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Dr. C. L. JonesBiosystems and Ag. Engineering

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)

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Dr. C. L. JonesBiosystems and Ag. Engineering

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…….

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Dr. C. L. JonesBiosystems and Ag. Engineering

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

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Dr. C. L. JonesBiosystems and Ag. Engineering

Mechanical Efficiency

• Ratio: • Power Output:

• English Units, HP:

• Efficiency

PowerOutput

PowerInput

oP WQ g

1714o

QPP

om

i

Pe

P

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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

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Dr. C. L. JonesBiosystems and Ag. Engineering

Pumps

• Two typesFlow rates Pressure Flow

characteristics

Displacement

- plunger

- piston

- rotary

Low High Pulsating

Dynamic

- centrifugal

- jet

- airlift

High Low Steady Flow

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Dr. C. L. JonesBiosystems and Ag. Engineering

Displacement Pumps

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Dr. C. L. JonesBiosystems and Ag. Engineering

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

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Dr. C. L. JonesBiosystems and Ag. Engineering

Displacement Pumps

• Rotary Pumps (gear, lobe, screw, vane)– Most popular: gear pumps– 90%+ mechanical eff.– Relatively constant output

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Dr. C. L. JonesBiosystems and Ag. Engineering

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

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Dr. C. L. JonesBiosystems and Ag. Engineering

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Dr. C. L. JonesBiosystems and Ag. Engineering

Performance Curves

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