The document discusses centrifugal pumps. It begins by defining what a pump is and its main purposes and categories. It then focuses on centrifugal pumps, describing their basic components as a casing, impeller, and driver/motor. It explains how centrifugal pumps work by using centrifugal force to increase pressure and flow of a liquid. The document outlines advantages like simplicity and lower costs, and disadvantages like inability to handle highly viscous liquids. It provides examples of impeller types and compares centrifugal pumps to other pump types. Overall, the document provides a high-level overview of centrifugal pump components, working mechanism, characteristics, and comparison to other pumps.

1. Fluid Power Engineering (2151903)
GANDHINAGAR INSTITUTE
OF
TECHNOLOGY
Topic:-Pump
Presented By:
Upadhyay Ayush. 150123119053

2. WHAT IS THE PUMP?WHAT IS THE PUMP?
A hydrodynamic pump machine is a device for converting the energy
held by mechanical energy into fluid
Pumps enable a liquid to:
1. Flow from a region or low pressure to one of high
pressure.
2. Flow from a low level to a higher level.
3. Flow at a faster rate.
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3. There are two main categories of pump:
• Rotodynamic pumps.
• Positive displacement pumps.
Diaphragm
Piston
Plunger
ReciprocatingRotary
Mixed flow
Gear
Lobe
Sliding Vane
Screw
Axial flow
Centrifugal
Rotodynamic
Turbine
Positive displacement
PUMPPUMP
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4. WHAT IS CENTRIFUGAL PUMP?
WORKING MECHANISM OF A CENTRIFUGAL PUMP
ADVANTEGAES AND DISADVANTAGES OF
CENTRIFUGAL PUMPS
CENTRIFUGAL
PUMP

5. Centrifugal pump works on the principle that when a certain mass of liquid is
made to rotate along the impeller from the central axis of rotation, it impresses a
centrifugal head. It causes the water to move radially outwards at higher velocity and
causes the water to rise to a higher level. The motion of water is restricted by casing of
pump, it result into pressure build up. In addition , the change in angular momentum
of liquid during its flow results into increase in pressure head.
The steps involved in operation of centrifugal pump are as follows :
1.The delivery valve is closed.
2.The priming of the pump is carried out. Priming involves the filling the liquid in
suction pipe and casing up to the level of delivery valve so that no air pockets are left in
the system.
if any air or gas pockets are left in this portion of pump, it may result into no
delivery of liquid by the pump.
Working of centrifugal pump

6. 3.The pump shaft and impeller is now rotated with the help of an external source of
power like a motor or any other prime mover.
The rotation of impeller inside a casing full of liquid produces a forced vortex
which is responsible in imparting the centrifugal head to the liquid. It creates a
vacuum at the eye of impeller and causes liquid to rise into suction pipe from the
sump.
4.The speed of impeller should be sufficient to produce the centrifugal head such that
it can initiate discharge from delivery pipe.
5. Now the delivery valve is opened and the liquid is lifted and discharge through the
delivery pipe due to its high pressure.
Thus the liquid is continuously sucked from the sump to impeller eye and it is
delivered from the casing of pump through the delivery pipe.
6. Before stopping the pump, it is necessary to close the delivery pipe otherwise the
back flow of liquid may take place from the high head reservoir.

7.  In case the priming of pump is not done and the pump is not done and the pump is not under
the operation, the water present in the pump and suction pipe will flow back to the sump. The
space occupied by water will be filled by air.
 If the pump is now started, the air pockets inside the impeller may give rise to vortices and
cause the discontinuity of flow. Under these condition, the flow of fluid does not commence
and the pump runs dry. It causes the rubbing and seizing of the wearing rings, increases noise
level and vibrations and finally may cause the serious damage to pump.
 The priming in reciprocating pumps is not required since the pumping is done by positively
moving the fluid out of the cylinder by the piston. Hence, the air will be displaced from the
casing when the pump starts and it will get a suction pressure which will draw the fluid from
the sump.
 Priming for small pumps is done by hand
 A foot valve is essential at the bottom of suction pipe
 A funnel or priming cup is provided to fill the water by hand. An air vent is provided in the
casing of pump. When the water is filled, the air escapes through the air vent. It is closed once
the priming is completed
The operation of filling the casing , impeller and suction pipe and the portion of delivery
pump up to delivery valve is called priming.
Priming of Centrifugal Pump

8. WHAT IS CENTRIFUGAL PUMP ?
Convert the mechanical energy into
hydraulic energy by centrifugal
force on the liquid
Constitute the most common type
of pumping machinery
Used to move liquids through a
piping system
Has two main components:
1. Stationary componets, casing,
casing cover and bearings
2. Rotating components, impeller
and shaft
Classified into three categories ;
Radial Flow, Mixed Flow, Axial
Flows

9. WORKING MECHANISM OF A CENTRIFUGAL PUMP
Simplest piece of equipment in any process
plant
Energy changes occur by virtue of impeller
and volute
Liquid is fed into the pump at the center of a
rotating impeller and thrown outward by
centrifugal force
The conversion of kinetic energy into pressure
energy supplies the pressure difference
between the suction side and delivery side of
the pump
Liquid flow path inside a
centrifugal pump

10. ADVANTAGES
 Simple in construction and cheap
 Handle liquid with large amounts of solids
 No metal to metal fits
 No valves involved in pump operation
 Maintenance costs are lower
Cannot handle highly viscous fluids
efficiently
Cannot be operated at high heads
Maximum efficiency holds over a narrow
range of conditions
DISADVANTAGES

11. POWER AND EFFICIENCY CALCULATIONS
 The power supplied to the pump:
Where m=mass flow rate, kg/s
∆H= total discharge head, N.m/k
η=efficiency
…………(1)
 The power delivered to the fluid:
…………(2)
 From equations (1) and (2) efficiency:

12. Specific speed that is used to classify pumps
nq is the specific speed for a unit machine that is geometric similar to a machine
with the head Hq = 1 m and flow rate Q = 1 m3
/s
43q
H
Q
nn ⋅=
qs nn ⋅= 55,51

13. What is a centrifugal pump?
Three basic components:
Volute, casing, body
or Diffuser
Impeller
or impellers
Driver (motor)
Pump Impeller types
 Open
 Semi-open
 Closed
• Single suction
• Double suction
 Non-clogging
 Axial flow
 Mixed flow

14. Parameter Centrifugal Pumps Reciprocating Pumps Rotary Pumps
Optimum Flow and Pressure
Applications
Medium/High Capacity,
Low/Medium Pressure
Low Capacity,
High Pressure
Low/Medium Capacity,
Low/Medium Pressure
Maximum Flow Rate 100,000+ GPM 10,000+ GPM 10,000+ GPM
Low Flow Rate Capability No Yes Yes
Maximum Pressure 6,000+ PSI 100,000+ PSI 4,000+ PSI
Requires Relief Valve No Yes Yes
Smooth or Pulsating Flow Smooth Pulsating Smooth
Variable or Constant Flow Variable Constant Constant
Self-priming No Yes Yes
Space Considerations Requires Less Space Requires More Space Requires Less Space
Costs Lower Initial
Lower Maintenance
Higher Power
Higher Initial
Higher Maintenance
Lower Power
Lower Initial
Lower Maintenance
Lower Power
Fluid Handling Suitable for a wide range
including clean, clear, non-
abrasive fluids to fluids with
abrasive, high-solid content.
Not suitable for high viscosity
fluids
Lower tolerance for entrained
gases
Suitable for clean, clear, non-
abrasive fluids. Specially-
fitted pumps suitable for
abrasive-slurry service.
Suitable for high viscosity
fluids
Higher tolerance for entrained
gases
Requires clean, clear, non-
abrasive fluid due to close
tolerances
Optimum performance with
high viscosity fluids
Higher tolerance for entrained
gases
Difference between Centrifugal Reciprocating Rotary
pumps
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15. 1 Casing:-
II. Circular casings for low head and high capacity.
A volute is a curved funnel
increasing in area to the discharge
port.
Volute
SuctionImpeller
Construction of
Centrifugal Pumps
Casing generally are two types:
I. Volute casings for a higher head.
Have stationary diffusion vanes
surrounding the impeller periphery that
convert velocity energy to pressure
energy. 6

16. Radial flowAxial flow
Mixed flow
2 Impeller
Three main categories of centrifugal pumps exist
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17. Thanks for listening