Unit Operation ModelsS T E A D Y S T A T E S I M U L A T I O N10AspenTech7R E F E R E N C E M A N U A LAspen Plus7VersionCOPYRI GHT 19811998 Aspen Technol ogy, I nc.ALL RI GHTS RESERVEDThe fl owsheet graphi cs and pl ot components of ASPEN PLUS were devel oped byMY-Tech, I nc.ADVENT, Aspen Custom Model er, Aspen Dynami cs, ASPEN PLUS, AspenTech,Bi oProcess Si mul ator (BPS), DynaPLUS, Model Manager, Pl antel l i gence, thePl antel l i gence l ogo, POLYMERS PLUS, PROPERTI ES PLUS, SPEEDUP, andthe aspen l eaf l ogo are ei ther regi stered trademarks, or trademarks of AspenTechnol ogy, I nc., i n the Uni ted States and/or other countri es.BATCHFRAC and RATEFRAC are trademarks of Koch Engi neeri ng Company,I nc.Acti vator i s a trademark of Software Securi ty, I nc.Rai nbow Senti nel SuperPro i s a trademark of Rai nbow Technol ogi es, I nc.l an Li cense Manager i s a trademark of l an Computer Group, I nc., Mountai nVi ew, Cal i forni a, USA.Mi crosoft Wi ndows, Wi ndows NT, and Wi ndows 95 are ei ther regi stered trademarksor trademarks of Mi crosoft Corporati on i n the Uni ted States and/or other countri es.Al l other brand and product names are trademarks or regi stered trademarks ofthei r respecti ve compani es.The Li cense Manager porti on of thi s product i s based on:l an Li cense Manager1989-1997 l an Computer Group, I nc.Al l ri ghts reservedUse of ASPEN PLUS and Thi s ManualThi s manual i s i ntended as a gui de to usi ng ASPEN PLUS process model i ng software. Thi sdocumentati on contai ns AspenTech propri etary and confi denti al i nformati on and may not bedi scl osed, used, or copi ed wi thout the pri or consent of AspenTech or as set forth i n theappl i cabl e l i cense agreement. Users are sol el y responsi bl e for the proper use of ASPEN PLUSand the appl i cati on of the resul ts obtai ned.Al though AspenTech has tested the software and revi ewed the documentati on, the sol ewarranty for ASPEN PLUS may be found i n the appl i cabl e l i cense agreement betweenAspenTech and the user. ASPENTECH MAKES NO WARRANTY ORREPRESENTATION, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THISDOCUMENTATION, ITS QUALITY, PERFORMANCE, MERCHANTABILITY, ORFITNESS FOR A PARTICULAR PURPOSE.Uni t Operati on Model s i i iVersi on 10ContentsAbout the Unit Operation Models Reference ManualFor More I nformati on..............................................................................................................xTechni cal Support ..................................................................................................................xi1 Mixers and SplittersMi xer .....................................................................................................................................1-2Fl owsheet Connecti vi ty for Mi xer ....................................................................................1-2Speci fyi ng Mi xer ...............................................................................................................1-3FSpl i t.....................................................................................................................................1-5Fl owsheet Connecti vi ty for FSpl i t...................................................................................1-5Speci fyi ng FSpl i t ...............................................................................................................1-6SSpl i t.....................................................................................................................................1-8Fl owsheet Connecti vi ty for SSpl i t ....................................................................................1-8Speci fyi ng SSpl i t ...............................................................................................................1-82 SeparatorsFl ash2....................................................................................................................................2-2Fl owsheet Connecti vi ty for Fl ash2..................................................................................2-2Speci fyi ng Fl ash2 .............................................................................................................2-3Fl ash3....................................................................................................................................2-5Fl owsheet Connecti vi ty for Fl ash3..................................................................................2-5Speci fyi ng Fl ash3 .............................................................................................................2-6Decanter ................................................................................................................................2-8Fl owsheet Connecti vi ty for Decanter ..............................................................................2-8Speci fyi ng Decanter .........................................................................................................2-9Sep.......................................................................................................................................2-12Fl owsheet Connecti vi ty for Sep ......................................................................................2-12Speci fyi ng Sep .................................................................................................................2-13Sep2.....................................................................................................................................2-14Fl owsheet Connecti vi ty for Sep2 ....................................................................................2-14Speci fyi ng Sep2...............................................................................................................2-153 Heat ExchangersHeater ...................................................................................................................................3-2Fl owsheet Connecti vi ty for Heater..................................................................................3-2Speci fyi ng Heater .............................................................................................................3-3HeatX ....................................................................................................................................3-5Fl owsheet Connecti vi ty for HeatX...................................................................................3-5Speci fyi ng HeatX..............................................................................................................3-6References ...........................................................................................................................3-18i v Uni t Operati on Model sVersi on 10MHeatX.............................................................................................................................. 3-19Fl owsheet Connecti vi ty for MHeatX ............................................................................ 3-19Speci fyi ng MHeatX........................................................................................................ 3-20Hetran ................................................................................................................................ 3-23Fl owsheet Connecti vi ty for Hetran .............................................................................. 3-23Speci fyi ng Hetran .......................................................................................................... 3-24Aerotran ............................................................................................................................. 3-26Fl owsheet Connecti vi ty for Aerotran ........................................................................... 3-26Speci fyi ng Aerotran ....................................................................................................... 3-274 ColumnsDSTWU ................................................................................................................................ 4-3Fl owsheet Connecti vi ty for DSTWU ................................................................................ 4-3Speci fyi ng DSTWU........................................................................................................... 4-4Di stl ...................................................................................................................................... 4-6Fl owsheet Connecti vi ty for Di stl ...................................................................................... 4-6Speci fyi ng Di stl ................................................................................................................ 4-7SCFrac.................................................................................................................................. 4-8Fl owsheet Connecti vi ty for SCFrac ................................................................................. 4-8Speci fyi ng SCFrac............................................................................................................ 4-9RadFrac.............................................................................................................................. 4-11Fl owsheet Connecti vi ty for RadFrac............................................................................ 4-12Speci fyi ng RadFrac........................................................................................................ 4-13Free-Water and Ri gorous Three-Phase Cal cul ati ons .................................................. 4-20Effi ci enci es ..................................................................................................................... 4-20Al gori thms...................................................................................................................... 4-22Rati ng Mode................................................................................................................... 4-23Desi gn Mode................................................................................................................... 4-24Reacti ve Di sti l l ati on ...................................................................................................... 4-25Sol uti on Strategi es ........................................................................................................ 4-25Physi cal Properti es ........................................................................................................ 4-28Sol i ds Handl i ng ............................................................................................................. 4-28Mul ti Frac ........................................................................................................................... 4-30Fl owsheet Connecti vi ty for Mul ti Frac.......................................................................... 4-31Speci fyi ng Mul ti Frac..................................................................................................... 4-33Effi ci enci es ..................................................................................................................... 4-41Al gori thms...................................................................................................................... 4-42Rati ng Mode................................................................................................................... 4-42Desi gn Mode................................................................................................................... 4-42Col umn Convergence..................................................................................................... 4-43Physi cal Properti es ........................................................................................................ 4-46Free Water Handl i ng..................................................................................................... 4-46Sol i ds Handl i ng ............................................................................................................. 4-46Si zi ng and Rati ng of Trays and Packi ngs .................................................................... 4-47PetroFrac............................................................................................................................ 4-48Fl owsheet Connecti vi ty for PetroFrac.......................................................................... 4-49Speci fyi ng PetroFrac...................................................................................................... 4-51Effi ci enci es ..................................................................................................................... 4-57Uni t Operati on Model s vVersi on 10Convergence....................................................................................................................4-58Rati ng Mode....................................................................................................................4-59Desi gn Mode ...................................................................................................................4-59Physi cal Properti es.........................................................................................................4-60Free Water Handl i ng .....................................................................................................4-60Sol i ds Handl i ng ..............................................................................................................4-61Si zi ng and Rati ng of Trays and Packi ngs .....................................................................4-61RateFrac..............................................................................................................................4-62Fl owsheet Connecti vi ty for RateFrac............................................................................4-63The Rate-Based Model i ng Concept................................................................................4-65Speci fyi ng RateFrac .......................................................................................................4-66Mass and Heat Transfer Correl ati ons...........................................................................4-77References ...........................................................................................................................4-85Extract ................................................................................................................................4-87Fl owsheet Connecti vi ty for Extract...............................................................................4-87Speci fyi ng Extract ..........................................................................................................4-885 ReactorsRStoi c....................................................................................................................................5-2Fl owsheet Connecti vi ty for RStoi c ..................................................................................5-2Speci fyi ng RStoi c..............................................................................................................5-3RYi el d....................................................................................................................................5-6Fl owsheet Connecti vi ty for RYi el d..................................................................................5-6Speci fyi ng RYi el d .............................................................................................................5-7REqui l ...................................................................................................................................5-8Fl owsheet Connecti vi ty for REqui l ..................................................................................5-8Speci fyi ng REqui l .............................................................................................................5-9RGi bbs.................................................................................................................................5-10Fl owsheet Connecti vi ty for RGi bbs ...............................................................................5-10Speci fyi ng RGi bbs ..........................................................................................................5-11References ...........................................................................................................................5-15RCSTR ................................................................................................................................5-16Fl owsheet Connecti vi ty for RCSTR...............................................................................5-16Speci fyi ng RCSTR ..........................................................................................................5-17RPl ug...................................................................................................................................5-21Fl owsheet Connecti vi ty for RPl ug.................................................................................5-21Speci fyi ng RPl ug ............................................................................................................5-22RBatch ................................................................................................................................5-25Fl owsheet Connecti vi ty for RBatch...............................................................................5-25Speci fyi ng RBatch ..........................................................................................................5-266 Pressure ChangersPump .....................................................................................................................................6-2Fl owsheet Connecti vi ty for Pump ...................................................................................6-2Speci fyi ng Pump ...............................................................................................................6-3Compr ....................................................................................................................................6-9Fl owsheet Connecti vi ty for Compr ..................................................................................6-9Speci fyi ng Compr ............................................................................................................6-10vi Uni t Operati on Model sVersi on 10MCompr .............................................................................................................................. 6-13Fl owsheet Connecti vi ty for MCompr ............................................................................. 6-13Speci fyi ng MCompr ........................................................................................................ 6-15References .......................................................................................................................... 6-19Val ve................................................................................................................................... 6-20Fl owsheet Connecti vi ty for Val ve................................................................................. 6-20Speci fyi ng Val ve ............................................................................................................ 6-20References .......................................................................................................................... 6-29Pi pe..................................................................................................................................... 6-30Fl owsheet Connecti vi ty for Pi pe ................................................................................... 6-30Speci fyi ng Pi pe .............................................................................................................. 6-31Two-Phase Correl ati ons ................................................................................................ 6-35Cl osed-Form Methods.................................................................................................... 6-39References .......................................................................................................................... 6-40Pi pel i ne .............................................................................................................................. 6-42Fl owsheet Connecti vi ty for Pi pel i ne............................................................................. 6-42Speci fyi ng Pi pel i ne ......................................................................................................... 6-43Two-Phase Correl ati ons ................................................................................................ 6-47Cl osed-Form Methods.................................................................................................... 6-50References .......................................................................................................................... 6-527 ManipulatorsMul t ...................................................................................................................................... 7-2Fl owsheet Connecti vi ty for Mul t...................................................................................... 7-2Speci fyi ng Mul t................................................................................................................ 7-3Dupl ...................................................................................................................................... 7-4Fl owsheet Connecti vi ty for Dupl ...................................................................................... 7-4Speci fyi ng Dupl ................................................................................................................ 7-5Cl Chng ................................................................................................................................. 7-6Fl owsheet Connecti vi ty for Cl Chng................................................................................ 7-6Speci fyi ng Cl Chng............................................................................................................ 7-68 SolidsCrystal l i zer .......................................................................................................................... 8-3Fl owsheet Connecti vi ty for Crystal l i zer .......................................................................... 8-3Speci fyi ng Crystal l i zer ..................................................................................................... 8-4References .......................................................................................................................... 8-11Crusher ............................................................................................................................... 8-13Fl owsheet Connecti vi ty for Crusher ............................................................................. 8-13Speci fyi ng Crusher ........................................................................................................ 8-14References .......................................................................................................................... 8-18Screen ................................................................................................................................. 8-19Fl owsheet Connecti vi ty for Screen ............................................................................... 8-19Speci fyi ng Screen........................................................................................................... 8-19References .......................................................................................................................... 8-22FabFl .................................................................................................................................. 8-23Fl owsheet Connecti vi ty for FabFl................................................................................. 8-23Speci fyi ng FabFl ............................................................................................................. 8-23Uni t Operati on Model s vi iVersi on 10References ...........................................................................................................................8-26Cycl one ................................................................................................................................8-27Fl owsheet Connecti vi ty for Cycl one................................................................................8-27Speci fyi ng Cycl one ..........................................................................................................8-28References ...........................................................................................................................8-35VScrub.................................................................................................................................8-36Fl owsheet Connecti vi ty for VScrub ................................................................................8-36Speci fyi ng VScrub ...........................................................................................................8-37References ...........................................................................................................................8-39ESP......................................................................................................................................8-40Fl owsheet Connecti vi ty for ESP .....................................................................................8-40Speci fyi ng ESP................................................................................................................8-41References ...........................................................................................................................8-44HyCyc..................................................................................................................................8-45Fl owsheet Connecti vi ty for HyCyc..................................................................................8-45Speci fyi ng HyCyc ............................................................................................................8-46References ...........................................................................................................................8-51CFuge ..................................................................................................................................8-52Fl owsheet Connecti vi ty for CFuge ................................................................................8-52Speci fyi ng CFuge............................................................................................................8-53References ...........................................................................................................................8-55Fi l ter ...................................................................................................................................8-56Fl owsheet Confi gurati on for Fi l ter ................................................................................8-56Speci fyi ng Fi l ter .............................................................................................................8-56References ...........................................................................................................................8-59SWash .................................................................................................................................8-61Fl owsheet Connecti vi ty for SWash................................................................................8-61Speci fyi ng SWash ...........................................................................................................8-62CCD.....................................................................................................................................8-64Fl owsheet Connecti vi ty for CCD...................................................................................8-64Speci fyi ng CCD...............................................................................................................8-659 User ModelsUser .......................................................................................................................................9-2Fl owsheet Connecti vi ty for User .....................................................................................9-2Speci fyi ng User .................................................................................................................9-3User2.....................................................................................................................................9-4Fl owsheet Connecti vi ty for User2 ...................................................................................9-4Speci fyi ng User2...............................................................................................................9-510 Pressure ReliefPres-Rel i ef...........................................................................................................................10-2Speci fyi ng Pres-Rel i ef ....................................................................................................10-2Scenari os .........................................................................................................................10-3Compl i ance wi th Codes ..................................................................................................10-6Stream and Vessel Composi ti ons and Condi ti ons ........................................................10-6Rul es to Si ze the Rel i ef Val ve Pi pi ng............................................................................10-7Reacti ons .........................................................................................................................10-9vi i i Uni t Operati on Model sVersi on 10Rel i ef System ............................................................................................................... 10-10Data Tabl es for Pi pes and Rel i ef Devi ces................................................................... 10-12Val ve Cycl i ng ............................................................................................................... 10-16Vessel Types................................................................................................................. 10-16Di sengagement Model s ............................................................................................... 10-18Stop Cri teri a ................................................................................................................ 10-18Sol uti on Procedure for Dynami c Scenari os................................................................ 10-19Fl ow Equati ons ............................................................................................................ 10-20Cal cul ati on and Convergence Methods ...................................................................... 10-23Vessel I nsul ati on Credi t Factor .................................................................................. 10-24References ........................................................................................................................ 10-25A Sizing and Rating for Trays and PackingsSi ngl e-Pass and Mul ti -Pass Trays..................................................................................A-2Modes of Operati on for Trays .........................................................................................A-8Fl oodi ng Cal cul ati ons for Trays......................................................................................A-8Bubbl e Cap Tray Layout .................................................................................................A-9Pressure Drop Cal cul ati ons for Trays ..........................................................................A-10Foami ng Cal cul ati ons for Trays ...................................................................................A-11Packed Col umns ............................................................................................................A-12Packi ng Types and Packi ng Factors.............................................................................A-12Modes of Operati on for Packi ng....................................................................................A-12Maxi mum Capaci ty Cal cul ati ons for Packi ng .............................................................A-13Pressure Drop Cal cul ati ons for Packi ng ......................................................................A-15Li qui d Hol dup Cal cul ati ons for Packi ng......................................................................A-16Pressure Profi l e Update ................................................................................................A-17Physi cal Property Data Requi rements .........................................................................A-17References ..........................................................................................................................A-18IndexUni t Operati on Model s i xVersi on 10About the Unit OperationModels Reference ManualVol ume 1 of the ASPEN PLUS Reference Manual s, Unit Operation Models,i ncl udes detai l ed techni cal reference i nformati on for al l ASPEN PLUS uni toperati on model s and the Pres-Rel i ef model . The i nformati on i n thi s manual i sal so avai l abl e i n onl i ne hel p and prompts.Model s are grouped i n chapters accordi ng to uni t operati on type. The referencei nformati on for each model i ncl udes a descri pti on of the model and i ts typi calusage, a di agram of i ts fl owsheet connecti vi ty, a di scussi on of the speci fi cati onsyou must provi de for the model , i mportant equati ons and correl ati ons, and otherrel evant i nformati on.An overvi ew of al l ASPEN PLUS uni t operati on model s, and general i nformati onabout the steps and procedures i n usi ng them i s i n the ASPEN PLUS User Guideas wel l as i n the onl i ne hel p and prompts i n ASPEN PLUS.x Uni t Operati on Model sVersi on 10For More InformationOnl i ne Hel p ASPEN PLUS has a compl ete system of onl i ne hel p andcontext-sensi ti ve prompts. The hel p system contai ns both context-sensi ti ve hel pand reference i nformati on. For more i nformati on about usi ng ASPEN PLUS hel p,see the ASPEN PLUS User Guide, Chapter 3.ASPEN PLUS Getti ng Started Bui l di ng and Runni ng a Process Model Thi s tutori al i ncl udes several hands-on sessi ons to fami l i ari ze you wi thASPEN PLUS. The gui de takes you step-by-step to l earn the ful l power and scopeof ASPEN PLUS.ASPEN PLUS User Gui de The three-vol ume ASPEN PLUS User Guideprovi des step-by-step procedures for devel opi ng and usi ng an ASPEN PLUSprocess si mul ati on model . The gui de i s task -ori ented to hel p you accompl i sh theengi neeri ng work you need to do, usi ng the powerful capabi l i ti es ofASPEN PLUS.ASPEN PLUS reference manual seri es ASPEN PLUS reference manual sprovi de detai l ed techni cal reference i nformati on. These manual s i ncl udebackground i nformati on about the uni t operati on model s and the physi calproperti es methods and model s avai l abl e i n ASPEN PLUS, tabl es ofASPEN PLUS databank parameters, group contri buti on method functi onalgroups, and a wi de range of other reference i nformati on. The set compri ses: Unit Operation Models Physical Property Methods and Models Physical Property Data User Models System Management Summary File ToolkitASPEN PLUS appl i cati on exampl es A sui te of sampl e onl i ne ASPEN PLUSsi mul ati ons i l l ustrati ng speci fi c processes i s del i vered wi th ASPEN PLUS.ASPEN PLUS I nstal l ati on Gui des These gui des provi de i nstructi ons onpl atform and network i nstal l ati on of ASPEN PLUS. The set compri ses: ASPEN PLUS I nstallation Guide for Wi ndows ASPEN PLUS I nstallation Guide for OpenVMS ASPEN PLUS I nstallation Guide for UNI XThe ASPEN PLUS manual s are del i vered i n Adobe portabl e document format(PDF) on the ASPEN PLUS Documentati on CD. You can al so order pri ntedmanual s from AspenTech.Uni t Operati on Model s xiVersi on 10Technical SupportWorl d Wi de Web For addi ti onal i nformati on about AspenTech products andservi ces, check the AspenTech Worl d Wi de Web home page on the I nternet at:http://www.aspentech.com/Techni cal resources To obtai n i n-depth techni cal support i nformati on on theI nternet, vi si t the Techni cal Support homepage. Regi ster at:http://www.aspentech.com/ts/Approxi matel y three days after regi steri ng, you wi l l recei ve a confi rmati on e-mai land you wi l l then be abl e to access thi s i nformati on.The most current Hotl i ne contact i nformati on i s l i sted. Other i nformati oni ncl udes: Frequentl y asked questi ons Product trai ni ng courses Techni cal ti psAspenTech Hotl i ne I f you need hel p from an AspenTech Customer Supportengi neer, contact our Hotl i ne for any of the fol l owi ng l ocati ons:If you are located in: Phone Number Fax Number E-Mail AddressNorth America & theCaribbean+1-617/949-1021+1-888/996-7001 (toll free)+1-617/949-1724 support@aspentech.comSouth America (Argentina office) (Brazil office)+54-1/326-9835+55-11/5506-0756+54-1/394-8621+55-11/5506-0567tecnoba@aspentech.comtecnosp@aspentech.comEurope, Gulf Region, & Africa (Brussels office) (UK office)+32-2/724-0100+44-1223/312220+32-2/705-4034+44-1223/366980atesupport@aspentech.comatuksupport@aspentech.comJapan +81-3/3262-1743 +81-3/3262-1744 atjsupport@aspentech.comAsia & Australia +85-2/2838-6077 +85-2/2833-5642 atasupport@aspentech.comy y y yxi i Uni t Operati on Model sVersi on 10Uni t Operati on Model s 1-1Versi on 10Chapter 11 Mixers and SplittersThi s chapter descri bes the uni t operati on model s for mi xi ng and spl i tti ngstreams. The model s are:Model Description Purpose Use ForMixer Stream mixer Combines multiple streamsinto one streamMixing tees. Stream mixing operations.Adding heat streams. Adding work streamsFSplit Stream splitter Divides feed based on splitsspecified for outlet streamsStream splitters. Bleed valvesSSplit Substream splitter Divides feed based on splitsspecified for eachsubstreamStream splitters. Perfect fluid-solidseparators1-2 Uni t Operati on Model sVersi on 10Mixers andSplittersMixerStream MixerUse Mi xer to combi ne streams i nto one stream. Mi xer model s mi xi ng tees or othertypes of mi xi ng operati ons.Mi xer combi nes materi al streams (or heat streams or work streams) i nto onestream. Sel ect the Heat (Q) and Work (W) Mi xer i cons from the Model Li brary forheat and work streams respecti vel y. A si ngl e Mi xer bl ock cannot mi x streams ofdi fferent types (materi al , heat, work).Flowsheet Connectivity for MixerMaterialWater (optional)Material(2 or more)Flowsheet for Mixing Material StreamsMaterial StreamsInlet At l east two materi al streamsOutlet One materi al streamOne water decant stream (opti onal )Uni t Operati on Model s 1-3Versi on 10Chapter 1HeatHeat(2 or more)Flowsheet for Adding Heat StreamsHeat StreamsInlet At l east two heat streamsOutlet One heat streamWorkWork(2 or more)Flowsheet for Adding Work StreamsWork StreamsInlet At l east two work streamsOutlet One work streamSpecifying MixerUse the Mi xer I nput Fl ash Opti ons sheet to speci fy operati ng condi ti ons.When mi xi ng heat or work streams, Mi xer does not requi re any speci fi cati ons.1-4 Uni t Operati on Model sVersi on 10Mixers andSplittersWhen mi xi ng materi al streams, you can speci fy ei ther the outl et pressure orpressure drop. I f you speci fy pressure drop, Mi xer determi nes the mi ni mum ofthe i nl et stream pressures, and appl i es the pressure drop to the mi ni mum i nl etstream pressure to compute the outl et pressure. I f you do not speci fy the outl etpressure or pressure drop, Mi xer uses the mi ni mum pressure from the i nl etstreams for the outl et pressure.You can sel ect the fol l owi ng val i d phases:Valid Phase Solids? Number of phases? Free Water? Phase?Vapor-Only Yes or no 1 No VLiquid-Only Yes or no 1 No LVapor-Liquid Yes or no 2 No Vapor-Liquid-Liquid Yes or no 3 No Liquid Free-Water Yes or no 1 Yes Vapor-Liquid Free-Water Yes or no 2 Yes Solid-Only Yes 1 No SCheck Use Free Water Calculations checkbox on the Setup Specifications Global sheet.An opti onal water decant stream can be used when free-water cal cul ati ons areperformed.Mi xer performs an adi abati c cal cul ati on on the product to determi ne the outl ettemperature, unl ess Mass Bal ance Onl y Cal cul ati ons i s speci fi ed on the Mi xerBl ockOpti ons Si mul ati onOpti ons sheet or the Setup Si mul ati onOpti onsCal cul ati ons sheet.Use the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for Mi xer:Use this form To do thisInput Enter operating conditions and flash convergence parametersBlockOptions Override global values for physical properties, simulation options, diagnostic message levels,and report options for this blockResults View Mixer simulation resultsDynamic Specify parameters for dynamic simulationsUni t Operati on Model s 1-5Versi on 10Chapter 1FSplitStream SplitterFSpl i t combi nes streams of the same type (materi al , heat, or work streams) anddi vi des the resul ti ng stream i nto two or more streams of the same type. Al l outl etstreams have the same composi ti on and condi ti ons as the mi xed i nl et. Sel ect theHeat (Q) and Work (W) FSpl i t i cons from the Model Li brary for heat and workstreams respecti vel y. Use FSpl i t to model fl ow spl i tters, such as bl eed val ves.FSpl i t cannot spl i t a stream i nto di fferent types. For exampl e, FSpl i t cannot spl i ta materi al stream i nto a heat stream and a materi al stream.To model a spl i tter where the amount of each substream sent to each outl et candi ffer, use an SSpl i t bl ock. To model a spl i tter where the composi ti on andproperti es of the output streams can di ffer, use a Sep bl ock or a Sep2 bl ock.Flowsheet Connectivity for FSplitMaterial(2 or more)Material(any number)Flowsheet for Splitting Material StreamsMaterial StreamsInlet At l east one materi al streamOutlet At l east two materi al streams1-6 Uni t Operati on Model sVersi on 10Mixers andSplittersHeat(2 or more) Heat(any number)Flowsheet for Splitting Heat StreamsHeat StreamsInlet At l east one heat streamOutlet At l east two heat streamsWork(2 or more) Work(any number)Flowsheet for Splitting Work StreamsWork StreamsInlet At l east one work streamOutlet At l east two work streamsSpecifying FSplitTo spl i t materi al streams Gi ve one of the fol l owi ng speci fi cati ons for eachoutl et stream except one: Fracti on of the combi ned i nl et fl ow Mol e fl ow rate Mass fl ow rate Standard l i qui d vol ume fl ow rate Actual vol ume fl ow rate Fracti on of the resi due remai ni ng after al l other speci fi cati ons are sati sfi edFSpl i t puts any remai ni ng fl ow i n the unspeci fi ed outl et stream to sati sfy materi albal ance. You can speci fy mol e, mass, or standard l i qui d vol ume fl ow rate for one ofthe fol l owi ng: The enti re stream A subset of key components i n the streamUni t Operati on Model s 1-7Versi on 10Chapter 1To speci fy the fl ow rate of a component or group of components i n an outl et stream,speci fy a group of key components and the total fl ow rate for the group (the sum ofthe component fl ow rates) on the I nput Speci fi cati ons sheet, and defi ne the keycomponents i n the group on the I nput KeyComponents sheet.Outl et streams have the same composi ti on as the mi xed i nl et stream. For thi sreason, when you speci fy the fl ow rate of a key component, the total fl ow rate ofthe outl et stream i s greater than the fl ow rate you speci fy.When FSpl i t has more than one i nl et, you can do one of the fol l owi ng: Enter the outl et pressure on the FSpl i t I nput Fl ashOpti ons sheet Let the outl et pressure defaul t to the mi ni mum pressure of the i nl et streamsTo spl i t heat streams or work streams Speci fy the fracti on of the combi nedi nl et heat or work for each outl et stream except one. FSpl i t puts any remai ni ngheat or work i n the unspeci fi ed outl et stream to sati sfy energy bal ance.Use the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for FSpl i t:Use this form To do thisInput Enter split specifications, flash conditions and calculation options, and keycomponents associated with split specificationsBlockOptions Override global values for physical properties, simulation options,diagnostic message levels, and report options for this blockResults View split fractions for outlet streams, and material and energy balanceresults1-8 Uni t Operati on Model sVersi on 10Mixers andSplittersSSplitSubstream SplitterSSpl i t combi nes materi al streams and di vi des the resul ti ng stream i nto two ormore streams. Use SSpl i t to model a spl i tter where the spl i t of each substreamamong the outl et streams can di ffer.Substreams i n the outl et streams have the same composi ti on, temperature, andpressure as the correspondi ng substreams i n the mi xed i nl et stream. Onl y thesubstream fl ow rates di ffer. To model a spl i tter i n whi ch the composi ti on andproperti es of the substreams i n the output streams can di ffer, use a Sep bl ock ora Sep2 bl ock.Flowsheet Connectivity for SSplitMaterial(2 or more)Material(any number)Material StreamsInlet At l east one materi al streamOutlet At l east two materi al streamsSpecifying SSplitFor each substream, speci fy one of the fol l owi ng for al l but one outl et stream: Fracti on of the i nl et substream Mol e fl ow rate Mass fl ow rate Standard l i qui d vol ume fl ow rateSSpl i t puts any remai ni ng fl ow for each substream i n the unspeci fi ed stream.You cannot speci fy standard l i qui d vol ume fl ow rate when the substream i s oftype CI SOLI D, and mol e and standard l i qui d vol ume fl ow rates when thesubstream i s of type NC.Uni t Operati on Model s 1-9Versi on 10Chapter 1You can speci fy mol e or mass fl ow rate for one of the fol l owi ng: The enti re substream A subset of components i n the substreamYou can speci fy the fl ow rate of a component i n a substream of an outl et stream. Todo thi s, defi ne a key component and speci fy the fl ow rate for the key component.Si mi l arl y, you can speci fy the fl ow rate for a group of components i n a substream ofan outl et stream. To do thi s, defi ne a key group of components and speci fy the totalfl ow rate for the group (the sum of the component fl ow rates).Substreams i n outl et streams have the same composi ti on as the correspondi ngsubstream i n the mi xed i nl et stream. For thi s reason, when you speci fy the fl owrate of a key, the total fl ow rate of the substream i n the outl et stream i s greaterthan the fl ow rate you speci fy.When SSpl i t has more than one i nl et, you can do one of the fol l owi ng: Enter the outl et pressure on the I nput Fl ashOpti ons sheet. Let the outl et pressure defaul t to the mi ni mum pressure of the i nl et streams.The composi ti on, temperature, pressure, and other substream vari abl es for al loutl et streams have the same val ues as the mi xed i nl et. Onl y the substream fl owrates di ffer.Use the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for SSpl i t:Use this form To do thisInput Enter split specifications, flash conditions, calculation options, and key componentsassociated with split specificationsBlockOptions Override global values for physical properties, simulation options, diagnostic messagelevels, and report options for this blockResults View split fractions of each substream in each outlet stream, and material and energybalance resultsy y y y1-10 Uni t Operati on Model sVersi on 10Mixers andSplittersUni t Operati on Model s 2-1Versi on 10Chapter 22 SeparatorsThi s chapter descri bes the uni t operati on model s for component separators, fl ashdrums, and l i qui d-l i qui d separators. The model s are:Model Description Purpose Use ForFlash2 Two-outlet flash Separates feed into two outletstreams, using rigorous vapor-liquid or vapor-liquid-liquidequilibriumFlash drums, evaporators, knock-outdrums, single stage separatorsFlash3 Three-outlet flash Separates feed into threeoutlet streams, using rigorousvapor-liquid-liquid equilibriumDecanters, single-stage separators withtwo liquid phasesDecanter Liquid-liquid decanter Separates feed into two liquidoutlet streamsDecanters, single-stage separators withtwo liquid phases and no vapor phaseSep Component separator Separates inlet streamcomponents into multiple outletstreams, based on specifiedflows or split frractionsComponent separation operations, suchas distillation and absorption, when thedetails of the separation are unknown orunimportantSep2 Two-outlet componentseparatorSeparates inlet streamcomponents into two outletstreams, based on specifiedflows, split fractions, or puritiesComponent separation operations, suchas distillation and absorption, when thedetails of the separation are unknown orunimportantYou can generate heati ng or cool i ng curve tabl es for Fl ash2, Fl ash3, andDecanter model s.2-2 Uni t Operati on Model sVersi on 10SeparatorsFlash2Two-Outlet FlashUse Fl ash2 to model fl ashes, evaporators, knock-out drums, and other si ngl e-stage separators. Fl ash2 performs vapor-l i qui d or vapor-l i qui d-l i qui d equi l i bri umcal cul ati ons. When you speci fy the outl et condi ti ons, Fl ash2 determi nes thethermal and phase condi ti ons of a mi xture of one or more i nl et streams.Flowsheet Connectivity for Flash2VaporLiquidWater (optional)Heat (optional)Heat(optional)Material(any number)Material StreamsInlet At l east one materi al streamOutlet One materi al stream for the vapor phaseOne materi al stream for the l i qui d phase. (I f three phases exi st, the l i qui doutl et contai ns both l i qui d phases.)One water decant stream (opti onal )You can speci fy l i qui d and/or sol i d entrai nment i n the vapor stream.Uni t Operati on Model s 2-3Versi on 10Chapter 2Heat StreamsInlet Any number of heat streams (opti onal )Outlet One heat stream (opti onal )I f you gi ve onl y one speci fi cati on (temperature or pressure) on the I nputSpeci fi cati ons Sheet, Fl ash2 uses the sum of the i nl et heat streams as a dutyspeci fi cati on. Otherwi se, Fl ash2 uses the i nl et heat stream onl y to cal cul ate thenet heat duty. The net heat duty i s the sum of the i nl et heat streams mi nus theactual (cal cul ated) heat duty.You can use an opti onal outl et heat stream for the net heat duty.Specifying Flash2Use the I nput Speci fi cati ons sheet for al l requi red speci fi cati ons and val i dphases. For val i d phases you can choose the fol l owi ng opti ons:You can choose the followingoptions Solids? Number of phases? Free Water?Vapor-Liquid Yes or no 2 NoVapor-Liquid-Liquid Yes or no 3 NoVapor-Liquid-FreeWater Yes or no 2 YesUse the I nput Fl ashOpti ons sheet to speci fy temperature and pressure esti matesand fl ash convergence parameters.Use the I nput Entrai nment sheet to speci fy l i qui d and sol i d entrai nment i n thevapor phase.Use the Hcurves form to speci fy opti onal heati ng or cool i ng curves.Use the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for Fl ash2:Use this form To do thisInput Enter flash specifications, flash convergence parameters, and entrainment specificationsHcurves Specify heating or cooling curve tables and view tabular resultsBlock Options Override global values for physical properties, simulation options, diagnostic messagelevels, and report options for this blockResults View Flash2 simulation resultsDynamic Specify parameters for dynamic simulations2-4 Uni t Operati on Model sVersi on 10SeparatorsSolidsAl l phases are i n thermal equi l i bri um. Sol i ds l eave at the same temperature asthe fl ui d phases.Fl ash2 can si mul ate fl ui d phases wi th sol i ds when the stream contai ns sol i dsubstreams or when you request el ectrol ytes chemi stry cal cul ati ons.Sol i d Substreams Materi al s i n sol i d substreams do not parti ci pate i n phaseequi l i bri um cal cul ati ons.El ectrol yte Chemi stry Cal cul ati ons You can request these on the Properti esSpeci fi cati ons Gl obal sheet or the Bl ockOpti ons Properti es sheet. Sol i d sal tsparti ci pate i n l i qui d-sol i d phase equi l i bri um and thermal equi l i bri umcal cul ati ons. The sal ts are i n the MI XED substream.Uni t Operati on Model s 2-5Versi on 10Chapter 2Flash3Three-Outlet FlashUse Fl ash3 to model fl ashes, evaporators, knock-out drums, decanters, and othersi ngl e-stage separators i n whi ch two l i qui d outl et streams are produced. Fl ash3performs vapor-l i qui d-l i qui d equi l i bri um cal cul ati ons. When you speci fy outl etcondi ti ons, Fl ash3 determi nes the thermal and phase condi ti ons of a mi xture ofone or more i nl et streams.Flowsheet Connectivity for Flash3Vapor2nd Liquid1st LiquidHeat (optional)Heat(optional)Material(any number)Material StreamsInlet At l east one materi al streamOutlet One materi al stream for the vapor phaseOne materi al stream for the fi rst l i qui d phaseOne materi al stream for the second l i qui d phaseYou can speci fy l i qui d entrai nment of each l i qui d phase i n the vapor stream. Youcan al so speci fy entrai nment for each sol i d substream i n the vapor and fi rstl i qui d phase.2-6 Uni t Operati on Model sVersi on 10SeparatorsHeat StreamsInlet Any number of heat streams (opti onal )Outlet One heat stream (opti onal )I f you gi ve onl y one speci fi cati on on the I nput Speci fi cati ons Sheet (temperatureor pressure), Fl ash3 uses the sum of the i nl et heat streams as a dutyspeci fi cati on. Otherwi se, Fl ash3 uses the i nl et heat stream onl y to cal cul ate thenet heat duty. The net heat duty i s the sum of the i nl et heat streams mi nus theactual (cal cul ated) heat duty.You can use an opti onal outl et heat stream for the net heat duty.Specifying Flash3Use the I nput Speci fi cati ons sheet for al l requi red speci fi cati ons.Use the I nput Entrai nment sheet to speci fy sol i d entrai nment.To speci fy opti onal heati ng or cool i ng curves, use the Hcurves form.Use the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for Fl ash3:Use this form To do thisInput Enter flash specifications, key components, flash convergence parameters, andentrainment specificationsHcurves Specify heating or cooling curve tables and view tabular resultsBlock Options Override global values for physical properties, simulation options, diagnosticmessage levels, and report options for this blockResults View Flash3 simulation resultsDynamic Specify parameters for dynamic simulationsSolidsAl l phases are i n thermal equi l i bri um. Sol i ds l eave at the same temperature asthe fl ui d phases.Fl ash3 can si mul ate fl ui d phases wi th sol i ds when the stream contai ns sol i dsubstreams, or when you request el ectrol yte chemi stry cal cul ati ons.Sol i d Substreams Materi al s i n sol i d substreams do not parti ci pate i n phaseequi l i bri um cal cul ati ons.Uni t Operati on Model s 2-7Versi on 10Chapter 2El ectrol yte Chemi stry Cal cul ati ons You can request these on the Properti esSpeci fi cati ons Gl obal sheet or on the I nput Bl ockOpti ons Properti es sheet. Sol i dsal ts do parti ci pate i n l i qui d-sol i d phase equi l i bri um and thermal equi l i bri umcal cul ati ons. You can onl y speci fy apparent component cal cul ati ons (Sel ectSi mul ati on Approach=Apparent Components on the Bl ockOpti ons Properti essheet). The sal ts wi l l not appear i n the MI XED substream.2-8 Uni t Operati on Model sVersi on 10SeparatorsDecanterLiquid-Liquid DecanterDecanter si mul ates decanters and other si ngl e stage separators wi thout a vaporphase. Decanter can perform: Li qui d-l i qui d equi l i bri um cal cul ati ons Li qui d-free-water cal cul ati onsUse Decanter to model knock-out drums, decanters, and other si ngl e-stageseparators wi thout a vapor phase. When you speci fy outl et condi ti ons, Decanterdetermi nes the thermal and phase condi ti ons of a mi xture of one or more i nl etstreams.Decanter can cal cul ate l i qui d-l i qui d di stri buti on coeffi ci ents usi ng: An acti vi ty coeffi ci ent model An equati on of state capabl e of representi ng two l i qui d phases A user-speci fi ed Fortran subrouti ne A bui l t-i n correl ati on wi th user-speci fi ed coeffi ci entsYou can enter component separati on effi ci enci es, assumi ng equi l i bri um stage i spresent.Use Fl ash3 i f you suspect any vapor phase formati on.Flowsheet Connectivity for DecanterHeat(optional)Heat(optional)1st Liquid2nd LiquidMaterial(any number)Material StreamsInlet At l east one materi al streamOutlet One materi al stream for the fi rst l i qui d phaseOne materi al stream for the second l i qui d phaseYou can speci fy entrai nment for each sol i d substream i n the fi rst l i qui d phase.Uni t Operati on Model s 2-9Versi on 10Chapter 2Heat StreamsInlet Any number of heat streams (opti onal )Outlet One heat stream (opti onal )I f you speci fy onl y pressure on the I nput Speci fi cati ons sheet, Decanter uses thesum of the i nl et heat streams as a duty speci fi cati on. Otherwi se, Decanter usesthe i nl et heat stream onl y to cal cul ate the net heat duty. The net heat duty i s thesum of the i nl et heat streams mi nus the actual (cal cul ated) heat duty.You can use an opti onal outl et heat stream for the net heat duty.Specifying DecanterYou can operate Decanter i n one of the fol l owi ng ways: Adi abati cal l y Wi th speci fi ed duty At a speci fi ed temperatureUse the I nput Speci fi cati ons sheet to enter: Pressure Temperature or dutyUse the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for Decanter:Use this form To do thisInput Specify operating conditions, key components, calculation options, valid phases,efficiency, and entrainmentProperties Specify and/or override property methods, KLL equation parameters, and/or usersubroutine for phase split calculationsHcurves Specify heating or cooling curve tables and view tabular resultsBlock Options Override global values for physical properties, simulation options, diagnosticmessage levels, and report options for this blockResults Display simulation resultsDynamic Specify parameters for dynamic simulations2-10 Uni t Operati on Model sVersi on 10SeparatorsDefining the Second Liquid PhaseI f two l i qui d phases are present at the decanter operati ng condi ti on, Decantertreats the phase wi th hi gher densi ty as the second phase, by defaul t.When onl y one l i qui d phase exi sts and you want to avoi d ambi gui ti es, you canoverri de the defaul t by: Speci fyi ng key components for i denti fyi ng the second l i qui d phase on theI nput Speci fi cati ons sheet Opti onal l y speci fyi ng the threshol d key component mol e fracti on on the I nputSpeci fi cati ons sheetWhen Decanter treats theTwo liquid phases are present Phase with the higher mole fraction of key components as the second liquid phaseOne liquid phase is present Liquid phase as the first liquid phase, unless the mole fraction of key components exceedsthe threshold valueMethods for Calculating the Liquid-Liquid DistributionCoefficients (KLL)When cal cul ati ng l i qui d-l i qui d di stri buti on coeffi ci ents (KLL), by defaul tDecanter uses the physi cal property method speci fi ed for the bl ock on theProperti es PhaseProperty sheet or Bl ockOpti ons Properti es sheet.On the I nput Cal cul ati onOpti ons sheet, you can overri de the defaul t by doi ng oneof the fol l owi ng: Speci fy separate property methods for the two l i qui d phases usi ng theProperti es PhaseProperty sheet Use a bui l t-i n KLL correl ati on. Enter correl ati on coeffi ci ents on theProperti es KLLCorrel ati on sheet. Use a Fortran subrouti ne that you speci fy on the Properti es KLLSubrouti nesheetSee ASPEN PLUS User Models for more i nformati on about wri ti ng Fortransubrouti nes.Phase SplittingDecanter has two methods for sol vi ng l i qui d-l i qui d phase spl i t cal cul ati ons: Equati ng fugaci ti es of two l i qui d phases Mi ni mi zi ng Gi bbs free energy of the systemYou can sel ect a method on the I nput Cal cul ati onOpti ons sheet.Uni t Operati on Model s 2-11Versi on 10Chapter 2I f you sel ect Mi ni mi zi ng Gi bbs free energy of the system, the fol l owi ng must bethermodynami cal l y consi stent: Physi cal property model s Bl ock property methodYou cannot use the Mi ni mi zi ng Gi bbs free energy of the system method when:You specify On this sheetSeparate property methods for the two liquidphasesProperties PhasePropertyThe built-in correlation for liquid-liquiddistribution coefficient ( KLL) calculationsInput CalculationOptionsA user subroutine for liquid-liquid distributioncoefficient (KLL) calculationsInput Calculation OptionsEquati ng fugaci ti es of two l i qui d phases i s not restri cted by physi cal propertyspeci fi cati ons. However, Decanter can cal cul ate sol uti ons that do not mi ni mi zeGi bbs free energy.EfficiencyDecanter outl et streams are normal l y at equi l i bri um. However, you can speci fyseparati on effi ci enci es on the I nput Effi ci ency sheet to account for departure fromequi l i bri um. I f you sel ect Li qui d-FreeWater for Val i d Phases on the I nputCal cul ati onOpti ons sheet, you cannot speci fy separati on effi ci enci es.Solids EntrainmentI f sol i ds substreams are present, they do not parti ci pate i n phase equi l i bri umcal cul ati ons, but they do parti ci pate i n enthal py bal ance. You can use the I nputEntrai nment sheet to speci fy sol i ds entrai nment i n the fi rst l i qui d outl et stream.Decanter pl aces any remai ni ng sol i ds i n the second l i qui d outl et stream.2-12 Uni t Operati on Model sVersi on 10SeparatorsSepComponent SeparatorSep combi nes streams and separates the resul t i nto two or more streamsaccordi ng to spl i ts speci fi ed for each component. When the detai l s of theseparati on are unknown or uni mportant, but the spl i ts for each component areknown, you can use Sep i n pl ace of a ri gorous separati on model to savecomputati on ti me .I f the composi ti on and condi ti ons of al l outl et streams of the bl ock you aremodel i ng are i denti cal , you can use an FSpl i t bl ock i nstead of Sep.Flowsheet Connectivity for SepHeat(optional)Material(2 or more)Material(any number)Material StreamsInlet At l east one materi al streamOutlet At l east two materi al streamsHeat StreamsInlet No i nl et heat streamsOutlet One stream for the enthal py di fference between i nl et and outl et materi alstreams (opti onal )Uni t Operati on Model s 2-13Versi on 10Chapter 2Specifying SepFor each substream of each outl et stream except one, use the Sep I nputSpeci fi cati ons sheet to speci fy one of the fol l owi ng for each component present: Fracti on of the component i n the correspondi ng i nl et substream Mol e fl ow rate of the component Mass fl ow rate of the component Standard l i qui d vol ume fl ow rate of the componentSep puts any remai ni ng fl ow i n the correspondi ng substream of the unspeci fi edoutl et stream.Use the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for Sep:Use this form To do thisInput Enter split specifications, flash specifications, and convergence parameters for the mixed inletand each outlet streamBlockOptions Override global values for physical properties, simulation options, diagnostic message levels,and report options for this blockResults View Sep simulation resultsInlet PressureUse the Sep I nput Feed Fl ash sheet to speci fy ei ther the pressure drop or thepressure at the i nl et. Thi s i s useful when Sep has more than one i nl et stream. Thei nl et pressure defaul ts to the mi ni mum i nl et stream pressure.Outlet Stream ConditionsUse the Sep I nput Outl et Fl ash sheet to speci fy the condi ti ons of the outl etstreams. I f you do not speci fy the condi ti ons for a stream, Sep uses the i nl ettemperature and pressure.2-14 Uni t Operati on Model sVersi on 10SeparatorsSep2Two-Outlet Component SeparatorSep2 separates i nl et stream components i nto two outl et streams. Sep2 i s si mi l ar toSep, but offers a wi der vari ety of speci fi cati ons. Sep2 al l ows puri ty (mol e-fracti on)speci fi cati ons for components.You can use Sep2 i n pl ace of a ri gorous separati on model , such as di sti l l ati on orabsorpti on. Sep2 saves computati on ti me when detai l s of the separati on areunknown or uni mportant.I f the composi ti on and condi ti ons of al l outl et streams of the bl ock you aremodel i ng are i denti cal , you can use FSpl i t i nstead of Sep2.Flowsheet Connectivity for Sep2MaterialMaterialHeat(optional)Material(any number)Material StreamsInlet At l east one materi al streamOutlet Two materi al streamsHeat StreamsInlet No i nl et heat streamsOutlet One stream for the enthal py di fference between i nl et and outl et materi alstreams (opti onal )Uni t Operati on Model s 2-15Versi on 10Chapter 2Specifying Sep2Use the I nput Speci fi cati ons sheet to speci fy stream and/or component fracti onsand fl ows. The number of speci fi cati ons for each substream must equal thenumber of components i n that substream.You can enter these stream speci fi cati ons: Fracti on of the total i nl et stream goi ng to ei ther outl et stream Total mass fl ow rate of an outl et stream Total mol ar fl ow rate of an outl et stream (for substreams of type MI XED orCI SOLI D) Total standard l i qui d vol ume fl ow rate of an outl et stream (for substreams oftype MI XED)You can enter these component speci fi cati ons: Fracti on of a component i n the feed goi ng to ei ther outl et stream Mass fl ow rate of a component i n an outl et stream Mol ar fl ow rate of a component i n an outl et stream (for substreams of typeMI XED or CI SOLI D) Standard l i qui d vol ume fl ow rate of a component i n an outl et stream (forsubstreams of type MI XED) Mass fracti on of a component i n an outl et stream Mol e fracti on of a component i n an outl et stream (for substreams of typeMI XED or CI SOLI D)Sep2 treats each substream separatel y. Do not: Speci fy the total fl ow of both outl et streams Enter more than one fl ow or frac speci fi cati on for each component Enter both a mol e-frac and a mass-frac speci fi cati on for a component i n astreamUse the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for Sep2:Use this form To do thisInput Enter split specifications, flash specifications, and convergence parameters for the mixed inletand each outlet streamBlock Options Override global values for physical properties, simulation options, diagnostic message levels,and report options for this blockResults View Sep2 simulation results2-16 Uni t Operati on Model sVersi on 10SeparatorsInlet PressureUse the I nput Feed Fl ash sheet to speci fy ei ther the pressure drop or pressure atthe i nl et. Thi s i nformati on i s useful when Sep2 has more than one i nl et stream.The i nl et pressure defaul ts to the mi ni mum of the i nl et stream pressures.Outlet Stream ConditionsUse the I nput Outl et Fl ash sheet to speci fy the condi ti ons of the outl et streams.I f you do not speci fy the condi ti ons for a stream, Sep2 uses the i nl et temperatureand pressure.y y y yUni t Operati on Model s 3-1Versi on 10Chapter 33 Heat ExchangersThi s chapter descri bes the uni t operati on model s for heat exchangers and heaters(and cool ers), and for i nterfaci ng to the B-JAC heat exchanger programs. Themodel s are:Model Description Purpose Use ForHeater Heater or cooler Determines thermal and phaseconditions of outlet streamHeaters, coolers, condensers, and so onHeatX Two-stream heat exchanger Exchanges heat between twostreamsTwo-stream heat exchangers. Ratingshell and tube heat exchangers whengeometry is known.MHeatX Multistream heat exchanger Exchanges heat between anynumber of streamsMultiple hot and cold stream heatexchangers. Two-stream heatexchangers. LNG exchangers.Hetran Shell and tube heatexchangerProvides interface to theB-JAC Hetran shell and tubeheat exchanger programShell and tube heat exchangers,including kettle reboilersAerotran Air-cooled heat exchanger Provides interface to theB-JAC Aerotran air-cooled heatexchanger programCrossflow heat exchangers, including aircoolers3-2 Uni t Operati on Model sVersi on 10HeatExchangersHeaterHeater/CoolerYou can use Heater to represent: Heaters Cool ers Val ves Pumps (whenever work-rel ated resul ts are not needed) Compressors (whenever work-rel ated resul ts are not needed)You al so can use Heater to set the thermodynami c condi ti on of a stream.When you speci fy the outl et condi ti ons, Heater determi nes the thermal andphase condi ti ons of a mi xture wi th one or more i nl et streams.Flowsheet Connectivity for HeaterHeat (optional)MaterialMaterial(any number)Heat(optional)Water (optional)Material StreamsInlet At l east one materi al streamOutlet One materi al streamOne water decant stream (opti onal )Heat StreamsInlet Any number of heat streams (opti onal )Outlet One heat stream (opti onal )Uni t Operati on Model s 3-3Versi on 10Chapter 3I f you gi ve onl y one speci fi cati on (temperature or pressure) on the Speci fi cati onssheet, Heater uses the sum of the i nl et heat streams as a duty speci fi cati on.Otherwi se, Heater uses the i nl et heat stream onl y to cal cul ate the net heat duty.The net heat duty i s the sum of the i nl et heat streams mi nus the actual(cal cul ated) heat duty.You can use an opti onal outl et heat stream for the net heat duty.Specifying HeaterUse the Heater I nput Speci fi cati ons sheet for al l requi red speci fi cati ons and val i dphases.Dew poi nt cal cul ati ons are two- or three-phase fl ashes wi th a vapor fracti on ofuni ty.Bubbl e poi nt cal cul ati ons are two- or three-phase fl ashes wi th a vapor fracti on ofzero.Use the Heater I nput Fl ashOpti ons sheet to speci fy temperature and pressureesti mates and fl ash convergence parameters.Use the Hcurves form to speci fy opti onal heati ng or cool i ng curves.Thi s model has no dynami c features. The pressure drop i s fi xed at the steadystate val ue. The outl et fl ow i s determi ned by the mass bal ance.Use the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for Heater.Use this form To do thisInput Enter operating conditions and flash convergence parametersHcurves Specify heating or cooling curve tables and view tabular resultsBlock Options Override global values for physical properties, simulation options, diagnosticmessage levels, and report options for this blockResults View Heater results3-4 Uni t Operati on Model sVersi on 10HeatExchangersSolidsHeater can si mul ate fl ui d phases wi th sol i ds when the stream contai ns sol i dsubstreams or when you request el ectrol yte chemi stry cal cul ati ons.Al l phases are i n thermal equi l i bri um. Sol i ds l eave at the same temperature asfl ui d phases.Sol i d Substreams Materi al s i n sol i d substreams do not parti ci pate i n phaseequi l i bri um cal cul ati ons.El ectrol yte Chemi stry Cal cul ati ons You can request these on the Properti esSpeci fi cati ons Gl obal sheet or the Heater Bl ockOpti ons Properti es sheet. Sol i dsal ts parti ci pate i n l i qui d-sol i d phase equi l i bri um and thermal equi l i bri umcal cul ati ons. The sal ts are i n the MI XED substream.Uni t Operati on Model s 3-5Versi on 10Chapter 3HeatXTwo-Stream Heat ExchangerHeatX can model a wi de vari ety of shel l and tube heat exchanger types i ncl udi ng: Countercurrent and cocurrent Segmental baffl e TEMA E, F, G, H, J, and X shel l s Rod baffl e TEMA E and F shel l s Bare and l ow-fi nned tubesHeatX can perform a ful l zone anal ysi s wi th heat transfer coeffi ci ent andpressure drop esti mati on for si ngl e- and two-phase streams. For ri gorous heattransfer and pressure drop cal cul ati ons, you must suppl y the exchangergeometry.I f exchanger geometry i s unknown or uni mportant, HeatX can perform si mpl i fi edshortcut rati ng cal cul ati ons. For exampl e, you may want to perform onl y heatand materi al bal ance cal cul ati ons.HeatX has correl ati ons to esti mate sensi bl e heat, nucl eate boi l i ng, andcondensati on fi l m coeffi ci ents.HeatX cannot: Perform desi gn cal cul ati ons Perform mechani cal vi brati on anal ysi s Esti mate foul i ng factorsFlowsheet Connectivity for HeatXCold OutletWater (optional)Hot OutletWater(optional)HotInletCold Inlet3-6 Uni t Operati on Model sVersi on 10HeatExchangersMaterial StreamsInlet One hot i nl etOne col d i nl etOutlet One hot outl etOne col d outl etOne water decant stream on the hot si de (opti onal )One water decant stream on the col d si de (opti onal )Specifying HeatXConsi der these questi ons when speci fyi ng HeatX: Shoul d rati ng cal cul ati ons be si mpl e (shortcut) or ri gorous? What speci fi cati on shoul d the bl ock have? How shoul d the l og-mean temperature di fference correcti on factor becal cul ated? How shoul d the heat transfer coeffi ci ent be cal cul ated? How shoul d the pressure drops be cal cul ated? What equi pment speci fi cati ons and geometry i nformati on are avai l abl e?The answers to these questi ons determi ne the amount of i nformati on requi red tocompl ete the bl ock i nput. You must provi de one of the fol l owi ng speci fi cati ons: Heat exchanger area or geometry Exchanger heat duty Outl et temperature of the hot or col d stream Temperature approach at ei ther end of the exchanger Degrees of superheati ng/subcool i ng for the hot or col d stream Vapor fracti on of the hot or col d stream Temperature change of the hot or col d streamUse the fol l owi ng forms to enter speci fi cati ons and vi ew resul ts for HeatX:Use this form To do thisSetup Specify shortcut or detailed calculations, flow direction, exchanger pressure drops, heat transfercoefficient calculation methods, and film coefficientsOptions Specify different flash convergence parameters and valid phases for the hot and cold sides, HeatXconvergence parameters, and block-specific report optionGeometry Specify the shell and tube configuration and indicate any tube fins, baffles, or nozzlesUserSubroutines Specify parameters for user-defined Fortran subroutines to calculate overall heat transfer coefficient,LMTD correction factor, tube-side liquid holdup, or tube-side pressure dropHot-Hcurves Specify hot stream heating or cooling curve tables and view tabular resultscontinuedUni t Operati on Model s 3-7Versi on 10Chapter 3Use this form To do thisCold-Hcurves Specify cold stream heating or cooling curve tables and view tabular resultsBlockOptions Override global values for physical properties, simulation options, diagnostic messagelevels, and report options for this blockResults View a summary of results, mass and energy balances, pressure drops, velocities, andzone analysisDetailed Results View detailed shell and tube results, and information about tube fins, baffles, andnozzlesDynamic Specify parameters for dynamic simulationsShortcut Versus Rigorous Rating CalculationsHeatX has two rati ng modes: shortcut and ri gorous. Use the Cal cul ati on Typefi el d on the Setup Speci fi cati ons sheet to speci fy shortcut or ri gorous rati ngcal cul ati ons.I n shortcut rati ng mode you can si mul ate a heat exchanger bl ock wi th themi ni mum amount of requi red i nput. The shortcut cal cul ati on does not requi reexchanger confi gurati on or geometry data.For ri gorous rati ng mode, you can use exchanger geometry to esti mate: Fi l m coeffi ci ents Pressure drops Log-mean temperature di fference correcti on factorRi gorous rati ng mode provi des more speci fi cati on opti ons for HeatX, but i t al sorequi res more i nput.Ri gorous rati ng mode provi des defaul ts for many opti ons. You can change thedefaul ts to gai n compl ete control over the cal cul ati ons. The fol l owi ng tabl e l i ststhese opti ons wi th val i d val ues. The val ues are descri bed i n the fol l owi ngsecti ons.3-8 Uni t Operati on Model sVersi on 10HeatExchangersVariable Calculation MethodAvailable inShortcut ModeAvailable inRigorous ModeLMTD CorrectionFactorConstantGeometryUser subroutineDefaultNoNoYesDefaultYesHeat TransferCoefficientConstant valuePhase-specific valuesPower law expressionFilm coefficientsExchanger geometryUser subroutineYesDefaultYesNoNoNoYesYesYesYesDefaultYesFilm Coefficient Constant valuePhase-specific valuesPower law expressionCalculate from geometryNoNoNoNoYesYesYesDefaultPressure Drop Outlet pressureCalculate from geometryDefaultNoYesDefaultCalculating the Log-Mean Temperature DifferenceCorrection FactorThe standard equati on for a heat exchanger i s:Q U A LMTD where LMTD i s the l og-mean temperature di fference. Thi s equati on appl i es forexchangers wi th pure countercurrent fl ow.The more general equati on i s:Q U A F LMTD where the LMTD correcti on factor, F, accounts for devi ati on from countercurrentfl ow.Use the LMTD Correcti on Factor fi el d on the Setup Speci fi cati ons sheet to enterthe LMTD correcti on factor.Uni t Operati on Model s 3-9Versi on 10Chapter 3I n shortcut rati ng mode, the LMTD correcti on factor i s constant. I n ri gorousrati ng mode, use the LMTD Correcti on Method fi el d on the Setup Speci fi cati onssheet to speci fy how HeatX cal cul ates the LMTD correcti on factor. You canchoose from the fol l owi ng cal cul ati on opti ons:If LMTD Correction Method is ThenConstant The LMTD correction factor you enter is constant.Geometry HeatX calculates the LMTD correction factor using the exchanger specificationand stream propertiesUser subroutine You supply a user subroutine to calculate the LMTD correction factor.Calculating the Heat Transfer CoefficientTo determi ne how the heat transfer coeffi ci ent i s cal cul ated, set the Cal cul ati onMethod on the Setup U Methods sheet. You can use these opti ons i n shortcut orri gorous rati ng mode:If Calculation Method is HeatX uses And you specifyConstant value A constant value for the heat transfer coefficient The constant valuePhase-specific values A different heat transfer coefficient for each heat transferzone of the exchanger, indexed by the phase for the hotand cold streamsA constant value foreach zonePower law expression A power law expression for the heat transfer coefficient asa function of one of the stream flow ratesConstants for the powerlaw expressionI n ri gorous rati ng mode, three addi ti onal val ues are al l owed:If Calculation Method is ThenExchanger geometry HeatX calculates the heat transfer coefficient using exchanger geometry and streamproperties to estimate film coefficients.Film coefficients HeatX calculates the heat transfer coefficients using the film coefficients. You can useany option on the Setup Film Coefficients sheet to calculate the film coefficients.User subroutine You supply a user subroutine to calculate the heat transfer coefficient.3-10 Uni t Operati on Model sVersi on 10HeatExchangersFilm CoefficientsHeatX does not cal cul ate fi l m coeffi ci ents i n shortcut rati ng mode. I n ri gorousrati ng mode, i f you use fi l m coeffi ci ents or exchanger geometry for the heattransfer coeffi ci ent cal cul ati on method, HeatX cal cul ates the heat transfercoeffi ci ent usi ng:1 1 1U h hc h +Where:hc= Col d stream fi l m coeffi ci enthh= Hot stream fi l m coeffi ci entTo choose an opti on for cal cul ati ng fi l m coeffi ci ents, set the Cal cul ati on Methodon the Setup Fi l m Coeffi ci ents sheet. The fol l owi ng are avai l abl e:If Calculation Method is HeatX uses And you specifyConstant value A constant value for the film coefficient A constant value to beused throughout theexchangerPhase-specific values A different film coefficient for each heattransfer zone (phase) of the exchanger,indexed by the phase of the streamA constant value foreach phasePower law expression A power law expression for the film coefficientas a function of the stream flow rateConstants for the powerlaw expressionCalculate from geometry The exchanger geometry and streamproperties to calculate the film coefficientThe hot stream and col d stream fi l m coeffi ci ent cal cul ati on methods arei ndependent of each other. You can use any combi nati on that i s appropri ate foryour exchanger.Pressure Drop CalculationsTo enter exchanger pressure or pressure drop for the hot and col d si des, use theOutl et Pressure fi el ds on the Setup Pressure Drop sheet. I n shortcut rati ng modethe pressure drop i s constant.Uni t Operati on Model s 3-11Versi on 10Chapter 3I n ri gorous rati ng mode, you can choose how pressure drops are cal cul ated bysetti ng the pressure opti ons on the Setup PressureDrop sheet. The fol l owi ngpressure drop opti ons are avai l abl e:If Pressure Option is ThenOutlet Pressure You must enter the outlet pressure or pressure drop for the stream.Calculate from geometry HeatX calculates the pressure drop using the exchanger geometry and streampropertiesHeatX cal l s the Pi pel i ne model to cal cul ate tube-si de pressure drop. You can setthe correl ati ons for pressure drop and l i qui d hol dup that the Pi pel i ne model useson the Setup PressureDrop sheet.Exchanger ConfigurationExchanger confi gurati on refers to the overal l patterns of fl ow i n the heatexchanger. I f you choose Cal cul ate From Geometry for any of the heat transfercoeffi ci ents, fi l m coeffi ci ents, or pressure drop cal cul ati on methods, you may berequi red to enter some i nformati on about the exchanger confi gurati on on theGeometry Shel l sheet. Thi s sheet i ncl udes fi el ds for: TEMA shel l type (see the next fi gure, TEMA Shel l Types) Number of tube passes Exchanger ori entati on Tubes i n baffl e wi ndow Number of seal i ng stri ps Tube fl ow for verti cal exchangers3-12 Uni t Operati on Model sVersi on 10HeatExchangersTwo Pass Shellwith Longitudinal BaffleOne Pass ShellE ShellF ShellG ShellH ShellJ ShellX ShellSplit FlowDouble Split FlowDivided FlowCross FlowTEMA Shell TypesUni t Operati on Model s 3-13Versi on 10Chapter 3The Geometry Shel l sheet al so contai ns two i mportant di mensi ons for the shel l : I nsi de shel l di ameter Shel l to bundl e cl earanceThe next fi gure shows the shel l di mensi ons.Outer TubeLimitShell to BundleClearanceShell DiameterShell DimensionsBaffle GeometryCal cul ati on of shel l -si de fi l m coeffi ci ent and pressure drop requi re i nformati onabout the baffl e geometry wi thi n the shel l . Enter baffl e geometry on theGeometry Baffl es sheet.HeatX can cal cul ate shel l -si de val ues for both segmental baffl e shel l s and rodbaffl e shel l s. Other requi red i nformati on depends on the baffl e type. Forsegmental baffl es, requi red i nformati on i ncl udes: Baffl e cut Baffl e spaci ng Baffl e cl earancesFor rod baffl es, requi red i nformati on i ncl udes: Ri ng di mensi ons Support rod geometry3-14 Uni t Operati on Model sVersi on 10HeatExchangersThe next two fi gures show the baffl e di mensi ons. The Baffl e Cut i n theDi mensi ons for Segmental Baffl es fi gure i s a fracti on of the shel l di ameter. Al lcl earances are di ametri c.Baffle CutTube HoleShell to BaffleClearanceDimensions for Segmental BafflesRing OutsideDiameterRing InsideDiameterRod DiameterDimensions for Rod BafflesTube GeometryCal cul ati on of the tube-si de fi l m coeffi ci ent and pressure drop requi rei nformati on about the geometry of the tubebank. HeatX al so uses thi si nformati on to cal cul ate the heat transfer coeffi ci ent from the fi l m coeffi ci ents.Enter tube geometry on the Geometry Tubes sheet.Uni t Operati on Model s 3-15Versi on 10Chapter 3You can sel ect a heat exchanger wi th ei ther bare or l ow-fi nned tubes. The sheetal so i ncl udes fi el ds for: Total number of tubes Tube l ength Tube di ameters Tube l ayout Tube materi al of constructi onThe next two fi gures show tube l ayout patterns and fi n di mensi ons.TubePitch30oTriangle45oTubePitchRotatedSquare60oTubePitchRotatedTriangle90oTubePitchSquareDirection of FlowTube Layout PatternsOutsideDiameterFin ThicknessRoot MeanDiameterFin HeightFin DimensionsNozzle GeometryCal cul ati ons for pressure drop i ncl ude the cal cul ati on of pressure drop i n theexchanger nozzl es. Enter nozzl e geometry on the Geometry Nozzl es sheet.Model CorrelationsHeatX uses open l i terature correl ati ons for cal cul ati ng fi l m coeffi ci ents andpressure drops. The next four tabl es l i st the model correl ati ons.3-16 Uni t Operati on Model sVersi on 10HeatExchangersTube-side Heat Transfer Coefficient CorrelationsMechanism Flow Regime Correlation ReferencesSingle-phase LaminarTurbulentSchlunderGnielinski[1][1]Boiling - vertical tubes Steiner/Taborek [2]Boiling - horizontal tubes Shah [3, 4]Condensation - vertical tubes LaminarLaminar wavyTurbulentShear-dominatedNusseltKutateladzeLabuntsovRohsenow[5][6][7][8]Condensation - horizontal tubes AnnularStratifyingRohsenowJaster/Kosky method[8][9]Shell-side Heat Transfer Coefficient CorrelationsMechanism Flow Regime Correlation ReferencesSingle-phase segmental Bell-Delaware [10, 11]Single-phase ROD Gentry [12]Boiling Jensen [13]Condensation - vertical LaminarLaminar wavyTurbulentShear-dominatedNusseltKutateladzeLabuntsovRohsenow[5][6][7][8]Condensation - horizontal Kern [9]Tube-side Pressure Drop CorrelationsMechanism CorrelationSingle-phase Darcys LawTwo-phase See Chapter 6See Pipeline, Two-Phase Correlations, for the correlations available for two-phase pressure drop in apipe.Shell-side Pressure Drop CorrelationsMechanism Correlation ReferencesSingle-phase segmental Bell-Delaware [10, 11]Single-phase ROD Gentry [12]Two-phase segmental Bell-Delaware method with Grants correction for two-phase flow[10, 11], [14]Two-phase ROD Gentry [12]Uni t Operati on Model s 3-17Versi on 10Chapter 3Flash SpecificationsUse the Opti ons Fl ash Opti ons sheet to enter fl ash speci fi cati ons.If you want to performthese calculations Solids? Set Valid Phases toVapor phase Yes or no Vapor-onlyLiquid phase Yes or no Liquid-only2-fluid flash phase Yes or no Vapor-Liquid3-fluid flash phase Yes or no Vapor-Liquid-Liquid3-fluid phase free-water flash Yes or no Vapor-Liquid-FreeWaterSolids only Yes Solid-onlyPhysical PropertiesTo overri de gl obal or fl owsheet secti on property speci fi cati ons, use theBl ockOpti ons Properti es sheet. You can use di fferent physi cal property opti onsfor the hot si de and col d si de of the heat exchanger. I f you suppl y onl y one set ofproperty speci fi cati ons, HeatX uses that set for both hot and col d si decal cul ati ons.SolidsAl l phases are i n thermal equi l i bri um. Sol i ds l eave at the same temperature asthe fl ui d phases.HeatX can si mul ate fl ui d phases wi th sol i ds when the stream contai ns sol i dsubstreams, or when you request el ectrol yte chemi stry cal cul ati ons.Sol i d Substreams Materi al s i n sol i d substreams do not parti ci pate i n phaseequi l i bri um cal cul ati ons.El ectrol yte Chemi stry Cal cul ati ons You can request these on the Properti esSpeci fi cati ons Gl obal sheet or HeatX Bl ockOpti ons Properti es sheet. Sol i d sal tsparti ci pate i n l i qui d-sol i d phase equi l i bri um and thermal equi l i bri umcal cul ati ons. The sal ts are i n the MI XED substream.3-18 Uni t Operati on Model sVersi on 10HeatExchangersReferences1. Gni el i nski , V., "Forced Convecti on i n Ducts." I n: Heat Exchanger Desi gnHandbook. New York: Hemi sphere Publ i shi ng Corporati on, 1983.2. Stei ner, D. and Taborek, J., "Fl ow Boi l i ng Heat Transfer i n Verti cal TubesCorrel ated by an Asymptoti c Model ." I n: Heat Transfer Engi neeri ng, 13(2):43-69, 1992.3. Shah, M.M., "A New Correl ati on for Heat Transfer Duri ng Boi l i ng Fl owThrough Pi pes." I n: ASHRAE Transacti ons, 82(2):66-86, 1976.4. Shah, M.M., "Chart Correl ati on for Saturated Boi l i ng Heat Transfer:Equati ons and Further Study." I n: ASHRAE Transacti ons, 87(1):185-196,1981.5. Nussel t, W., "Surface Condensati on of Water Vapor." Z. Ver. Dtsch, I ng.,60(27):541-546, 1916.6. Kutatel adze, S.S., Fundamental s of Heat Transfer. New York: Academi cPress, 1963.7. Labuntsov, D.A., "Heat Transfer i n Fi l m Condensati on of Pure Steam onVerti cal Surfaces and Hori zontal Tubes." I n: Tepl oenergeti ka, 4(7):72-80,1957.8. Rohsenow, W.M., Webber, J.H., and Li ng, A.T., "Effect of Vapor Vel oci ty onLami nar and Turbul ent Fi l m Condensati on." I n: Transacti ons of the ASME,78:1637-1643, 1956.9. Jaster, H. and Kosky, P.G., "Condensati on Heat Transfer i n a Mi xed Fl owRegi me." I n: I nternati onal Journal of Heat and Mass Transfer, 19:95-99,1976.10. Taborek, J., "Shel l -and-Tube Heat Exchangers: Si ngl e Phase Fl ow." I n: HeatExchanger Desi gn Handbook. New York: Hemi sphere Publ i shi ngCorporati on, 1983.11. Bel l , K.J., "Del aware Method for Shel l Si de Desi gn." I n