The axial flow pump is a low and high displacement pump that is usually suitable for irrigation and canal installations. There should be some distance between the impeller blade root and the impeller ball to ensure that you can adjust the blade and increase the high-efficiency level. Changing the pressure between the blade surfaces causes leaks in the main bore area, which reduces hydraulic performance and operational stability.
Principle of operation of the axial flow pump
The axial flow pump can be defined as a pump in which the liquid (i.e., water) flows in the axial direction. We use a similarly axial word here. Axial means that the fluid flows in the direction of the rotation axis.
In this type of centrifugal pump, the radial position of the fluid inlet and outlet on its axis of rotation does not change.
Axial flow pumps can be considered as the opposite point of axial flow response turbines.
When we need to provide more flow and relatively low heads, we use axial flow pumps.
Axial Flow Pump Components
The axial pump has the following main components:
There is a central pole on the axial current pump, and on this central axis of the axial current pump, several blades or blades can be installed. Therefore, a central hub with multiple vanes or vanes is defined as an impeller of the rotor or axial flow pump.
The impeller blades are mounted in the center of the axial flow pump so that fluid (i.e., water) can pass axially through these impeller blades.
The impeller rotates inside the cylinder housing. A gap is created between the impeller and the cylindrical body, which should be as small as possible to avoid leaks.
3) Guide Blade
These fixed drive vans are installed at the inlet of the axial flow pump to direct the liquid (i.e., water) to the rotating van correctly and without vibration.
There is also a fixed outlet guide at the outlet of the axial flow pump, as shown in the figure above. The axial flow pump outlet usually has a fixed outlet guide vane to change the direction of movement of the fluid discharge at the impeller outlet.
As the fluid exits the impeller outlet, it produces a vortex velocity component with an axial velocity component. Fixed output pickups reduce rotational speed. After passing through the fixed guides of the exit van, the fluid flows approximately in an axial direction, i.e., parallel to the axis of rotation.
Why do Axial Thrusts occur in centrifugal pumps?
Due to the asymmetry, an axial axis is created in the centrifugal pump. The spaces between the rear of the impeller and the casing cover and the front of the impeller and the casing are filled with high-pressure liquid. The resulting pressure acts on the impeller. Since the dorsal surface is larger than the anterior surface, it creates a pure stimulus that acts in the opposite direction to the flow of fluid. Therefore, the net axial thrust is the difference between the forces acting on the front and rear bumper.
Why are axial-thrust problems challenging to manage?
In an axial, centrifugal pump, the single-suction impeller rotates axially, usually with great force. Understanding the pressure crash principle is easy. However, there are some complex factors and uncertainties that are difficult to determine. Therefore, if there is a problem with axial thrust, it is difficult to determine the cause and correct it.
Understanding Hydraulic Thrusts in Centrifugal Pumps
During the operation of the centrifugal pump, the force of movement of the pumped liquid is converted into pressure. The fluid in the continuous flow of pressure continues to flow along the circumference of the impeller. The fluid also remains in the space between the impeller and the liner.
The high-pressure fluid flow creates two forces, one in the longitudinal direction and the other in the transverse direction, relative to the axis.
Radial thrust: The force created is hereafter referred to as radial thrust. The radial thrust is due to the different pressures created during the movement.
Axial thrust – This is the pressure created in the longitudinal direction. Several areas of the impeller are exposed to the pressurized fluid, which creates an axial force.
Advantages of Axial Flow Pumps
- Designed to process large quantities of raw water
- Suitable for various applications such as flooding and precipitation, large-volume drainage, and using raw water for irrigation.
- There is a lot of water, like a water park.
- Water level control in areas near the coast
- Loading and unloading from dry docks and port facilities
- Fill or empty the tank
- The wastewater is treated
- Extraction of the central cooling water
- Other medium and low/high flow programs.
Application of Axial Pumps
- Evaporation and crystallization cycle for chemicals
- Government wastewater digestion tank
- The general purpose of an axial pump is to pump raw water, control floods, and transport ballast water by ship.
- Axial pumps are used in the flood industry, sugar cane, corn, and sugar evaporators industries.