1. The document describes modifications made to improve an industrial pipe cooling system. The original system cooled extruded metal pipes with water nozzles but took too long (52 feet) and inconsistently cooled the pipes before the plastic coating melted. 2. The proposed solution added chillers and increased the water pressure and flow rate through nozzles. Modeling showed this would reduce the required cooling length to 24 feet, freeing up plant space. 3. A cost analysis determined the modifications would cost $34,838.05 but that the additional plant space alone would offset the cost within a quarter by enabling new processes and manufacturing.

1. 1
IMPROVEMENT OF INDUSTRIAL EXTRUDED
PIPE COOLING SYSTEM
MAE 4071: THERMAL SYSTEMS DESIGN
BY:
THADDEUS BERGER
MARTIN BONILLA
CLAUDE BROOKS
CLYDE BROWN
ALEXANDER EIERLE
JONAS FUGLAS
ELIZABETH HEEKE
JOHN HILKER
PAUL KEPINSKI
ANDRE-LOUIS POUNDER
AUSTIN SPAGNOLO
NATE VORIS
SUBMITTED:
23 NOV. 2015
INSTRUCTOR:
DR. GROVES

2. 2
CONTENTS
Figures................................................................................................................................................................................................3
Tables.................................................................................................................................................................................................3
Executive Summary .........................................................................................................................................................................4
Introduction......................................................................................................................................................................................5
Problem Statement.....................................................................................................................................................................5
Objectives .....................................................................................................................................................................................5
Conceptual Design...........................................................................................................................................................................5
Proposed Solution.......................................................................................................................................................................5
Fluid and Heat Transfer Analysis...............................................................................................................................................6
Reliability.......................................................................................................................................................................................9
Cost Analysis...............................................................................................................................................................................11
Modeling.....................................................................................................................................................................................12
Results..............................................................................................................................................................................................16
Conclusion.......................................................................................................................................................................................17
Appendix..........................................................................................................................................................................................18
A: Team Responsibilities*........................................................................................................................................................18
B: Budget.....................................................................................................................................................................................19
References.......................................................................................................................................................................................20

3. 3
FIGURES
Figure 1: Original cooling bay in use at industrial plant............................................................................................................5
Figure 2: Proposed cooling bay system schematic....................................................................................................................6
Figure 3: Nozzle..............................................................................................................................................................................10
Figure 4: Chiller..............................................................................................................................................................................10
Figure 5: Centrifugal pump. .........................................................................................................................................................10
Figure 6: Reservoir tank................................................................................................................................................................10
Figure 7: Full system......................................................................................................................................................................11
Figure 8: Original system before modifications.......................................................................................................................12
Figure 9: Modified system............................................................................................................................................................13
Figure 10: Close-up view of modified system...........................................................................................................................13
Figure 11: Close-up view of tanks and piping...........................................................................................................................14
Figure 12: Top view of cooling bay system. ..............................................................................................................................14
Figure 13: Top view system drawing..........................................................................................................................................15
TABLES
Table 1: Castiron pipe data used for system analysis..............................................................................................................7
Table 2: Minor loss factors for pipe fittings................................................................................................................................7
Table 3: Failure rates for system components. ..........................................................................................................................9
Table 4: Table of results................................................................................................................................................................16
Table 5: Team responsibilities.....................................................................................................................................................18
Table 6: Budget for modified system. ........................................................................................................................................19

4. 4
EXECUTIVE SUMMARY
A system to extrude metal pipes coated with thermoplastic for applications in oil rigumbilicalswas originally
cooled usingnozzles which sprayed the pipe with water at 60 F as itmoved down a conveyor in an industrial plant.
The original systemcooled the pipein 52 feet and was not ableto consistently cool the extrusion before the
thermoplastic coatingbegan to melt. To address the issue,nozzle flow rate was increas ed by increasingthewater
pressure,and temperature difference was increased by addingchillersto the system. For an additional $34,838.05,
the solution improved the system by reducingthe length of conveyor required to cool the pipe to 24 feet, reduced
waste, and opened approximately 560 squarefeet of additional spaceon the plantfloor. Given the design of the
existingmanufacturingfloor and its preset coolingbay structurethe closestreduction was brought to 27ft without
drastically alteringthe system. Without consideringthe changes in power and wasted materials (amongother
factors),the additional spacealonewas determined to be enough to balancethe cost of the improvements in less
than one quarter.

5. 5
INTRODUCTION
PROBLEM STATEMENT
Piping for oil rig umbilical’s consists of extruded metal coated in a
protective layer of thermoplastics.The pipe is extruded atabout 2,200 F
and then quenched with room temperature water, cooling it to 325 F.
The pipethen moves to the Steel CoolingBay where 60F water is sprayed
on alternatingsides at 100 psi. This is done to bring the steel down to a
standard manufacturing room temperature of 80 F. Then the steel pipe
proceeds to the thermoplastic extrusion section where a plastic coating
is applied to the outside of the steel pipe for protection. If the pipe does
not reach its target temperature of 80 F then bubbles or deformities will
occur in the plastic extrusion section rendering said product unusable.
This ultimately causes a reduction in manufacturing efficiency,
profitability and increased fluctuations of waste.
OBJECTIVES
The objective of this project is an optimized system which can
consistently and efficiently cool the extruded pipe within the desired
time range so that the thermoplastic being extruded onto the pipe
coatingwill not melt. Ideally,to further optimize the system, the length
of the coolingprocess could bereduced by increasingthe coolingrateof
the steel pipe after the clenching phase. This will shorten the length of
the overall cooling bays and dramatically open plant floor space, which
provides the availability for new manufacturing process and space
availability.This would improvethe overall efficiency and profitability of the plant.
CONCEPTUAL DESIGN
PROPOSED SOLUTION
The proposed solution consisted of chillers in parallel cooling water to be pumped from a reservoir through a high-
flow rate circulation pump.The pump chosen used 1.5 hp and had a flow rate of 40 gpm, which resulted in a 0.3918
gpm flow rate from each of the 32 nozzles.The chillers(5 hp) could operate up to 15 gpm and each had a 36 gallon
capacity.A 60 gallon reservoir was used between the chillers and thepump. A schematic of the solution is shown in
Figure 1, and a more detailed breakdown of the components and their respectivecosts can be found in Appendix B.
Figure 1: Original cooling bay in use at industrial
plant.

6. 6
Figure 2: Proposed cooling bay system schematic.
From the reservoir,the water will be flowingat 40 gpm due to the centrifugal pump. The coolingwater entering
the chillersis assumed to be at a room temperature of 72.
For the control volume of a chiller,thevolumetric flowrate would be a third of the total flowrate. Then, a pplying
an energy balanceto the control volume:
𝑞 = ( 𝑚𝑎𝑠𝑠 𝑓𝑙𝑜𝑤) ∗ 𝑐 𝑝
( 𝑇𝑜𝑢𝑡 − 𝑇𝑖𝑛
)
It is found that the outlet temperature from each chiller will be64;therefore, the coolingwater will enter the
nozzles atthe temperature. This is a decent temperature change for a total flowrate of 40 gpm.
FLUID AND HEAT TRANSFER ANALYSIS
The followingassumptions weremade in the analysisof the problem:
1. The nozzles arearrayed around the circumference of the pipeso that they completely cover a section of
pipe 7.14 inches longwith water at 40 F.
2. Water flows with constantvelocity.
3. Neglect heat loss dueto convection of air.
4. Constant coolingrate.
5. The pipe exits the quencher at 325 F.
6. The pipe’s desired ending temperature is 80 F.

7. 7
Piping assumptions
Pipe Type Inner Diameter Friction Factor
CastIron Fittings 0.824 in 0.025
Table 1: Cast iron pipe dataused for system analysis.
Fitting Minor Loss
Threaded Tee 0.9
90 Degree Threaded 1.5
Union Threaded 0.08
Table 2: Minor lossfactorsfor pipe fittings.
The constants used for analysis were:
● ρ = 0.2834 lbm/in3
● cp = 0.12
● Tinfinity = 40F
● Ts, final = 80F
● Ts, initial = 325F
● Thickness = 0.25 in
● k = 7.743 x 10-6 in2/s
● v = 239.616 x 10-5 BTU/s in F
● Pr = 10.518
● Nozzle Spray Swath: 7.14 in
● Nozzle Exit Velocity: 91.11 in/s
● Tube Extrusion Speed: 0.75 in/s
● Nozzle Array Distribution:1 array every 3 ft of cooler length
● z1 = 0 in, centrifugal pump is on floor
● z2 = 36 in,system is 36 in off the floor
● P1 = 25 psi,pump pressureoutput
● P2 = 100 psi,specification pressureof nozzles
● hL = 0, due to no major losses
● a1 = 1, basealpha
● a2 = (1 + 𝜁𝐿/𝐷 + 𝛴𝑘)

8. 8
Usingthe modified Bernoulli equation shown below, we wanted to find the flowrate for all 32 nozzles.
(𝑃1 /𝜌𝑔 + 𝛼1(𝜈1/2𝑔) + 𝑧1) = (𝑃2 /𝜌𝑔 + 𝛼2(𝜈2/2𝑔) + 𝑧2) + ℎ 𝐿
The area of analysisisfromthe pump to the nozzle head,
𝛼2 = ( 1 + 0.025 ∗ (30.5/0.824) + 4.22) = 6.145
The pump chosen has a flow rate of 40 GPM thus,
𝑉1 = 40 𝑔𝑝𝑚 = 9240 𝑖𝑛3
/𝑚𝑖𝑛 ≫ 𝜐1 = (3240𝑖𝑛3
/𝑚𝑖𝑛) (1/0.53𝑖𝑛2
)(1 𝑚𝑖𝑛/60 𝑠) = 288 𝑖𝑛/𝑠
Now plugginginto the Bernoulli equation gives,
(25/(0.036 ∗ 386 ) + (1) 288/ (2 ∗ 386) + 0 = (100/(0.036 ∗ 386) + (6.145)𝜐2
/(2 ∗ 386) + 36) + 0
𝜐2
= 91.11 𝑖𝑛/𝑠 ≫ 𝑉2 = 48.3 𝑖𝑛3
/𝑠 𝑜𝑟 12.54 𝐺𝑃𝑀
From our analysis wedetermined the resultingflowrate to 12.54 GPM the combine nozzle flow rate, thus each
individual nozzleexperiences a flowrate of 0.3918 GPM.
Rate of Temperature Loss
Reynolds Number (Length)
Nusselt Number (Length)
Convection Heat Transfer Coefficient (Length)

9. 9
Final Cooler Length
ℎ 𝑥 = 0.000115063 ∗ √(91.11 − 0.75)/𝑥
We assumethat the rate of temperature loss isconstant,thus we set dT/dt equal to itself and found:
𝑑𝑇/𝑑𝑡 = [−0.00230126√91.11 − 0.75/𝑥 (𝑇 − 40)]/(0.2834 ∗ 0.25 ∗ 0.12)
Thus, we determined the required total spray swath to be 50.77 inches:
285/40 = √ 𝑥1/𝑥2 → 𝑥1/𝑥2 = 81225/1600 → 𝑥1 = 50.77𝑥2
With that we were able to calculatethe Reynolds number, Nusseltnumber and the convection heat transfer at
startof the process 0.0011 BTU/s-F-in2 and the heat transfer atend of the process.That and our constants we
were able to calculatethe final cooler length.
𝑅𝑒2 = 0.75 ∗ 50.77/239.616 ∗ 10−5
= 15891.1
𝑁𝑢2 = 0.332(15891.1).5
∗ 10.5181/3
= 91.7
ℎ2 = (7.743 ∗ 10−6
/50.77) ∗ 91.7 = 0.00015 𝐵𝑇𝑈/𝑠𝐹𝑖𝑛2
𝐹𝑖𝑛𝑎𝑙 𝐿𝑒𝑛𝑔𝑡ℎ = 36𝑖𝑛 ∗ (50.77𝑖𝑛/7.14𝑖𝑛) = 255.98 𝑖𝑛𝑐ℎ𝑒𝑠 = 21.33 𝑓𝑡
This measurement is strictly required by the nozzle array set-up, so takingto accountthe needed empty space,the
actual cooler length comes out to be 24ft.
RELIABILITY
Reliability in Series:
𝑅𝑠 = 𝑒− ∑ 𝜆𝑡
Reliability in Parallel:
𝑅|| = 𝑒−𝜆1 𝑡
+ 𝑒−𝜆2 𝑡
− 𝑒−(𝜆1+𝜆2)𝑡
t = 2000 hours
Part Reliability (rate/hour)
90 Degree Elbow 0.2x10-6
SplittingT 0.5x10-6
Nozzle 10.0x10-6
Pump 60.0x10-6
Chiller 85.0x10-6
Tank 5.0x10-6
Table 3: Failure ratesfor system components.

10. 10
Figure 3: Nozzle.
𝑅𝑠1
= 𝑒−(0.2𝑥10−6
+10𝑥10−6
)(2000 )
= 0.97
𝑅𝑠2
= 𝑒−(0.2𝑥10−6
+0.5𝑥10−6
)(2000)
= 0.99
𝑅𝑠3
= 𝑒−(10𝑥10−6
)(2000)
= 0.98
𝑅𝑠1 ||𝑠2
= (0.97 + 0.98) − (0.97)(0.98) = 0.99
𝑅 𝑇 = (0.99)(0.99) = 0.98
𝑅𝑠17 𝑁𝑜𝑧𝑧𝑙𝑒𝑠
= 0.9817
= 0.70
𝑅𝑠17 ||𝑠17 = (0.7 + 0.7) − 0.72
= 0.91
Figure 4: Chiller.
𝑅 𝑐ℎ𝑖𝑙𝑙𝑒𝑟1 ||𝑐ℎ𝑖𝑙𝑙𝑒𝑟2
= 2𝑒−(85𝑥10−6
)(2000 )
− 𝑒−(2∗85𝑥10−6
)(2000 )
= 0.9755
𝑅 𝑐ℎ𝑖𝑙𝑙𝑒𝑟3
= 𝑒−(85𝑥10−6
)(2000 )
= 0.84
𝑅 𝑐ℎ𝑖𝑙𝑙𝑒𝑟1 ||𝑐ℎ𝑖𝑙𝑙𝑒𝑟2||𝑐ℎ𝑖𝑙𝑙𝑒𝑟3
= (0.9755 + 0.84) − (0.84)(0.9755) = 0.996
Figure 5: Centrifugal pump.
𝑅 𝑝𝑢𝑚𝑝 = 2𝑒−(60𝑥10−6
)(2000)
− 𝑒−(2∗60𝑥 10−6
)(2000)
= 0.9872
𝑅 𝑝𝑢𝑚𝑝3
= 𝑒−(60𝑥10−6
)(2000)
= 0.8869𝑅 𝑝𝑢𝑚𝑝1 ||𝑝𝑢𝑚𝑝2||𝑝𝑢𝑚𝑝3
= (0.9872 + 0.8869) − (0.8869)(0.9872) = 0.998
Figure 6: Reservoir tank.
𝑅𝑡𝑎𝑛𝑘 = 𝑒−(5𝑥10−6
)(2000 )
= 0.99

11. 11
Figure 7: Full system.
𝑅𝑠𝑦𝑠𝑡𝑒𝑚 = (0.998)(0.996)(0.91)(0.99) = 0.8955
Reliability of System:89.55%
COST ANALYSIS
By reducing the total length of the coolingbay by almosthalf,we have freed up spacein the manufacturingfacility.
The facility is rented at $20 per squarefoot per month. Usingthe renting priceover the opened area,we found the
time to balancethe costof the changes and improvements of the coolingbay is only 2 months and 23 days.
L = length of coolingblock
W = width of coolingblock area
p = priceper squarefoot
𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝐶𝑜𝑠𝑡 𝑝𝑒𝑟 𝑀𝑜𝑛𝑡ℎ = 𝐿 ∗ 𝑊 ∗ 𝑝𝑟𝑖𝑐𝑒 = 52 ∗ 48 ∗ $20.00 = $49,920.00 𝑝𝑒𝑟 𝑚𝑜𝑛𝑡ℎ
𝑁𝑒𝑤 𝐶𝑜𝑠𝑡 𝑝𝑒𝑟 𝑀𝑜𝑛𝑡ℎ = 27 ∗ 20 ∗ $20.00 = $25,920.00 𝑝𝑒𝑟 𝑚𝑜𝑛𝑡ℎ
Cost of changes = $34,838.05
𝑇𝑖𝑚𝑒 𝑡𝑜 𝑅𝑒𝑐𝑢𝑝𝑒𝑟𝑎𝑡𝑒 𝐶ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝐶𝑜𝑠𝑡 = 𝐶𝑜𝑠𝑡 𝑜𝑓 𝑐ℎ𝑎𝑛𝑔𝑒𝑠 ÷ 𝐶ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑐𝑜𝑠𝑡 = 34,838 ÷ (49,920 − 25,920)
= 1.45 𝑚𝑜𝑛𝑡ℎ𝑠

12. 12
MODELING
The CAD modeling of the solution was done in SolidWorks.Theassembly can be seen on the followingpages.Figure
7 illustrates the plant if the assembly were to stay at its given length of 52 ft long. The current setup utilizes 4
recycling tanks which collect all of the drained water after it has come in with the hot steel pipe. There are 3 low
gradeheat exchangers which then cool the water and feed them back into the nozzles.Figure 8 illustrates thesystem
after the heat transfer process has been overhauled to be more efficient. This system incorporates two recycling
tanks, 3 pumps and 3 heat exchangers of high quality. The water first is collected through the drains in the steel
coolingbays and funneled into the recyclingtanks (Figure 10). From there the recycled water is then sucked out of
the tanks and into the (chiller) heatexchanger so that the 80F water can be cooled down to 40F (Figures 9 and 11).
After the water has been chilled itis thesucked out of the heat exchanger by use of the pump atroughly 15 gpm per
pump and into the nozzle spray apparatuses (Figures 9 and 11). Then through the use of pipereducers, the water is
funneled from ¾ in pipeto ⅛ in nozzles where the psi is drastically increased (Figure 9). From there the nozzles then
spray the steel pipes in a manner at which 50% of one sideis sprayed and then 50%of the other sideis then sprayed
at a 100 psi and 40F. The water is then once again drained from the coolingbays and repeated over and over again
in an open-loop heattransfer process. The drawing(Figure12,pg.16) of the assembly demonstrates the dimensional
Figure 8: Original system before modifications.

13. 13
analysisof the final reduced system. The overhaul of the system reduced the steel coolingbay from 52 ft longto 27
ft long.This left the system with 3 total heat exchangers,3 15 Gpm pumps, and two tanks being used.
Figure 9: Modified system.
Figure 10: Close-up view ofmodified system.

14. 14
Figure 11: Close-up view oftanksand piping.
Figure 12: Top view ofcooling bay system.

15. 15
Figure 13: Top view system drawing.

16. 16
RESULTS
The final results of the modified system are shown below:
Required Total Spray Swath 50.77 Inches
Final Cooler Length 24 Feet
Rate of Temperature Loss 10.35 F/s
Initial Convection Heat Transfer Coefficient 0.00015 BTU/s-in2-F
Final Convection Heat Transfer Coefficient 0.0011 BTU/s-in2-F
Total Flow Rate 12.54 GPM
Individual NozzleFlow rate 0.3918 GPM
System Reliability 79.58%
Cost $34,838.05
Time to Recover Cost 3.11 months
Table 4: Table ofresults.

17. 17
CONCLUSION
By increasingthepressureand addingchillers to thesystem, the length of the coolingbay was reduced by 52%, while
consistently coolingtheextruded pipe to 80 F before addingthe thermoplastic coating.Thenew system will improve
plant profitability by reducing waste and opening additional space on the plant floor. The reliability of the system
was found to be about 89%. The improved design will cost an additional $34,838.05, which is more than balanced
by the improved ability of the system to cool the extruded pipe consistently to an acceptabletemperature and the
additional floor spacethatbecomes availableas a resultof shorteningthe coolingbay.In fact, the extra spacealone
can balanceout the costof the improvements in its firstquarter of use.

18. 18
APPENDIX
A: TEAM RESPONSIBILI TIES*
*Everyone helped with the presentations.
Name Position Responsibility
Thaddeus Berger Technical Writing Lead Writing
Martin Bonilla CAD Analyst CAD
Claude Brooks Technical Writer Writing
Clyde Brown Team Lead CAD
Alexander Eierle Reliability Calculations Calculations
Jonas Fuglas CAD Analyst CAD
Elizabeth Heeke Technical Writer Writing
John Hilker Cost Calculations Calculations
Paul Kepinski Fluids Calculations Calculations
Andre-Louis Pounder Heat Calculations Calculations
Austin Spagnolo Calculations CAD
Nate Voris Heat Calculations Calculations
Table 5: Team responsibilities.

19. 19
B: BUDGET
Part Unit Price Quantity Total Price
Circulation Pump for
water, 1.5 hp 208-
240/460 V AC, 40 gpm
flow rate
$661.95 3 $1985.85
High-Flow, Circulating
Process Chiller,60
kBTU/hr, 460 V/3 PH, 5
hp, 15 gpm flow rate, 36
gal tank
$10,619.44 3 $31,858.32
Horizontal Polyethylene
Tank w/ Legs, 60 gal w/
drain,38.5” length
$496.94 2 $993.88
Total $34,838.05
Table 6: Budget for modified system.

20. 20
REFERENCES
 Incropera,F.P., DeWitt, D.P., Bergman T., and LavineA., Fundamentals of Heat and Mass Transfer,6th
Edition, Wiley (2006).
 Cengel, Y.A., and J.M. Cimbala,Fluid Mechanics –Fundamentals and Applications,3rd Ed., McGraw-Hill
(2014).
 Parts:
"Circulation Pumps." McMaster-Carr. N.p., n.d. Web.
"Easy-Drain Cylindrical Tanks." McMaster-Carr. N.p., n.d. Web.
"Polyethylene Tanks." McMaster-Carr. N.p., n.d. Web.