Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow. The rotational energy typically comes from an engine or electric motor. In the typical case, the fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber (casing), from where it exits.
Common uses include water, sewage, petroleum and petrochemical pumping. The reverse function of the centrifugal pump is a water turbine converting potential energy of water pressure into mechanical rotational energy.
Centrifugal pumps can be grouped into several types using different criteria such as its design, construction, application, service, compliance with a national or industry standard, etc. Thus one specific pump can belong to different groups and oftentimes this becomes descriptive of the pump itself.
Some of these groups are:
- Based on type of volute
- Based on nozzle location
- Based on orientation of case-split
- Based on bearing support
- Based on shaft connection to driver
- Based on compliance with industry standards
- Based on impeller suction
- Based on number of impeller/s in the pump
- Based on type of volute
Kinetic pumps can be divided into two classes, centrifugal and regenerative. In kinetic pumps a velocity is imparted to the fluid. Most of this velocity head is then converted to pressure head. Even though the first centrifugal pump was introduced about 1680, kinetic pumps were little used until the 20th century.
Centrifugal pumps include radial, axial, and mixed flow units. A radial flow pump is commonly referred to as a straight centrifugal pump; the most common type is the volute pump.
