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CLEARINGHOUSEFOR FEDERAL SCIENTIFIC AND TECHNICAL INFORMATION

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UNITRD STATESDEPARTMENT OF THE INTERIOR

STEWART L.. UDALL, SECRETARY

IOENNETH HOLUM, ASSI3TA SECREITARY

FOR WATER AND POWER DEVELOHIT

RESEARCH AND DEVELOPMET PROGRESS REPORT NO. ii-9

AN L9VESTIGATION OF THE USE OF ACOUSTIC VThRATIONS TOIMPROVE HEAT TR3EER RATES AND REDUCE SCALING

IN DISTILLATION UT USED FOR SAlINE WATER CO!JVEIßIOII

BY

I. A. Raben, George Coerfor, and. Robert DietertSOUTHWEST RESEARCH INSTITUTE

San AaLouio, Texas

FOR

OCE OF SALINE WATER

Charles F MacGowan, Director

W, Sherman Glllam, Chief, Division of Research

E. A. Hag]un:1, Fí&ysical Chemist

MARCH 1961

TiBLE OF CONTENTS

Page

LIST Ô? !LLJTP4TIO'L

LIST OF TABLES

TABLE OF NOMENCLATURE

I. INTRODUCTION i

Water Side Heat Transfer Study i

Steam Condensation Study i

Scaling Study i

II. LITERATURE SURVEY 3

III . WATER SIDE ifEAT TRANSRER STUDY 6

A. Rxperimental 6

Apparatus Utilizing Plane Waves in vater 6

Apparatis Utilizing Longitudinal Vibrationof the Test Section 13Apparatus Utilizing Transverse Vibrationof the Test Section 15

Apparatus UtilizLrig Transverse Vibrationof a Pipe vi.th Water Flowing on the Outside of the Pipe 17

B. Procedure 17

Experimental Procedure for Approachesi, 2and3 17

Experinìantal Procedure for Approach 4 20

C. Discussion of Results 21

IV STEAM CONDENSATION SrJDY 53

L General 53

B. Effect of Acoustic Vilrations on Steam Condensation 53

Experimantal 53

Discussion of Results 57

TABLE OF CONTENTS (Contad)

Page

C. Effect of Acoustic Vibrations on Steam Condensationin the Presence of a Noncondensable Gas 67

Experimental 672, Discussion of Results 69

V, SCALING STUDY 74

A. Experimental 74

1, ApparatusProcedure 74

B, Discussion of Results 76

CONCLUSION AND RECOMMENDATIONS 100

BIBLIOGRAPIrr 103

APPENDIX A. TYPICAL EXPERIMENTAL DATA 104

APPENDIX B, PHOTOGRAPHS 112

LIST OF ILLUSTRATIONS

i Schematic Diagram of Apparatus for Heat TransferStudies 7

2 Schematic Diagram of Apparatus for the Study ofthe Effect of Acoustic Vibration in Water on HeatTransfer 10

3 Diagram of Thermocouple Installation on Apparatusfor the Study of the Effect of Acoustic Vibration inWater on Heat Transfer li

4 Schematic Diagram of Apparatus for the Study of theEffect of Acoustic Vibration in Water on Heat Transfer 12

Schematic Diagram of Apparatus for the Study of theEffect of Longitudinal Vibration on Heat Transfer

6 Schematic Diagram of Apparatus for the Study of theEffect of Transverse Vibration on Heat Transfer 16

Schematic Diagram of Apparatus for the Study of theEffect of Transverse Vibration on Heat Transfer withWater Flowing on the Outside of the Test Section in ankinular Space la

Diagram of End Connections for the Test Section 19

The Effect of Vibration on Heat Transfer from thePIpe Sides 24

10 The Effect of Vibration on Heat Transfer from thePipe Front and Back 2

11 Variation of Heat Transfer Coefficient with (Re)f forMaximum (Re) for Rims 15 through 20 26

12 Typical Temperature Difference Data for Run 15,((Re)f = i418) 33

13 Effect of Frequency on Heat Transfer Coefficient 34




LIST OF ILLUSTRATIONS (Cont'd)

Figure Page

17 Effect of Amplitude on Heat Transfer Coefficient

Effect of Amplitude ou Heat Transfer Coefficient 39.

19 Effect of Amplitude on Heat Transfer Coefficient 40

20 Effect of Amplitude on Heat Transfer Coefficient 41

21 Conparison of ¿Ts Along the Pipe Wall with andwithout Vibration for Run 21 - Re = 500 47

22 Comparison ofATs Along the Pipe Wall with andwithout Vibration for Run 22 - Re = 191 48

23 Schematic Diagram of Apparatii for the Study ofCondensing Film Coefficients under Conditions ofVibration 54

24 Diagrnm of Mthod of Connection of Driving Rod toPipe for Apparatns in Figure 23 55

25 The Effect of Vibration on the Condensate Film HeatTransfer Coefficient for Run 23 64

26 The Effect of Vibration on the Condensate JUI HeatTransfer Coefficient for Run 23 65

27 The Effect of Vibration on the Condensate Film HeatTransfer Coefficient for ibm 23, 24, and 25 66

28 Condensate Film under Conditions of Vibration 68

29 Schematic Diagram of Apparatns for Study ofCondensate Film Coefficients with Air in Inlet Steam

30 Comparison of Steam Film Coefficients underConditions of Vibration with arid without Noncondensa-tie Gases 72

31 Comparison of Steam Film Coefficients under Conditions of Vibration with and without NoncondensabieGases 73

32 Schematic Diagram of Ìpnaratus for Scaling StudIes 75

33 Calcium Sulfate Scale Removal under Conditions ofVibration 77

LIST OF ILLiJSTRATIONS (Cont'd)

F1g Page

34 CaSO4 Scaling Rim No. 5

35 CaSO4 Scaling Run No. 7 32


37 CaSO4 Scaling Run No . 10 and 22 88

38 CaSO4 Scaling Run Nos. 11 and 21 89


40 Sea Water Scaling Run Nos. 15, 19 and 20 93

LIST OF TABLES

i Sunimary of Data for Run 15 28

2 Sunnnary of Data for Run 16 29

3 Sununary of Data for Run 17 30

/4 Summary of Data for Run 18 31

5 &urrniary of Data for Runs 19 and 20 32

6 Sunary of Data on Acoustic Vibrations in WaterStream 43

7 Sumnary of Data on the Effect of Acoustic Vibrationin the Water Stream - Run 21 45

8 Summary of Data on the Effect of Acoustic Vibrationin the Water Stream - Run 22 46

9 Summary of Data for longitudinal Vibration of Pipe 50

10 Sary of Data for Transverse Vibration of Pipe 52

11 Sumnary of Data on the Effect of Vibration onCondensate Film heat Transfer Coefficient for Rim 23 58

12 Summary of Data on the Effect of VibratIon on CondensateFilin Heat Transfer Coefficient for Run 24

13 Siniunary of Data on the Effect of Vibration on CondensateFilm Heat Transfer Coefficient for Run 25 62

14 Sutuinary of Data on the Effect of Vibration on CondensateFilin Heat Transfer Coefficient with Noncondensables inthe Steam 71

15 Surnnary of Scaling Runs 78

16 Calcium Sulfate Scaling - Run No. 5 79


18 Calcium Su1fat Scaling Run No. 9 84


LIST OF TABLES (Cont'd)

Table





24 Sea Water Scaling - Run No. 15 96



i2iA

Aa

A0

C

Cp

d

di

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H

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K

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TABI2 0F NOMENCLATURE

Heat Transfer Area, ft2

Heat Transfer Area of Pipeat Average Diameter, ft2

Heat Transfer Area of Pipeat Inside Diameter, ft2

Heat Transfer Area of Pipeat Outside Diameter; ft2

Constant

Specific Heat. of Water, Btu/lb. -°F

Diameter of Pipe, ft.

Outside Diameter of Inner Pipe, ft.

Inside Diameter of Outer Pipe, ft.

Equivalent Diameter, ft. =

Frequency of V1braion, cycles/second

Amplitude of Vibration, ft.

Heat Transfer Coefficient with Vibration,Btu/hr,.-.ft2-°F

Heat Transfer Coefficient without Vibration,Btu/hr. _ftZ°F

Mean Heat Transfer Coefficìent for EntireLength of Pipe

Heat Transfer Coefficient for Condensate FHm,Btu/hr,-ft2-°F

Heat Transfer Coefficient for Water Film,Btu/hr.

Thermal Conductivity of Water, Btu/hr--ft2(°F/ft

Thermal Conductivity of Pipe Wall, Btu/hrft2(°F/f t.)

Wall Calculated

Wall Calculated

Wall Calculated

TÎBL1 OF NOMENCLATURE 'd)

Smbo1

L - Length of Pipe Transferring Heat, ft.

m - Mass Flow Rate, lbjhr.

n - Exponent

Q - Rate of Heat Transfer, Btu/hr.

Q' - Heat Flux, Btu/hr.-ft2

Rc - Resistance of Condensate Film, hr.-F/Btu

Rs - Resistance of Pipe Wall, hr. °F/Btu

R - Resistance of Water Film, lìr.-°F/Btu

(Re)f - Flow Reinolds number, dímansionless = dv O

-:7;--(Re) Vibrational Rpìolds number, dimensionless

de P

T1 - Water Inlet Temperature, °F

T2 - Water Outlet Teirrperature, °F

iL T - Mean Overall Temperature Difference, 0F

T0 - Temperature Difference without Vibration, 0F

A Tv - Temperature Difference 1th Vibration, °F

T8 - Temperature of Pipe Wall, 0F

T - Temperature of Water, 0F

U - Overall Heat Transfer Coefficient, Btu/hr.-.ft2-°F

y Velocity of Water, ftjsec.

1f - Average Velocity of Vibrating Pipe, ft./sec. = 2 FI!

X8 - Thickness of Pipe Wall, ft.

- Density of Water, lb./ft.3

ft- Viscosity of Water, lb./ft.-hr.

I. INTRODUCTION

The object of this study is to determine the feasibility of usingacoustical energy to improve the economy of evaporator operation asrelated to saline water conversion, Improvements to be sought are: (a)increased film heat transfer coefficients on the water side, (b) possiblepromotion of dropwise condensation on the steam side, and (e) reducedscale formation,

The experimental program has been divided into three major sectionsdescribed as follows:

A. Water Side Heat Transfer Sti

Heat transfer coefficients for water f ums were detennined in thesystem with and without acoustic vibration, The frequency and amplitudeof vibration were varied, and flow rates in the viscous and turbulentranges were empicred. Vibrational energy was applied in each of thefollowing systems:

Water was pumped through an electrically heated pipe.Acoustical energy was applied to tl-ìe fluid in the direction of flow toinduce turbulence in the laminar layer.

Water was pumped through an electrically heated pipe and thepipe was vibrated along its axis of symmetry. This direction of vibrationis defined as longitudinal.

Water was passed through an electrically heated pipe and thepipe was vibrated in a director perpendicular to its axis This istermed transverse vibration.

4 Water wis pumped past the outside of an electrically heatedpipe in an anmilus, and the hot pipe was vibrated transversely

B. Steam Condensation Stu

Steam condensation on the outer sumface of a water cooled verticalpipe was studied to determine the effect of transverse vibration of thepipe on the film heat transfer coefficient of condensing steam. The pur.pose of vibrating the pipe was to determine if dropwise steam condensatiöncould he promoted. This would be accomplished. by breaking the laminarlayer of condensate and throwing it away from the pipe . Heat transferdata was obtained with and without vibrations The effect of thepresence of a noncondensable gas (air) was also evaluated.

C , Sca]Jn

Overall heat transfer coefficients from condensing steam to a scalingliquor were measured to determine the effect of the mechanical vibrationof the pipe on scale formation, Steam condensed inside the vertical pipe

i

and the scaling liquor vas pumped countercurreiit -hi the annulus . Calciumsulfate in distilled water an.d sea water froni Cofpus Christi Bay were thescaling liquors studied. Two possible mechan isn by which vibration of apipe might maintain a high heat transfer rate are: (i) flaking of thescale due to mechanical bending of the pipe which would leave the pipe sur-face clean for efficient heat transfer; and (2) increased agitation nearthe surface of the vibrating pipe, which would reduce the stagnant waterfilm at the heat transfer surface, arid thus rethice the tendency to formscale. Several runs were made without vibration to define the rate ofscale formation and the change in heat transfer coefficient with time.Sixteen runs were made using vibrations of various frequencies andamplitudes.

II. LITERATURE SURVEY

Very little data have been published conceruing the effect ofacoustical vibration on heat tranfer. One of the earliest studies wasmade by Martinelli and Boelter13) in 1939. They studied the effect ofvibration on heat transfer by free convection from a horizontal cylinderínnersed in water. Their experiments indicated improvement in heattransfer coefficients.

Lemlich(i2) studied the effect of vibration on natural convectiveheat transfer. He carried out experiments using electrically heated wiresof three different diameters subjected to transverse vibration in air.Marked improvement in heat transfer coefficient was obtained by usingvibration at frequencies of 39 to 122 cycles per second. An increase incoefficient was observed for an increase in arnplitude or frequency. Noeffect was observed for change in direction of vibration.

Hwu(6) studied the effect of vibration on forced convective heattransfer by using a horizontal double pipe steam to air heat exchanger.Vibration as Thduced acoustically and superposed directly onto the airstream. The independent variables studied were flow of air, frequencyand amplitude of vibration. The imposed vibration was found to haveeffect only when it was at such frequencies that standing waves with appre-dable amplitude were set up in the heat exchanger tube. Under theseconditions, improvement of approximately 4O was obtained at a Remoldsnumber of 2080, but decreased as flow rate increased. At a Reynoldsnthnber of 5920, improvement was less than lOs.

West and Taylor(-8) studied the effect of pulsation on heat transferin the .ubulent flow range for water inside tubes . They reportedincreases in coefficients as much as 7O for Reynolds number of 30,000 to5,000. A reciprocating pump was used to produce pulsations. There

appears to be an optimum degree of dampening, since severe pulsationswere not as efficient.

Shai and Rotem() recentiy reported the results of their study onheat transfer to vater in turbulent pulsating flow in internally heatedamnuli, Based on 33 series of test runs no significant change in heattransfer coefficients was obtained at Reynoldsr1umber of 30,000 to 65,000.Their resu]:ts did not agree with that of West and Taylor, primarily dueto the fact that West, et al. did not calibrate the experimental unit forstationary flow, according to Shal..

Mueiier(15) recently analyzed pulsating flow heat transfer and alsoobtained experimental data using air in the turbulent range. His analy-sis predicted a very small reduction in heat transfer at low frequencies(i-2 cps), and this was substantiated by experimental results.

Scanion(16) reported pronounced beneficial effects of nomal surfacevibration on laminar forced eonvective heat transfer. He presented

3

results which showed 2-3 fold improvement in heat transfer coefficients.Scanlon also developed an equation which would predict local heat

transfer coefficients.

nantanarayanan(l) studied the influence of vibration on heattransfer from an electrically heated nichrome wire to parallel air streams.The independent variables were velocity (34 - 63 ft./sec.), frequency(75 - 120 cycles/sec.), arid amplitude. The heat transfer coefficientsincreased with both frequency and amplitude. An increase as high as 130%was obtained in the coefficients,

Jackson() studied the effect of acoustic vibrations on free andforced convection from steam to air. He reported that the sound pressureappreciably begins to affect the heat transfer coefficient at arQximately141 decibels when using a horizontal tube. Jac1son and Sourlock9) alsoreported that the effect of sound appeared significant at a sound pressurelevel of 110 decibels in a vertical tube. He recommended that furtherexperimental work be carried out.

Jackson and.Jobnson(8) investigated the convective flow due toacoustic vibrations in a horizontal tube. The flew was made visible-b-yilluminating smoke particles in the air by means of a 200 watt-secondflash filament source and recording motion photographically.

Fand and Kaye() reported the influence of sound on free convectionfrom a horizontal cylinder. They showed that thermoacoustic streamingcauses a marked increase in the coefficient of heat transfer from a heated

cylinder, based on experimental data presented. For a given temperaturedifference, the superposition of a sound field can increase the heat trans-fer coefficient by a factor of 3, relative to the free convection heattransfer coefficient in the absence of sound. An empirical equation waspresented to calculate the heat transfer coefficient in the presence ofhorizontal transverse sound fields. KayeTs article includes a good

literature survey.

Kubanski() studied the influence of standing sound waves on heattransfer by natural convection from a heated horizontal tuba. His resultsshowed that coefficients were Increased by a factor of two as a result of

vibration.

Ho1man() studied the effect of high constant pressure soimd fieldson free convection heat transfer from a horizontal cylinder. Coefficientswere increased approximately 100% In the presence of constant sound fields

above 134 db.

McAdams(14) presents a good discussion of dropwise condensation of

steam. He summarizes from the paper of Drew, Magie and Smith:

( :i) Dropwise condensation of steam iS oltained wLen the

condensing surface is contaminated with a suitable bromo terthat prevents the condensate from wetting the surface.

(2) Some of the important promoters are: Mercaptans oncopper; oleic acid on copper, brass, nickel and chromium.

If the surface contaminant reduces the interfacialtension sufficiently to render the suriace non-wettable, thecondensate vdll collect in drops that grow in size until dovm-wind forces cause them to roll down the surface. Since at anymoment a substantial fraction of the tube is free of condensate,much higher rates of condensation are obtained with a giventemperature difference than with a wettable surface that isinsulated with a continuous film of condensaté.

Film coefficients for dropwise condensation of steam havebeen reported to average 13,000 Btu/br ft2°F,

It is hoped by the use of acoustic vibrations, the tube surface canbe maintained free of condensate and therefore high condensing coefficientswill be obtained.

A critical review of the literature on foxmaiçn and prevention ofscale was prepared by W. L. Badger and Assoeiates) . They discussed--mech--anism of scale formation, the role of supersaturation, scaling rateinvestigations, means of reducing potential scale and means of reducingscale adherence.

Qordon(4) studied scale deposition on heated surfaces. He evaluatedthe effect of supersaturation, the effect of solution velocity, the effectof boiling ¿nd type of scale. He correlated time required for first visualobservation of scale with percent supersaturation. Solution velocity hadlittle effect on calcium sulfate scale foxuation. Nonboiling runs required20 minutes for beginning of scale formation, vth!le for boiling runs thetimes were l3]J minutes. Two types of scale were observed, a fine rownscale coming out below 217°F and a white crystalline scale above 217 F.

III. WATER SIDE hEAT TRANSJR STUDY

General

Four different approaches were studied in the evaluation of acousticvibrations on the water side heat transfer coefficient. All experimentswere directed toward creating a turbulence in the laminar water film whichnonnally restricts heat transfer.

The first apparatus utilized acoustic vibrations impressed directlyinto the water stream flowing in an electrically heated pipe. The pipe onthis arrangement was stationary and the acoustic plane waves traversed thelength of the water column in an "organ pipe" type of resonance . Thereare two postulated ihechanisms tich could cause a reduction in the waterfilm thickness. One was that at a pressure node, where the vibratory dis-placement of the water was a maximum, the relative motion between thewater and the pipe wall would create a turbulence thus reducing the thick-ness of the film. The second was that at a pressure loop or maximum, thepressure fluetuaionawouldcauze a radial displacement of the watercausing more mixing between the water in the center of the pipe and thelaminar film.

The second apparatus utilized longitudinal vibration of the pipewith no vibration impressed into the water stream. The postulated mech-

anisms which could cause heat transfer improvement in this case was thatthe relative motion between the pipe wall and the water stream wouldcreate turbulence and eddy currents in the region of the film thusreducing its thickness.

The third apparatus utilized transverse vibration of the pipe withno vibration impressed into the water stream. The postulated mechanismwhich could cause heat transfer improvement was that the transversemovement of the water in the pipe would cause greater mixing with thestagnant film.

The fourth approach was to study the effect of transverse vibrationof a pipe with water flowing on the outside of the pipe in an annularspace. Data was obtained at various frequencies (32-4 cps) and ampli-tudes ( .O25- . 150 inches) and several differenb Reynolds numbers (500-20 ,000) . Very significant improvement was obtained in the water sideheat transfer coefficient.

Details of the four methods are described below:

A. Exterimental

1. Utilizin Plane Waves in Water

A schematic diagram of the apparatus which has been asseirbiedfor heat transfer studies utilizing acoustic vibrations impressed directlyinto the water stream is shown in Figure 1. The system vins essentially a

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A section of stainless steel pipe of 1" O.D. x .035" wallthickness x 6' long was used as the test section. The vibrator wasmounted at one end of this test section and was coupled to the system by

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means of a small piston which was glued to a thin rubber diaphragm whichsealed the end of the pipe. The other end of the -test section was pro/vided with a flange so the other equipment could be attached which wouldaffect the resonance of the system. Four feet eight inches of this testsection was wrapped with an electrical heating tape which served as asource of heat. The tape was heavily insulated in order to minimizeheat loss. This electric,.l heater was capable of generating 4 K.W. ofheat of 12,000 Btu/hr./ft heat flux through the heat transfer surface.

Provisions were made for addiag a stiffening bar to the shaftextending from the vibrator. This bar was rigidly fixed at both endswith the center fastene& to the shaft.. Saverai.thicesses of bars wereprovided to a1iov. for adjustment of the frequency of the system asneeded. The support for this bar, the vibrator, and the test sectionitself were all mounted on heavy, rigid supports which were all boltedto a common channel iron foundation.

Two thermocouples were installed in the section of pipe coveredby the heating tape. The hot junctions were soldered directly to thepipe, and the cold junctions were inserted in a thermowell which extendedto the center of the water strean, This arrangement allows for the temper-ature difference from the pipe to the water to be read directly and withmuch more accuracy than separate thermocouples. The inlet and outletwater lines to the test section also contained a temperature differene.ethermocouple arrangement with four junctions at each end. This allows forvery accurate temperature difference measurements for energy balancepurposes.

Gear pumps were installed in the inlet and outlet water lines tothe test section. The purpose of these pumps was to block the pressurewaves from leakIng out of the test section, thus reducing their amplitude.These gear pumps were powered by variable speed electric motors and weredesigned -to float on the line without providing any positive pumpingaction,

Three taps were provided on the bottom of the test section forconnecting the pressure transducer, so that the waves may be monitered atseveral points. These connections were located on the bottom so that airwould not be trapped in them, thus destroying their accuracy.

The auxiliary equipment consisted of a cooler, surge tank,primary circulation pump, and orifice meter. The cooler consisted of 20ft. of jacketed 1" copper pipe, The cooling water flow to -the jacket wascontrolled by a temperature recorder controller which monitored the

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temperature of the circulating water leaving the cooler. The thermocoupleand thermowell for this instrument were designed for fast response in orderthat the instrument could be set for a fast response. The surge tank wasa

r,1gallon stainless steel vessel with a sight glass for level indica-

tion. The orifice meter contained five orifice sizes which were allcalibrated with water at l4O°F Â mercury manometer was used to measurepressure drop across the orificeS It was estimated that the flow ratecould be measured th an accuracy of 2. There were some importantmodifications which were found necessary when it as attempted to put theequipment into operation. These modifications are shown in Figures 2and 3 . The primary change was in the method of measuring the temperaturedifference between the pipe wall arid the water stream. The old methodutilized a cold junction n the water stream and a hot junction on theoutsidesurfacc of the pipe. Two of these pairs were installed in thetest section. The modified method utilized a cold junction in a thermowellin the inlet line to the test section. Six hot junctions were installedalong the test section at 9-inch intervals. These hot junctions could beswitched individually in series 'with the cold junction by means of a multi-plo switch. The hot junctìon thermocouple wires were led through asection of hypodermic needle tubing which entered one wall between twowraps of the heating tape and dead ended into the opposite wall in thecenter of a wrap of the heating tapeZ The thermocouple junction itseiÇwas placed in a tangential groove in the .035-inch wail pipe. The groovewas filled with silver solder and smoothed off to the natural roundness ofthe pipe. This complicated method of running the thermocouple wiresthrough the pipe itself was found necessary, since in the previous arrange-ment the high temperature heating tape in contact with the thermocouplewires close to their junctions caused an erroneous reading.

A third expermenta1 set-up was designed to study the effect ofacoustic vibration in the water stream on the b'at transfer coefficient.Figure 4 is a schematic diagram of the modified unit. Negative resultswere obtained in each of the previous trials; however, deficiencies in theexperimental apparatus warranted further improrement irL the equipment andadditional experimental work before this approach was discontinued, Theimprovements which this final experimen;al arrangement contained are asfollows:

a. The water inlet and outlet ports were small compared to thediameter of the test section itself. This prevented the acoustic pressurewave from leaking out of bhe system in the inlet and outlet lines and thuseliminated the need for the vibration blocking gear pumps used previously.

b. The test section was mounted in a vertical position so thatthermal convection effects would he largely eliminated. This allowed useof extremely small flOW rates that were the range in which heat transferimprovement would chow up more readily,

c. The pipe wall was heated by means of resistance electricalheating with current flowing directly in the pipe wall. This method ofheating facilitated more accurate temperature measurement of the outersurface 'of the pipe wall since the electrical heating tapes were eliminated.

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12

Thermocouple sspaced three inchesapart along pipe wall

d. A flexible brass bellows was used th couple the vibratorshaft to the water column instead of the thin rubber diaphragm which wasused earlier. This prevented the frequent ruptures vthich occurred andalso allowed much greater pressure amplitudes to be built up in thewater column.

The test section was fabricated from a 36 inch section of i' ODX .0:35 stainless steel pipe. The brass bellows was silver soldereddirectly to the bottom of the pipe and the "Bozak" vibrator end tuningbar were mounted directly below the bellows, A " steel rod connectedthe vibrator, tuning bar, and bellows. Copper support brackets fabri--cated from )-" copper plate, were mounted on the top and bottom of thetest section. These provided a means of mounting the equipment on thechannel iron foundation and also provided the electrical connections forthe high amperage heating current.

The auxiliary cooler and circulating system were the same aspreviously described. The instrumentation was the same as that used onprevious experiments . The temperature difference of the water flowingtìirough the apparatus was measured by means of a multiple junction ironconstantan thermocouple iith four hoi,, junctions on the outlet and fourcold junctions on the inlet. The temperature of the pipe wall was meas-ured with temperature difference thermocouples which bad a cold junctionin the inlet line and a hot junction on the pipe wail, Ten hot junctionswere spaced at inch intervals over the length of the test section. Amultiple thernocouple sititch was used to switch each hot junction inseries with the cold junction as the readings were taken. Three smallvalves were installed on side taps from the test section. These werefor the purpose of installing pressure transducers at different locationsin order to monitor the variations in the amplitude of the pressure wave.

2. AparatusJilizing T..1onitudinai Vibration cf the Test Section

Figure 5 is a schematic diagram of the arrangement of theequipment for study of the effect of longitudinal vibration of the pipewall on the heat transfer coefficient. This arrangement employed the sameauxiliary equìpment as shown ifl Figure 1.

i.t was found by previous experience that heating by means ofelectrical heating tapes was not entIrely satisfactory; therefore, thistest setup was designed to utilize electrical resistance heating withelectric current flowing directly in the pipe wall. Titis technique ofheat generation eliminates the need for high teuperalure heating tapessurrounding the pipe and facilitates the measurement of the pipe wallteoperature by means of thermocouples since the thexocouple junctionscan be soldered -to the outside suaface of the pipe without the inter-ference of a high. temperature source near the junction. The source ofelectric current was a 5 KVA transformer with a 12Qirolt powerstat. Thusthe output current cciii d be varied from O to 500 amps.

13

Flex

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6

4. Apparatus Utilizing Transverse Vibration of a Pipe with WaterFlowingjhe Outside of the Pi e

A schematic diagram of the apparatus on which these heat transferstudies were made is shown in Figure 7.

The test section was fabricated fran 1" OD. stainless steel pipewith a .035" wall thickness and was 41" long. The test section was mounted

inside of 3" I. D. pyrex glass pipe so as to form an annular space withwater flowing on the outside of the test section. The pyrex pipe shell

around the test section was 38" long with the ends of the inner pipeextending through the end plates about l" as shown in Figure 8. n "O"

ring seal waa used to prevent water leakage between the inner and outerpipe. This allowed the center pipe to be relatively free for thermalexpansion, and also allowed the pipe to v.brate as a "pivot end" beam.Sixteen thermocouples were connected to the test section . Eight of these

were on the front surface (surface perpendicular to direction of vibration)

of the pipe and the other eight were on the side surface (su:face parallel

to direction of vibration) of the pipe and were spaced as shown in Figure

7. The thermocouple junctions were mounted in holes which were drilledin the pipe wall and were silver soldered into place. The thermocoupleleadwires were run inside the pipe and the ortside surface of the pipe wassmoothed to provide an undisturbed heat transfer surface. The thermocou-

ples were connected so that a temperature difference reading would indicate

the difference between the pipe wall and the inlet water.

The "Bozaic" vibrator and tuning bar were mounted in much the same

way as previously described, A -" steel rod connected the tuning bar to

the test section. This rod ren through the side opening of a glass teewhich was installed in the center of the apparatus. The seal around thisrod was made with flexible gum rubber tubing in order to minimize damping.

The auxiliary cooler end circulating system were the same as that

shown in Figure 1. The water entered the bottom of this apparatus and dis-

charged out the top. The temperature difference of the water flowingthrough the apparatus was measured by means of a multiDle junction ironconstantan thermocouple with four hot junctions on the outlet and fourcold junctions on the inlet.

The heat source was electrical resistance heating which wasgenerated by flowing a high amperage electrical current directly in the

pipe wnll . The equipment for the electrical hookup was the same as thatutilized for the three previously described experimental set-ups.

B. Procedure

i . Eperimental Procedure for ADDroachej

Then a run was started the circulating loop of water washeated up to the boiling point with the heat source in the test section,This was for the purpose of dc-aerating the water in the system sincedissolved air might affect the operation of the system under conditions

17

Special Connection of Pipe to EIdPlates

Three Inch "Corning"Glass Pipe

Bozak" Vibrator

Tuning Bar -

- Water Outlet\

//

//

Water Inlet

16 The rniocouplesLocated on the Frontand Sides of the pipe

FIGURE 7. SCHEMATIC DIAGRAM OF APPARATUS FOR THESTUDY OF THE EP'FECT OF TRANSVERSE VIBRATION ONHEAT TRANSFER WITH WATER FLOWING ON THE OUT-SIDE OF THE TEST SECTION 1N AN ANNULAR SPACE

1/4" Steel EndPlate

- Soldered Joint fromNotch Down forElectrical Contact

Assembly Pipe wasFilled with "Plaster ofParis" to PreventThermocouple Wiresfrom Vibrating

FIGURE 8. DIAGRAM OF END CONNECTIONS FOR THETEST SECTION

19

5/8" Hole to AccomodateThermocouple Wires

Brass Electrical Connector

"O" Ring Seal Allows Pipeto be Free to Move

- i" O. D. X . 03.5 WallThickness StainlessSteel Pipe

of vibrations. Dissolved air causes the vapor pressure of the water tobe greater; therefore, cavitation would occur sooner with aerated water.Then the controller was put on control at the desired inlet temperatureand the circulation was continued for several hours in order to reach

steady state conditions. Data on flow rates, temperatures, etc. werethen taken on the system without vibration. Various tuning bars wereinstalled on the vibrator and two complete sets of data taken at eachfrequency after about 15 minutes of operation. Data without vibrationwere also taken at regular intervals during the data-taking procedure.All of the data for each frequency was then averaged and the resultscompared. The temperature differences for each point on the pipe foreach frequency were examined for differences., Since no noticeable dif-ference was found in any of the runs on any of the thermocouple points,all of the temperature differences along the pipe for each frequencywere averaged to obtain one value for the heat transfer coefficient.

Detailed data will be found in Appendix A.

2. Ixperimental Procedure for Approach 4

Before a run was started, the water was circulated and. heatedto the boiling point for the purpose of de-aerating the water. Then the

flow rate and temperature control were adjusted to their proper valuesand circulation continued for several hours in order to reach steadystate. Data on temperature differences, flow rates, etc., were taken onthe system without vìbration. The flow rate and heat rate were maintainedas constant as possible throughout the run. Data were taken at various

amplitudes and freQuencies. The frequency was changed by changing thetuning bar on the system and the amplitude was changed by varying thesetting of the volume control on the amplifier. Data were taken at thefollowing four frequericies--2 cps, 42 cps, 62.5 eps, and 84 cp3. The

natural frequency of the system was 42 cps. Frequencies obtained with a3/8e? and timing bar were 62 . 5 and 84 cps, respectively. Thirty-twocpa were obtained by hanging a 2 lb weight on the vibrating system. The

maximum amplitude obtained was 0.150" at 32 and 42 cps. The maximumamplitude obtainable at a fixed frequency varied from run to run as0.150" was only obtainable at 32 cps part of the time. The water flowrate was adjusted so that a Reynolds n.unber range of 541 to 23,600 couldbe studied during the experimental program.

Two sets of data were taken at each data point after about 10minutes of continuous operation. These data were then averaged and asingle figure for temperature difference was obtained for each thermo-couple point . The temperature differences for the four central points onthe front of the pipe and the four central points on the side of thepipe were averaged to obtain twc separate temperature difference figuresfor the front and side of the pipe. All of the above mentioned thermo-couple points are within 4i-" of the center of the test section and theamplitude of all points were assumed to be the same as the center of thepipe.

C, Discussion of Results

The most significant data was produced by the experimental programwhich studied the effect of transverse viìration on the heat transfercoefficient wtth water flowing on the outside of the pipe in an annularspace. Heat transfer coefficients were determined with and without vibra-tions at various Reynolds numbers (541; 1418; 5000; 12,300; 16,000 and23, 600) which are in both the viscous and turbulent flow range. Heattransfer data were obtained at various frequencies (32-84 cps) andamplitudes (0.025-.150 in.).

A very definice improvement in heat transfer coefficients withvibration was obtained for most of the runs. The improvement was greatestat low flow rates and maximum frequencies and amplitudes. The resultsare plotted in Figure 11 and summarized below:

Heat Transfer ImDrovement

21

* At 42 cps and O . 150 in . anplitude

It is possible that greater improvement could be obtained at higherflow Reynolds number wtth the use of larger vibration equipment.

The results of all experinieìital data taken on the test unit arepresented in Tables 1-5. Heat transfer coefficients were calcu]ated sep-arately for the pipe front (pipe surface perpendicular to directi ofvibration) and the pipe side (pipe surface parallel to direction ofvibration) . These coefficients were computed from an average of the T's

across the hIn for the four central thermocouples on the test section.iU1 of these points do not vibrate with the cne amplitude. However, thedeviation from the amplitude at the center of the pipe (where the ampli-tude was measured) was small since all four of the thermocouples were

within 4f" of the center.

The film coefficient,h, was determined from the following relationship.

mQ (T - T )

A(T5 - Ti,)

ReynoldsNumber

Increase in Coefficient*

540 4501,400 280

5,000 13012,000 3016,000 1620,000 10

All physical properties for water were ta)en at 100°F which was theattempted control point for the average bulk temperature of the water.The water temperature (T) was obtained by adding a correction factor tothe inlet water temperature (T1). This accounted for the bulk tempera-ture rise of the water as it flowed through the system. The temperaturerise was assumed to be linear along the length of the electrically heatedtest section, since electric heat results in a constant value for Q. Acorrection factor was employed to account for the temperature drop inthe steel pipe wall between the thermocouple junction and the ousidesurface. Since the thermocouple junction was not on the inside surfaceof the pipe, but soldered in a hole in the pipe wall, it was difficult tomake a valid assumption as to the proper correction factor to use. Theassumption made was that the thermocouple junction was recording atemperature which was at an average of the inside and outside walltemperature. The relation used was as follows:

Q' X8

K5 4

It must be noted that the thiciiess of the pipe wall, X , would bedivided by 2 even if the thermocouple junctions were on the nside sur-face of the pipê wall due to the fact that not all of the heat passesthe full. thickness of the wall when using electric heat, since the heatwas generated wtthin the wall. A table of nomenclature vill he found atthe beginning of the report.

The vibrational input to the system was expressed as a vibrationalReynolds number in the sam m.nner as jnantanarayanan( i) , Lemiich(l2),and Martinelli and Boelter'. 13 ) In this relation, the average velocityof vibration of the pipe was substituted into the expression for the floReynolds number as follows:

(Re) =

22

de

when = 2FH

The heat transfer coefficients for the pipe side and the pipe frontwere fornid to give different values. Therefore, separate correlationsare presented for each surface to indicäte the variation of heat trans-fer coefficient with amplitude and frequency. These correlations arepresented in Figures 9 and 10 for the pe front and side, respectively.These curves are plots ofhv i vs e) This method of corre-

h0 (Re)f

lation was used by nantanarayana(-) iii the study of heat transfer from avibrating wire to air in parallel flow. In the case with water onestraight line was fitto all data for Reynolds numbers of 5000 and higher,while separate straight lines were fitted to. the data in the viscous flow

region. This may he due to the influence of free convection in heattransfer at low flow rates in the viscous region.

The equations for the straight lines obtained in Figures 9 and 10can be represented by the following general equation:

-1 = 0[(Re)vl3;jThe constants can be determined graphically, resulting in the

following series of equations for the effect of vibration on heat transfer.

For the pipe side with flow Re'nolds numbers of 5000 and greater:

t- 11.69h= .115 (Re)

h(Re)f

.1

For the pipe side with flow Reynolds number of l4l:i .69

h= .0235 (Re);

(:3) For the pipe side with flow Reynolds nimiher of 541:

i .69h

1 = .0042;

(4) For the pipe front with flow Reinclds number of 5000 and greater:

n

hV -

h0

23

-T 2.2e.039

t

Lf(5) For the pipe front with flow Re'nold nuaber of 14l:

2 . 2

-

1 = .2sa

5. 0

1.0

.01.2

ReV/Ref

FIGURE 9. THE EFFECT OF VIBRATION ON HEAT TRANSFERFROM THE PIPE SIDES

24

IV Run

Run

Run

I15

18

¿0

oRunl6-Ref=541-

--

Run17-Ref5000

Re1

RefRif

1418

= 12, 340-- 16,000

- T / /i'

f

,/1

1

s /lOo

0 /. ./

a', 4 A____.. C)aui

MliiiRUlli rSull LAR ° 111VRulli

iiIIiIr A1IIIVIII!

o

IVA 4IrEv AI; wr4a i

UT1I r__ _. 1_ RV1Iarii À :. _uIA lu

AI A ,r III

PA'

tI

/I7

IIHI MIi lit

1.0 10

5.0

1.0

i

.01

25

--T-- ..........liii .o Run 15 - Re1 = 1418o Ri 1.6 - Ref = 541A Run 17 - Ref = 5000i Run 18 Ref IZ, 340V Run 20 - Ref = 16, 000 4 A A

iiiAI'

I 4SIIAMRURauh, w a. . ; RIIIi' U

,Ai;'!11 .

J+Li ;

- a a .

1111111,1ft4AE!!i10 . t

H

ri) V f

r. .

.3 1.0 10 50ReV/Ref

FIGURElO. THE EFFECT OF VIBRATION ON HEAT TRANSFERFROM THE PIPE FRONT AND BACK

5. 0

4. 0

3.0

a. o

1.0

5, 0

00

NR

EV

= 2

3,60

0 (4

2 cp

s.1

50 in

. am

plitu

de) 15

, 000

10, 0

00N

RE

F

FIG

UR

E I

i: V

AR

IAT

ION

OF

HE

AT

TR

AN

SFE

R C

OE

FFIC

IEN

T W

ITH

NR

EFO

R M

AX

IMU

M N

RE

V F

OR

RU

NS

15 T

HR

OU

GH

20

F

(6) For the pipe front With flow Reynolds number of 541:

h (Re)- i = .000524 ____h0

(Re)f

Heat transfer coefficients for water flowing in annular spaces werecalculated from correlations rccornmended by Knudsen arid atz(i0)o Ca1culated results agreed reasonably well With eperimental data, themaximum deviation being approximately 30%. Part of this deviation may bedue to thermocouple installation. The thermocouple junctions were silversoldered in small holes in the pipe wall. These holes my cause slightirregularities in the flow of electric current in the vicinity of thethermocouple junctions thu$ causing a slight error in the reading. How-ever, since all results were expressed in the form of - I, errors

ho

which are peculiar to the apparatus tend to cancel out.

A plot of typical temperature difference data vs. position in theheated pipe is shown in Figure 12.

Figures 13 to 16 show the effect of frequency at constant mplitudeon heat transfer improvement at various Reynolds Numbers . In general, asthe frequency is increased the heat transfer rate increases . The rate ofincrease in heat transfer improvement depends on the amplitude applied.As the Reynolds Number increases the rate of change in heat transfercoefficient ith increased frequency is less at a given amplitude.

Future studies would include an expansion of the data over a widerange of frequencies, which requires a more powerful vibrator to maintainadequate amplitudes at higher frequencies.

Figures 17 to 20 show the effect of amplitude at constant frequencyon heat trans fer 1 mprovement at various Reynolds Numbers.

27

Surf

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Are

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/sec

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The experimental program also studied the effect of acousticvibrations on the water film heat transfer coefficient by three othermethods with water flowing inside the pipe. These are as follows:

(i) Acoustic vibration impressed directly into the waterstream.

Longitudinal vibration of the pipe with no vibrationimpressed into the water stream.

Transverse vibration of the pipe with no vibrationimpressed into the water stream.

The effect of acoustic vibration impressed in the water flowing insidea heated pipe was first studied at two Reynolds numbers (17,600 and 52,400)and at frequencies of 18-350 cps. Acoustic vibrations caused a slightimprovement in the heat transfer coefficient but in generai the resultswere inconclusive due to operating problems encountered during the experi-mental runs. The data is presented in Table 6. This approach waspromising enough to warrant additional work with a redesigned apparatus.

The primary difficulty was that the resonances were very unstable andtended to drift in frequency. On some occasions a resonance would be verysharp for a few minutes and then completely die away. Operation of thesystem was usually more successful at high flow rates. Another difficultywas that the temperature of the pipe wall was very difficult to measurewith theIilocouples, since the hot wraps of the electrical heating tapessurrounding the pipe interfered with the thermocouple lead wires. It wasfound necessary to route the thermocouple lead wires through hyjodennicneedle tubing through the center of the main pipe. This solved the problemsomewhat since the thermocouple lead wire close to the junction was notexposed to high temperature; however, the presence of an obstruction onthe water side of the pipe wall causes additional turbulence which changesthe local heat transfer coefficient in the vicinity of the thermocouplejunction.

From the experiences encountered with the initial test setup it wasconcluded that heating by conduction from electrical heating tapes wasunsatisfactory. The redesigned apparatus utilized electrical resistanceheating of th pipe wall by passing a high amperage electrical currentthrough the pipe . This method has the following advantages:

(1) The thermocouple junction soldered to the pipe wall isnot iri close proximity to a high temperature heatingsource,

( 2) the heating was more uniform since the cold spots in thejoints between heating tape wraps were eliminated and

(3) heat loss through the insulation was reduced considerablysince the temperature of the pIpe was only a few degrees.above the water temperature.

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Also, the rubber diaphragm and piston were replaced by a brassbellows as a means of impressing the vibration into the water stream.

The modified equipment for the experiments on acoustic vibration inthe water stream performed without mechanical difficulties. The brassbellows was very satisfactory as a means of transferring the mechanicalvibration of the TtBozak?T vibrator to pressure waves in the water column.Very high pressure amplitudes were possible as compared to the old methodof using a rubber diaphragm to seal the water and a small piston to trans.-fer the vibrational force. Electrical resistance heating of the pipe wallby means of a high amperage electrical current flowing directly in thepipe wall was a very satisfactory arrangement. The theiocouples silversoldered to the outside surface of the pipe wall gave very reliable tern-perature difference readings. One difficulty of operation was that onlyone pressure transducer was available and three side taps were availablealong the pipe. In the process of transferring the transducer from onetap to another, while the system was in operation, different resonant con-ditions were created due to the small side branch water column going tothe transducer. This was concluded since the system made a distinctlydifferent noise when the transducer was installed on different taps andthe readings did not confonn to ary logical wave form which could existin the pipe. Therefore, the transducer was left in the top tap whichalways gave 'the highest reading. Ali pressure amplitudes listed in thetables are for this point.

The results of the experiments canducted to determine the effect ofacoustic vibration in the water stream are presented in Tables 7 andand Figures 21 and 22. Two experimental runs (21 and 22) were made atextremely low flow rates which produced flow Re,rnolds numbers of 500 and191. These low flow rates were used since it was believed that heattransfer improvements would show up much more readily under these condi-tions. Figures 21 and 22 show the temperature differences from theoutside pipe wall temperature to the bulk water temperature at all thethermocouples along the pipe wall. These plots were made to determine ifany localized improvement would occur which would be overlooked when thetemperature differences were averaged in calculating the heat transfercoefficients shown in Tables 7 and & The deviation of the differencesshovn in Figures 21 and 22 are in general small and about what would beexpected from experimental error. Most of them at the first thermocouplefrom the inlet end were lower with vibration than without vibration.This may suggest a very slight improvement; however, in view of theextremely low Reynolds numbers this improvement was insignificant.. Ingeneral, the eqipment performed satisfactorily producing pressure wavesas high as 50 psi from peak to peak.

A recent doctoral thesis by H'wu(6), r'hich was received aftercompletion of the experiments described above, reports a significantimprovement in heat transfer from steam to air when a resonant fre-quency is impressed into the air stream. No improvement was obtained atnonresonant frequencies. The improvement was attributed to the presenceof a standing wavo of appreciable amplitude vthich is set up in the tubeonly at resonant frequencies. The total length of 'the air column in his

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apparatus was 8.5 ft. and he obtained resonance at 198 eps, 256 cps, and322 cps, which approximately correspond to the third, fourth, and fifthovertones in an open end tube. The greatest improvement was 50% at 256cps and Reynolds number of 1430. The improvement decreased gradually asthe flow rate increased into the turbulent flow range where the improvementwas negligible. It also became insignificant at Reynolds nunber below 2&At 322 cps, the maximimm improvement of 48% occmred at Reynolds nimiber of2080. This study covered flow rates vith Reynolds number from 565 to 5,920.Maximum improvement also appeared to correspond with maximum pressureamplitude. This work may indicate that a comparable range of conditionsexists at which acoustic iibrations will improve the water film heattransfer coefficient.

In order to correlate the present work with Hwu, it would be necessaryto operate at frequencies of approximately 2125 cps, 2975 tps, end 3875cps. These frequencies would correspond to the third, fourth and fifthovertones in a three foot closed end watercolumn. A wide range of flowrates, from viscous to turbulent flow, would also need to be studied.Various pressure amplitudes would be required in the study in order tademonstrate the possible existence of an optimum frequency-amplitude levelat various Reynolds numbers, It might be desirable to investigate thisin future work.

The experimental data for longitudinal vibration of the pipe arepresented in Table 9. Heat transfer coeffIcients were deteined at variousReynolds numbers (1410 to lZ.600Q) with and without vibration. Frequencieswere varied from 10 to 200 cps. The amplitudes of vibration were thelargest available with the equipment, The heat transfer coefficients withvibrations did not indicate significant improvement under any of the condi-tons öf flow rate, vibrational frequencies, or amplitudes studied.

The experimental data for transverse vibration of the pipe arepresented in Table 10. Heat transfer coefficients were determined at variousReynolds numbers (1117 to 24,000) with end without vibration, Frequencieswere varied from 17 to i 44 The heat transfer coefficients obtainedwith vibration did not indicate significant improvemeit under the conditionsstudied,

The experimental heat transfer coefficients without vibration agreedreasonabLy well with those predicted by standard heat transfer correlationsas shown in the attached tables. Run 6 gave the greatest deviation dueto free convection effects at low flow rates, resulting in a differencein temperature from the bottom to the top of the pipe, This problem waseliminated for transverse vibration by placing thexioco1es on all foursides of the pipe and averaging the results. In addition, Rim 9 wascarried out with test section in a vertical position.

49

TA

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Ill. STEAM CONDENSATION STUDY

General

The second phase of the investigation of the use of acoustic'ibrations to improve heat transfer was directed toward determining theeffect of mechanical vibration of a vertical pipe on the steam condens-Ing heat transfer coefficient. Normally steam eondening on the outsideof a vertical pipe causes a condensate film to form vLch clings to thesurface of the pipe and flows down the pipe in a laminar layer.. Thislaminar layer causes a considerable resistance to beat, transfer, espe-cially when the pipe or tube is very long since the entire condensatecondensing on the tube travels all the way to the bottom. The purposeof vibrating the pipe was to determine if drotiwlse steam condensationcould be promoted, thereby greatly increasing the rate of hea transfer.

Part II of the steam ccndensing study consisted of brief evaluationof the effect cf acoustic vibration on the steam condensing heat transfercoefficient when the steam contains a noncondensable gas.

. Effect of Acoustic Vibrations on Steam Condensation

IL. Experimental

a. ÂusA schematic diagram of the apparatus for the study of steam

condensate film coefficients under conditions of vibration was shown inFigures 23 and 24. This apçaratus consisted of a vertically mountedsection of pipe with cooling water flowing inside and steam condensingon the outside, Provisions were made to vibrate this section of pipetransversely.

The test section was fabricated from U' O,D. aluminum pipewith a .O49' wall tIlicicriesS and vs 41 inches long . This pipe wasinstalled inside of 3" I.D. pyrex glass pipe so as to form an annularspace with steam on the outside of the test section. The pyrex shellaround the inner pipe was 38 inches long with the ends of the inner pipeextending through the end plates about l inches . An ttO ring seal asused to prevent leakage between the inner and outer pipe . This allowedthe center pipe to be relati7ely free for theirl expansion and alsoallowed the inner pipe to vibrate as a pivot end beam.

The llBozak!t vibrator and timing bar were mounted to the sideof the verttcally mointcd pyrex pipe shell, A -U steel rod connected theIEozaktf vibrator, tuning bar, and inner pipe . This rod ran through the

SidE oaning of a glass tee whIch was initalled in the center of the shell.The seal around this rod was made with flexible gum rubber tubing inorder to mininize dampIng.

AluminumTuning Bar_\\

o zak"JVibrator

54

t

Y

''

'

II

/ // /1

II

//

I/I

/I

/I/

/

Steam in

Steam andcondensate out

1-Water in

FIGURE 23. SCHEMATIC DIAGRAM OF APPARATUS FOR THESTUDY OF CONDENSIM3 FILM COEFFICIENTS

UNDER CONDITIONS OF VIBRATION

Directicn ofVibration

¡Aluminum Yoke Allowing SpaceFor Condensate To Pass-j

Driving Rod from Vibrator andTuning Bar

Areas of CondensatConcentration

lU OD x .049 WallAluminum Pipe

FIGURE Z4 DIAGRAM OF METHOD OF CONNECTION OF DRIVINGROD TO PIPE FOR APPARATUS iN FIGURE 23

55

I

This apparatuB did not contatn thermocouples on the pipewall ibself; therefore local heat transfer coefficients could not bemeasured. Therm6couple wires could not be rim inside the pipe, sftcethis would interfere vd.tth the smooth flow of -the cooling water . Theproblem was also complicated by the fact that the pipe would be vibratingwith anrplitudes as large as -" , This would cause breakage of any finethermocouples run to the pipe vall through th..e annular space. Also thethermocouples lead wires could not be taped to the outside of the pipesince this would interfere dth the failing condensate film. Therefore,the system was instrumented to nìeas'ure the over-all heat transfer ecef-ficient of the entire pipe. The Tn1et and outlet water temperaturedifferential as measured with the saine miltip1e thermocouple used inprevious experiments . The inlet and outlet end each contained fourjunctions in order to increase the iìrîllivolt reading when very lowL\Tsare measured. Two thermocouples were med in order to check results. Apair of thermocouples were also installed to read the temperature differ-enti.l between the inlet water and the steam. ily one hot and coldjunction were used on each of these theiocouples since this temperat1uredifference was much greater and could readily be measured accurately,The inlet water line was also equipped with a thennometer which read thetemperature to the nearest O .2°F. This provided an accurate basetemperature for one side of each of the temperature differentialtherrioc upies,

b. Procedure

The entire circulatThg system was filled with de-aerateddistilled water prior to operation. This was done so that air bubblesand scale would not form on the inside surface of the aluminum pipe thuschanging the water side heat trensfer coefficient from that vthLch wouldbe calculated from formulas The circulation rate was then set at thehighest possible rate as limited by pressure drop through the system,and the temperature controller ivw set at the desired temperature .

excess of steam was allowed to flow through the annular space and outthe outlet with the condensate, The inlet steam rate was not measured;however, the sanie rate was used for all experiments. After steady statevas reached, data were taken at the various frequencies and amplitudes .

A set of data consisted of the following: (i) temperature of the inletwater, (2) two readings of the temperature difference between inlet indoutlet water, and (3:) two temperature difference readings between theinlet vrater and steam.

Data were taken at the following four frequencies22.5 eps,:3 cps, 73 eps , and 93 cps . The natural frequency of the system was 38eps . A maximum amplitude of 0.500 inch was obtained at this frequency.Seventy4hree and 98 cpa were obtained with 3/81t and k" tuning bars,respeçtiirely. A two pound weight was attached to the vibrating systemin order to obbain 22,5 eps. Data were taken at three separate waterinlet controlled temperatures . These 'were 1200F, 150°F, and 180°F.This resulted in over-a1Í Ts of approximately 90°F, 60°F, and 300F.

56

2. Discussion of Results

The results for the experiments directed toward determining theeffect of vibration on steam condensate film coefficients are presentedin Tables il through 13 and Figures 25 through 27.

A very definite improvement in heat transfer coefficient wasobtained. The improvement was greatest at high frequencies and highamplitudes; however, the maguitude of the improvement did not change withthe over-all temperature difference. Figure 27 is a plot of all heattransfer data taken for rImS 23, 2J, 25 which were made at approximately90°F, 60°F, and 30°F over-all temperature difference, respectively. Alldata were fitted raasonably close to one straight line which has thefollowing formula,

r 1.2 1 .205= .714 [(F) (H)

j

This cari be further simplified to give the following expression for theheat transfer coefficient under vibration.

h = .714 h F246 HO5

It can be seen by inspection of the above equation that it doesnot holdfor conditions of no vibration. Therefore, the equation was only goodfor a limited range and does not hold for very low values of frequencyand amplitude. This can be seen by inspection of Figure 27. At a valueof (Fi .2 H) of 5,2 the equation predicts a value of h equal to 1.0.

Above this point the equation was valid with all points falling fairlyclose to the line; and below this point the equation predicts a value of

less than h0 and was therefore meaningless.

The following equation was used to calculate the condensatefilm heat transfer coefficients which are shown in Tables 11 through 13.

h

h0

Q

Q

57

--R + R3 +

-,

1 +X+ I(1)

hA K5A 1iA

The moaning of the symbols are given in the Table of Nomenclature, ThISequation shows that for maximum accuracy of measurement and calculationof h0; R5 and Rw should be as small as possible. This was accomplishedby using a thin walled aluminum pipe with the water flow rate as high aspractical. The total heat transfer (Q) was determined by accuratelymeasuring the water flow rate and water temperature rise through the

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ater

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FIG

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5 T

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For

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cycl

es p

er s

econ

4

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2H F

or 9

8 cy

cles

per

sec

ond

FIG

UR

E 2

6. T

HE

EFF

EC

T O

F V

IBR

AT

ION

ON

TH

E C

ON

DE

NSA

TE

FIL

MH

EA

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RA

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ER

CO

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R R

UN

¿3

40

o

2. 0

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412

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H16

2024

2832

36 .4

0

FIG

UR

E 2

7. T

HE

EFF

EC

T O

F V

IBR

AT

ION

ON

TH

E C

ON

DE

NSA

TE

FIL

MH

EA

T T

RA

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ER

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23,

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ND

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OR

un 2

3

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;in 2

5

system. The estimated accuraey of the measurement of Q was 2%. Theovera11 temperature difference &AT) was measured 1y means of a twojunction iron-constantan temperature difference thermocouple betweenthe inlet water and the steam in the annular space. LAT was actuallycalculated as an arithmetic meanT since the teinperatare rise of thewater was very small, The estimated accuracy of measurexnentofTwas 2, The water film heat transfer coefficient (1ì) vías calculatedfrom the following equation, Fluid properties were evaluated atarithmetic mean bui k temperature.

r \ 0 ffhd\ I 'k (C \-1 =

036 (R) (_!___J L (2)

" KJb \Jb \KThe estirnated error involved in calculating a water film heat transfercoefficient from this foiala vas t 20%; however, since the water filmsresistance turned out to be much less than the cdensate film resistancethe error introduced into the caiculatioi of h0 -vas appro ximately ± 4%.therefore, the total estimated error in measuring h0 could be about 8%.However, it imst be pointed out that many of these erfors would be com-mon to all measurements of h made in these experiments; therefore, whencomparing one to another the relatIve error should be much less than 8L

The nature of the condensate film under conditions of vibrationwas very interesting. Figure 28 is a photograph of the vibrating pipe atthe extreme left position of the cycle while vibrating at 38 cycles persecond and 500 inch anrplitude. The sides of the pipe (surface parallelto direction of vibration) were swept relatively free of condensate film,rp

liquid accumulated on the front and back of the pipe (surface perpendicular to the direction of vilration) and splashed hack and forth withthe pipe; howeyer, very little of the condensate was thrown free from thepipe.

It would be well to note that the heat transfer coefficientscalculated in these experiments were average coefficients for the wholepipe. The local coefficient at the center of the pipe whore the maximumamplitude occurs would be greater. This fact was mentioned since thereèults of the experiment with water flowing in the annular space aroimdan electrically heated pipe were local heat transfer coefficients at thecenter of the pipe where the maximum amplitude occurred,

C, Effect of Acoustic Vibrations on Steam Condensation in the PresencePL J

The apparatus used for study of the effect of vibration on steamcondensing coefficients in presence of a noncondensable gas is similar tothe unit used for the study of pure condensing steam filin coefficients,

67

-0,054

68

FIGURE 28. CONDENSATE FILM UNDER CONDITIONS OF VIBRATION

Th11s apparatus consisted of a verica11y mounted section of pipe withcooling wat2r flowing riside and sbeam condensing on the outside. Pro-vision was made to irirate this section of the pipe transversely. nair line was connected to the inlet steam line and rotaineters wereprovided to measure the rate of flow of steam and air. The steam rota-meter was installed dovmstreajri of the throttle control valve so that themeasured steam would be superieated. Pn air cooled desuper'neater wasinstalled downstream from bhe rotsmeter in order to reduce the inlettemperature of the steam to a desired vaiae.

A schematic diagram of the unit is shown in Figure 29.

a, Procedure

The entire circulating system was filled with de-aerateddistilled water so that air hu1o'bles and scale would not effect the waterside heat transfer coefficient. The circulation rate was set at thehighest possible water rate as limited by pressure drop through the sys-tern, and the temperature controller was set at the desired temperature.Data was Obtained with and without vibration at 0%, 5 and 10% noncon-densahles mixed with the inlet steam, Inletstearn and air rates were-measured 'Dy rotameters and set at a value which would inaîìtain 5 or lOair in the steam. Mter steady state was reached, data was taken at 15minute intervals over the period of the iain. Data was taken at 3 cpa,the natural frequency of the system, amplitudes of 0.1 - 0.5 inch andsteam to water temperature differences of approximately 30 and 60°F.

2. Discussion of Results

The results of the experiments directed toward deteniiining theeffect of vibration on steam condensate film coefficients in the presenceof a noncondensable gas are presented in Table 14 and Figures 30 and 31,

A very definite improvement in heat transfer coefficient wasohtained , The greatest improvement obtained wns 22 . 5% when 5% air wasmixed with the inlet steam. This value was obtained at a frequency of 3cps and an amplitude of 0,3 inch, Data was oniy ta7en at 3 cps which wasthe natural frequency of the system.

Figures 30 and 31 are a comparison of steam film coefficientsunder conditions of vihration with and without ixìerts, It can be seenthat the improvement was 1CSS than that ohtaired en pure steam was used.

( Heat transfer coefficients were calculated by the methoddescrihed in detail in Section B.

69

AluminumTuning Bar

\ttBozakHVibrator

Water Out

Ai rRotameter

t SteamRo tam etc r

Learn,Condensate,And Air Out

Water In

Steam In60 psig

De superheater

FIGURE Z9. SCHEMATIC DIAGRAM OF APPARATUS FOR STUDY OFCONDENSATE FILM COEFFICIENTS WITH AIR IN INLET STEAM

H

Cha

nge

Am

plitu

de%

Air

inin

Wat

erof

Vib

ratio

n,In

let

Tem

p.In

ches

Stea

mA

T in

°F

TA

BL

E 1

4. S

UM

MA

RY

OF

DA

TA

ON

TH

E E

FFE

CT

OF

VIB

RA

TIO

N O

N C

ON

DE

NSA

TE

FIL

MH

EA

T T

RA

NSF

ER

CO

EFF

ICIE

NT

WIT

H N

ON

CO

ND

EN

SAB

LE

S IN

TH

E S

TE

AM

Freq

uenc

y=

38 c

ycle

s/ec

Flow

Rat

e=

. 83

lbs/

sec

Inle

tW

ate

rT

emp,

"F

Stea

mIn

let

Tem

p, °

F

00

2,06

180.

021

1.1

05

1.57

180.

020

8.7

.100

51.

7118

0.0

208.

7.2

005

1.77

180.

020

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0.0

208.

7

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020

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1918

0.0

205.

9.3

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020

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2.68

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320

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130

05

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3¿0

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mT

otal

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Out

let

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t Tra

nsT

emp,

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r

Ove

rai

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r ft

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5

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=

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t Tra

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d. S

ide

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/hr

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600

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1800

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trol

led

Tem

pera

ture

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ycle

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r se

c0

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m O

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ata

from

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gres

s R

epor

t No.

4o

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nlet

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am10

% A

ir ir

A I

nlet

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am

.100

.200

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plitu

de, I

nche

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00.4

00.5

00

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UR

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0. C

OM

PAR

ISO

N O

F ST

EA

M F

ILM

CO

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NT

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ND

ER

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ND

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NS

OF

VIB

RA

TIO

N W

ITH

AN

D W

ITH

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T N

ON

CO

ND

EN

SIB

LE

GA

SES

1. 6

00

1, 4

00

1. 2

00

o -1. 0

00

1. 6

0,

1. 4

W

1. ¿

0

11. 0

0 80

1500

Con

trol

led

Tem

pera

ture

38 C

ycle

s pe

r se

cO

Ste

am O

nly

- D

ata

from

Pro

gres

s R

epor

t No.

45%

Air

in I

nlet

Ste

am

O05

0

FIG

UR

E 3

1. C

OM

PAR

ISO

N O

F ST

EA

M F

ILM

CO

EFF

ICIE

NT

S U

ND

ER

CO

ND

ITIO

NS

OF

VIB

RA

TIO

N W

ITH

AN

D W

ITH

OU

T N

ON

CO

ND

EN

SIB

LE

GA

SES

300

.100

.200

Am

plitu

de, I

nche

s.4

00.5

00

V. SCALING ry

A. imenta1

Apparatus

A schematic diagrin of the apparatus for the study of scaling isshovm in Figure 32. This apparatus is a vertically mounted, double-pipetype heat exchanger. The inner pipe is a 1" O.D. aluinurn pipe with a0.049 inch wall thickness and is 41 inches long. The outer pipe ís 2"

I,D. Pyrex pipe with a tee at the center. The outer pipe and end connec-tions foriii a shell 39 inches long and the inner pipe extends i iiichthrough either end plate. 'iO" ring seal similar to that shown in Fig-ure 8 is used between the inner pipe snd the end plates. A desuperheatedsteam supply is connected to the top of the inner pipe, and the bottom isconnected to a steam trap and calibrated ondensate collection tank. The

anxiular space is connected to a water circulating system with the inletat lower end, of apparatus.

The Bozak vibrator is connected to the center of the inner pipethrough the side arm of the Pyrex pipe tee. Transverse vibrations can

thus be imposed upon the inner pipe.

Procedure

Both natural saline water and calcium sulfate solutions wereused in this series of tests. The natural saline water was obtained fromCorpus Christi Bay and contained 19 parts per thousand of chloride. The

calcium sulfate solution was prepared in 60 gallon batches by dissolving

CaSO4 - H20 in distilled 'water to a concentration of 0.260% sulfate.

The water circulating system was filled with sufficient saitsolution to prevent inclusion of air bubbles in the circulating stream,and circulation started. Steam was admitted to the inner pipe' to heatthe water to its 'boiling point. Steam pressure in the inner pipe andwater flow rate in the annular space were maintained as. nearly constantas poSsible throughout the rimS A small feed pump continuously added saitwater to the circulating system to make up evaporation losses. Data wastaken periodically from the start of boiling, and consisted of time andcondensate level readings.

Nineteen runs were completed using ±he calcium sulfate solution.Three of these were preliminary runs . Five runs were made with no vibra-

tien; eight were made at a vibrational frequency of 33 to 35 cps; and

three were made at a frequency of 94 to 95 cps. The amplitude of vibra-

tion was varied at 33 to 35 eps, but was approximately 0.055 inch at 94to 95 cps. Various steam pressures were used throughout the experimentsin order to study the effect of wall temperature on rate of formationand removal of scale. The run time varied from three to six hours.

74

'Bozak" JVibrator

Alum mumTuning Ba

7

75

CondensateColi e c tor

CaSO 4Solution Out

'Pyrex" Glass Pipe

/

CaSO4Solution In

Steam SightTrap Glass

FiGURE 32. SCHEMATIC DIAGRAM OF APPARATUS FORSCALING STUDIES

e

To Drain

Three runs were made using the natural saline water. Thesevaried in length from four to tvelve hours, but only the 12-hou-r run con-centrated the o1ution sufficiently to form scale on the inner pipe. Thefrequency of vibration was 34 cps 'with an amplitude of 0.300 inch.

B. DiscussionQ

This experimental program was directed toward determining theeffects of mechanical vibration of a vertical pipe on the formation ofscale on the heat transfer surfaces Calcium sulfate in distilled waterand sea water were used for scaling liquors, Calcium sulfate was usedbecause of its inverse solubility so that the solubility was lowest atthe heat transfer surface and because it is the most difficult scale toprevent from depositing on a tubewall. The sea water was used so thatthis vibration technique could be evaluated using a typical feed to asaline water conversion plant.

Mechanical vibration of a pipe might have two possible mechanismsfor maintaining high heat transfer rates in a scaling liquor. One is thatineehanieal bending of the pipe might cause flaktng off of the scale andthus leave the pipe surface clean for efficient heat transfer. The otheris that the increased agitation caused by the vibrating pipe would reducethe stagnant filjn next to the heat transfer surface and in turn reduce thetendency to scale.

The three prelmTnary runs definitely demonstrated that the calciumsulfate scale periodically flaked off the center section of the pipe whichis subject to the maximum bending during vibration. Scale immediatelybegan to reform on the exposed tube wall until enough had deposited toagain cause it to flake off. A series of photographs, Fig. 33, demon-jstrates the flaking action. Overall heat transfer coefficients for thesepreliminary nine is given in Appendix A. A summary of data for all ofthe scaling runs is given in Table No. 15 which lists three heat transfercoefficients for each tim, The Initial coefficient is either the firstreading taken after start of boiling or an average of data prior to startof scaling. The coefficient at start of scaling Is the first readingtaken after scale formation has been observed on the pipe . The steadystate coefficient is an average of data taken after scaling has proceededto a degree such that flaking of the scale seems to balance foxation ofnew scale.

0f the runs made without vibration, Nos . 5 and 7 have been chosen astypical . The -N'i tial coefficient of heat transfer for these runs wasapproxímately 50 Bin/hr-ft2 OF, After the pipe vías completely coveredwith , the coefficient leveled off at approxImately 335 . This rep-resents a loss of 40 in the overall coefficient. The temperaturedifference from condensing steaii to boiling water was 37.7°F in Run No.5 and 46.°F in Run No, 7, Data Cor Runs 5 and 7 are given in TableNos. 16 and 17 and are plotted in Figures 34 and 35. Other run data aregiven in Appendix Â. Photographs of CaSO4 and sea water scaling are inAppendix B,

76

2,B

elow

Vib

rato

r

I.B

elow

Vib

rato

r

4.A

bove

Vib

rato

r

3.A

bove

Vib

rato

r

6.A

bove

Vib

rato

r8.

Abo

ve V

ibra

tor

5.A

bove

Vib

rato

r7.

Abo

ve V

ibra

tor

FIG

UR

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3.C

AL

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JM S

UL

FAT

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UN

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No.

(min

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e to

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(min

.)T

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to S

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all

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0¿4

9.7

37.7

410

Sea

Wat

er

1522

8N

o sc

ale

340.

355

227.

1-24

9.7

13.1

-35.

783

8 (A

vg.)

--19

370

No

scal

e--

350.

340

¿49.

735

.772

8 (A

vg.)

--¿0

715

502

572

340.

300

¿49.

735

.770

468

040

8

1.

Scal

e st

arte

d fl

akin

g of

f pi

pe.

3.N

o sc

ale

form

ed.

2. S

team

was

shu

t off

aft

er in

itial

for

mat

ion

of s

caie

,al

low

ing

scal

e to

dis

solv

e.St

eam

was

turn

ed o

n ag

ain

and

new

sca

le d

epos

ited

4.D

ata

take

n on

ly a

fter

sca

le h

ad f

orm

ed a

nd s

tart

edfl

akin

g of

f pi

pe.

TimePeriod(min.)

TABLE 16. CALCIUMSULFATESCALING - RUNNO. S

Condensate HeatCollected Transferred

(cm.) Q(Btu/hr)

Ove railCoefficient

U(Btu/hr ft2 °F)

79

632 8.5532 24. 5

32578 66

100508 112

1224Z 129.544C 144.5

152440 159.5440 174.5

182403 189.5348 204. 5

212.344 220344 236

242330 249.5312 264.5

272348 279.5348 294.5

302299 312275 324

332

Timefrom Start CaSO4of Boiling Conc.(min.)

o. 159

o ..2.08

0. 210

0. 195

0.186V\».Averaged for5

steady state0. 189 coefficient

0. 178

0. 179

0. 177

0. 176

Reni a rkd

17 3.915 2.9

68 14.3

20 3.7

15 2.315 2.4

15 ¿.4I.)

15 Z.Z15 1.9

16 2.012 1.5

15 1.815 1.7

15 1.915 1.9

18 1.912 1.2

Reynolds No. (non-bniling) 23,600Heat Transfer Area 0.840 ft2Water Boiling Temp. 212°F

AT 37. 7°F

Vibration: Freq. o cps; Amp. O inchSteam Pressure 15 psigSteam Temp. 249. 7°F

AH 945. 7 Btu/lb

20,05016 ,890

18 ,380

16170

13 40014,980

14,98014,980

. 12,82011 070

10 92010 920

io 4909,900

11 07011 070

9 , 2.208 , 740

Ave ragedfor initialCoefficient

Scaling

TABLE 17. CALCIUM SULFATE SCALING - RUN NO. 7

Vibration: Freq. O cps; Amp. 0 inch Reynolds No. (non-boiling)Steam Pressure ZO psig Heat Transfer AreaSteam Temp. Z58.8F Water Boiling Temp

939.5Btu/lb

80

23,60020.840 ft

¿j 2 °F46. 8°F

TimePeriod(min.)

CondensateCollected(cm.)

HeatTransferred

Q(Btu/hr)

OverallCoefficient

U(Btu/hr ft2 °F

T ini efrom Startof Boiling(min.)

CaSO4Conc.

Remarks

30 No level20 4.6 19970 577 40 Scaling

.

50 0.21015 2.6 15,050 384 57.514 2.5 15,500 396 72

79 0.21030 5.9 l707O 437 94

109 020816 3.0 16,280 416 11714 2.6 16,1z0 413 132

139 0.19715 3.0 17,360 445 146.513 2.3 15,360 392 160.5

167 0.19915 2.6 15,050 384 174.515 2.4 1389O 356 189. 5 Averaged for

197 0.190 steady state17 2.6 13,280 338 205.5 coefficient13 2.0 13,360 341 .220.5

227 0.19415 2.2 12730 326 234.515 2.2 12,730 326 249.5

257 0.20314 2.0 12,400 317 26415 1.5 8,680 222 278.5

286. 0.203

120@

ç'-4

l0.

800

(J o '-s-4

400

-4 (J o¿0

)

II

F

o ----

-"--

--+

---o

-o

Scal

e St

arte

d to

For

m

oo

o.o

-o-

No

Vib

ratio

n=

37.

7°F

o H

eat T

rans

fer

Coe

ffic

ient

so

Con

cent

ratio

ns o

f C

aSO

4+

Cha

ract

eriz

atio

n Po

ints

4080

izO

160

200

¿40

280

Tim

e fr

om S

tart

of B

oilin

g4 M

in.

FIG

UR

E 3

4.C

aSO

4 SC

AL

ING

RU

N N

O. 5

1200

1000 800

600

o

200 o

No

Vib

ratio

n-

LT

=46

.8°F

O H

eat T

rans

fer

Coe

ffic

ient

sC

once

ntra

tions

of

CaS

O4

+ C

hara

cter

izat

ion

Poin

ts

Scal

e St

arte

d to

For

m

o

----

-o

--

- --

J-- +

-o -

- o

o

100

o

200

O40

8012

016

020

024

028

032

036

0T

ime

from

Sta

rt o

f B

oilin

g, M

in.

FIG

UR

E 3

5.C

aSO

4 SC

AL

ING

RU

N N

O. 7

400

r+

oo

Other nonvibratiorial runs (4 nd 6) were also made at 37.7°FternperatuTe difference and agreed generally with Run No. 5. The temper-ature differential for Run No. was 22.8°F and gave a higlaer overallcoefficient of heat transfer, but approximately the same degree of lossdue to scalhg.

The imp1itude of vibration was varied at a frequency of 33 cps to:33 cps in Run Nos. 9, 10, 11, 21, and 22. The temperature difference was37.70F except for Rwi No. 11 vÌuich was 27,4°F. Data for Run No, 9 is4ven :1n Table No . 18 and resrlts are plotted in Figure 36 . Runs 21 and22 were made as checks on Runs Il and 10, respectively, and are plottedwith the results of these runs in Figures 37 and 38. The initial overallcoefficients of heat transfer were: Run No. 9, 634; Rim No. 10, 824; andRun No. il, 933 Btu/iir-ft°F. These correspond to amplitudes of vibra-tian of 0.100 inch, 0.200 inch, and 0.300 inch respectively. Theincreasing amplitudes represent increasing power inìput which results inimproved heat transferS After scaling had progressed to the point atthicb frequent f1aing off of the 3cale occurred, the overall heat trans-fer coefficients fell to a 370, 410, and 405 for Run Nos.9, 22, and 21,respectIvely, This indicates an improvement over the rtonvibrationaLnmsafter scaling of 10% to 20%. A photograph showing typical flaking of theCaSO4 scale is included in Appendix B as Figure SB.

ìly three runs were made at a frequency of 94 to 95 cps and no scalewas foïned during one of these . The amplitude of vibration was O 055inch. The data for Run No. l is given in Table 21; and results areplotted in Figure 39 . The initial overa.11 coefficient of heat transferwas 665 which fell to an average of 568 after scale formed on the pipe.Run No. 17 had an initial overall coefficient of 440 vthich increased to625 at the start of scaling. This waa followed by a decrease to 382 andprobably would have continued to fafl if the nia had been lengthened.These runs cantliiued for only 2 hours and 2- hours after start of scaling)and this generally was not a long enough period to establish a "steadystate" condition , It would probably 'be necessary to use a more powerfulv-ibrator to achieve a wide range of amplitudes at frequencies above the34 cps level, and largr amplitudes appear to be required for ainimprovement in heat trrnfer coefficients.

A nonboi]ing condition was tried in two nine (12 and 13) . At the endof Run No. 12, the steam was shut off and circulation continued for onehour, The temperature dropped from 2100F to l8OF and almost all scalerag remored from the pipe . In Run No , 13 , the boiling was continued only

long enough to form scale on the pipe and then the steam was shut off for45 minutes . During this time the scale was coxxmletely removed from thepipe at a temperature of 200°F. Steam was started agì' and scalerformed on the pipe . The Thieat transfer coefficient decreased morerapidly on formation of scale the second time than it had on initial for-nation of scale. Steam was shut off for another 45 minutes, but a smallamount of scale was not removed near the top of the pipe . The run wasterminated at this point.

83


Vibration; Freq. 35 cps; Amp. 0.1 inchSteam Pressure 15 psigSteam Temp. 249.7°F

945.7 Btu/lb

Reynolds No. (non.-boiling)Heat Transfer AreaWater Boiling Temp.

L T

23,6000.840 ft221 2 °F37. 7 °F

TimePeriod(min.)


HeatTransferredQ(Btu/hr)

OverallCoefficien.t

U(Btu/hr ft2°F)

T im efrom Startof Boiling

(min.)

CaSO4Conc.

% Ren

19 4.3 19,780 623 9.5 Averaged15 3.6 ¿0,970 661 26.5 for initiai

34 0. 194 coefficient30 6.8 19,810 626 49

64. 0. 19125 4.2 14,680 462 76.5 Scaling

.

89 0.lI[18 2.8 13,590 429 9814 2.5 15,600 492 114

121 0.19715 2.5 14,560 459 128.515 2. t 15,150 417 143.5

151 0. 19015 2.6 15,150 477 158.515 2.5 14,560 459 173.5

181 0.19515 2.3 13,400 423 188.514 1.9 11,860 372 ¿03 Averaged for

¿10 0. 191 1 steady state15 2.0 11,650 367 217.5 coefficient15 2.2 12,820 405 232.5

24015 2.0 11,650 367 247.515 2.0 11,650 367 262.5

270 0.19115 2.1 12,230 384 277.515 1.8 10,490 330 292.5

C) o C) o u C)

ri) cd rd C)

rd C)

Q

'zoo

1000 800

600

400

200

Scal

e St

arte

d to

For

m

oo

oO

Oo

oO

DC

once

ntra

tions

of

CaS

O4

Cha

ract

eriz

atio

n Po

ints

C

O--

4o-

---o

---

200

240

Tim

e Fr

om S

tart

of

Boi

ling,

Min

.FI

GU

RE

36.

CaS

O4

SCA

LIN

G R

UN

NO

. 9

Vib

ratio

n: F

req.

35

cps;

Am

p. 0

. 1 in

chT

=37

.7°F

oH

eat T

rans

fer

Coe

ffic

ient

s

280

o

C- 32

0o

,36

0_J,

zoo

loo

C) Q O U

D rd u o o rd C) o o o

TABL 19 CALCIUM SULFATE SCALING - RUN NO. lo

Vibration: Freq. 33 cps; Amp. 0.2 inchSteam Pressure 15 psigSteam Temp. 249.7°F

945. 7 Btu/lb

Timefrom Start CaSO4of Boiling Conc.(min.)

6la19.534.54249.564.57279.594

101108122.5130137.5152.5160167.5182.5190198¿13¿20¿27.5242.5250

86

Reynolds No. (non-boiling)Heat Transfer AreaWater Boiling Temp.

AT

0.207

0. 208

Q ¿14

0. 202

0.213

0.210

0. 204

0.197

J0.202

23,60020. 840 ft

212°F37. 7 °F

Rein arks

Scaling

A. raged :Steady State

lent

Time CondensatePeriod Collected(min.) (cm.)

HeatTransferred

Q(Btu/hr)

OverallCoefficient

U(Btu/hr ft2 °F)

12 3.6 26,210 824

15 3.3 19,220 60415 3.0 17,480 550

15 27 15,730 49415 2.9 16,890 530

.

15 2.8 l6310 51214 2.5 15,600 492

14 2.2 13,730 43215. 2.1 12,230 384

15 2.5 14,560 45815 2.1 12,230 384

15 1.9 11,070 34815 1.6 9,320 293

16 1.7 9,280 29214 1.4 8,740 275

15 1.8 10,490 33015 1.6 9,320 ¿93


Vibration: Freq. 34 cps; Amp. 0.3 inch Reynolds No. (non-boiling) 23,600Steam Pressure 10 psig Heat Transfer Area 0.840 ftSteam Temp. 239.4°F Water Boiling Temp. 2 1 2 °F

LH 952.6 Btu/lb 27. 4°F

Time CondensatePeriod Collected(mij (cm.)

HeatTransfe'red

Q(Btu/hr)

OverallCoefficient

U(Btu/hr ft2°F)

Tim efrom Startof Boiling(min.)

CaSO4Conc.

R e m a rk s

1315

3.23.1

21,67018,190

933785

6. 520.528 0.202

15 3.1 18,190 785 35.515 2.9 17,020 735 50. 5 S caling

58 0. 21414 2.5 15,720 677 6515 2.2 12,910 558 79.

87 0. 21615 1.9 11,150 481 94. 516 2.. 2 12,100 522 11014 1.7 10,690 464 12530 4.0 11 740 505 147

162 0.21230 3.8 11, 1 50 481 17715,14

1.71.4

9,9808,800

432380

199. 5214

Averaged forsteady state

221 0.208 coefficient15 1.6 9,390 404 228. 515 1.6 9390 404 243.515 1.5 8,800 380 258.515 1.6 9,390 404 273 515 1.7 9,980 432 288rn. 5

296.0 0.211

'zoo

Scal

e St

arte

d to

For

m

D

T.

4

Vib

ratio

nì:

'req,

33-

34; A

mpS

.. 0.

2 in

ch¿T

= 3

77°F

o R

unN

o 10

.

Hea

t Tra

nsfe

r C

oeff

icie

nts

A4

Run

No.

22

DC

once

ntra

tions

of

CaS

O4

--C

hara

cter

izat

ion

Poin

ts. z

oo

44%

o

oo

Is--

- -

ôL4

Run

No.

a---

__

---i

----

- -

-- -

- -

¿b

oR

unN

o. 1

0

22

¿14

.100

o

o CID cd o o o (I o u

oo

o - o

«--o

-

1535

5575

9511

513

515

5T

ime

from

Ste

ady

Stat

e, M

in. (

Run

¿2)

175

403O

140

i6o

zoo

¿40

280

. 320

380

Tim

e fr

om S

tart

of

Boi

ling,

Min

. (R

un 1

0)

FIG

UR

E 3

7.C

aSO

4 SC

AL

ING

RU

N N

OS.

10

AN

D 2

2

400

200

1200

L

1000

800

i) ç-)

600

o co cri H 4

00cd cl

)

-4 cd

200

o

Scal

e St

arte

d to

For

m

\

\O

a\

NN

N o

4080

-S-

rr

Vib

ratio

n: F

req.

34

cps;

Am

p, Q

rCh

¿T =

274°

FH

eat T

rans

fer

Coe

ffic

íens

Con

cent

ratio

ns o

. CaS

O4

+ C

hara

cter

izat

ion

Poin

ts L.

F-I

IO

4O60

8010

012

014

0T

ime

from

Ste

ady

Stat

e, M

in.

(Run

21

J o

120

160

200

240

280

320

360

Tim

e fr

om S

tart

of

Boi

ling,

Min

. (R

un 1

1)FI

GU

RE

38.

CaS

O4

SCA

LIN

G R

UN

NO

. 11

AN

D 2

1

- 20

0

100

-4 cl)

Ç) o C

I) cri o '-4 o o -4 cri

4-à

cl) u o o

o-S

-o S-S

----

.-

TABLE ¿I. CALCIUM SULFATE SCALING RUN NO. 18

90

TimePeriod(min.)


HeatTransferred

Q(Btn/hr)

OverallCoefficient

U(Btu/hr ft2 °F)

Timefrom Startof Boiling

(min.)

CaSO4Conc.

Remarks

0 0.20221 0.6 2,540 200 10.581 7i7 8,440 665 61.523 ¿.0 7,720 608 113.564 5.1 7,070 557 157

189 0. 19813 1.3 8,880 700 1955 Scaling29 2.3 7,040 555 ¿16. 5 Averaged for34 3.0 7,830 617 248 steady state

265 0.208 coefficient38 2.9 6,770 534 284

303 0.203

Vibration: Freq. 94 cps; Amp. 0.055 inch Reynolds No. (non-I:còiling) ¿3,6002Steam Pressure 5 psig Heat Transfer Area 0. 840 ft

Steam Temp. ¿27. 1. °F Water Boiling Temp. ¿12F960.6 Btu/lb ¿T 15.1F

1000

('J

900

800

.70

0

H o

600

C)

Q)

(J)

400

1200

1100

1OØ

r-

Scal

e st

arte

d to

for

m

o

IL

¿04Ó

6ÖO

i ÖY

TZ

1 4

TO

Tim

e fr

om S

tart

of

3oi1

ing

Min

.

FIG

UR

E 3

9.C

aSO

4 SC

AL

ING

RU

N N

O. 1

8O

- t-

----

- -

o

Vib

ratio

n: F

req.

94

cps;

Am

p. 0

.055

inch

30db

T =

15.1

°F

V L)

V a1 o cì:i u o o Q)

L) o L)

IO

Hea

t Tra

nsfe

r C

oeff

icie

nts

0 zo

D C

once

ntra

tions

of

CaS

O4

+ C

hara

cter

izat

ion

Poin

ts

+

o

The results of three runs made with sea water are plotted in Figure40 . Data for these runs are given in Table Nos . 22, 23 , and 24 . Thefirst of these, Thin No, 15, was started vftth a temperature differentialbetween the steam and boiling water of 13.1°F. After operating for a fullday with no scale formation, the temperature differential as increased to35.7°F. ThIs still did not initiate scaling on the pipe. The averageoverall coefficients of heat transfer were p338 the first day and 750Btu/hr-ft2°F the second day. The water was dumped after the second dayof operation because it had become so cloudy that the heat transfer sur-face could not be observed, Run No, 19 was made at a temperaturedifferential of 35.7°F, but failed to form scale in six hours of opra-tion. The average heat transfer coefficient was 728. Run No. 20 wascontinued over a period of two days at 35,7°F temperature differentialand started forming scale after approximately 8 hours. The average heattransfer coefficient before scaling was 704 Btu/h-ft2°F, and aftersteady state was established it was 408 Btu/hr-ft'OF, The frequency forall these runs was 34-35 cps and the amplitude was 0.300 inch to 0,355inch. Scale started to form in Run No, 20 only after concentrating thesea water from 19 parts/l000 chloride to 60.6 parts/l000. No nms weremade under norìviTbrating conditions with the sea water, The scale formedby sea water differed considerablr from the CaSO4 scale. . At least twodistinct layers of scale were formed on the pipe. The first was a lightgray and the second layer was dark gray. A photograph of the scale for-mation on the pipe at the end of Rim No. is included in Appendix B asFigure 6B. Most of the flaking óccurs on the center half of the pipe.

This study of scaling was limited to a determination of thefeasibility of scale removal by the use of' acoustic vfbration and didnot attempt to delineate scaling rates or to differentiate betweenimprovement of the overall coefficient of heat transfer due to increasedboiling film coeffIcients and reduced scaling. A comprehensive study ofboiling film coefficients is included in a proposai for future work.Also, other scaling studies have been reported previously, A literaturesurvey by W. L. Badger and Associates, ifl.(2) discusses various means ofreducing potential scale, and means of preventiiig, reducing, or removingscale. Further work by W. L. Badger and Associates, Inc. with an LTVevaporator pilot plant at Wrightsviile Beach, N. C., studied scale for-nation in the tubes. Although this work demonstrated that alkalinescale could be controlled, calcium sulfate scaling was not prevented.In one run which maintained a temperature differential of 10°F to 13°F,and a feed temperature of 200°F to 245°F, the heat transfer coefficientfell from approximately 660 to 525 Btu/hr-ft2°F in 130 hours of operation.These conditions are approximately the same as Run No. 12 which had a Tof 15.1°F, water boiling at 212°F, but with the addition of vibration ata frequency of 34 cps and cmplitude of 0.352 inch. The average coeffi-oient of heat transfer in this run was 830 before scale formed anddropped to 612 Btu/hr-ft2F at steady state condition. This run onlycontinued for 3- hours and therefore it is not definite that thisimprovement could be maintained . The LTV evaporator was also using afalling film inside the tube; vthereas, the viThration test had the boilingwater in an annular space outside the vibrating tube.

92

Ö 4 X tu t,) X z o z I-. z tu Q z o Q tu o z o 1

X o t- u. z X tu Q u. u. tu o Q z w u. u) z 4 z I-. I- w

80 60 40 20 O

800

600

400

200 o

040

8020

6020

024

028

032

036

0'O

044

0T

IME

FR

OM

ST

AR

T 0

F B

0ILG

(M

N.)

FIG

UR

E 4

0. S

EA

WA

TE

R S

CA

LIN

G. R

UN

NO

S. 1

5,9,

AN

D 2

0

T

RU

N

HE

AT

VIB

RA

flON

:

TE

MP

ER

AT

UR

E

CO

NC

rNT

RA

TO

N

NO

.

TR

AN

SF

ER

FR

EQ

UE

NC

YA

MP

LiT

UD

E0I

FE

RE

NT

IAL,

C0a

FF

ICE

NT

OF

CH

LOR

IDE

T

15

34cD

s0.

355

I3J'

FA

och

35.7

*FV

920

35cp

34cp

sO

.34n

. 03

in.

35.7

SF

357

FO

-ia

u

-

J

I

i

SC

ALE

ST

AR

TE

DT

OF

OR

M,R

UN

NO

.20

A

RU

NN

O.i5

¿

A¿

A

Q S

TE

AM

PR

ES

SU

RE

CH

AN

GE

Dj

ii

+

AY

O

7y

_Q_

-

480

520

560

600

640

680

420


Vibration: Freq. 33 cps; Amp. 0.3inch Reynolds No. (non-boiling) 23,600Steam Pressure 15 psig Heat Transfer Area 0.840 ftSteam Temp. ¿49.7°F Water Boiling Temp. 212°F

945.7 Btu/lb AT 37.7°F

.94

Heat Overall . Time fromTransferred Coefficiet Steady State

Q(Btu/hr) U(Btu/hr ft °F) (min.)

TimePeriod(min.)

CondensateCollected(cm )

10 1.716 ¿.512 2.016 2.429 4. 116 2.015 2.3

7 2.521 1.514 1.921 3.1

14,850 469 5

13,650 430 1814,560 460 3213,110 415 4612,350 391 68. 510,920 346 9113,400 424 106.531,210 985 117.56,240 197 131.5

11,860 373 14912,900. 406 16.5

Remarks

No data was recordeduntil scale hadformed and start.dto peel off pipe.Entire run wasaveraged for steadystate coefficient


Vibration: Freq 34 cps; Amp. 0.2 inchSteam Pressure 15 psigSteam Temp. 249.7°F

AH 945.7 Btu/lb

95

Reynolds No, (non-boiling) 23,600Heat Transfer Area 0.840 ft2Water Boiling Temp. 212°F

AT 37.7°F

Time fromSteady State

(min.) Rem arks

7 Nodatawas21 5 recorded until36. 5 scale had formed51 5 and started to66. 5 peel off pipe.81.5 Entirerunwas98. 5 averaged for

113. 5 steady state126 coefficient.140.5155.5171

TimePeriod


Heat OverallT ransfe rred Coefficient

Q(Btu/hr) U(Btu/hr ft°F)

14 2.1 13,110 41515 2.4 14 980 44215 13,400 42415 2.4 14,980 44215 2.3 13,400 42415 2.0 11 650 367

19 2.7 12,420 39111 2.1 16 680 526

14 ¿.0 12 480 39415 2.1 12,230 38515 2.1 12,230 38516 2.1 11,470 361

TABLE 24. SEA WATER SCALING - RUN NO. 15

Vibration: Freq. 34 cps; Amp. 0.355 inch Reynolds No. (non-boiling) 23,600Steam Pressure 5 psig Heat Transfer Area 0. 840 ftSteam Temp. 227.1°F Water Boiling TempS 214°F

960.6 Btu/lb iT 13.1°F

96

Tim ePeriod(min.)


Ove railC oefficiet


(min.) Remarks

15 1.3 699 7.518 1.8 807 2416 1.6 807 41

14 1.7 979 56

15 1.5 807 73.515 1.6 861 85. 517 1.9 902 101 . 512 1.3 874 11630 3.0 807 13716 1.8 907 I 6014 1.3 749 17516 1.8 908 19014 1.4 807 205 No scale

1.7 857 220 formed.

TABLE 24. SEA WATER SCALING - RUN NO. 15 (Cont'd)

Vibration: Freq. 34 cps;Anip. 0.355 inch Reynolds No. (non-boiling) 23,60CSteam Pressure 15 psig Heat Transfer Area 0.840 ftSteam Temp. 249.7°F Water BoiiingTenp 214°F

945.7 Btu/lb 35.7°F

TimePeriod(min.)


Ove railC oefficient

U(Btu/hr ft2 °F)


(min.) Remarks

12 3.5 850 23430 8.0 777 25513 4.0 897 276.513 3.1 695 289.515 3.8 738 303.516 42 765 31923 5.5 697 338.5

9 4.8 736 359.560 14.0 680 39930 5.2 505 44413 3.2 717 465.515 2.8 544 479.515 3.8 738 494.515 4.1 797 509.515 3.3 641 524. 5 No scale15 3.3 641 5385 formed.

9

TABLE 25. SEA WATERSCALING - RUNNO. 19

Vibration: Freq. 35 cps; Amp. 0.34 inch Reynolds No. (non-boiling) 2326002Steam Pressure 15 psig Heat Traìsfer Area 0.840 ft

Steam Temp. 249.7°F Water B.iiing Temp. 214°F945.7 Btu/lb ¿T 35.73F

TimePeriod(min.)

CondensateCollected

(cm.)

OverallCoefficieT1t

U(Btu/hr ft °F)

Time fromStart of Boiliflg

(min.)

ChlorideConcentration(Parts/1000) Remarks

30 7.9 767 15.515 4.1 797 37.527 6.8 734 58.567 16.9 735 105.523 5.7 722 150.538 7.7 590 18122 7.3 967 21138 92 706 24125 6.1 711 272.519 4.4 675 294.552 13.1 734 33014 3.5 729 363 No scale

370 44 formed

T im ePeriod(min.)

CondensateColle cted(cm.)

TABLE ¿6. SEA WATER SCALING - RUN NO. 20

Ove railCoefficient

U(Btu/hr ft2 °F

99

Time f romStart of Boiling

(min

'71I.L

ChlorideConcentration

(Parts / 1000)

63.9-J

Remarks

LAve ragedfor initial

. coefficient

Scaling

Averaged for(' steady stateH coefficient

14 2.0 416 724 5.6 680 2665 15.4 690 70. 522 5.6 742 11436 91 737 i 4333 8.0 706 177.560 14.4 700 22431 7.7 724 269. 550 12.1 705 310

335 449 2.3 745 339. 5

31 7.3 686 359. 518 4.4 712 38429 7.1 713 407.512 30 729 42822 5.0 662 44521 4.5 624 466. 5

477 60.6¿5 3.2 373 489.515 3.5 680 509. 555 5.9 313 544.513 1.9 426 578.5

58335 4.7 391 60. S¿2 2.3 305 63118 3.2 518 65133 4.8 424 676.522 3.1 411 704

Vibration: Freq. 34 cps; Amp. 0.3 inch Reynolds No. (non-boiling) 23,6002Steam Pressure J. 5 psig Heat Transfer Area 0.840 ft

Steam Temp. 249.7°F Water Boiling Temp. 214F945.7 Btu/lb 35.7°F

o 19

Another recent study of scaling was conducted by J, T. Banchera andKenneth F, Gordon(4) . The purpose of this work was to determine the timerequired for appearance of scale with and without boiling at various solu-tion and surface temperatures, concentrations, and flow rates. The timeróquired for scaling was independent of flow rate between 2 and 10 ft/see,but increased as temperature of the surface or percent supersaturationdecreased. The time required was 2 to 360 minutes as supersaturationdecreased from 9Oa to %. Because of the small size and stability ofoperating conditions, the formation of the first crystals could be easilyobserved and accurately timed. However, in the vibration study, no effortwas made to deteiíne precisely the time at which scale initially depos-ited on the pipe, but was taken as that time when a noticeable accumulationof scale had foriiied at top and bottom of the vibrating tube. The time

b4ticn -tudy i genorully longer than Lha determinedfor CaSO4 by Banchero and Gordon, and does not seem to correlate withtheir data.

The scaling study has definitely shown. that transverse vibration ofthe pipe causes flaking of the scale near the center of vibration. Itfurther demonstrated some increase inthe overaliheat transfer coeffi-dent, but did not define this improvement between increased boiling filmcoefficient and reduced scale. Reduction of scaling by vibration requiresfurther separate study in order to quantitatively evaluate the advantageto be gained from acoustic vibration and to define the factors whichinfluence scaling.

CONCLUSIONS AND REO OI'AMENDATIONS

Conclusions

It has been shown that improvement in water side heat transfercoefficients can be obtained in viscous and turbulent flow by the use ofacoustic vibration.

Improvement was highest in viscous flow; 450% greater at aRejnolds number of 540 with vibration as compared to data withoutvibration.

Improvement in heat transfer gradually decreased as the flowRejnolds number increased, but this may be improved by the use of largervibration equipment.

The most effective method of applying acoustic vibrations, thusfar, is the utilization of transverse vibration of a pipe with waterflowing on the outside of the pipe in an annular space.

Acoustic vibration imposed in the water stream did not prciucesignificant heat transfer improvement under test conditions.

100

Longitudinal vibration of a pipe with water flowing inside thepipe did not produce significant heat transfer improvement under testconditions,

Vibration of a pipe in a transverse direction with water flowinginside the pipe did not produce significant heat transfer improvementunder test conditions.

8, The use of acoustic vibration produced a 57 improvement insteam condtmsing heat transfer coefficient at a frequency of 75 cps andan amplitude of 2 inch, This represents a possible 30% increase inevaporator capacity.

Vibrations definitely improved the steam condensing coefficient,when noncondensable gases are present in the steam. Heat transferimprovement was as high as 23%.

Vibrations definitely cause flaidng of the calcium sulfate scaleand sea water scale from the pipe surface under both boiling andnonboiling conditions,

Better removal of scale under nonboiling conditions was obtained,

Recommendations

The effect of higher frequencies (1000-5000 cps) should beinvestigated as to their effect on the heat transfer coefficient,

The use of larger vibration equipment to determine whethergreater heat transfer improvement cari he obtained at higher flow Reynoldsnumbers should be studied.

The effect of inner to outer pipe diameter on heat transferimprovement should be evaluated.

4,. The correlation previously presented should be extended to abroader range of amplitudes and frequencies.

5 , Pressure drop data with and without vibration should be obtainedunder broader range of flow conditions,

6. As a basis for a preliminary econoìwîc study, the amount ofacoustic energy required at various amplitudes arid frequencies should bedetf 'mined.

7, The effect of acoustic vibration on steam condensation on theinside and outside of a tube should be studied further.

101

8. The effect of tranvere vibration of a pipe on the boilIng heattrmsfer coefficient should be investigated.

9' The effect of vibrations at higher frequencies on the reniovaJ. ofacale should be investigated,

102

BIBLIOGRAPHY

Anantanarayanan, R,, Trans AIMB, Oct., 1952, p. 426.

Badger, L L. & Associates, Office of Tec]mical Services, U, S.Department of Contuerce, PB 161399.

F'and, R. M. and Kaye, J., AME-AIChE Heat Transfer Conference,August 1960, Paper No, 60.HT-14.

/Gordon, K. F., and Banchera, 3. T., Scale Deposition on HeatedSurfacas, Office of Saline Water Report for 1959.

Holinan, 3., WIDC Tecbnical Note 5-32, Dec., 1952.

Hu, C. K., Fn,D, Thesis, University of Cincinnati, 1959.

7 . Jackson, , W . , Feb . , 1959, p . 6.a: Jackson, . W. , ard Johnson, . C . , Air Force Final Report , Contract

fly 4963459, March 1960.

Jackson, T, W,, and Spurlock, Jack, WADC Project A-33, June 1959.

Knudsen, James G. and Katz, Donald L., Hea1McGraw-Hill Book Co , Inc . , New York, 1958.

11. Kubanki, P. M,, (USSR.), Vol. 22, 1952, p. 55.12 . Lemlich, . , Ind , En. (len. , , 1955 , p. 1175.

13. Mcrtine11í, R. C. and Boelter, L, M., Proc, 5th lut, Congress forApplied Mechaìrtcs, p. 1939.

14 . McAdas, W. H. , 3rd Ed . , 1954,

Maeller, W. K, UD.Lversity of Illinois Thesis, l96, Publicaticii No.19853 .

Scanlan, J. A., Völ. 50, Oct., l95, p. 1565,17, Shai, I. and Roten, Z,, ÀSEAIChE Heat Conference, August 1960,

Part 1 - StatIonary Flow, Part 2 - Pulsating Flow.

l. West, F., and Taylor, A., ¿, 1952, p 39,

103

APPENDIX A

TYPICAL EXPERIMENTAL DATA

EFFECT OF ACOUSTIC VIBRATION IN THE WATER STREAMINSIDE THE PIPE

104

The rmocouple

Nurn be rs ¿ST, °F

-1

8

910

Inlet to Outlet Li TInlet Temp 85.3°F

TEMPERATURE DIFFERENCE DATARUN 21 - REYNOLDS NUMBER 500

105

CorrectionFactor forTemp Rise

of Water, °F

Without Vibration

Corrected1ST. 'F

() I41.0 21.8 19 . 244.7 ¿4. 6 20. 146.7 27.3 19.4

Av 19.48L.Tinwa11 .36

19. 11

30. 0 °F

i 21.6 ¿.7 18. 9¿ 27.5 5. 5 ¿2.03 26.9 8.2 18.74 30.5 lo. t, 19.65 31.2 13.6 17 G6 35.5 Ib. 1,. ¿

TEMPERATURE DIFFERENCE DATARUN ¿1 - REYNOLDS NUMBER 500

Frequency 90 cps - Amplitude 50 psi

106

Av 19.05ATinwall .36

18.69

Inlet to Outlet A T 30. 7%Inlet Temp - 85,00?

The rmo-couple

Numbers AT, °F


of Water, °FCo rrected

A T

1 19.1 2.8 16. 3

¿ 27.2 5.6 21.63 27.2 8.4 18.84 31.7 11.2 ¿0.55 31.7 14.0 17.76 35.5 16.7 18.87 39.Z 19. 5 19. 78 41.2 22.3 18. 9

9 44.2 ¿5,1 19. 1

10 470 27.9 19. 1

TEMPERATURE DIFFERENCE DATARUN 21 (CONT'D) - REYNOLDS NUMBER 500

Frequency 260 cps - Amplitude 37. 5 psi

inlet to Outlet T 30 60FInlet Temp - 85. 1 °F

107

The rmo-couple

Numbers .T, °F

Co rrectionFactor forTemp Rise

of Water, °FÇorrected¿T °F

1 2L7 2.8 1892 27.4 5.6 21.83 27.4 8.3 19.14 30.5 11.1 1945 31.6 13.9 17.76 3s.8 16.7 1917 38.7 19.5 1928 41.3 22.2 19.19 44.9 25.0 19.9

10 46. 9 27. 8 19.1Av 19.33

iTinwa11 .3618.97

TEMPERATURE DIFFERENCE DATARUN 22 - REYNOLDS NUMBER 191

108

Av 9.65iTinwa11 .13

9. 52

Inlet to Outlet T - 29.8SFInlet Temp - 85.3

Thermo-couple

CorrectionFactor forTemp Rise Corrected

Numbe rs ¿ST,. °F òfWater, °F LT) °F

Without Vibration

1 12.5 2.7 9 a2 15.5 5.4 10. 13 17.3 8. 1 9. 2t 20.0 10.8 9. 25 22.3 13. 5 8.86 25.8 16. 2 9. 67 28.9 19. 0 9 98 31.6 21...7 9. 99 34.2 ¿4.4 9.8

10 37.3 27. I 10.2


Frequency loo cps - Amplitude 50 p51

109

Thermo-couple

Numbers 4T °F


of Water, °FCorrected

T, °F

1 11.4 2.7 8.72 15.5 5.4 10.13 17.4 8.1 9.34 20.5 l08 9.75 22.6 13.5 9.16 25.8 16.1 9.77 29.6 18.8 10.88 31.8 21.5 10.39 34.4 ¿4.2 10.2

10 37:9 26.9 11.0Av 9.89

¿Tmnwall .139.76

Inlet to Outlet T - 29. 6°FInlet Temp - 85.3°F



110

Av 979¿Tinwall .13

9. 66

Inlet to Outlet L T - 30. 0 °FInlet Temp - 85.4°F

The rmo-couple

Numbe rs ¿ST, °F


of Water, °FCorrected

T, G

1

2

11.915.5

¿.75.5

92lo, O

3 17.9 8.2 9,74 20.8 10.9 9.95 22. 3 13.6 8.76 26. 1 16. 3 9.87 29 O 19. 1 9,98 31.8 21.8 10. 1

9 34,7 ¿4. 6 lo, 1lo 37.8 27.3 1o, 5



111

Av 9.62¿sTinwall.13

9' 49

Inlet to Outlet iT - 30. Z°FInlet Temp - 85.0F

Thermo-couple

N um be rs tT, °F


of Water, °FCorrectedAT, °F

1 11.9 2. 7 9. 22 15.5 5. 5 lO. O3 17.5 8.2 9. 34 20.8 11.0 9.85 22.4 13.7 8.76 ¿6.3 16.4 9. 97 28.8 19.2 9. 68 31.2 21.9 9,39 34.7 ¿4. 7 10.0

10 37.8 27.4 10. 4

EFFECT OF ACOUSTIC VIBRATION OF THE PIPE WITH WATERFLOWING INSIDE THE PIPE

112

The rrno -couple

Numb e r s

TYPICAL DATA FOR LONGITUDINAL VIBRATIONRUN 4 - REYNOLDS NUMBER 19, 300

Thermoccuples are numbered from inlet endof pipe and are spaced 6 inches apart.

OutsidePipe Wall TMinus Inlet

AT, °F

CorrectionFactor f rTemp Rise

of Water, °F

No Vibration

113

CorrectionFactor forTemp Drop

Thru Pipe, °FCorrected

¿IT, °F

Avg, 27. 0

i 30. 0 L 3 2 Z 26. 5z 30. 3 z, 6 z, Z 25. 53 30. 2 3 9 Z, Z 24. 14 32. 4 5. 2 Z Z 25. 05 38. 4 6. 5 Z, Z 29. 76 37. 1 7, 8 Z, Z 27. 17 36. 9 9, 1 a. Z z5 6

Avg 26. 2

Inlet to ouLlet ¿T - 10.Inlet Temp - 134. 6° F

i 32 I

z 33 63 32. 24 32. 35 37, 36 36. 67 36. 5

Inlet to outlet T - 10.Inlet Temp - 134. 1°F

38°F

51°F

Frequency 10. 5 cps

1 3

z, 63, 95 Z6. 57 89, 1

2 Z Z6. i2 Z 24. 92 Z 28. 6& Z 26. 62. 2 25. 2

z, z 28. 62, Z 28, 8

Thermo-couple

Nurnbe r s

TYPICAL DATA FOR LONGITUDINAL VIBRATIONRUN 4 - REYNOLDS NUMBER 19, 300 (Cont'd)

Out sidePipe Wall TMinus Inlet

AT, °F

Inlet to outlet AT - 10. 39°F

Inlet to outlet AT - 10. 36°FInlet Temp - 134. 4° F


of Water, °F

Frequency 32. 2 cps

3

6

92

5

89, 1

Frequency 51. 0 cps

1. 3z. 63 9

¿58

9. i

114

CorrectionFactor forTemp Drop

Thru Pipe, °FCorrected

AT, °F

i 30. 1z 32. 43 32. 24 33. 65 39. 56 38. 87 38. 6

Inlet Temp - 134. 6°F

i 31. 92 32. 93 32. 24 32. 55 37. 86 36. 67 36. 5

z, z .. '-.

z. z 27. 62. 2 26. 1z. z 26. 2z. z 30. 8z, z 28. 82. 2 27. 3

Avg 27. 6

z, z 28. 4z, z 28. i2. 2 26. 12. 2 25. 1z, z 29, 1z. z 26, 62, 2 25, 2

Avg 26. 9

The rmocouple

Numbe rs

TYPICAL DATA FOR LONGITUDINAL VIBRATIONRUN 4 - REYNOLDS NUMBER 19, 300 (Cont!d)

OutsidePipe Wall TMinus Inlet

¿ST, °F

Inlet to outlet T - 10. 41°FInlet Temp 134. 2°F

Inlet to outlet T - 10. 43°FInlet Temp - 134, 3°F


of Water, °F

Frequency 81. 0 cps

115

Cor rectionFactor forTemp Drop

Thru Pipe, °F

2, Z2. 2z, ¿2, 22, 22, 2z, Z

Corrected¿ST, °F

28, 431

24, 428, 5

2

24, 8

Avg 26. 4

26, 128, Ï¿L 426. 730. 427; O25, 1

Avg ¿L 3

i 31.9 1. 3z 32. .1 2, 63 31, 2 3. 94 31. 8 5, 25 37. 2 6. 56 36, 2 7, 87 36. 1 9. 1

Frequency 160 cps

i ¿9, 6 1.3 2, 2¿ 32, 9 2, 6 2, 23 33, 5 3. 9 2, 24 34. i 5. 2 2. 25 39, 1 6. 5. -L, ..

6 37, 0 7, 8 Z Z7 36. 4 9 i 2, 2

Thermocouples are Numbered from Inlet End of Pipe at Distancesof and 33" on a 48" Length of Pipe15", 21", 27",

TYPICAL DATA FOR TRANSVERSE VIBRATIONRUN 8 - REYNOLDS NUMBER 24,, 000

Inlet to Outlet T - 9.49°FInlet Temp -99. 0°F

116

Avg 31. 5

Correction CorrectionThermo- Factor for Factor forcouple Location Temp Rise Temp Drop C o r r e c t ed

Numbers on Pipe ¿T,°F of Water, °F Thru Pipe, °F ¿ST, °F

Without Vibration

i Back 34. 7 3. 0 I. 2 29.52 35. 0 4. 2 1.2 29. 63 36. 7 5. 3 1.2 30. 24 38. 1 6. 5 1. 2 30. 45 Bottom 34. 9 3.0 1.2 30. 76 35. 8 4. 2 1.2 30. 47 35.8 5. 3 1.2 29. 38 35. 8 6. 5 1.2 27. 89 Front 34. 3 3. 0 1.2 30. 1

10 35. 8 4. 2 1.2 30. 4il 36. 8 5. 3 1.2 30. 312 36. 9 6. 5 1.2 29. 213 Top 38. 0 3. 0 1. 2 33.8.14 40. 5 4, 2 1.2 .35:015 44. 5 5. 3 1.2 38. i16 46. 2 6. 5 1. 2 38. 5

Thermo-couple

Number s

TYPICAL DATA FOR TRANSVERSE VIBRATIONRUN 8 - REYNOLDS NUMBER 24, 000 (ConVd)

Locationon Pipe


LT, °F of Water, °F

Frequency 18. 0 cps

117

CorrectionFactor for

Temp DropThru Pipe, °F

Corrected¿ST, °F

Avg 31. 5

Inlet to Outlet T - 9. 55F

i Back 34 4 3. 0 i. 2 30. 2¿ 35. 0 4. 2 1.2 29. 63

4

'p

t'36. 537 . 9

5. 46. 6

1.21.2

29. 930. 1

5

6Bottom

t'34. 4J.

3. 04. 2

i. 21.2

30. 230. 2

7 I? 35 ¿ 5.4 i _)J.. '- 38. 68 'p 35, 4 6. 6 1.2 27. 69

loii

F r ontt,

't

34. 235. 137. 0

3. 04. 25. 4

1.2L 21.2

30. 029. 730. 4

12 36.4 6. 6 1.2 23. 613 Top 38. 2 3. 0 1.2 34. 014 40. 0 4. 2 1.2 34. 615 't 44. 5 5.4 1.2 37. 916 't 46. 2 6. 6 1.2 38. 4


Frequency 30. 5 cps

i Back 34.4 3. 0 i, 2 30. 22 " 34.4 4. 2 1.2 ¿9. 03 t, 39.6 5.4 1.2 33. 04 tt 37.9 6. 5 1. 2 30. 25 Bottom 34.7 3. 0 1.2 30. 56 ' 34.9 4. 2 1.2 ,f. -L7. D7 t' 353 5. 4 1.2 ¿8. 78 " 35.5 6. 5 1.2 ¿7, 8

hermocouple Locationumbers on Pipe

TYPICAL DATA FOR TRANSVERSE VIBRATIONRUN 8 - REYNOLDS NUMBER 24, 000 (Cont'd)

tNT, °F

CorrectionFactor forTemp Riseof Water, °F

Frequency 30. 5 cps (Cont'd)

11


Temp DropThru Pipe, °F

Corrected¿ìT, °F

Avg 31. 2

inlet to Outlet ¿T - 9. 51°F

Avg 31. 5

Inlet to Outlet LT - 9. 65°FInlet Temp - 98. 2°F


Frequency 41 cps

i Back 34. 4 3. O 1. 2 30. Z¿ 35. 4 4. 2 1.2 30. 034

'It'

Out38. 3

5.46. 6

L Z1.2

Out30. 5

5 Bottom 34.9 3. 0 1.2 30. 767 t'

35.435. 8

4. 25.4

1.2I. 2

30. 0¿9. 2

8 't 35. 6 6. 6 1.2 27. 89 Front 34. 5 3. 0 1. Z 30. 3

IO 35. 5 4. 2 1.2 30. O1112

tt'

37. 137. 2

5.46. 6

1.21.2

30. 529.4

13 Top 37 5 3. 0 1 2 33. 314 39. 8 4. 2 1.2 34. 41516

I,

t'44. 646.4

5.4f ,o. o

1.21. Z

38. 038. 6

9 Front 33. 9 3. 0 1. 2 29. 710 35. 1 4. 2 1. 2 29. 711 36. 4 5. 4 I. 2 ¿9. 812 36. 5 6. 5 1.2 28. 813 Top 36. 4 3. 0 1.2 32. Z14 39. 2 4. 2 I. 2 33. 815 43. 9 5. 4 1.2 37. 316 u 45. 5 6. i 1.2 37. 8



¿ST, °F of Water, °F

Frequency 57 cps

119


Temp Drop CorrectedThru Pipe, °F LT, °F

Avg 31.4

Inlet to Outlet T - 9.60°F

I Back 34. 6 3. 0 1.2 30.4z34

'tt,

't

35. 2Out38. 7

4. 25.46. 8

1.2i. z1.2

¿9. 8Out30. 9

5 Bottom 34. 9 3. 0 1.2 30. 76 35. 3 4. 2 1.2 29.97 35. 5 5.. 4 1.2 28. 78 't 35. 8 6. 6 1.2 28. 09 Front 34. 4 3. 0 1.2 30. Z

10 't 35. 8 4. 2 1.2 30.4il t' 37. 1 5.4 1.2 30. 51213

t,

Top37. 136. 5

6. 63. 0

1.21.2

29. 332. 3

14 't 39.9 4. 2 1.2 34. 515 t' 43. 8 5.4 1.2 37. 216 t' 45. 5 6. 6 1.2 37. 7


Frequency 144 cps

i Back 34. 6 3. 0 1.2 30.4Z " 34.5 4. 2 i, 2 ¿9. 13 Cut 5.4 1.2 Out4 1 38.4 6. 5 1.2 30. 75 Bottom 35.0 3. 0 1.2 30. 86 't 35,4 4. 2 1.2 . 30.07 t, 35.4 5. 4 1.2 ¿8. 88 " 35.6 6. 5 1.2 27. 9

Thermo-couple Location

Number3 on Pipe


Number s on Pipe



¿T, °F of Water, °F

Frequency 144 cps (Cont'd)

Inlet to Outlet ¿T - 9. 54°FInlet Temp 98. 5°F

120


Temp Drop CorrectedThru Pipe, °F ¿ST, °F

9 Front 34. 1 3. 0 1.2 29. 91011 t'

35. 736.4

4. 25.4

1. 21.2

30. 329. 8

12 't 36.9 6. 5 1.2 29. 213 Top 37. 1 3. 0 1.2 32. 91415

't.

t't'

40, 244. 045.9

4. 25. 46. 5

1.21.21.2

34. 837.438. 2

Avg 31.0

EFFECT OF TRANSVERSE VIBRATION OF THE PIPE WITHWATER FLOWING IN AN ANNULUS

121

The nno -couple Location

Numbers on Pipe

TYPICAL TEMPERATURE DIFFERENCE DATARUN 15 - REYNOLDS NUMBER 1418

Thermocouples arc numbered from exit end ofpipe at spacings as shown in Figure 1

Inlet to Outlet A T - 10. 06°FInlet Temp - 95.°F

LT, FWithout Vibration


cfWater, °FCorrected¿ST, cF

122

1 Front 51.2 9.5 41.7¿ II 52.8 7.9 44.93 49.2 6.3 42.94 44.8 5.4 39.45

67

'tt,

t47.847.844.9

4.63.8¿.2

43244.042.7

8 f 40.2 .5 39.79

loSide

t'49.749.6

9.57.9

40.241.7

11 't 47.4 6.3 41.112 t 42.2 5.4 36.813 't 47.8 4.6 43.214 't 50.2 . 3.8 46.415 46,2 ¿.2 44.016 t 25.2. . 5 24.7

T he rm o-couple

Ni.irnbe rs

IrYPICAL TEMPERAT URE DIFFE PENCE DATA (Cont.1 d)RUN 15 REYNOLDS NUMBER 1418

Frequency 32 cps - Amplitude . 100g'

ÇorrectionFactor for

Location Temp Rise Correctedon Pipe L T, °F of, °F A T, °F

Inlet to Outlet A T - 9. 89°FIñlet Temp - 95. 5°F

123

i Front 540 9.4 44.62 ' 47.2 7.7 39.53 36.7 6.1 30.64 " 33.8 5.3 28.55 " 32.3 4.5 27.86 " 31.6 3.7 27.97 U 42.5 2.1 40.48 " 34.3 .5 33.89 Side 50.2 9.4 40.8

10 t! 37Ø 7.7 29.311 " 31.8 6.1 25.712 " 30.3 5. 3 25.O13 " 20.8 4.5 16.314 " 23.9 3.7 20.215 " 31.4 2.1 29.316 " 20.4 .5 19.9

TYPICAL TEMPERATURE DIFFERENCE DATA (Cont'd)RUN 15 - REYNOLDS NUMBER 1418

Frequency 32 cps - Amplitude .050"

Co r rectionThermo- / Factor-for

couple Location Temp Rise Corrected

Inlet to Outlet AT - 10. ¿3°FInlet Temp - 95. 5°F

124

T, °F of Water1 F AT, °F

52.9 9.7547 8.0 46.752.7 6.4 46.346.3 5.5 40.848.0 4.7 43.350.5 3.9 46.650.2 ¿.2 48.035.4 .5 34.949.3 9.7 39.646.7 8.0 38.742.5 6.4 36.138.7 5.5 33.Z37.8 4.7 33.141.8 3-9 37..943.8 ¿.2 41.623.0 .5 _2z.5

Numbers on Pipe

1 Frontz It

3

45

67 I,

8

9 Side10 II

11.121314 J1

1516

TYPICAL TEMPERATURE DIFFERENCE DATA (Cont'd)RUN 15 * REYNOLDS NUMBER 1418

Frequency 32 cps - Amplitude 025"

Inlet to Outlet T - 10. 20°FInlet Temp - 95. 6°F

125

The rmo-couple

NumbersLocationon pipe AT, °F


ofWater, °FCorrected

AT, °F

i Front 51.3 9.7 41. 62 t' 532 8.0 45. 23 t? 49.8 6.4 43.44 't 44. 7 5. 5 39. 25 't 49, 2 4.7 44. 56 t 48. 3.9 44 . 3

7 It 50.2. 2.2 48 . O

8 I' 35.4 0.5 34.99 Side 50.4 9. 7 40. 7

loli

t,

t'49. 646. 5

8.06.4

41.640. 1

12 t? 41.2 5.. 5 35.713 t' 44. 5 4.7 39. 814 ti 46. 5 3.9 42. 615 t' 46. 9 2. 2 44. 7i,10 'I 22. 8 0.5 22. 3

TYPICAL TEMPERATURE DIFFERENCE.DATA (Cont'd)RUN 15 - REYNOLDS NUMBER 1418

F requency 42 cps - Amplitude 150"'

CorrectionThermo- Factor for

couple Location Temp Rise CorrectedNumbers onipe T, °F of Water, F T, 'F


126

i Front 50.2 9.6 40.62 Iv 31.0 7.9 23.13 'I 18.1 6.3 11.84 t' 18.8 5.5 13.35 " 16.4 4.6 11.86 n 13.9 3.8 10.17 " 25.4 2.2 23.28 t? 343 0.5 33.89 Side 42.0 9.6 32.4

10 " 27.9 7.9 Z0011 " 18.8 6.3 12.513 " 18. 1 5.5 12.613 13.3 4.6 8.714 " 15.9 3.8 12.115 " 22.1 2.2 19.916 ' 21.0 0.5 20.5

TYPICAL TEMPERATURE DIFFERENCE DATA (Cont'd)RUN 15 REYNOLDS NUMBER 1418

Frequency 42 cps - Amplitude . 100"

Inlet to Outlet T 10 15°FInlet Temp - 95.7°F

127

The xmo -couple

NumbersLocationon pipe ¿ST, °F

CorrectionFactor forTemp. Rise

of Water, °FCorrectedLT, °F

i F ront 54.0 9.6 44. 4z 41.2 8.0 33.23 31.8 6. 3 ¿5. 54 32.0 5.. 5 26. 55 27.4 4.7 22.76 't 26. 3 3.8 ¿2. 57 35. 6 2.2 33.48 36.9 0.5 36.49 Side 46. 8 9. C) 37.2

10 32. 1 8.0 ¿4. 1li 28.8 6.3 22. 512 27.9 5. 5 22.413 17.9 4.7 13.214 21.9 3.8 18. 115 27.0 2.2 24.816 21.4 0. 5 20 9


Frequency 42 cps - Amplitude .050

Inlet to Outlet T - 10.03°FInlet Temp - 95. 5°F

i2

The rmo-couple

Nurnber3Locationon pipe 1 T, °F


of Water, °FCorrected¿T, °F

i Front 52.9 9.5 43.42 51.8 7.9 43.93 46.7 6.2 40.54 It 42.5 5.4 37.15 u 4L2 4.6 36.66 It 44.0 3.8 40.27 u 48.7 2.2 46.58 " 35.4 0.5 34.99 Side 49.3 9.. 5 39.8

10 I' . 41,2 79 33.311 It 347 6.2 28.512 1 33.0 5.4 27.613 'I 28.5 4.6 ¿3.914 U 32.7 3.8 ¿8.915 37.8 2.2 35.616 t 22.3 0.5 ¿1.8


Frequency 42 cps Amplitude .025"


129

The mio-cbuple

NumbersLocationon pipe z T, °F


of Water, °FCorrected¿ST, °F

1 Front 50.2 9.4 40.8Z " 52.7 7.8 44.93 1 51.3 6.2 45.14 44.7 5.4 39.35 46.9 4.6 42.36 " 49.2 3.7 45.57 48.7 2.1 4668 36.1 0.5 35.69 Side 47.6 9.4 38.2

10 " 47.3 7.8 39.511 43.8 6.2 37.612 39.4 5.4 34.013 43.2 4.6 38614 46.9 3.7 43.215 45.6 2.1 43,516 23.0 0.5 22.5

TYPICAL TEMPERATURE DIFFERENCE DATA lCont'd).UN 15 - REYNOLDS NUMBER 141

Frequency 62. 5 cps - Amplitude . 100'

Inlet to Outlet ¿T - 9.92°FInlet Temp - 95.3°F

130

Thernio-couple

NumbersLocationon pipe T, °F


f Water, oCorrected

T, 'T

i Front 54.4 94 45O2 " 37.2 7.8 29,43 28.6 6.2 22.44 27.0 5.4 21.65 " 25.2 4.6 20.66 23.7 3.8 19.97 30.3 2.1 2828 35.0 0.5 34.59 Side 45.0 9.4 356

10 " 27.0 7.8 19.211 23.9 6.2 17.712 24.1 5.4 18.713 14.8 46 10,214 17.5 3.8 13.715 21,9 2.1 19,816 19.9 0.5 19.4

TYPICAL TEMPERATURE DIFFERENCE DATA (Conttd)RUN 15 - REYNOLDS NUMBER 1418

Frequency 62.5 cps Amplitude .05011

inlet Temp - 95.4°F

131

Thermo-couple

NumbersLocationon pipe AT, °F

Co r rectionFactor forTemp Rise

of Water, °FCo rrected

T, °F

i¿

FrontII

53850.5

9.47.8

44.442.7

3 It 41.8 6. 2 35 64 H 37.2 5,4 31.85 II 36. 5 4. 6 31.96 tI 37. 4 3.8 33 67 tI 46. 2 2. 1 44, 18 It 35.4 0. 5 33.99 Side 51.3 9.4 41.9

10 1t 38.0 7. 8 30. 211 It 31.4 6. 2 25. 212 29. 6 5 4 24 Z13 23.4 4. 6 1. 8 . 8

14 26. 1 3.8 22 315 34.0 2. 1 31.916 it 39. 2 0. 5 38.7

Inlet to Outlet A T - 9.97°F

The rnio-couple

Numbe rs

iz3

4s67

8

9lo11'z13141516


Frequency 62. 5 cps - Amplitude .025"

Locationon pipe

Front

side

Inlet to Outlet T - 10. 02°FInlet Temp - 95. 5°F

LT, °F

0.72.01.8

44. 147.851 249.335.849.346. 240. 536. 33.038.42.221.2

132


ofWater, UF

9.S7.86. 2

.44 63.82. 20 5

9 s7.86. 2

,44.63 82.. 20.5

Corrected¿ST, °F

41.244 Z4.338.743 Z4744T 138.339838434, 330 930 414 740.020 7


Frequency 84 cps - Amplitude . 050"

Inlet to Outlet T - 9.98°FInlet Temp - 95. 5°F

133

F routt,

52.449. 2

9.47.8

43.941.4

't 42.0 6. 2 35.8

t,38.336. 7

5.44. 6

32. 932.1

t 37.8 3.8 34.0t 45. 3 2.2 43. 1t 3 i 0 5 35. 6

Side 48.7 9.4 39. 3't 35.8 7.8 28. 0

30.8 6. 2 ¿4. 629. 2 5.4 23.8

7' ¿2. 1 4.6 17. 525.4 3.8 ¿1.631.8 2. 2 ¿9, 621.2 0.5 ¿0.7

Correction:hermo- F actor forcouple ocatïon Temp Rise Corrected

N um bers _L eF of Water. °F ,.,T1 °F

i23

45

67

89

ioii1213141516

TYPICAL TEMPERATURE DIFFERENCE DATA (ContÎd)RUN 15 - REYNOLDS NUMBER 1418

Frequency 84 cps - Amplitude .025"

134


Nurnber on pipe AT, °F

Co rrectionFactor forTemp Rise

of Water, °FCorrectedAT, °F

1 Front 50.5 9.2 41.32 51.8 7.6 44, 23 50.3 6.1 44,24 II 44.3 53 39. 05 T' 47.8 4.5 43.36 49.3 3.7 45,67 " 47.6 2,1 45,58 35.8 0.5 3 5 , 3

9 Side 49.8 9.2 40.610 " 45.2 7.6 37. 611 ti 42.2 6.1 36. 112 t' 37.4 5.3 32. i13 " 40.9 4.5 36,414 u 42.2 3.7 38.515 42,5 2.1 40 416 23.0 05 22. 5

inlet to Outlet A T - 9. 73 °FInlet Temp - 95.3°F

EFFECT OF TRANSVERSE VIBRATION OF THE PEPE ON SCALE FORMATIONSCALING LIQUOR FLOWING IN AN ANNULUS

135

RE

SUL

TS

OF

PRE

LIM

INA

RY

SC

AL

ING

RU

NS

Tim

e,M

in

Ove

rai

l Hea

tT

rans

Coe

ff,

Btu

/hr

ft2°

FT

ime,

Min

Ove

rall

Hea

tT

rans

Coe

ff,

Btu

/hr

ft2°

FT

ime,

Min

Ove

rall

Hea

tT

rans

Coe

ff,

Btu

/hr

ft2°

F57

533

2778

3li

769

8752

446

699

2577

311

053

56

653

4075

41

5752

392

553

5664

921

246

8ill

431

7351

224

645

112

943

887

460

284

399

i 71

434

103

483

328

363

210

438

118

493

367

307

241

365

i 33

487

405

307

271

341

i 52

473

433

315

180

480

204

437

228

363

255

303

275

314

295

349

313

259

328

276

348

287

373

236

391

276

408

247

426

259

443

261

457

251

Stea

m T

emp

=24

9.7°

FSt

eam

Tem

p =

242.

9°F

Stea

m T

emp

=24

9.7°

FW

ater

Tem

p =

212°

FW

ater

Tem

p =

212°

FW

ater

Tem

p =

212°

FSc

alin

g R

un i

Scal

ing

Run

2Sc

alin

g R

mi 3

=-

37.7

°F30

. 9°F

T=

37.

7°F

(with

out v

ibra

tion)

F re

quen

c38

cps

&. 2

am

pFr

eque

ncy

38 c

ps &

. 2 a

mp

CALCIUM SULFATE SCALING - RUN NO. 4

Vibration: Freq. O cps; Amp. 0 inch Reynolds No. (non-boiling) 23,600Steam Pressure 15 psig Heat Transfer Area 0.840 ftSteam Temp. 249. 7°F Water Boiling Temp. 212SF

945.7 Btu/lb 377FT im e

Time Condensate Heat Overall from Start CaSO4Period Collected Transferred Coefficient of Boiling ConcJ) (cm.) Q(Btu/hrj U(Btu/hr ft2 °F) (min.) Remarks

7 Nolevel o 0.1891413

29

33

1516

1215

1515

1614

1713

151514

15

1515

Averagedfor0. 172 inìtial overall

coefficient0.180

0.195

Started scaling0.205

0195

0.184Averaged forsteadystate

0.180 overailco-efficient

0.181

0.179

0.177

0.183

137

2.6 16,230 510 142.5 i6soo 58 27 5

316.6 19,890 624 48 5

655.6 14,830 467 79 5

962.3 .13,400 421 103.52.9 ìS,840 498 119

1302.0 14,560 457 1352.0 11,650 366 148.5

1562.8 16,310 513 163 52.4 13,980 438 178 5

1862. 1 11 4/0 360 1941.7 10,610 333 209

2162.2 11,310 355 224.51.5 10,080 330 239 5

2461.7 ',900 311 253 51.6 9,320 292 268 51.6 9,990 313 284

¿861.7 9,900 311 298 5

3061.6 9,320 293 313 51.5 8,740 274 38 5

336


37. 7°F

TimPeriod(min.)

CondensateCollected

(cm.)

HeatTransferred

Q(Btu/hr)

OverallCoefficient

U(Btu/hr ft2 °F)

Tim efron) Startof Boiling

(min.)

CaSO4Conc.

% Remarks

15 3.2 18,640 587 7515 0.215

15 2.8 16,310 512 22.515 2.8 16,310 512 37.5 S caling

45 0.21715 2.7 15,730 494 52.515 2.3 13,400 422 67.5 Averaged fo

75 0.214 steady state15 2.3 13,400 422 82.5 coefficient15 2.4 14,980 441 97.5

105 0.20813 2.1 14,120 443 113.515 2.3 13 400 422 127.5

135 0.20215 2.2 12,820 405 142.515 2.0 11,650 366 157.5

165 0.19315 ¿.0 11 650 66 172. 515 2.1 12,230 384 187.5

195 0.195

Reynolds No. (non-boiling) 23 600Heat Transfer Area 0.840 ft2Water Boiling Temp. 2 1 Z °F

Vibration: Freq. o cps; Amp. 0 inchSteam Pressure 15 psigSteam Temp. 249. 7°F

L H 945. 7 Btu/lb


Vibration: Freq. o cps; Amp. 0 inch Reynolds No. (non-boiling) 23,600Steam Pressure 8 psig Heat Transfer Area 0.840 ftSteam remp. 234. 7 °F Water Boiling Temp. 2 1 2

955.7 Btu/lb 22. 7 F

139


(min.)

TimePeriod(min.)


HeatT ransfe rred

Q(Btu/hr)

OverallCoefficient

U(Btu/hr ft2 °F)

13 2.0 13,590 69814 1.9 11,980 620

47 5.6 10,520 541

17 2.0 10,390 536il U6 12,840 658

15 1.7 10,010 51716 1.4 7,730 398

18 1.6 7,850 40411 1,0 8,030 413

15 1.5 8,830 45418 1.5 7,360 378

11 1.0 8,030 41319 L8 8,370 430

11 1.0 8,030 41315 1.3 7,650 394

16 1.4 7,730 39714 1.3 8,200 422

6 . 5202750. 57482. 596.. 5

I 02109. 5125133142I 56 . 5i 6z169.5186195 0. 199¿00. 521 5. 5225 0. 197230. 5243. 5a si 0. 193, co274281 0. 185

C aS 04Cone.

Remarks

Averaged forinitial c.oeff

0. 208

o. 208Scaling

o. 222

Averaged foro, ¿.zo steady state

coefficient

o. 213

Vibration: Freq. 34 cps; Amp. 0.352 inch Reynolds No. (non-boiling) 23,600Steam Pressure 5 psig Heat Transfer Area 0.840 ftSteam Temp. 227. 1°F Water Boiling Temp. 2lZ'F

960.6 Btu/lb iT 15.1°F

Time Condensate HeatPeriod Collected Transferred(min.) (cm.) Q(Btu/hr)


Tim eOverall from Start CaSO4

Coefficient of Boiling Conc.U(Btu/hr ft2 °F) (min.) Rem arks

25 2.9 10,300 1,623 12.5 Averaged25 0. 182 for initial

15 2.2 13,020 i O30 32. 5 coefficient15 2.1 12,430 977 47.5

55 0.19016 1.8 9,990 787. 6314 2.0 12,680 999 78

85 0.20015 2.1 12,430 977 92.516 2.0 11,100 . 872 108

116 0.21414 1.4 8,880 700 12314 1.5 9,510 748 137

144 0.21930 3.0 8,880 700 15930 3.2 9,470 747 189

204 0.22215 1.5 8,880 700 211.5 Scaling15 1.5 8,880 7GO 226.5 Averagedfor

234 0. ¿13 steady state15 1.3 7,690 606 241. 5 coefficient15 1.3 7,690 606 256.5

264 0.21715 L2 7,100 5C0 271.514 1.2 7,610 600 28615 1.4 8,280 653 300.515 1.2 7,100 560 315.515 1.3 7,690 606 330.5

140

CALCIUM SULFATE SCALING - RUN NO 13

Tim ePeriod(min.)

Condensate Heat OverallCollected T ransfe rred Coefficient

(cm.) Q(Btu/hr) U(Btu/hr ft2 °F)


(min.)

CaSO4Conc.

% Remarks0 0.179

17 ¿.7 14,100 1,112 8.535 4.7 11,920 940 34 535 4.2 10,650 840 69.522 2.3 9,280 732 98 Scaling

109 0,20749 Steam off. No heat transferred. Scale dissolved

9 1.3 12,820 1,011 162.517 1.9 9,920 782 175.513 1.3 8,880 700 190.5 Scaling30 2.1 6Z10 490 212

227 0.. 210

Vibration: Freq. 34 cps; Amp. 0.352 inch Reynolds No. (non-boiling) ¿3,600Steam Pressure 5 psig Heat Transfer Area 0.840 ftSteam Temp. ¿27. 1 °F Water Boiling Temp. 212°F

960.6 Btu/lb T 15.1°F

CALCIUM SULFATE SCALING RUN NO. 14

Vibration: Freq. 34 cps; Amp 0. 38 inch Reynolds No. (non-boiling) Z36OOSteam Pressure 2-3 psig Heat Transfer Area 0.840 ftSteam Temp. 219. 1°F Water Boiling Temp. 212°F

LH 965.7 Btu/lb ¿T 7.1F

142

TimePeriod(min.)

CondensateCollected

(cm.)

HeatTransferredQ(Btu/hr)

OverallCoefficient

U(Btu/hr)

Tim efrom Startof Boiling(min.)

CaSO4Conc.

Remarks

16 0.7 3,900 654 8

16 0.17414 0.9 5,740 962 2315 0.9 5,350 897 37.515 1.0 5,950 997 52.517 1.0 5,250 881 68.513 0.? 48O0 806 83.530 1.8 5,350 897 10536 ¿.2 5,450 915 13826 1.6 5,490 921 169

7 0.4 5,100 855 185 519 1. 5,640 945 198 536 ¿.6 6,440 1,080 ¿2624 1.8 6,690 1,122 ¿56 Scaling

268 0.21131 1.6 4,610 772 ¿83 529 1.1 3,380 567 313.515 0.8 4,760 798 335 515 0.8 4,760 798 350 5 Averaged15 0.9 5,350 897 365 5 for steady15 0.? 4,160 701 380 5 stale coeff.

388 O.Z15

CALCIUM SULFATE SCALING RUN NO. 16

Vibration: Freq. 94 cps; Amp. 0.065 inch Reynolds No. (non-boiling) 23,600Steam Pressure 5 psig Heat Transfer Area 0. 840 ftSteam Temp. 227. 1 °F Water Boiling Temp. 212°F

960.6 Btu/lb tT 15.1°F

143

TimePeriod(min.)

CondensateCollected T

(cm.)

Heatransfe rredQ(Btu/ hr)

OverallCoefficien

U(Btu/hr ft °F)

T im efrom Startof Boiling(min.)

CaSO4Conc.

R e m a rk s

25 1.8 6,390 504 12.517 1.3 6,790 535 33.5

4 0. 19818 1.2 5 , 920 467 5126 1.9 6,490 5.]' 7314 1.0 6,340 5oÖ 9315 1.3 7,690 607 107. 515 1.2 7 100 360 122 516 1.3 7 210 569 13317 1.3 6 790 535 154.512 0.9 6,660 525 169

175 0. 221 No scale16 1.3 7,210 569 183 formed


Vibration: Freq. 95 cps; Amp. 0.045 - 0.065 Reynolds No. (non-boiling) 23,600inch

ZSteam Pressure 15 psig Heat Transfer Area 0.840 ftSteam Temp. 249. 7°F Water Boiling Temp. 21 2 °F

945.7 Btu/lb 3 7 . 7 °F

TimePeriod(min.)


HeatTransferred

Q(Btu/hr)

OverallCoefflciert

U(Btu/hrft °F)


(min.)

CaSO4Conc.

R e m a rk s

o 0.21415 2.4 14,980 441 7.515 2.7 15,730 496 ZZ.5i6 3.0 16,380 517 3813 2.6 17,480 551 52.5

59. 0.21315 3.4 19,810 6Z5 66.5 Scaling50 8.9 .15550 491 9425 4.2 i4,680 463 136.5

149 0.22539 5.6 12,550 396 168.5 Averaged13 1.8 12,100 382 194.5 forsteady

201 0.223 state co-efficient

APPENDIX B

PHOTOGRAPHS

145

I

)

i

t L- k\7717

\\ \ \\7 777 1j 7\\\\

146

(J

í4

FIG

UR

E 2

B. L

ON

GIT

UD

INA

Li

VIB

RA

TIO

N O

F PI

PE-W

AT

ER

IN

SID

E P

IPE

FIG

UR

E 3

B. T

RA

NSV

ER

SE V

IBR

AT

ION

OF

PIPE

-WA

TE

R I

NSI

DE

PIP

E

149

FIGURE 4B TRANSVERSE VIBRATION OF PIPE-WATER OUTSIDE PIPE

150

FIGURE 5B. TYPICAL FLAKING OF CaSO4 SCALE ON VIBRATED PIPE

151

FIGURE 6B. TYPICAL FLAKING OF SEA WATER SCALE ON VIBRATED PIPE

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