axial thrust in centrifugal pump|axial thrust flow chart

(1) Close the discharge valve (2) Switch off the driver and observe the pump run down smoothly to a standstill. The pump rotor should not stop with a sudden jerk. (3) Switch off the oil pump. (4) The suction valve should remain open unless the pump is being taken . See more

Centrifugal pumps are widely used in various industries for transferring fluids and are known for their efficiency and reliability. However, one crucial factor that can impact the performance and longevity of centrifugal pumps is axial thrust. Understanding axial thrust in centrifugal pumps, its causes, consequences, and balancing methods is essential for ensuring the smooth operation of these critical pieces of equipment.

The axial thrust is the resultant force of all the axial forces (F) acting on the pump rotor. See Fig. 1 Axial thrust. Axial forces acting on the rotor in the case of a single-stage centrifugal pump. The axial impeller force (F 1) is the difference between the axial forces on the discharge-side (F d)

What is Axial Thrust in Centrifugal Pumps?

Axial thrust in a centrifugal pump refers to the force exerted in the axial direction, parallel to the pump shaft. This force is generated as a result of the pressure difference between the inlet and outlet of the pump, causing the fluid to exert a force on the impeller. Axial thrust is a common phenomenon in centrifugal pumps and needs to be carefully managed to prevent issues such as premature bearing wear, shaft deflection, and reduced pump efficiency.

Causes of Axial Thrust in Centrifugal Pumps

There are several factors that contribute to the generation of axial thrust in centrifugal pumps:

Pump Design

The design of the pump, particularly the impeller and casing geometry, can have a significant impact on the magnitude of axial thrust. Certain pump designs are more prone to generating higher axial thrust forces.

Operating Conditions

The operating conditions of the pump, such as flow rate, pressure, and speed, can influence the axial thrust experienced by the pump. Changes in operating conditions can lead to fluctuations in axial thrust levels.

Impeller Clearance

The clearance between the impeller and the casing plays a crucial role in determining the axial thrust in a centrifugal pump. Improper clearance can result in increased axial thrust and potential performance issues.

Consequences of Unbalanced Axial Thrust

Uncontrolled axial thrust in centrifugal pumps can have several detrimental consequences, including:

Bearing Wear

Excessive axial thrust can lead to increased bearing wear and premature failure of the pump bearings. This can result in costly repairs and downtime for maintenance.

Shaft Deflection

High axial thrust forces can cause the pump shaft to deflect, leading to misalignment issues and potential mechanical failures.

Reduced Pump Efficiency

Unbalanced axial thrust can impact the overall efficiency of the pump, resulting in increased energy consumption and decreased performance.

Balancing Axial Thrust in Centrifugal Pumps

Managing axial thrust in centrifugal pumps is essential for ensuring reliable and efficient pump operation. There are several methods for balancing axial thrust, including:

Axial Thrust Bearings

Axial thrust bearings are designed to counteract the axial forces generated in the pump. These bearings are positioned along the shaft to absorb the thrust and prevent it from affecting other pump components.

Impeller Adjustments

Optimizing the impeller design and clearance can help reduce the axial thrust experienced by the pump. Adjusting the impeller geometry and clearance can help minimize the axial forces acting on the pump.

Operating Conditions Control

Monitoring and controlling the operating conditions of the pump, such as flow rate and pressure, can help manage axial thrust levels. Maintaining stable operating conditions can prevent sudden changes in axial thrust.

Axial thrust in centrifugal pumps occur due to asymmetry. Check out the possible reasons for axial thrust generation and the various measures to rebalance it.

The impeller is the rotating component within the centrifugal pump design, which transfers the energy from the pump’s motor to the fluid. It is made up of vanes that come off an open inlet at the centre, known as the eye, which create a .

axial thrust in centrifugal pump|axial thrust flow chart