1. 4.0 Pumps

2. Overview of Lecture What is a Pump? Pump Types Displacement Pump
Axial-Flow Pump
Centrifugal Pump
Ejectors
Submersible Pumps

3. Disclaimer
The topic of PUMPS is substantial enough so as to warrant its own course. In this course, we will only have time to ‘scratch the surface’ of pumps.
What follows is an overview of pumps, with emphasis given to pumps that are used most often in the marine industry.

4. What is a Pump?
A pump is a machine used to raise liquids from a low point to a high point.
Alternatively it may simply provide the liquid with an increase in energy enabling it to flow or build up a pressure.

5. Head Pressure
refers to the pressure produced by a vertical column of fluid.
The pump provides the energy to develop the head and overcome any losses in the system.
Losses are mainly due to friction within the pipes and the difference between the initial and final liquid levels.

6. Head Pressure

7. Net Positive Suction Head
is the difference between the absolute pump inlet pressure and the vapor pressure of the liquid.
Note: Pump location will effect these values.

8. Pump Types There are FIVE main classes of pump in marine use:
1. Displacement
-rotary: which can handle viscous, nonabrasive liquids
reciprocating: which can handle low-solids, low-viscosity liquids.
screw: which can handle low-solids, low-viscosity liquids.
2. Axial flow: more suited for low heads and higher discharges.
Most Common
3. Centrifugal: which can handle abrasive, high-solid liquids.
4. Ejector: can be used to aerate sludge, such as heavy oil and sewage.
5. Submersible: does not have a long drive shaft.

9. Pump Types - Uses Centrifugal Pumps
Condensate and feed water pumps for steam power plants.
Auxiliary pumps for cooling systems, distilling plants, and tank drainage.
Fire fighting pumps for pumping sea water.
Sewage pumps
Cargo pumps for pumping liquid cargo.
Submersible pumps for pumping out tanks

10. Pump Types - Uses Positive Displacement Pumps Fuel transfer
Lube oil service
Aqueous film forming foam (AFFF) service pumps, which pump a foam and seawater mixture for fire fighting.
Proportioning pumps for metering injections of various materials into a system.
Bilge pumps
Stripping pumps for skimming impure layers in a fuel or oil tank
Miscellaneous service pumps

11. Displacement Pump (Reciprocating)
Self-Priming — The ability of a pump to purge air from its system and creating an area of low pressure that permits water to flow into the pump casing.

12. Displacement Pump (Rotary)
Self-Priming — The ability of a pump to purge air from its system and creating an area of low pressure that permits water to flow into the pump casing.

13. Displacement Pump (Screw)
Self-Priming — The ability of a pump to purge air from its system and creating an area of low pressure that permits water to flow into the pump casing.
A diagram of an Archimedes screw pump

14. Axial Flow Pump
An axial-flow pump uses a screw propeller to axially accelerate the liquid.
The outlet passages and guide vanes are arranged to convert the velocity increase of the liquid into a pressure.

15. Axial Flow Pump
Ship's Waterjet System

16. Centrifugal Pump

17. Single-entry centrifugal pump Double-entry centrifugal pump

18. Multi-stage centrifugal pump

19. Centrifugal Pump
Centrifugal pumps, while being suitable for most general marine duties, are not self priming and require some means of removing air from the suction pipeline and filling it with liquid.
Where the liquid to be pumped is at a level higher than the pump, opening an air cock near the pump suction will enable the air to be forced out as the pipeline fills up under the action of gravity.
If the pump is below sea water level, and sea water priming is permissible in the system, then opening a sea water injection valve and the air cock on the pump will effect priming.

20. Be sure to select “self priming” when self priming is needed
Centrifugal Pump
Pump manufacturers now offer Centrifugal Pumps which include automatic priming units.
Be sure to select “self priming” when self priming is needed

21. Ejectors An ejector is a form of pump which has no moving parts.
A high-pressure liquid or a vapour such as steam discharges from a nozzle as a high-velocity jet and entrains any gases or liquids surrounding the nozzle. The mixture enters a converging-diverging diffuser tube where some of the kinetic energy is converted into pressure energy.

22. Ejectors Effects/Principles - Venturi Effect
The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe.
The Venturi effect is named after Giovanni Battista Venturi (1746–1822), an Italian physicist.

23. Submersible Pumps
Electro-submersible pumps are turbine pumps that are close-coupled to an electric motor.
The motor and pump are in the one unit with the motor underneath keeping the unit submerged.
The pump is dimensioned for use in bores and is very long in comparison to its diameter.
The advantages of the electro-submersible pump are:
It does not have a long drive shaft.
It may be installed in a misaligned bore.
Marine uses include: sewage tanks, cargo oil tanks, and oil wells.

24. Pumps – What to Know MESD professionals should:
have an understanding of how the various types of pumps operate
know which pumps work best for various operational situations
be able to identify the various types of pumps

25. Recap What is a Pump? Pump Types Displacement Pump Axial-Flow Pump
Centrifugal Pump
Ejectors
Submersible Pumps

26. ANY QUESTIONS?