Finite Element Analysis Report for Drying Raw Mill new.docx

Finite Element Analysis Report for Drying Raw Mill new.docx

《Finite Element Analysis Report for Drying Raw Mill new.docx》由会员分享，可在线阅读，更多相关《Finite Element Analysis Report for Drying Raw Mill new.docx（13页珍藏版）》请在冰豆网上搜索。

FiniteElementAnalysisReportforDryingRawMillnew

FiniteElementAnalysisReportforDryingRawMill

1.Introduction

ThemaincomponentsanddimensionsofthemillCBMIdesignedareshowninfigure1.Themainshellisacylindricalvesselwith4.6minsidediameterby15.1mlonganddividedintofourchambersbythreediaphragms.OnemanholeisinchamberIandtheothermanholeisinchamberⅣ.Thetwoholesare180apart.Thedrivingtubeisacylindricalshellwith1.8minsidediameterbyabout2.832mlong,perforatedby6holes.Themainshellanddrivingtubearejointedbyboltswhicharesimulatedbyconstraintequation,whichmeanstakingthedrivingtubeandshellasawhole.Themillissupportedbyfour0.6mwidebearingpadsateachend.Theshellincontactwithbearingpadsarethickento100mmandaxiallydrivenatoutletendflangewithanormaloperatingpowerof3000kwat15rpm.Allotherdimensionsarereferredtorelevantengineeringdrawings.Figure2showsthelocalmagnifyingofthemanhole1.Figure3showslocalmagnifyingoftheholeofdischargedchamber3.

Figure1.FEmodelshowingmaincomponentsanddimensions

Figure2.localmagnifyingofthemanhole1

Figure3.localmagnifyingoftheholeofdischargedchamber3

2.Boundaryconditions

3-Dstructureelementandquadraticshellelementareusedtomodelthemill.

2.1Drivingtorqueandoffsetload

AdrivingtorqueT=1910000N.mwhichcorrespondstoabout3000kwat15rpmisappliedbycircumferentialforcesonendflange.Aloadof200736.3kginternalballsandmaterialisappliedasadditionalmassonbottompartofmainshellandoffsettotheleftasillustratedinfigure4.TheangularpositionsofAandBareapproximately-1800and-600respectively,foundbytrialanderrorsoastocounterbalancetheappliedadditionalmass.

Figure4.Drivingtorqueandoffsetload

Figure5Modelof8supportpads

2.2Linermasses

7559kgforheadlineratinletend,7942kgforheadlineratoutletend,14782.56kgforshelllinerinchamberI,38088kgforshelllinerinchamberⅡ,10760kgforshelllinerinchamberⅢ,22954kgforshelllinerinchamberⅣareappliedasadditionaldistributedmassofcorrespondingcomponents（headplatesandmainshell）.

2.3Diaphragm

16402kgweightfordiaphragmbetweenchamberIandⅡ,8201kgweightforthetwodiaphragmsrespectivelyindischargedchamberⅢ,alltheweightsareappliedasdistributedmassofanannularplateusingverysmallYoung'smodulussothatthediaphragmdoesnotcontributetothestiffnessoftheshell.

2.4Drivingtubeandshellmasses

12399kgfordrivingtube（SeedrawingNO.BMRaCD46.3.7）,122683kgforshell（SeedrawingNO.BMRaCD4685/35.3.4）,alloftheweightswillbecalculatedbydefiningdenseofthematerialthroughANSYSsystem,andultimatelyappliedtothemodel.

2.5Support

Thecontactmodelisintroducedtosimulatethefrictionlesscontactbetweenshellringsandthe200mmthicksupportpads.Radialreactionsillustrateinfigure5.

Totally,12modelsarestudied,eachoneforeveryhourpositioninaccordingtothepositionofpads,andonlyimportantandcriticalresultsarereportedbelow.

3.Resultanalysis

3.1Resultsforforcesandstressesonpads

Asillustratedinfigure5andthroughcontactmodelsimulation,

=551380，

=592676,

=666763N，

=964697N，

=581772N，

=557564N，

=581077N，

=948661N,finallytheverticalreactiontotallyequalsto4697300N（about479.36tons）.

With0.2mthickplatesforpads,themaximumVonMisesstressis7.57MPa（figure6）.Foranyotherthicknessofpads,byfunction

=

inMPaandtinmeter,basedonthefactthatbendingstressinplatesisinverselyproportionaltothesquareofitsthickness（

=

）.Usingtheyieldstrength185MPaofthepadsmaterialandsafetyfactor2,thefunctiongivesthethicknessofpadsis57mm.

Figure6ThemaximumVonMisesstressinpads

Padshaveasafetyfactorgreaterthan2whiletheyarestrongerthan57mmthickplate.

3.2Maximumstressindrivingtube

Asillustratedinfigure7,"TheVonMisesstressdistributionofdrivingtube"showsthemaximumVonMisesstressis17.6MPa.Consideringthestartuptorque2.5timesgreater,thenthesafetyfactoragainstyieldis200/17.6/2.5=4.54.Figure8showsthemaximumVonMisesstressofdrivingtubehole,whichis4.17MPa,muchsmallerthanthematerialbreakagelimit.

Figure7TheVonMisesstressdistributionofdrivingtube

Figure8TheVonMisesstressdistributionofdrivingtubehole

3.3stressanalysisofmanholes

3.3.1VonMisesstressaroundmanhole

Formanhole1,themaximumstaticVonMisesstressis66.7MPaat4hposition（seeFig9）;formanhole2,themaximumstaticVonMisesstressis79.4MPaat4hposition（seeFig10）;thesafetyfactorwithrespecttoyieldisf＝250/79.4＝3.15

Fig9MaximumVonMisesStressaroundmanhole1

Fig10MaximumVonMisesStressaroundmanhole2

3.3.2Fatiguestressaroundmanhole

Formanhole1,theworstprincipalstressrangeoccursontheedgeofshellbetween

maxat4h=68.4Mpaand

minat7h=-12.9Mpa（Fig11-12）.Thus,stressrange=68.4-（12.9）=81.3Mpa.SafetyfactorwithrespecttoallowableinfinitelifecategoryAstressaccordingtoAISC:

f=165（Mpa）/（81.3Mpa）=2.02。

Fig11Max.principalstressonmanhole1

Fig12Min.principalstressonmanhole1

Formanhole2,theworstprincipalstressrangeoccursontheedgeofshellbetween

maxat10h=82.1Mpaand

minat2h=-19.7Mpa（Fig13-14）.Thus,stressrange=82.1-（19.7）=101.8Mpa.SafetyfactorwithrespecttoallowableinfinitelifecategoryAstressaccordingtoAISC:

f=165（Mpa）/（101.8Mpa）=1.62。

Fig13Max.principalstressonmanhole2

Fig14Min.principalstressonmanhole2

3.4Fatiguestressarounddischargedhole

Forthesymmetricalcharacteristicsoftheholeinthedischargedpart,thisreportjuststudiesoneholewiththesamepositionofmanhole1ofeveryhourposition.

Forthedischargedhole,theworstprincipalstressrangeoccursontheedgeofinsideshellbetween

maxat4h=45.5Mpaand

minat10h=-14.7Mpa（Fig15-16）.Thus,stressrange

=45.5-（-14.7）=60.2Mpa.SafetyfactorwithrespecttoallowableinfinitelifecategoryAstressaccordingtoAISC:

=（165Mpa）/（60.2Mpa）=2.74

Fig15Max.principalstressondischargedhole

Fig16Min.principalstressondischargedhole

3.5Fatiguestressof“T”shapebuttjoint

Forthesymmetricalcharacteristicsofsliderring,takeonesideofthe“T”shapebuttjointinthepositionofinletendforexample.Theworstprincipalstressrangeoccursontheedgeofshellbetween

maxat1h=2.35Mpaand

minat3h=-9.5Mpa（Fig17-18）.Thus,stressrange

=2.35-（-9.5）=11.85Mpa.SafetyfactorwithrespecttoallowableinfinitelifecategoryAstressaccordingtoAISC:

=（165Mpa）/（11.85Mpa）=13.92

Fig17Max.principalstressof“T”shapebuttjoint

Fig18Min.principalstressof“T”shapebuttjoint

4Generalconlusions

1.Thesafetyfactorwithrespecttoyieldofmanholesandmainshell＝3.15whichmeetthestrengthrequirement.

2.Formanhole1,fatiguestressrange=81.3Mpa,safetyfactor=2.02;formanhole2,fatiguestressrange=101.8Mpa,safetyfactor=1.62;fordischargedhole,fatiguestressrange=60.2Mpa,safetyfactor=2.74.For“T”shapebuttjoint,fatiguestressrange=11.85Mpa,safetyfactor=13.92.Thefatiguestrengthofmanholesmeetdesignrequirement.

3.Themaximumstressondrivingtube=17.6Mpa,consideringthestartuptorque2.5timesgreater,safetyfactor=4.54，whicharesafeenough.

4.ThemaximumVonMisesstressofbearingpads=7.57Mpa.ThemaximumVonMisesstressofthecontactsurfaceofsliderring=10.0Mpa.

Inaword,thedesignofmillmeetsstaticandfatiguerequirement.