1. Pumps Outline: Where are pumps used
Pumps, fans, compressor differences
General HP and mechanical efficiency
Types of Pumps
Displacement
Dynamic
Reading:
Handouts:
Chapter 4 Principles of Process Engineering
Fluide Design Inc. Centrifugal Pump Fundamentals (download)
Dr. C. L. Jones
Biosystems and Ag. Engineering

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

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

4. Mechanical Efficiency
Ratio:
Power Output:
English Units, HP:
Efficiency
Dr. C. L. Jones
Biosystems and Ag. Engineering

5. Pump example 1
A pump provides 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.

6. Pumps Two types Flow rates Pressure Flow characteristics Displacement
- plunger
- piston
- rotary
Low
High
Pulsating
Dynamic
- centrifugal
- jet
- airlift
Steady Flow
Dr. C. L. Jones
Biosystems and Ag. Engineering

7. Displacement Pumps
Dr. C. L. Jones
Biosystems and Ag. Engineering

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

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

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

13. Dr. C. L. Jones
Biosystems and Ag. Engineering

14. Performance Curves
Dr. C. L. Jones
Biosystems and Ag. Engineering

15. Performance Curves
Dr. C. L. Jones
Biosystems and Ag. Engineering

16. Centrifugal Pump Affinity Laws
Dr. C. L. Jones
Biosystems and Ag. Engineering

17. Centrifugal Pump Affinity Laws
Dr. C. L. Jones
Biosystems and Ag. Engineering

18. Centrifugal Pump Fundamentals
Static head: the height of a column of liquid
Units: feet or meters
Pump imparts velocity to liquid…velocity energy becomes pressure energy leaving the pump. Head developed = vel. energy at the impeller tips.
Why do we use “feet” or “head” instead of “psi” or “pressure”?
Pump with impeller D will raise a liquid to a certain height regardless of weight of liquid
Dr. C. L. Jones
Biosystems and Ag. Engineering

19. Converting pressure to head in feet
Dr. C. L. Jones
Biosystems and Ag. Engineering

20. Suction Lift
Dr. C. L. Jones
Biosystems and Ag. Engineering

21. Suction Head
Dr. C. L. Jones
Biosystems and Ag. Engineering

22. Static Discharge Head
Static Discharge Head = vertical distance from pump centerline to the point of free discharge or the surface of the liquid in the discharge tank.
Dr. C. L. Jones
Biosystems and Ag. Engineering

23. Total Static Head
Vertical distance between the free level of the source of supply and the point of free discharge or the free surface of the discharge liquid.
Dr. C. L. Jones
Biosystems and Ag. Engineering

24. Total Dynamic Suction Lift or Head
(fluid below suction) Static suction lift - velocity head at suction + total friction head in suction line
(fluid above suction) Static suction head + velocity head at pump suction flange – total friction head in suction line
Velocity head = energy of liquid due to motion, Usually insignificant
Dr. C. L. Jones
Biosystems and Ag. Engineering

25. Total Dynamic Discharge Head
Static discharge head + velocity head at pump discharge flange plus discharge line friction
Total Dynamic Discharge Head (TH or TDH) (this is what we design for!!!)
Total dynamic discharge head – total dynamic suction head (tank above suction)…. Or….
Total dynamic discharge head + total dynamic suction lift (tank below suction)
Dr. C. L. Jones
Biosystems and Ag. Engineering

26. TDH includes friction losses due to piping and velocity
Total Dynamic Discharge Head (TH or TDH) (this is what we design for!!!)
TDH includes friction losses due to piping and velocity
Dr. C. L. Jones
Biosystems and Ag. Engineering

27. One last item to consider… NPSH (net positive suction head)
Dr. C. L. Jones
Biosystems and Ag. Engineering

28. NPSHR
Dr. C. L. Jones
Biosystems and Ag. Engineering

29. NPSHA
Dr. C. L. Jones
Biosystems and Ag. Engineering

30. NPSHA
Dr. C. L. Jones
Biosystems and Ag. Engineering

31. Capacity, Power, Efficiency
Capacity Q, gpm = 449 x A, ft2 x V, ft/sec
Where A = cross-sectional area of the pipe in ft V = velocity of flow in feet per second
Bhp = actual power delivered to pump shaft by driver
Whp = pump output or hydraulic horsepower
Dr. C. L. Jones
Biosystems and Ag. Engineering

32. Pump Efficiency Ratio of whp to bhp: Dr. C. L. Jones
Biosystems and Ag. Engineering

33. System Example: 80 ft of 4” ID galv
System Example: 80 ft of 4” ID galv. iron pipe with 3 elbows, 75’ lift, pumps from an open tank, discharges through a pipe to a tank at atm. Pressure (find rate, imp. dia., eff., motor size, rpm)
Ratio of whp to bhp:
Dr. C. L. Jones
Biosystems and Ag. Engineering

34. Homework Handout http://biosystems. okstate
Homework Handout hw.pdf

35. Questions???
Dr. C. L. Jones
Biosystems and Ag. Engineering