Basics Fundamentals and working Principle of Centrifugal Pump.SHASHI BHUSHAN
Basics Fundamentals and working Principle of Centrifugal Pump. Centrifugal pumps are the rotodynamic machines that convert mechanical energy of shaft into kinetic and pressure energy of Fluid which may be used to raise the level of fluid. A centrifugal pump is named so, because the energy added by the impeller to the fluid is largely due to centrifugal effects.
Basics of centrifugal. Topics covered are operating principles, energy conversion, components in centrifugal pump, the concept of NPSH, pump rating calculation and affinity laws
Basics Fundamentals and working Principle of Centrifugal Pump.SHASHI BHUSHAN
Basics Fundamentals and working Principle of Centrifugal Pump. Centrifugal pumps are the rotodynamic machines that convert mechanical energy of shaft into kinetic and pressure energy of Fluid which may be used to raise the level of fluid. A centrifugal pump is named so, because the energy added by the impeller to the fluid is largely due to centrifugal effects.
Basics of centrifugal. Topics covered are operating principles, energy conversion, components in centrifugal pump, the concept of NPSH, pump rating calculation and affinity laws
Minor losses are a major part in calculating the flow, pressure, or energy reduction in piping systems. Liquid moving through pipes carries momentum and energy due to the forces acting upon it such as pressure and gravity. Just as certain aspects of the system can increase the fluids energy, there are components of the system that act against the fluid and reduce its energy, velocity, or momentum. Friction and minor losses in pipes are major contributing factors.
Flow Through Orifices, Orifice, Types of Orifice according to Shape Size Edge Discharge, Jet, Venacontracta, Hydraulic Coefficients, Coefficient of Contraction,Coefficient of Velocity, Coefficient of Discharge, Coefficient of Resistance, Hydraulic Coefficients by Experimental Method, Discharge Through a Small rectangular orifice, Discharge Through a Large rectangular orifice, Discharge Through a Fully Drowned orifice, Discharge Through Partially Drowned orifice, Mouthpiece and its types. By Engr. M. Jalal Sarwar
This Presentation is about working principle of Pumps.Basic Presentation regarding pumps , will definitely help beginners to learn pump types , their working , their parts etc.
In this report , I shall shade the light on the two types :
1- Reciprocating positive displacement pumps .
2- Centrifugal dynamic pumps.
The comparison will include the following points for each type :
1- Working principle.
2- Usage.
3- Efficiency
4- Connection Methods (in series and in parallel )
Minor losses are a major part in calculating the flow, pressure, or energy reduction in piping systems. Liquid moving through pipes carries momentum and energy due to the forces acting upon it such as pressure and gravity. Just as certain aspects of the system can increase the fluids energy, there are components of the system that act against the fluid and reduce its energy, velocity, or momentum. Friction and minor losses in pipes are major contributing factors.
Flow Through Orifices, Orifice, Types of Orifice according to Shape Size Edge Discharge, Jet, Venacontracta, Hydraulic Coefficients, Coefficient of Contraction,Coefficient of Velocity, Coefficient of Discharge, Coefficient of Resistance, Hydraulic Coefficients by Experimental Method, Discharge Through a Small rectangular orifice, Discharge Through a Large rectangular orifice, Discharge Through a Fully Drowned orifice, Discharge Through Partially Drowned orifice, Mouthpiece and its types. By Engr. M. Jalal Sarwar
This Presentation is about working principle of Pumps.Basic Presentation regarding pumps , will definitely help beginners to learn pump types , their working , their parts etc.
In this report , I shall shade the light on the two types :
1- Reciprocating positive displacement pumps .
2- Centrifugal dynamic pumps.
The comparison will include the following points for each type :
1- Working principle.
2- Usage.
3- Efficiency
4- Connection Methods (in series and in parallel )
(disambiguation).
A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action, typically converted from electrical energy into hydraulic energy.
The pdf contains explanation about the centrifugal pumps. It is usually studied by Mechanical or Civil engineering students. This pdf file will help for the students from these fields.
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About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
1. Presentation
On
Centrifugal & reciprocating pumps
Applied Thermal &
Hydraulic Engineering
Submitted by:
Chauhan Karan(130120109004)/Electrical Engg./B-1
Chippa Abdul (130120109005) / Electrical Engg. / B-1
Submitted To:
(2140907)
GA N D H IN A GA R IN STITU TE OF
TEC H N OLOGY
3. A hydrodynamic pump machine is a device for converting the
energy held by mechanical energy into hydraulic energy of a
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.
1
4. 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
PUMP
2
5. Centrifugal pumps are similar to inward flow
reaction turbine but it is reverse in action.
In case water turbine the water flows outer
periphery radially inwards while the water in
centrifugal pump flow radially outwards towrds
the periphery.
In turbine the flow from higher pressure to lower
pressure & produces mechanical power at the
shaft. While in pump the water flows from lower
pressure towards higher pressure side on the
expense of mechanical energy.
In turbine the flow is accelerated due to
centrifugal action while the flow is
deaccelerated in pumps.
6. To pump water from source to fields for
agricultural and irrigation purposes.
In petroleum installations to pump oil.
In steam and diesel power plants to
circulate feed water & cooling water
respectively.
Hydraulic control systems.
Transfer of raw materials.
Pumping of water in buildings.
Fire fighting.
7.
8.
9.
10. 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
12. Heads of Pump:
where :
Vs = Velocity of fluid in the suction pipe.
Vd = Velocity of fluid in the delivery
pipe.
hs = Suction head.
hd = Delivery head.
hfs = head losses in the suction pipe.
hfd = head losses in the delivery pipe.
10
Static head (Hst)
Hst = hs + hd
13. Manometric head (Hm) :
)( sd
sd
m zz
pp
H
but fd
h
d
hd
p
and )( fss
s
hh
p
)2( 2
gV
D
L
fh dfd = Hst + hf +
g
Vs
2
2
where hf = hfs + hfd
L
w
Lm H
g
UV
HhH 22
(where HL = impeller losses)
Total head (H)
g
VV
zz
pp
H sd
sd
sd
2
)(
22
H = hs + hfs + hd + hfd +
g
Vd
2
2
(where )
= Hst + hf +
g
Vd
2
2
Hm = H + )(
2
1 22
ds VV
g
When Vs = Vd
Hence Hm = H
11
14. 1) hydraulic losses:(i)losses in pump:(a)loss
of head due to friction in impeller.
(b)Loss of head due to shock & eddy’s from
inlet to exit of impeller.
(c)Loss of head in guide vanes due to
diffusion and in casing.
(ii)Other hydraulic losses:(a)friction loss in
suction & delivery pipes.
(b)Loss of head in heads, fittings, valves etc.
2)Mechanical losses
3)Leakage losses
15. Pump Efficiencies
1- Hydraulic Efficiency (ζh)
)(
)('
e
h
HHeadEuler
HHeadTotalsPump
22UV
gH
w
h The normal value varies between 60% - 90%
2- Manometric Efficiency(ζm)
)(
)('
e
m
m
HHeadEuler
HHeadManometricsPump
22UV
gH
w
m
m
3 -Volumetric Efficiency (ζv)
QQ
Q
v
The normal value lies between 97% to 98%
14
16. 4- Mechanical Efficiency (ζ)
It is due to losses in the shaft, coupling, and other operation losses as vibration
shafttheatPower
impellerthetoinPower
ShaftPower
UVQQ w)( 22
The normal value is 95% - 98%
5 - Overall Efficiency (ζo)
.T
QH
P
P
in
out
o
hQQ
QH
P
P
P
P
P
P
lin
t
in
t
t
out
o
)(
hvmo The normal value is 71% - 86%
Discharge of a Centrifugal Pump
222111 ff VbDVbDQ
15
17. The performance of a pump is
show by its characteristic curve,
where the flow capacity (Q) is
plotted against the delivery
pressure or developed head (H).
Head is measured in metres.
/smQFLOW 3
18. A centrifugal pump uses the conservation of energy
principle .It changes velocity energy into pressure
energy .
As the differential head (H) increases ,the flow rate
(Q)decreases .The performance curve looks like this .
19. A centrifugal pump uses the conservation of energy
principle .It changes velocity energy into pressure
energy .
As the differential head (H) increases ,the flow rate
(Q)decreases .The performance curve looks like this .
20. A centrifugal pump incurs head losses due to friction.
The friction is caused by the fluid changing direction
when travelling through the pump and by clearances
within the pump .These losses vary with both head
and flow.
21. Subtracting the losses from the ideal gives the actual performance curve for
the pump.
Ideal Head –Losses =Actual Head
It is possible to determine the useful power of a pump by the formula
22. The centrifugal pumps with two or more
number of identical impellers are called
multistage centrifugal pumps.
The impellers of these pumps may be
attached on the same or on different
shafts. the multistage pumps are needed
either to increase the head or the
discharge compared to a single stage
pump, accordingly the impellers are
connected in series or parallel .
23. Twice the pressure
Same amount of water
Direction of Flow
24. Methods of priming:
1. priming by hand
2.connection with city water mains
3.by providing priming pumps
4.self priming devices
25. Pumps are used to increase the energy level of
water by virtue of which it can be raised to a
higher level.
Reciprocating pumps are positive displacement
pump, i.e. initially, a small quantity of liquid is
taken into a chamber and is physically displaced
and forced out with pressure by a moving
mechanical elements.
The use of reciprocating pumps is being limited
these days and being replaced by centrifugal
pumps.
26. For industrial purposes, they have become
obsolete due to their high initial and
maintenance costs as compared to centrifugal
pumps.
Small hand operated pumps are still in use that
include well pumps, etc.
These are also useful where high heads are
required with small discharge, as oil drilling
operations.
27. A reciprocation pumps consists of a plunger or a piston
that moves forward and backward inside a cylinder with
the help of a connecting rod and a crank. The crank is
rotated by an external source of power.
The cylinder is connected to the sump by a suction pipe
and to the delivery tank by a delivery pipe.
At the cylinder ends of these pipes, non-return valves
are provided. A non-return valve allows the liquid to
pass in only one direction.
Through suction valve, liquid can only be admitted into
the cylinder and through the delivery valve, liquid can
only be discharged into the delivery pipe.
28.
29. When the piston moves from the left to the right, a
suction pressure is produced in the cylinder. If the pump
is started for the first time or after a long period, air
from the suction pipe is sucked during the suction
stroke, while the delivery valve is closed. Liquid rises
into the suction pipe by a small height due to
atmospheric pressure on the sump liquid.
During the delivery stroke, air in the cylinder is pushed
out into the delivery pipe by the thrust of the piston,
while the suction valve is closed. When all the air from
the suction pipe has been exhausted, the liquid from
the sump is able to rise and enter the cylinder.
30. During the delivery stroke it is displaced into the
delivery pipe. Thus the liquid is delivered into the
delivery tank intermittently, i.e. during the delivery
stroke only.
31. Following are the main types of reciprocating pumps:
According to use of piston sides
Single acting Reciprocating Pump:
If there is only one suction and one delivery pipe and
the liquid is filled only on one side of the piston, it is
called a single-acting reciprocating pump.
Double acting Reciprocating Pump:
A double-acting reciprocating pump has two suction
and two delivery pipes, Liquid is receiving on both
sides of the piston in the cylinder and is delivered into
the respective delivery pipes.
32.
33. According to number of cylinder
Reciprocating pumps having more than one cylinder are
called multi-cylinder reciprocating pumps.
Single cylinder pump
A single-cylinder pump can be either single or double
acting
Double cylinder pump (or two throw pump)
A double cylinder or two throw pump consist of two
cylinders connected to the same shaft.
35. Let
A = cross sectional area of cylinder
r = crank radius
N = rpm of the crank
L = stroke length (2r)
Discharge through pump per second=
Area x stroke length x rpm/60
This will be the discharge when the pump is single
acting.
60
N
LAQth
36.
37. Discharge in case of double acting pump
Discharge/Second =
Where, Ap = Area of cross-section of piston rod
However, if area of the piston rod is neglected
Discharge/Second =
60
)(
60
LNAAALN
Q P
th
60
)2( LNAA
Q P
th
60
2ALN
38. Thus discharge of a double-acting reciprocating pump is
twice than that of a single-acting pump.
Owing to leakage losses and time delay in closing the
valves, actual discharge Qa usually lesser than the
theoretical discharge Qth.
39. Slip of a reciprocating pump is defined as the
difference between the theoretical and the actual
discharge.
i.e. Slip = Theoretical discharge - Actual discharge
= Qth. - Qa
Slip can also be expressed in terms of %age and given by
10011001
100%
d
th
act
th
actth
C
Q
Q
Q
QQ
slip
40. Slip Where Cd is known as co-efficient of discharge and
is defined as the ratio of the actual discharge to the
theoretical discharge.
Cd = Qa / Qth.
Value of Cd when expressed in percentage is known as
volumetric efficiency of the pump. Its value ranges
between 95---98 %. Percentage slip is of the order of 2%
for pumps in good conditions.
41. It is not always that the actual discharge is lesser than
the theoretical discharge. In case of a reciprocating
pump with long suction pipe, short delivery pipe and
running at high speed, inertia force in the suction pipe
becomes large as compared to the pressure force on the
outside of delivery valve. This opens the delivery valve
even before the piston has completed its suction stroke.
Thus some of the water is pushed into the delivery pipe
before the delivery stroke is actually commenced. This
way the actual discharge becomes more than the
theoretical discharge.
Thus co-efficient of discharge increases from one and
the slip becomes negative.
42. Centrifugal Pumps Reciprocating Pumps
1. Steady and even flow 1. Intermittent and pulsating flow
2. For large discharge, small heads 2. For small discharge, high heads.
3. Can be used for viscous fluids e.g. oils,
muddy water.
3. Can handle pure water or less viscous
liquids only otherwise valves give frequent
trouble.
4. Low initial cost 4. High initial cost.
5. Can run at high speed. Can be coupled
directly to electric motor.
5. Low speed. Belt drive necessary.
6. Low maintenance cost. Periodic check
up sufficient.
6. High maintenance cost. Frequent
replacement of parts.
7. Compact less floors required. 7. Needs 6-7 times area than for centrifugal
pumps.
8. Low head pumps have high efficiency 8. Efficiency of low head pumps as low as
40 per cent due to the energy losses.
9. Uniform torque 9. Torque not uniform.
10. Simple constructions. Less number of
spare parts needed
10. Complicated construction. More
number of spare parts needed.