Engineering stuff

1. Presented By
Hriday Biswas (51)
Shubham Nath (75)
Prasun Bairagi (74)
B.P.C.I.T
BRANCH:- ELECTRICAL
Selection of Pump

2. What Is Pump ?
 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.
Pumps can be classified into
three major groups according to
the method they use to move
the fluid: direct
lift, displacement,
and gravity pumps.

3. Mechanical pumps serve in a wide range of applications
such as:
1- Pumping water from wells, aquarium filtering, pond
filtering, and aeration,
2- In the car industry for water-cooling and fuel
injection,
3- In the energy industry for pumping oil and natural
gas or for operating cooling towers and other
components of heating, ventilation and air conditioning
systems.
4- Dewatering in flood
5- Water supply in houses
Application Of Pump -

5. Piston Pump -
1.transmission of
fluids or gases
under pressure.
2.Power
consumption is low.
3.Ensure maximum
safety.

6. Plunger pump -
1.Have high efficiency.
2.Capable of developing very high pressures.
3.Low and easy maintenance

7. Diaphragm Pump-
When the volume of a chamber of
either type of pump is increased
(the diaphragm moving up), the
pressure decreases, and fluid is
drawn into the chamber. When
the chamber pressure later
increases from decreased volume
(the diaphragm moving down),
the fluid previously drawn in is
forced out. Finally, the diaphragm
moving up once again draws fluid
into the chamber, completing the
cycle.

8. Centrifugal Pump-
•Liquid forced into
impeller
•Vanes pass kinetic
energy to liquid and
liquid rotates and
leaves impeller
•Volute casing converts
kinetic energy into
pressure energy

10. Total Suction Head:
The static head, sometimes referred to as the pressure
head, is a term primarily used in Hydraulics to denote
the static pressure in a pipe, channel, or duct flow. It
has the physical dimensions of length (hence the term
“head”) and represents the flow-work per unit weight of
fluid. In practice the static head is equivalent to the
vertical distance from a given streamtube to the
piezometric head line or the hydraulic gradient line. If
P is the pressure in a streamtube, the static head is
defined by P/ρg. Using this definition it is apparent
that in a open channel flow, where the pressure is
assumed to be hydrostatic, the static head is the
distance from the streamtube to the water surface.

12. Major Items to be considered for
pump selection
Pump selection: Based on the fluid
characteristics, turn-down ratio,
discharge
pressure and system requirements,
availability of
space, lay-out, energy and pump costs,
code

13. The BHP required to drive a pump at a
specific duty point is:
*When gpm = Gallon Per Minute
Sp.Gv. = Specific Gravity

14. Motor
Of
Efficiency
%
3960
Water
Of
Gravity
Specific
Loss
Head
GPM
HP




0.70
3690
1
30
400
HP




HP = 4.64
GPM = 400
Head= 30
SGW = 1
EOM= 0.70

15. Net positive suction head :
NPSH is defined as the combination of atmospheric
pressure and static suction head that causes liquid to
flow thru the suction piping and finally enter the eye of
the impeller.
The NPSH increases with flow due to pump internal losses like
friction.
NPSH can be divided into :
NPSHR – required by pump at duty point, found on the pump
performance curve.
NPSHA – Available in the system and must be determined by
calculation.
* NPSHA > NPSH

16. PA = atmospheric pressure or pressure in tank (psia);
PV = vapor pressure of liquid at maximum pumping
temperature; Sp. Gr. = specific gravity at pumping
temperature; HE = elevation head (ft); and HF =
friction loss in suction line (ft). Refer to following
pages for example calculations. Values for vapor
pressure (PV ) and atmospheric pressure (PA ) found
in pump handbooks. (see attached)

17. Affinity Laws : The affinity laws express the
mathematical relationships between the
several variables involved in pump
performance.
Q1 = capacity
H1 = Head (feet)
N1 – rpm
Q2 = capacity
H2 = Head (feet)
N2 – rpm

19. References
en.wikipedia.org
www.Google.com

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