Francesco di Giorgio Martini

Advantages and Disadvantages of Centrifugal Pumps • Centrifugal Pumps are the most widely used type of pump for the transfer of liquids. There are many advantages and disadvantages associated with Centrifugal Pumps: • Advantages: – Simple operation. – Low first cost and maintenance. – Insignificant excessive pressure build up in casing. – Impeller and shaft are the only moving parts. – Quiet operations. – Wide range of pressure, flow and capacities. – Utilize small floor space in different positions.
Advantages and Disadvantages of Centrifugal Pumps Continued….. • Disadvantages: – High viscous liquids are not handled well. – Centrifugal Pumps usually don’t have the capabilities of handling high pressure applications in comparison to other types of pumps, i.e., Regenerative turbines. – In general, Centrifugal pumps cannot deliver high pressure without changes in design and are not suitable for high pressure delivery at low volumes except the multistage pumps.
Centrifugal Pump can be defined as a mechanical device used to transfer liquid of various types.As the name suggests, it relies on the principal of Centrifugal force.It converts the energy provided by a prime mover, such as an electric motor, steam turbine, or gasoline engine, to energy within the liquid being pumped.
According to Reti, the first machine that could be characterized as a centrifugal pump was a mud lifting machine which appeared as early as 1475 in a treatise by the Italian Renaissance engineer Francesco di Giorgio Martini.^[3] True centrifugal pumps were not developed until the late 17th century, when Denis Papin built one using straight vanes. The curved vane was introduced by British inventor John Appold in 1851.
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. They are a sub-class of dynamic axisymmetric work-absorbing turbomachinery.^[1] 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 which it exits.
Common uses include water, sewage, agriculture, petroleum, and petrochemical pumping. Centrifugal pumps are often chosen for their high flow rate capabilities, abrasive solution compatibility, mixing potential, as well as their relatively simple engineering.^[2] A centrifugal fan is commonly used to implement an air handling unit or vacuum cleaner. The reverse function of the centrifugal pump is a water turbine converting potential energy of water pressure into mechanical rotational energy
Like most pumps, a centrifugal pump converts rotational energy, often from a motor, to energy in a moving fluid. A portion of the energy goes into kinetic energy of the fluid. Fluid enters axially through eye of the casing, is caught up in the impeller blades, and is whirled tangentially and radially outward until it leaves through all circumferential parts of the impeller into the diffuser part of the casing. The fluid gains both velocity and pressure while passing through the impeller. The doughnut-shaped diffuser, or scroll, section of the casing decelerates the flow and further increases the pressure.
Operation Principals continued.…. • Centrifugal Pump consists of a rotating impeller inside a stationary volute (casing). • Liquid enters the pump through the suction inlet into the eye of the impeller. • The speed of the rotating impeller then forces the liquid out through the discharge nozzle.
Different Types of Impeller The impeller of a Centrifugal Pump can be of three types: • Open Impeller: The vanes are cast free on both sides. • Semi-Open Impeller: The vanes are free on one side and enclosed on the other. • Enclosed Impeller: The vanes are located between the two discs, all in a single casting.
Centrifugal pump Curves- Characteristics • Head and Capacity – A rating curve indicates the relationship between the head (pressure) developed by the pump and the flow through the pump based on a particular speed and impeller diameter when handling a liquid. – As the capacity increases, the total head which the pump is capable of developing decreases. – In general, the highest head the Centrifugal Pump can develop is at the point where there is no flow through the pump.