1. Pumps – Lectures 1
• Outline:
• Where are pumps used
• Pumps, fans, compressor differences
• General HP and mechanical efficiency
• Types of Pumps
– Displacement
– Dynamic
• Reading:
– Handouts:
• ITT Goulds Pumps Centrifugal Pump Fundamentals (in class) read all
• Fluide Design Inc. Centrifugal Pump Fundamentals (download)
Dr. C. L. Jones
Biosystems and Ag. Engineering
1
2. Pumps, Fans, Compressors--
Turbomachines
• Turbomachines: change energy level of flowing fluid
by means of momentum exchange
• 2nd only to electric motors in number
• Wide spread in ALL industries
– Power units: cars/trucks, tractors
– Computers
– Grain elevators
– Oilfield
– Water supply/treatment
– Food processing
– And…….
Dr. C. L. Jones
Biosystems and Ag. Engineering
2
3. Pumps, Fans, Compressors--
Turbomachines
• Differences between pumps, fans,
compressors
– Pumps: move liquids
– Fans: move gases with little increase in
pressure
– Compressors: move gases with greater
increase in pressure
Dr. C. L. Jones
Biosystems and Ag. Engineering
3
4. Mechanical Efficiency
PowerOutput
• Ratio: PowerInput
• Power Output: Po = WQ ρ g
QP
• English Units, HP: Po =
1714
• Efficiency Po
em =
Pi
Dr. C. L. Jones
Biosystems and Ag. Engineering
4
5. Pump example 1
• A pump provides 0.009 m^3/s of water
and total head of 10.6 m. Determine
the power output of the pump. If the
power input is 1310 W, determine the
mechanical efficiency of the pump.
• Pump Example 2, English Units
– Will be shown in class
5
6. Pumps
• Two types
Flow rates Pressure Flow
characteristics
Displacement Low High Pulsating
- plunger
- piston
- rotary
Dynamic High Low Steady Flow
- centrifugal
- jet
- airlift
Dr. C. L. Jones
Biosystems and Ag. Engineering
6
8. Displacement Pumps
• Reciprocating and Piston Pumps
– Crank
– Connecting rods
– Pistons or plungers
– Vol. efficiencies > 97%, Mech. eff. approx. 90%
– For more stable flow, increase number of
cylinders
Dr. C. L. Jones
Biosystems and Ag. Engineering
8
9. Displacement Pumps
• Rotary Pumps (gear, lobe, screw, vane)
– Most popular: gear pumps
– 90%+ mechanical eff.
– Relatively constant output
Dr. C. L. Jones
Biosystems and Ag. Engineering
9
12. Dynamic Pumps
• Centrifugal
– Relative simplicity
– Mech. eff. as high as 90%
– Can handle fluids containing suspended solids
– Ease of maintenance…good for food products
– 2 parts: impeller and casing
– Radial, mixed, axial flow
Dr. C. L. Jones
Biosystems and Ag. Engineering
12
13. Dr. C. L. Jones
Biosystems and Ag. Engineering
13
