Centrifugal pump is a type of turbomachinery which is dynamically axisymmetric and work absorbing in nature.
In more simpler terms it’s a pump which is used to lift liquids from a lower area to a higher area.
Its most widely used in industries where sensitive fluids as in chemical industries are required to be moved.
The basic principle of centrifugal pumps is the conversion of rotational kinetic energy to hydrodynamic energy of fluid movement.
The fluid enters through the pump impeller near the rotating axis and gets accelerated reaching the desired destination.
Parts of a centrifugal pump :
Rotating Parts :
Impeller:
It is the heart and soul of a centrifugal pump it has following subtypes.
Open Impeller:
This impeller does not have a crown and base plate, it finds wide application where physical impurities in the liquid to be pumped has to be kept at bay.
Closed Impeller:
It is completely covered with no scope of any foreign body entering. Widely used for pumping water.
Semi-Open Impeller:
Lacks a crown plate and is suited for fluids which might have charged debris in them.
Shaft:
This is the component which is responsible for the rotation of the impeller. It also transmits torque to the impeller and keeps it in sync with other components of the centrifugal pump.
Shaft Sleeve:
Its a covering for the shaft assembly and protects the unit from corrosion. Its open from one end.
CENTRIFUGAL PUMP
Casings:
Casings used in a centrifugal pump are of two types: the volute casings and vortex casings.
Volute casings are funnel-shaped and are designed to reduce the overall pressure of the fluid on the shaft of a centrifugal pump.
It acts as a safety measure and keeps the fluid velocity in check, on the other hand, vortex casings have vanes which convert the kinetic energy into pressure.
Suction Pipe:
It’s a pipe which connects the source of the fluid or the liquid to be pumped to the centrifugal pump.
Generally, the lower end of the pipe which gets dipped in the fluid has a strainer which acts as the first line of defence for debris and other non desired material from entering the pump.
Also, a valve is present which only allows the upward movement of the fluid.
Types of centrifugal pumps-
Vertical Centrifugal Pumps:
They are also known as cantilever pumps, they are unique in design as it allows for the volute to hang in the sump while keeping the bearings outside the sump.
Froth Pumps:
It is a kind of open impeller centrifugal pump and is widely used in minerals industry or the industries where keeping the impurities at bay becomes crucial.
In mining for minerals, a lot of froth is generated, this froth over the course of time generates air which blocks the conventional pumping setup, froth pumps act as a remedy to this problem.
Multistage centrifugal pumps:
Its the most complex type of centrifugal pump and has a unique configuration.
In this type of pump, the impellers can be mounted on a single shaft or on multiple shafts depending upon the use.
This pump also has many stages of fluid movement. In every stage, the fluid is moved to centre before getting discharged.
In case of higher pressures the impellers are connected in series and for the higher output, they are connected in parallel.
Advantages of centrifugal pump :
No leakage issues.
Can be used for pumping sensitive fluids like petrol and diesel.
No loss of power due to friction.
Economical to operate
Disadvantages :
At times clogging of pipes may occur
Any external vibration can damage the pump
Low flow may cause overheating
Risk of cavitation is high.
