Operating principle of centrifugal pump

Working principle of a centrifugal pump - water, moving axially through the suction pipe, enters the rotating impeller. Due to the force of inertia, the water changes its direction of flow - from the center to the periphery of the impeller. Spiraling in the direction of rotation, the water is collected in the volute casing and exits the pump.

The volute casing in the pump housing is designed to discharge the flow coming out of the impeller and convert its dynamic pressure to static pressure. The volute casing, in its shape, resembles a diffuser.

In a centrifugal pump, a double increase in the impeller rotation frequency leads to a double increase in its discharge, a fourfold increase in pressure, and an eightfold increase in energy consumption.

The impeller is mounted on the motor shaft, and the pump housing is attached to the motor housing, forming a single mounting unit.

Pump noise

The higher the rotation frequency and power of the pump, the higher the noise level. Typically, pumps are equipped with motors with a shaft rotation frequency of 2900 and 1450 revolutions per minute.

Motors with a rotation frequency higher than 1500 rpm are called high-speed, while motors with a lower rotation frequency are called low-speed.

Electric motors of low-speed pumps have a more complex construction and, consequently, a higher price. Low-speed pumps are more economical, quiet, and expensive than high-speed ones, so they are installed in systems where noise and operational characteristics are more important than one-time capital expenses.

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