Upload
dothien
View
219
Download
1
Embed Size (px)
Citation preview
For Heating or Cooling of Corrosive Media
> Immersion > Tube Plate > Gas/Liquid > Shell and Tube
CALORPLAST Heat Exchangers
1
Immersion Style Heat ExchangersIntroduction
Inhighlycorrosivemedia,theprocessofexchanging
heatbetweentwofluidsisextremelycritical.Itssuccess
dependsnotonlyuponthemechanicalpropertiesof
materials,butalsotheirresistancetothecombined
elementsofchemicalattack,hightemperaturesand
pressures.
Therearemanyexoticmaterialsthatcanbeusedtohandle
corrosivechemicals,suchasspecialglass,titanium,
zirconium,tantalum,andchrome/nickelcontainingalloys.
However,ashortservicelifemaybeexpected.
CALORPLASTisanall-plasticheatexchangerdesigned
specificallyforheatingorcoolinghighlycorrosivemedia.
CALORPLASTheatexchangersaremanufacturedfrom
PVDF(polyvinylidenefluoride),polypropylene,and
polyethylene.TheextremechemicalinertnessofPVDF
anditsflexibilityinfabricationmakeitanidealmaterial
ofconstructioninmanychemicalprocesses.Thesmooth
surfaceofplasticstendstowardverylowcontamination
andincrustation,eveninextremeapplications.This
enablesuseoftheCALORPLASTinapplicationswhere
metalexchangersrequirefrequentmaintenancetoremove
buildupfromexchangertubes.
Althoughfluoropolymerheatexchangershavesuccessfully
replacedcostlymetallicdesigns,untilintroduction
ofCALORPLASTtherehadalwaysbeenproblemsin
satisfactorilyconnectingheatexchangertubestothe
headermanifold.CALORPLASTisproducedbyapatented
processofcontinuoustubeextrusionandmanifold
injectionovermoldingassuringtightconnectionsbetween
theexchangertubesandthemanifolds.Thereareno
mechanicaljointswhichcaninotherexchangerdesignsbe
weakspotssubjecttochemicalattackandstresscracking.
CALORPLASTisconstructedofmodularelements
whichenabletheheatexchangertobeadaptedtosuita
particularvesselgeometry.Inaddition,largeheattransfer
surfacesarecontainedinarelativelysmallvolume.Unlike
manyotherplasticheatexchangers,CALORPLASTisa
self-supportingdesign.Hangers,brackets,etc.,arenot
necessaryunlessspecificallyrequestedbythecustomer.
MostheattransfermediacanbeusedintheCALORPLAST.
Themostcommonlyusedheattransfermediaaresteam
andhotwaterforheatingandwater/glycolforcooling.
Advantages of CALORPLAST Heat Exchangers1. Superiorcorrosionresistancetomostacidsand
solutions.
2. Largeheattransfersurfaceinaconfinedspace.
3. All-plasticdesignwithnoelastomers,sealsor
mechanicaljoints.
4. Plasticdesigneliminateseffectofstraycurrentin
platingapplications.
5. Openflowtubebundle–tubesdonottouch.
6. Modularconstructionenablescustomadaptabilityto
particularvesselgeometry.
7. Exceptionallylowfoulingfactors.
8. Tough,impactresistanttubes,notcapillary-typetubing.
9. Lowpressuredropsenhancingturbulentflowresulting
inmaximizedheattransfercapability.
10.Handlesteamupto35psigsaturated.
11.Easilyrepairedatplantsitewithahotairweldinggun.
PLASTIC TUBE
heated, temperaturecontrolled pin
CAVITY
CORE
temperating fluid
MOLD RIGHT
MOLD LEFT
2
Limitations1. Maximum continuous use
temperature = 281°F (PVDF)
2. Maximum saturated steam
pressure = 35 psig (PVDF)
3. Maximum operating pressure
at 68°F = 232 psig (PVDF)
4. Superheated steam may not
be used as a heating medium.
Mechanical Strength
Temperature of Medium °F 68 104 140 176 212 248 281
PVDF MaximumOperatingPressure
psig 232 174 145 109 87 65 35
PP MaximumOperatingPressure
psig 116 87 58 29 — — —
PE MaximumOperatingPressure
psig 116 87 58 (160°Fmax.)29
— — —
Chemical Resistance
TheCALORPLASTimmersionheatexchangercanbeusedforheatingorcooling
mostcorrosivechemicalsinopentanks.Generally,theapplicationareasforPVDF,
polypropylene,andpolyethyleneheatexchangerswillbethesameasthosefor
SYGEF®PVDF,polypropylene,andpolyethylenepipingsystems.Thefollowing
guidelinesareusedwhenselectingtheappropriateheatexchangerforaspecific
application:
1) Forsteamheatingofinorganicandorganicacidscommonlyusedinplating
(chrome,phosphoric,nickel,sulfuric,hydrochloric,nitric,hydrofluoricetc.)use
PVDF.
2) Foraqueoussaltsolutionsandalkalisolutions,usepolypropylene,or
polyethylene.
3) Foranyheatingapplicationutilizingsteamastheheatingmedium,PVDFmustbe
used.PVDFcanbeusedupto281°F(35psigsaturatedsteam).
4) Forcoolingsulfuricacidsolutions,polypropyleneorpolyethyleneshouldbeused,
asitismosteconomical.
5) Fordetailedchemicalresistanceinformation,visitourwebsiteat
www.gfpiping.comorrefertotheGFPipingSystemsEngineeringHandbook,
ChemicalResistanceGuide.
3
TheCALORPLASTheatexchangerisdesignedinmodular
elementsconnectedtoprovidetherequiredheattransfer
surfaceareaforaspecificapplication.Theexchanger
modulesareonefootwideandareavailableinthefollowing
lengths:1.7,2.4,3.1,3.7,4.4,5.0,5.7,7.0,and8.3ft.The
modulesareheatfusedtogetheratthemanifoldheadersto
provideacontinuousheatexchangergrid.
• Individualtubesare6mmOD/4.8mmID
• ModulesinPVDFareavailablewith3or5tuberows
• ModulesinPE-RTareonlyavailablein5tuberowdesign
• ModulesinPPareonlyavailablein3tuberowdesign
• Moduleswith3rowshave117tubeseachmodule,and
moduleswith5rowshave195tubesineachmodule
Tubularspacerssupporttheconsistencyofshapeand
intertubulardistancesinthegrid.Assemblyofmodulesis
performedusingheatfusiontechniquesbetweenheaders,
withstandardaccessoriesandtools.Interconnectionof
modulesismadetogiveparallelorseriesflowpatterns
accordingtothespecificdesignrequirementoftheheat
exchanger.
Asanexample,refertoTableNo.1.Supposeaparticular
applicationforpolypropylenerequires17sq.ft.ofheat
transferarea.Thiscouldbeaccomplishedbyeithera1
ft.x3.1ft.heatexchanger(consistingofasinglemodule
3.1ft.long)ora2ft.x1.7ft.heatexchanger(consisting
oftwo1.7ft.longmodulesfusedtogetherattheheader).
Theconfigurationselecteddependsonpriceandtank
configuration.
IfforPVDForpolyethylene180sq.ft.ofheattransfer
surfacewererequired,asingleheatexchanger2ft.x8.3
ft.oroneheatexchanger4ft.x4.4ft.couldbeused.Both
havetherequired180sq.ft.andtankconfigurationwill
determinewhichisselected.Allmodulesare2.2inches
thinwhichisthethicknessofallCALORPLASTheat
exchangers.Thisthinprofileenablestheexchangertofit
mostplating/picklingtankswithoutinterferingwithparts
beingprocessed.
CALORPLASTimmersionheatexchangersmaybe
usedwitheitherverticalorhorizontaltubing.Selection
ofaspecificconfigurationdependsontankgeometry.
Generally,verticaltubingispreferredforsteamheating
applicationsbecausethisisthemostefficientdesign.In
theverticalconfiguration,theheightoftheexchanger
willbethelengthofamoduleplus4inchestoaddan
anti-buoyancyweight.Theanti-buoyancyweightsmaybe
addedtothesideoftheexchangerifthevesselislimitedin
verticalspace.Thehorizontaldimensionwillbe1ft.times
thenumberofmodulesplusapproximately7"fortheinlet
andoutletpiping.Forexample,aPVDF60sq.ft.steam
heatexchangerconsistingoftwo3.1ft.modulesfused
togetherwillhaveanoveralldimensionofapproximately
3’4"verticalx2’7"horizontalx2.2"thick.
PVDFHeatExchangerfabricatedforcylindricaltank.
Polyethyleneheatexchangersofferexcellentchemicalresistancetosulfuricacidattemperaturesupto160°F.
Exchanger Configurations
4
Table No.1: Surface Area for Polypropylene CALORPLAST Modules (Square Feet)
H(ft) L(ft) 1.7 2.4 3.1 4.4 5.7 7.0 8.3
1.0 8.8 13.1 17.4 26.0 34.8 43.5 52.2
2.0 17.6 26.2 34.9 52.1 69.5 86.9 104.4
3.0 26.5 39.3 52.3 78.1 104.2 130.4 156.5
4.0 35.3 52.4 69.7 104.1 139.0 173.9 208.7
5.0 44.1 65.5 87.1 130.2 173.8 217.3 260.9
6.0 52.9 78.6 104.6 156.2 208.5 260.8 313.1
Table No. 2: Surface Area for PVDF and Polyethylene CALORPLAST Modules (Square Feet)
H(ft) L(ft) 1.7 2.4 3.1 3.7 4.4 5.0 5.7 7.0 8.3
1.0 15 23 30 38 45 52 60 75 90
2.0 30 45 60 75 90 105 120 150 180
3.0 45 68 90 113 135 158 180 225 270
4.0 60 90 120 150 180 210 240 300 360
5.0 75 113 150 188 225 263 300 375 450
6.0 90 135 180 225 270 315 360 450 540
ModuleLengthL
ModuleThickness=2.2"
Mod
uleLe
ngth
H
Anti-Buoyancy WeightsAplasticheatexchangermayfloatinafluiddependingontheheatingor
coolingmediumandonthespecificgravityofthetankfluid.Toprevent
floating,weightsareaddedtothebottomoftheheatexchangerswhere
needed.TheweightsconsistofsteelbarencapsulatedineitherPVDF,
polypropyleneorpolyethylene.Theweightsareweldedtotheexchanger
manifold.Nometalisexposedtothetankfluid.Aweightisalways
requiredforthefollowingheatexchangeapplications.
1. Steamheatingapplications(alwaysPVDF).
2. Allpolypropyleneandpolyethyleneapplications.
3.PVDF–heatingorcoolingwithwaterwhenspecificgravityoftank
fluidisgreaterthan1.35.
5
Foranyheatexchangeapplication,therearefour
resistancestoheattransferencountered:theheat
exchangertubewall,theinsidefilmandoutsidefilm
resistancesandanadditionalfoulingresistance.
Whencomparingmetalversusplasticheatexchangers,the
followingshouldbenoted.Formetalheatexchangers,the
tubewallprovidesverylittleresistancetoheattransfer.
Thesurfaceandfoulingresistanceshavethegreatest
effectontheoverallheattransfercoefficient.Plastic
heatexchangersaregenerallylessefficientthanmetal
onesbecausethetubewallisthegreatestresistanceto
heattransfer.However,metalheatexchangershavea
muchgreatertendencytobecomefouledthandoplastic
exchangers.Foulinggreatlyreducestheoverallheat
transfercoefficientofmetalexchangers.Asanexample,
whencomparingmetalwithplasticexchangers,assuming
nofoulingofthetubewall,aplasticexchangerwillrequire
approximately6timesasmuchheattransfersurfaceasa
∆Tm= meanlogarithmicdifferenceintemperaturebetween
hotandcoldside(°F)
k = thermalconductivityoftubingmaterial(BTU/fthr°F)
A =
metalexchanger.Whennormalfoulingofthetubewallis
considered,thisratioisreducedtoabout3:1.(Note:The
overallheattransfercoefficientisnotdirectlyrelatedto
thethermalconductivityoftheexchangertubing.Ascan
beseeninTable No. 3,theratioofthermalconductivities
forstainlesssteelandPVDFis900:1buttheratioofheat
transfercoefficientsisapproximately3:1.)
Therelativelylowthermalconductivityoftheplastic
materialwillbelessandlesssignificantiftheouterand
innerfilmbecomethelimitingresistances.Suchconditions
areencounteredinthefollowingapplications:
1.Oneoftheheatexchangefluidsishighlyviscousand
flowsatlowvelocity(opentankapplications)
2.Heatisexchangedbetweenaliquidandagas.
3.Heatisexchangedbetweentwogases.
4.Heatisexchangedbetweenacondensableandanon-
condensable.
Basic Calculations for Immersion Heat ExchangersTheintegratedsteadystatemodificationofFourier’s
generalequationisacceptedas:Q=UA∆Tm
Usingvariationsofthisbasicequation,itispossibleto
readilycalculatetheheatexchangersurfaceneeded,the
timetoaccomplishaheat-upoperation,orthetemperature
ofafluidbathattheconclusionofapresetperiodoftime
forthefollowingbasicheatexchangerapplications:1.Maintainingaconstantbatchtemperatureusing
condensingsteam.2.Condensingsteamtoheatupanaqueouschemical
solution.3.Circulatinghotwatertoheatupanaqueouschemical
solution.4.Circulatingcoldwatertocoolanaqueouschemical
solution.
Todeterminetheheatexchangersurfaceareaneeded,it
isrecommendedtheheatexchangersbesizedaccording
tothefollowingapproximatecalculations.Foradetailed
sizing,pleasecontactaGFrepresentative.
A = heatingsurface(ft2)
Q = totalheattransferred(BTU/hr)
U = overallheattransfercoefficient(BTU/hrft2°F)
t = tubingwallthickness(ft)Q
∆Tm•U(ft2)
Table No. 3Thermal Conductivity of Materials
Copper 225 390
Aluminum 117 203
Graphite 87 151
Tantalum 31 54
CarbonSteel 27 47
316SS 94 16.3
Titanium 9.2 16
Ni-Cr-MoAlloys 5.2 9
PE(HD) 0.24–0.29 0.42–0.51
Nylon 0.12–0.17 0.21–0.30
ETFE 0.133 0.23
PFA 0.127 0.22
PP 0.127 0.22
FEP 0.116 0.20
PVDF 0.104 0.18
k( )BTUhr ft °F
Wm Kk( )
General Applications
6
Typical Steps for Heat Exchanger Calculations1.Determineheatlossesfromopentopandtankwalls.
2.Determineheatlossorgainfromadditionofliquidsor
metalstotank.
3.Determineheatloadtoheatorcoolthebathliquid,ifa
timelimitforheatuporcooldownexists.
4.Calculatetherequiredandavailableheatingorcooling
capacity.
5.Establishin/outtemperaturesforbothliquidsormedia
andcalculatethelogmeantemperaturedifference.
6.Calculate/estimateoverallheattransfercoefficientU.
7.Calculaterequiredheattransferarea.
8.Sizethemodule(s)accordingtotankdimensionsand
calculatedheattransferarea.
9.Checktolerablepressuredropthroughmodule(s).
Heat Loss TabulationHeatlossestobeconsideredinclude:
1. Totalheattobegivenortakenawayfromthebathor
tank.
2. Heatlossesfromthetopsurfaceofanopentankor
vessel.
3. Heatlossesthroughthetankwall.
4. Heatlossesfromheating/coolinganymaterialsbeing
treatedand/oraddedtothebath.
5. Heatlossesduetomakeupfluidsbeingadded.
6. Heatlossesduetosplashingoftreatedmaterials.
Pressure DropVerylowpressuredropsoccurinCALORPLASTheat
exchangersduetotheextremelysmoothinsidetube
surfacesandtheoptimaltubingI.D.of0.189inches.
Additionally,theheatexchangersurfaceconsistsofmany
paralleltubesenablingverylowpressuredrops.Pressure
dropvaluesperlinearfootofmodulemaybeapproximated
bythefollowingequations(forPVDF).
For laminar flow:
∆p(psi/ft)=0.00035xvelocityinft/min
For turbulent flow:
∆p(psi/ft)=0.0006xvelocityinft/min
Crosssectionalareaoftubesinonemodule=5.46sq.in.
Forexample,thepressuredropforamodule8.2ft.
longwithfluidflowat20gpm(70ft./min.velocity)is
approximately0.25psi.Thepressuredropacrossa180°
closereturnbendelbow(usedtojointwomodulesinseries
insomedesigns)is0.04psiundertheseconditions.
7
Regardlesswhethertheheatexchangerequirementis
forheatingorcoolingofthetankfluid,theheatloadis
calculatedusingthefollowing:
Q=mCp∆T
WhereQ=Heattoberemovedoradded,inBTU/hr.
m=Quantityoffluidtobeheatedorcooledinlbsperhour
(incorporatesrateofheat-up/cool-down).
Cp=Heatcapacityofthefluidtobeheatedorcooled
(consultfactoryorassumevalueof1BTU/lb°F).
T=Differencebetweeninitialandfinaltemperatureoftank
fluid,in°F.
Notethatiftheheatexchangeristobesizedtoovercome
tankheatlossesonly,thecalculationformediaheatup
requirementmaybeignored.
Cooling to Remove Electrical Energy InputCalculatetheelectricalheatinputusing:
Watts = Amps x Volts
ToconverttoBTU/Hour,use:
Volts x Amps x 3.412 = BTU/HR
Calculating the Overall Heat Transfer Coefficient (U)“U”isanoverallheattransfercoefficientbasedon
temperaturedifferentialandunitheattransferarea.The
reciprocalofUisanoverallthermalresistancewhichcan
beconsideredashavingthefollowingcomponents:
1.Aninsidefilmcoefficient(hi).
2.Awallcoefficient(k/t).
3.Anoutsidefilmcoefficient(ho).
4.Foulingfactorstoallowforscalingonbothsidesofthe
heatexchangertubes(f).
FoulingFactors:Industrialexperiencehasshownthat
foulingfactors(f)forCALORPLASTheatexchangersmay
beconsideredinconsequentialformostapplications.
Determinationsoftheoverallheattransfercoefficient(U),
theinsidefilmcoefficient(hi)andtheoutsidefilmcoefficient
(ho)takeintoaccountseveralfactors,includingtheNusselt
Number,laminarflow,turbulentflow,naturalconvection
(unagitatedbath)andforcedconvection(agitatedbath).
Precisevaluesforthefilmcoefficientsmaybecalculated
onlyforextremelywelldefinedheattransfer(conduction)
andflowregimes.
Approximated for PVDF:
U= 1 (BTU/hr•ft2•°F)
1 + 0.00197 + 1
hi 0.104 ho
ApproximatedforPolypropylene:
U= 1 (BTU/hr•ft2•°F)
1 + 0.00197 + 1
hi 0.127 ho
ApproximatedforPolyethylene:
U= 1 (BTU/hr•ft2•°F)
1 + 0.00197 + 1
hi 0.25 ho
Calculation of ∆Tm
∆Tm = ∆T1-∆T2
Ln(∆T1)∆T1= Hotfluidinlettemperature—
coldfluidinlettemperature
∆T2= Hotfluidoutlettemperature—
coldfluidoutlettemperature
∆T2
Tank Fluid Heat Requirements
8
Approximation of OverallHeat Transfer
Coefficient “U”
Forestimatesofheattransferarea
requirements,anapproximatevaluemaybe
usedfortheoverallheattransfercoefficient.
Pleaserefertothefollowingtablefor
approximate“U”values:
Application “U” Value
(Btu/hr-
sqft-°F)
SteamHeating(PVDFonly) 42
HotwaterPVDF 38
ColdwaterPVDF 33
Hotwaterpolypropylene 40
Coldwaterpolypropylene 35
Hotwaterpolyethylene 48
Coldwaterpolyethylene 39
Lowtemperature(below50°F),contactGF.
Note: Theseareonlyapproximate"U"
values.FordetailedcalculationcontactaGF
representative.
PVDFexchangersforcoolingacid
10
Material of construction
PVDFpolyethyleneandpolypropylene
Applications
Forheattransferbetweencorrosivefluids.Verysuitable
forhighpurityDIwaterandotherhighpurityfluids.For
condensationofaggressivevapors.
Cleaning
Heatexchangersconstructedentirelyofcorrosionresistant
plasticsshouldbechemicallycleaned.
Temperature
Inaccordancewiththematerialofconstructionand
allowableoperatingpressure,thefollowingtemperatureis
possible:
PVDF: 281°F PP: 180°F
PE: 160°F
Layout
AllCALORPLASTheatexchangersarecustomdesignedfor
specificoperatingconditions.Pleasesubmityouroperating
datatoreceiveaquotation(seedatasheetatbackofthis
section)
Design
TheCALORPLASTtubeplateheatexchangerisanentirely
newconceptinheatexchangerdesign.Itisdesignedto
handlemostcorrosiveheatingandcoolingapplications
whenanexternaltypeheatexchangerisrequired.
Theheattransfersurfaceconsistsofanumberoftube
plateswhichareheatfusedoneontopoftheother.The
stackedtubeplatesformacontinuousparallelseriesof
tubesacrosswhichtheshellfluidflows.Thetubefluid
flowswithintheindividualtubes.
Tube Plate Heat ExchangersAdoublewallplasticpressurevesselisobtainedby
stackingofthetubeplates.Eachtubeplateconsistsof
35plastictubeswhichterminateinasquareopensided
header.Thetubeplatesareheatfusedtogetherattheside
oftheheadersothatacontinuousheaderisformed;the
lengthoftheheaderdependsonthenumberoftubeplates.
Theflowdirectionofthetubingisperpendiculartothe
lengthoftheexchanger.
Thesquareheaderofeachtubeplateispartitioned
diagonallyatthecornerstoformaninletandoutletheader.
Ifallofthetubeplatesarelinedupinthesamedirection,
thetubesidefluidwillflowthroughthetubeplatesina
parallelflowpattern.Ifeveryothertubeplateisrotated
90°,thetubesidefluidwillflowinseriesthrougheachrow
oftubes.Regardlessofthetubesideflowconfiguration,the
shellsidefluidalwaysflowsinthecentralchannelformed
bytheinsideofthetubeplateheader.Theflowofthe
shellsidefluidisalwaysperpendiculartothetubesidefluid
flow.
Sincetheentireheatexchangerisheatfused,thereisno
needforamechanicalsealbetweentheshellsideand
tubesidefluids.Becausetheentireheattransfersurfaceis
fabricatedfromcorrosionresistantplastic,Calorplastheat
exchangersareideallysuitedforapplicationswhereboth
thetubesideandshellsidefluidsarecorrosive.
PVDFtube-plateexchangersareidealforhigh-puritymedia.
Tube Plate Cross Section
15.75"
Shellsidecrossflowpattern
Tubesideflowpattern,customizedtoachievetherequiredthermalandhydraulicperformance.
11
DimensionsTubesize: 5mmo.d.Ø 4mmi.d.Ø
15.75"
10.24" 12.60"
15.75"
10.24"
10.24"
11.02"15.75"
Condenser Heatexchangerinverticalposition
Heatexchangerinhorizontalposition
L=Lengthdependingondesignrequirements
L L
L
n2
n1
Flowarrangement
n1=Numberofplatesperpassn2=Numberofpassesperheatexchanger
Joiningofmodules
12
PVDF,polyethyleneandpolypropylenetube-plateheatexchangers,inverticalorientation.
Permissible Working PressuresTemperature of medium (°F) 68 104 140 176 212 248 284
PVDFrupturepressure(psig) 1160 798 725 580 435 325 253
maxworkingpressure(psig) 232 174 130 108 87 65 35
PPrupturepressure(psig) 362 260 203 116
maxworkingpressure(psig) 115 87 58 29
PErupturepressure(psig) 362 260 203 116
maxworkingpressure(psig) 115 87 58 29at160°F
Typical Overall Heat Transfer CoefficientsForestimatingrequiredheattransfersurface,thefollowingvaluesmaybeusedforoverallheattransfercoefficient.For
detailedsizing,consultaGFrepresentative.
Application"U" (Btu/hr-sqft - °F)
PVDF Polypropylene Polyethylene
steamtoaqueoussolutions 60 — —
hotwatertoaqueoussolutions 53 60 80
coldwatertoaqueoussolutions 48 53 71
14
CALORPLASTgas/liquidheatexchangersaredesigned
specificallyforcondensingand/orreheatinghighly
corrosivegasstreams.Manufacturedfromtough,impact-
resistantPVDF(polyvinylidenefluoride)polyethyleneorPP
(polypropylene),theseexchangersarecapableofhandling
gasstreamtemperaturesupto280°F(PVDF).Though
standardconfigurationsexist,eachexchangeriscustom
builttooperateforthespecificheatload,gasvolume
andvelocityoftheapplication.Theyprovideasignificant
costsavingswhencomparedtoconventionalalloy/
metallicexchangers.Theirsmoothplasticsurfacetends
towardverylowfoulingandincrustation,eveninsevere
environments.Apatentedprocesscompletelyeliminates
elastomers,sealsandmechanicaljointswhichmight
otherwiseproduceweakspotssubjecttochemicalattack,
stresscrackingandleakage.
Typicaluses,amongothersinclude:
•Condensationrecoveryofacidiccomponentsfromgas
streamsgeneratedingarbageandbiologicalwaste
incineration
•Reheatingofstackgasesforplumereduction
•Wasteheatrecoveryfromcorrosivestreams
CALORPLAST Gas/Liquid Heat Exchangers for Corrosive Gases
DesignTheexchangerplastictubingis
containedwithinstandardized
injectionmoldedmodules.
Thesemodulesareconfigured
dependingonprocess
requirementsandinstalledwithin
thecorrosionresistanthousing.
Theutilityfluidflowsthroughthe
tubingwhilethegasescooland
condenseontheoutsidetube
surface.
CALORPLASTheatexchangers
arecleanedbymeansof
pressurizedwateror,ifnecessary,
byuseofchemicaldetergents.
Thehighdegreeofcorrosion
resistanceallowschemical
cleaningoftheCALORPLASTheat
exchanger.
15
Tubeside Pressure RatingsTemperatureofmedium °F 68 104 140 176 212 248 280
PVDF Workingpressure psig 232 174 145 109 87 65 35
PP Workingpressure psig 116 87 58 29 — — —
PE Workingpressure psig 116 87 58 29at160°F
Characteristics• Materials:PVDF,polyethyleneand
polypropylene
• Allowableoperatingtemperatureasa
functionofthematerialchosen–22°Fto
280°F(PVDF)
• Outerpipediameter0.25"/6.4mm,wall
thickness0.024"/0.6mm
• Liquidcollectorandcleaningsystem,
constructedofplastic,canbeinstalled
• Strongplasticcasingwithload-bearing
reinforcingribs
• Casinggastightweldedincluding
condensatecollector
• Casingpressureisdependenton
temperature(consultfactory)
Eachheatexchangercanbeequippedwithspraynozzlesforcleaning.TubingisavailableinPVDFpolyethyleneorpolypropylene.Casingavailableinplasticorothermaterials,dependingonapplication.
Gas/liquidheatexchanger:forcondensing/recoveryofacidfromlow-pressurecorrosivegasstreams.
17
Material of ConstructionPVDF,PFA,polyethylene(PE)andpolypropylene(PP)
ApplicationsForcooling,heating,condensingorevaporatingof
aggressive,cleanorhighpuritymedia.
CleaningTheheatexchangersareeasytocleanwithpressurized
water,steamorchemicals.
TemperatureInaccordancewiththeselectedmaterialofconstruction
andallowablepressureofmedia,thefollowingmaximum
temperatureispossible:
PVDF:284°F PFA:390°F
PE: 160°F PP: 180°F
LayoutAllCALORPLASTheatexchangersarecustomdesignedfor
specificoperatingconditions.Pleasesubmityouroperating
datatoreceiveaquotation(seedatasheetatbackofthis
section).Thetubebundlecanbeusedwithouttheshell.
DesignTheCALORPLASTShellandtubeheatexchangeris
designedtohandlemostcorrosiveheatingandcooling
applications,aswellashighpurityapplications.The
shellandtubeismanufacturedwithoutsealsorgaskets,
providingaleak-freesystemforlowmaintenanceandlong
servicelife.
Thecounterfloworientationprovidesmoreefficientheat
transferbetweenthehotandcoldmedia.Thetubefluidwill
flowwithintheindividualtubes,whiletheshellfluidflows
aroundthetubes.
Forhighpurityapplicationstheshellandtubecanbe
fabricatedandpressuretestedinaCleanRoom.
Characteristics• Highdutyofheattransfercapacitybytheemploymentof
thin-walled,smoothnon-foulingtubes.
• Highresistancetohighlycorrosivemedia.
• Easy,compactdesign
• Smallpressureloss:approx.0.1–0.5bar(1.2–7.3psig)
• Smallmaintenancecost
Shell and Tube Heat Exchangers
Endcapremovedtoshowinsidetheexchanger;capisnormallyweldedon.
18
Permissible Working PressuresTemperature of medium (°F) 68 104 140 176 212 248 284
PFARupturepressure(psig) 870 696 565 435 290 174 87
Maxworkingpressure(psig) 145 116 94 73 51 29 15
PVDFRupturepressure(psig) 1160 798 725 580 435 325 253
Maxworkingpressure(psig) 174 145 109 87 65 51 43
PP/PERupturepressure(psig) 362 261 203 116
Maxworkingpressure(psig) 116 87 58 29
Shell and Tube Arrangement
HeatTransferArea: 0.1to25m2(1.08to269ft2)TubeDiameter,d: 4;6;8mmWallThickness: 0.4;0.6;0.8mmShellDiameter,D: upto180mm(~7in.)
TotalLength,L: upto6000mm(~236in.)ConnectionsN1-N4: Flanges PipeUnions ThreadedConnections
N2 N3 N1
N4
L
L1
D d