models, the axial flow pumps are able to deliver big volume of fluid while maintain relatively low head at high efficiency.

3.1 Higher Efficiency 

3.11 Less Dynamic Loss.  The short blades of the propeller of the aixal flow pumps are able to reduce the fluid turbulence, and in this way the dynamic losses can be reduced, meanwhile the pump efficiency can be increased.

3.12 Unique Design.  The axial flow propeller pumps are designed and built with advance hydraulic models. The axial flow propeller pumps are designed and built with advance hydraulic models, their propeller and guide vanes are optimized to reduce the turbulence in the pump elbow.

3.13 Higher Energy Conversion.  The streamlined design of the pump elbow and the optimized propeller of axial flow pumps sharply reduce the engergy loss, and lead to higher pump efficiency.

3.14 Sealing & Lubrication.  

The mechancial seal and flush plan is the essential part of an axial flow propeller pump, they function well to prevent leakage to the environment. Meanwhile, the lubricating system keeps the shaft rotating smoothly by maintaining the shaft immersed into lubricating oil the bearing housing.

3.2 Less Maintenance Design. The robust structure and simple design of axial flow elbow pumps is the key factor of less maintenance compared to other types of pumps.

3.3 Flow Adjustability. The adjustable propeller baldes of the axial flow pumps enable themselves to meet various flow rate and discharge head, it is an advantage compared to most of the other types of pumps.

3.4 Flexible Structure Desgin. To meet the different requirements of installation of axial flow pumps, we are able to tailor produce our propeller pumps as horizontal or vertical structure, or we can offer different arrangements for the pump and motor to make sure the elbow pumps are suitable for the restrictions at client's site.

4. What Are the Applications of Axial Flow Pumps? 

4.1 Chlor-alkali Industry: Due to adopting of super duplex stainless steels and Titanium materials, our axial flow pumps have excellent performance in hanlding corrosive and high temperature mediums like calcium chloride, caustic soda, brine and chlorine alkali...

4.2 Lithium Battery Industry:  The axial flow propeller pumps are widely employed in processing lithium due to their excellent capability of handling the conentration of lithium-rich brine.

4.3 Fertilizer Industry: The high-efficiency axial flow elbow pump is the ideal choice for ammonium nitrate and urea evaporators. Its large-flow design boosts heat transfer in multi-effect evaporators and by optimizing forced circulation, lowers energy use versus traditional pumps, directly enhancing fertilizer production efficiency.

4.4 MVR & ZLD:  Axial flow pumps are highly efficient pumping devices which are suitable for demanding applications like MVR and ZLD evaporators for high brine content wastewater and large-scale cooling systems. Their robust structure ensures reliable handling of high-TDS liquids while saving energy.

4.5 Evaporation Crystallization: Specifically designed for precision evaporation systems, the low-speed chemical axial flow pump is an ideal pumping device for crystal-sensitive applications like salt concentration and pharmaceutical production. Its low speed design maintains flow without damaging crystals, while its corrosion-resistant construction ensures reliability with strong acids.

4.6 Irrigation and Flood Control: The capability of pumping big amout of water in a short period of time enables the axial flow pumps to be the ideal pumping devices for flood control and irrigation.

5. What Is The Role of Axial Flow Pumps In Multi-Effect Evaporation Systems?

The axial flow pumps are used for the purpose of forced circulation of pumping fluid between the effects in mult-effect evaporators. Their reliable performance and capability of conveying large amount of fluids in an efficient way enables those axial pumps to be the only choice for circulation of fluids in evaporation systems.

6. What Are The Advantages of Axial Flow Pumps In Evaporation Systems?

6.1 High efficiency: Thanks to the optimized hydraulic models of our axial flow pumps, they can work in an efficient way to transfer the fluids between different effects of an evaporation system.

6.2 Easy Maintenance: Due to the simple and compact design, the axial flow propeller pumps require low maintenance compared to other type of pumps, thus enable the smooth and continuous operation.

6.3 Operation-Cost-Low: Because of the feature of high efficiency, the axial flow pumps require lower power consumption compared to other design of pumps, therefore can save a lot of cost during operation.

6.4 Crystal Protection Ability: With the feature of low speed design of axial flow elbow pumps, the crystals in the fluids would not be damaged during the operation of pumps, thus the quality of brine products will be improved.

7. Summary 

Axial flow pumps play an essential role in evaporation industries including ZLD, MVR and multi-effect evaporation systems. Their capacity to manage large volume of fluid while consuming minimal energy positions them as an efficient and economical solution for evaporation industries. By gaining insight into their design, structure, operation, and benefits, you can make the right decisions to enhance process efficiency and realize substantial cost reductions.