ppfl

1. 1
Pumps Turbines

2. 2
TURBOMACHINERY
Pumps Turbines
Defn: Mechanical devices that either extract energy from a fluid or add energy to a fluid
as a result of dynamic interactions between the device and the fluid
The purpose of a pump is to add energy to a fluid, resulting in an increase in fluid
pressure, not necessarily an increase of fluid speed across the pump.
The purpose of a turbine is to extract energy from a fluid, resulting in a decrease of
fluid pressure, not necessarily a decrease of fluid speed across the turbine.

3. 3
Other Types of pumps
Machines that move gases
A fan is a gas pump with relatively low pressure rise and high flow rate
A blower is a gas pump with relatively moderate to high pressure rise and moderate to
high flow rate
A compressor is a gas pump designed to deliver a very high pressure rise, typically at
low to moderate flow rates.

4. 4
The Centrifugal Pump
2 main components: an
impeller attached to a
rotating shaft, and a
stationary casing, housing,
or volute enclosing the
impeller
The impeller consists of a
number of blades(vanes),
arranged in a regular pattern
around the shaft

5. 5
Functions
Impeller is a rotating component of a centrifugal pump which transfers energy from the motor
that drives the pump to the fluid being pumped by accelerating the fluid outwards from the
center of rotation.
The casing contains the liquid and acts as a pressure containment vessel that directs the flow
of liquid in and out of the centrifugal pump.
Centrifugal pumps use an impeller to create a low pressure zone at the impellers eye or open
inlet, which is rotating. The pressure in the eye of the impeller is now lower than the atmosphere
pressure acting on the product being pumped. As a result the water/product will flow into the low
pressure zone/eye of the impeller and this creates kinetic energy which propels the fluid outward.

6. 6
How does a centrifugal pump works
1
2
A

7. 7
It increases the
static pressure
It increases the
dynamic pressure
(kinetic energy)
It raises
the
elevation
(potential
energy)
It overcomes
irreversible
head losses
Functions of a pump

8. 8
Net head is proportional to the useful power actually delivered to
the fluid.
Water horsepower
minimum power required to run water pump
Pump efficiency:
The external power supplied to the pump is called the brake horsepower(bhp)

9. 9
)
The maximum volume flow rate (free delivery) when net head (H = 0
Pump Performance (Design)

10. 10
The head-discharge curve for a centrifugal pump is
given by the following data:
The pump discharges water to a tank 25 m vertically above it
through a 130 mm diameter pipe which is 65 m long. If the
Fanning coefficient of friction is 0.009:
Determine the operating point of the pump
The power of the pump if its efficiency is 65%
Example

11. 11
Solution
g
V
D
L
f
z
Hsys
2
.
.
4
2




2
4
/
D
Q
V
A
Q
V
VA
Q




2
2
4
.
2
1
.
.
4 








D
Q
g
D
L
f
z
Hsys

2
4
.
5207
25 Q
Hsys 


12. 12
Solution Cont..

13. 13
Solution Cont..
At the operating point;
kW
4
.
24
)
1000
1
/(
81
.
9
9
.
42
058
.
0
1000
(kW) 





P
If the efficiency is 65%, power required = 24.4/0.65 = 37.5kW