A centrifugal pump is primarily a rotodynamic pump that uses a pivoting impeller to raise the rate of a liquid. Its main role is to switch the energy of a motor to kinetic energy which in turn pressures out the fluid from the pump.
The change in energy takes place in the volute and the impeller. While the volute turns the kinetic energy into pressure, the impeller turns driver energy into kinetic energy.
When the liquid reaches the pump section and the impeller, the centrifugal force is born. The impeller upon revolving turns the liquid present in the hallow imparts centrifugal acceleration and pushes itself outwards. As the liquid makes its way out from the impeller eye, a low pressure is created drawing more water into the impeller.
Multistage Centrifugal Pumps:
A multistage centrifugal pump contains more than one impeller. They can be installed on similar or different shafts. It renders two vital functions – eject large amount of liquid and generate high lead.
If high head is to be achieved, impellers need to be installed on the same shaft in a serial pattern. If large amount of water to be pumped is the primary purpose, then the impellers have to be installed on different shafts.
Three General Categories:
A centrifugal pump is made of three distinct and general categories – axial flow, radial flow and mixed flow. Radial flow is one where pressure is boosted by centrifugal force. Mixed Flow is one where pressure in increased by centrifugal force and lift of impeller’s vanes on the fluid. Axial flow is one where pressure is increased by lifting action or propelling action of the impeller’s vane on the liquid.
Impeller and Shafts: Important Parts
Both impeller and shafts form vital parts of a centrifugal pump because speed is essentially used to identify impellers dependence on their types and proportions. Shafts are made of shaft sleeves that extend to outer facade of seal gland plate to prevent shaft from corrosion, erosion and wear.
The CRI centrifugal pumps are widely categorized as Centrifugal monoblock pumps – designed to deliver high performance with low temperature rise resulting to increased durability, the monoblock CT/CF series – designed to function in heavy voltage fluctuations and the CRI regenerative pumpsets – feature non-self priming with end suction and radial delivery.