concise data about pumps , very help for engineering students

1. Presented By:
Ameer Hamza DDP-SP13-BEC-10
M. Atif Rauf DDP-SP13-BEC-48
Hafiz Tariq javid DDP-SP13-BEC-22
Fakhar Hayat DDP-SP13-BEC-18
Thermodynamics 2
Comsats institute of information and technology Lahore

3. Pump:
Pump is a mechanical device, pumps increases the mechanical energy of fluid,
Increasing its velocity, pressure or elevation.
Positive Displacement pump Centrifugal Pump

4. Positive Displacement Pump:
PD pumps apply pressure directly to the fluid by reciprocating motion.

5. Types of PD Pump:
Positive displacement pump
Reciprocating
 Apply direct pressure to fluid by
reciprocating piston
 Contain moveable piston or
plunger to displace fluid
Rotary
 The chamber moves
from inlet to discharge
and back to the inlet

6. Reciprocating pump:
 Piston pump
 Plunger pump
 Diaphragm Pump
Rotary Pump:
 Gear Pump
 Lobe pump
 Van Pump
 Peristalic Pump

7. Piston Pump:
 Discharge pressure up to 50 atm
Application:
High pressure purpose

8. Plunger pumps :
Use to produce 1500 atm or more
Mostly motor driven
Single acting

9. Diaphragm pumps :
Use to produce 100 atm
Application:
Corrosive or toxic liquid handling

10. Mechanical Efficiency of Reciprocating:
 For small pumps: 40 to 50 %
 For large pumps: 70 to 90%
 Efficiency independent of speed under normal conditions.
 Decrease slightly with a increase suction pressure
 Volume efficiency
The ratio of the volume of fluid discharge to the volume swept by the
piston or plunger is called volumetric efficiency

11. Gear Pump:
 Minimize leakage due to close tolerance between moving and stationary parts
 Liquid must be clean, moderately viscous fluids i.e. light lubricating oil
Spur-gear pump Internal-gear pump

12. Lobe pump:
Vane Pump :

13. Peristalic Pump:
 Use for small flow rates and constant flow rates
 No air leakage or possibility to air (leakproof)
Application
Production of biomedical, pharmaceuticals etc.

14. Centrifugal Pump:
Centrifugal force generates high rotational velocities, then convert the resulting
K.E of the fluid to pressure energy.

15. Parts of Centrifugal Pump:
 Stationary components
 Casing
 Volute
 Circular
 Seal chamber and stuffing box

16.  Moving Components
 Impeller
 Shaft

17. Types of Centrifugal pump:
 Multistage centrifugal pump
 Leak proof centrifugal pump
 Canned-rotor pump
 Magnetic-derive pump

18. Multistage Centrifugal Pump:
When a head greater than 200 ft (60 m) is needed, two or more impeller s
Can be mounted in series on a single shaft multistage pump is obtained, the
Discharge from the first impeller provides suction for the 2nd and second for
The 3rd, and so forth.

19. Leakproof centrifugal pump:
Used for handling dangerous liquids.
 Canned-rotor pumps
A canned like stainless steel
structure cover the rotor
which keep the pumped fluid
away from the rotor.
 Magnetic-derive pump
Impeller carries magnetic is driven
by the magnetic disk on the other
side of casing walls.

20. If the suction pressure is slightly greater than vapor pressure of the liquid
Some liquid may flash to vapors inside the pump
 It greatly reduces the pump capacity
 Causes serve erosion
Cavitation:
Disadvantages:

21. Selection parameters:
 Amount of the fluid
 The fluid properties
 Head required
 Type of the flow
 Power supply
 Cost compared to efficiency

22. Pressure developed by the pump :
Depends on,
 Impeller dia
 No. of impeller
 Size of the impeller eye
 Shaft speed
Size of Pump:
depends on,
 Head
 capacity
Key parameters for determining efficiency:
Depends on,
 Flow
 Head
 Power

23. Head:
Head is the height at which a pump can raise water up.

24. Power requirement:
Power supplied to the pump derive from external source
PB= mWp
Power delivered to the fluid is calculated by mass flow rate and head developed
Pf=mΔH

25. Pump Priming:
To remove the entrapped air inside the pump is called pump priming
When we do it?
 First start up after a long time
 First start up after maintenance
 First start up for a new pump
How we do it ?
 If there is any air entrapped in the suction line, we need to replace this
air with liquid.
 Air can be displaced by liquid from any tank into the suction line and
submerge the pump impeller
Note: Positive displacement pump can compress the gas to a required discharge
pressure, that’s why they are known to self priming