Fluid Mechanic
Design Project
It is desired to design a pump-piping system to keep a 1-million-gallon capacity water tank filled. The plan is to use a modified (in size and speed) version of the model 1206 centrifugal pump manufactured by Taco Inc., Cranston, Rhode Island. Test data have been provided to us by Taco Inc. for a small model of this pump:
D =
5.45 in. , Omega=
1760 rpm , tested with water at 20 °C:
The tank is to be filled daily with rather chilly (10 °C) groundwater from an aquifer, which is 0.8 miles from the tank and 150 ft lower than the tank. Estimated daily water use is 1.5 million gal/day. Filling time should not exceed 8 h/day. The piping system should have four gate valves with variable openings, 10 elbows of various angles, and galvanized iron pipe of a size to be selected in the design. The design should be economical
—
both in capital costs and operating expense. Taco Inc. has provided the following cost estimates for system components:

Q
, gal/min
0
5
10
15
20
25
30
35
40
45
50
55
60
H
, ft
28
28
29
29
28
28
27
26
25
23
21
18
15
Efficiency, %
0
13
25
35
44
48
51
53
54
55
53
50
45
Pump and motor Pump speed Valves
Elbows
Pipes Electricity cost
$3500 plus $1500 per inch of impeller size Between 900 and 1800 rpm
$300 plus $200 per inch of pipe size
$50 plus $50 per inch of pipe size
$1 per inch of diameter per foot of length 10¢ per kilowatt-hour
Your design task is to select an economical pipe size and pump impeller size and speed for this task, using the pump test data in nondimensional form as design data. Write a brief technical report (five to six
printed
pages) showing a schematic diagram of the pump-piping system design, the calculations and graphs, and the references used.