pump its classification its working procedure its applications

1. Assignment on
pump
rajshahi university of engineering and technology
SLIDE REPRESENTATION BY-
NAME ROLL
ASFAQUZZAMAN---------------------------- 132031
SIFAT TASNIM--------------------------------- 132032
OISHWARJA FERDOUS ------------------- 132033
RASEL AHMED------------------------------- 132034
ABDUR RAHMAN----------------------------- 132035
MD.RAFSAN JANI PRANTO--------------- 132036
SAJIB RYHAN---------------------------------- 132037
MARUFA SULTANA -------------------------- 132038
MD.MUHAIMANUL ISLAM------------------ 132039
G.M. NAZMUL ISLAM------------------------ 132040
DEPT. OF ME
RUET
23/8/2014 1
Submitted to:-
Dr. Mohammad Rofiqul
Islam
Head of Department
Department of Mechanical
Engineering
RUET

2. PUMP:
A pump is a device that moves fluids
(liquids or gases), or sometimes
slurries, by mechanical action.
When a fluid, be it hot or cold, has to be
"moved" in a system, pumps are used.
In other words, in a more technically
appropriate manner, the pump is a
machine which has the function of
increasing the total (mechanical)
energy of a liquid;
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3. Different parts of a pump:
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4. Classification of pump:-
Pumps are in general classified as Centrifugal
Pumps (or Roto-dynamic pumps) and Positive
displacement pumps.
Pumps can be classified by their method of
displacement into positive displacement
pumps, impulse pumps,velocity
pumps, gravity pumps, steam
pumps and valveless pumps.
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5. Centrifugal Pumps (Roto-
dynamic pumps):-
 The centrifugal or roto-dynamic pump
produce a head and a flow by
increasing the velocity of the liquid
through the machine with the help of a
rotating vane impeller. Centrifugal
pumps include radial, axial and mixed
flow units.
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6. INTERIOR OF A CENTRIFUGAL
PUMP:-
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7. HERE IS A VIDEO OF A CENTRIFUGAL
PUMP:-
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9. Positive Displacement Pumps:
The positive displacement pump operates by
alternating of filling a cavity and then displacing
a given volume of liquid. The positive
displacement pump delivers a constant volume
of liquid for each cycle against varying
discharge pressure or head.
The positive displacement pump can be
classified as:
Reciprocating pumps - piston, plunger and
diaphragm
Power pumps
Steam pumps
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10. POSITIVE DISPLACEMENT PUMPS:-
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11. Pump performance data such as this is usually
supplied by the manufacturer before pump
selection. Pump efficiencies tend to decline
over time due to wear(e.g. increasing
clearances as impellers reduce in size).
When a system design includes a
centrifugal pump, an important issue it its
design is matching the head loss-flow
characteristic with the pump so that it
operates at or close to the point of its
maximum efficiency.
Pump efficiency is an important aspect
and pumps should be regularly tested.
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12. HERE IS A VIDEO OF A positive displacement
PUMP:-
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14. Figure of a centrifugal pump:
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15. Working procedure of a centrifugal
pump:
Standard operating procedure to operate
centrifugal pump is:
The first-step in the operation of a centrifugal
pump is priming. Priming is the operation in
which the suction pipe, casing of the pump and
portion of the delivery pipe up to the delivery
valve are completely filled with the liquid which is
to be pumped, so that all the air from this portion
of the sump is driven out and no air pocket is left
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17. It has been observed that even the presence of
a small air pocket in any of the portion of pump
may result in no delivery of liquid from the
pump.
The necessity of priming a centrifugal pump is
due to the fact that the pressure generated in a
centrifugal pump impeller is directly proportional
to the density of the fluid that is in contact with
it.
Hence if an impeller is made to rotate in the
presence of air, only a negligible pressure would
be produced with the result that no liquid will be
lifted up by the pump
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18. Centrifugal pump:-
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19. As such it is essential to properly prime a
centrifugal pump before it can be started. The
various methods used for priming a centrifugal
pump are discussed later.
After the pump is primed, the delivery valve is still
kept closed and the electric motor is started to
rotate the impeller. The delivery valve is kept closed
in order to reduce the starting torque for the motor.
The rotation of the impeller in the casing full of
liquid produces a forced vortex which imparts a
centrifugal head to the liquid and thus results in an
increase of pressure throughout the liquid mass.
The increase of pressure at any point is
proportional to the square of the angular velocity
and the distance of the point from the axis of
rotation
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20. Thus if the speed of the impeller of the pump is
sufficiently high, the pressure in the liquid
surrounding the impeller is considerably increased.
Now as long the delivery valve is closed and the
impeller is rotating, it just churns the liquid in the
casing. By opening the delivery valve the liquid is
forced to flow out from the pump casing outlet
portion. At the eye of the impeller due to the
centrifugal action a partial vacuum is created. This
causes the liquid from the sump, which is at
atmospheric pressure, to rush through the suction
pipe to the eye of the impeller thereby replacing the
liquid which is being discharged from the entire
circumference of the impeller. The high pressure of
the liquid leaving the impeller is utilized to flow the
liquid to higher end through the delivery pipe.
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21. A PUMP ON ITS WORKING STATE:-
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22. As the liquid flows through the rotating impeller
it receives energy from the vanes which results
in an increase in both pressure and velocity
energy. As such the liquid leaves the impeller
with a high absolute velocity. In order that the
kinetic energy corresponding to the high velocity
of the leaving liquid is not wasted in eddies and
efficiency of the pump thereby lowered, it is
essential that this high, velocity of the leaving
liquid is gradually reduced to a lower velocity of
the delivery pipe, so that the larger portion of
the kinetic energy is converted into useful
pressure energy.
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23. Usually this is achieved by shaping the
casing such that the leaving liquid flows
through a passage of gradually, expanded
area, the gradually increased cross-
sectional area of the casing also helps in
maintaining uniform velocity of flow
throughout, because as the flow proceeds
from the tongue T to the delivery pipe,
more and more liquid is added from the
impeller. This is how a pump workes.
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24. Pump Applications:-
Pumps are used for many different
applications. Different types of pumps are
used in different sector. Some of them are
given below:-
Boiler Feed Pumps - built to control the
amount of water that enters a boiler. They
are centrifugal pumps, and most are
multistage.
Fire Pumps - a type of centrifugal pump
used for fire fighting. They are generally
horizontal split case, end suction or vertical
turbine.
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25. Pool Pumps - used to circulate the water
in a pool.
Water Pumps - a type of equipment
used to move water through a piping
system. They rely upon principles of
displacement, gravity, suction, and
vacuums to move water. They can be
both positive displacement or centrifugal
pumps.
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26. ..…THE END …..
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