Understanding Liquid Entry in Centrifugal Pumps

A centrifugal pump is a type of pump used to move liquids by converting rotational kinetic energy into the hydrodynamic energy of the liquid flow. The rotational energy typically comes from an engine or electric motor.

Let's look at how liquid flows through a centrifugal pump:

• Liquid is drawn into the pump through the suction nozzle.
• This suction nozzle is connected to the central part of the impeller, often called the "eye" of the impeller.
• The rotating impeller vanes catch the liquid entering the eye.
• As the impeller spins, it accelerates the liquid outwards towards its periphery due to centrifugal force.
• The liquid leaves the impeller tips at a higher velocity and pressure and enters the pump casing (volute or diffuser).
• The casing collects the liquid and directs it towards the discharge nozzle.

Where Does Liquid Enter the Centrifugal Pump Impeller?

Based on the working principle, the liquid enters the pump at the central point of the impeller. This is the lowest pressure point within the pump during operation, which helps draw the liquid in from the suction line.

Therefore, the liquid makes its way into the pump through the inlet pipe and directly into the impeller's eye, which is located at the centre of the impeller.