搅拌机外文翻译

ComparingmixingperformanceofuniaxialandbiaxialbinblendersAmitMehrotra,FernandoJ.MuzzioDepartmentofChemicalandBiochemicalEngineering,RutgersUniversity,Piscataway,NJ,08855,UnitedStatesAbstractThedynamicsinvolvedinpowdermixingremainsatopicofinterestformanyresearchers;howeverthetheorystillremainsunderdeveloped.Mostofthemixersarestilldesignedandscaleduponempiricalbasis.Inmanyindustries,includingpharmaceutical,themajorityofblendingisperformedusing“tumblingmixers”.Tumblingmixersarehollowcontainerswhicharepartiallyloadedwithmaterialsandrotatedforsomenumberofrevolutions.Somecommonexamplesincludehorizontaldrummixers,v-blenders,doubleconeblendersandbinblenders.Inallthesemixerswhilehomogenizationinthedirectionofrotationisfast,mediatedbyaconvectivemixingprocess,mixinginthehorizontal(axial)direction,drivenbyadispersiveprocess,isoftenmuchslower.Inthispaper,weexperimentallyinvestigateanewtumblingmixerthatrotateswithrespecttotwoaxes:ahorizontalaxis(tumblingmotion),andacentralsymmetryaxis(spinningmotion).Adetailedstudyisconductedonmixingperformanceofpowdersandtheeffectofcriticalfundamentalparametersincludingblendergeometry,speed,filllevel,presenceofbaffles,loadingpattern,andaxisofrotation.InthisworkAcetaminophenisusedastheactivepharmaceuticalingredientandtheformulationcontainscommonlyusedexcipientssuchasAvicelandLactose.Themixingefficiencyischaracterizedbyextractingsamplesafterpre-determinednumberofrevolutions,andanalyzingthemusingNearInfraredSpectroscopytodeterminecompositionaldistribution.Resultsshowtheimportanceofprocessvariablesincludingtheaxisofrotationonhomogeneityofpowderblends.1.IntroductionParticleblendingisarequiredstepinavarietyofapplicationsspanningtheceramic,food,glass,metallurgical,polymers,andpharmaceuticalsindustries.Despitethelonghistoryofdrysolidsmixing(orperhapsbecauseofit),comparativelylittleisknownofthemechanismsinvolved[1–3].Acommontypeofbatchindustrialmixeristhetumblingblender,wheregrainsflowbyacombinationofgravityandvesselrotation.Althoughthetumblingblenderisaverycommondevice,mixingandsegregationmechanismsinthesedevicesarenotfullyunderstoodandthedesignofblendingequipmentislargelybasedonempiricalmethods.Tumblersarethemostcommonbatchmixersinindustry,andalsofinduseinmyriadofapplicationasdryers,kilns,coaters,millsandgranulators[4–8].Whilefree-flowingmaterialsinrotatingdrumshavebeenextensivelystudied[9,10],cohesivegranularflowsinthesesystemsarestillnotcompletelyunderstood.Littleisknownabouttheeffectoffundamentalparameterssuchasblendergeometry,speed,filllevel,presenceofbaffles,loadingpatternandaxisofrotationonmixingperformanceofcohesivepowdersorthescalingrequirementsofthedevices.However,conventionaltumblers,rotatingaroundahorizontalaxis,allshareanimportantcharacteristic:whilehomogenizationinthedirectionofrotationisfast,mediatedbyaconvectivemixingprocess,mixinginthehorizontal(axial)direction,drivenbyadispersiveprocess,isoftenmuchslower.Inthispaper,weexperimentallyinvestigateanewtumblingmixerthatrotateswithrespecttotwoaxes:ahorizontalaxis(tumblingmotion),andacentralsymmetryaxis(spinningmotion).Weexaminetheeffectsoffilllevel,mixingtime,loadingpatternandaxisofrotationonthemixingperformanceofafree-flowingmatrixofFastFlolactoseandAvicel102,containingamoderatelycohesiveAPI,micronizedAcetaminophen.WeuseextensivesamplingtocharacterizemixingbytrackingtheevolutionofAcetaminophenhomogeneityusingaNearInfraredspectroscopydetectionmethod.AftermaterialsandmethodsaredescribedinSection2,resultsarepresentedinSection3,followedbyconclusionsandrecommendations,whicharepresentedinSection4.2.MaterialsandmethodsThematerialsusedinthestudyarelistedinTable1,alongwiththeirsizeandmorphology.Acetaminophenisblendedwithcommonlyusedexcipientsandisusedasatracertoevaluatethedegreeofhomogeneityachievedasafunctionofnumberofrevolutions.Acetaminophenisoneofthedrugsmostwidelyusedinmixingstudies,andAvicelandLactosearecommonlyusedpharmaceuticaexcipients.IntheinterestofbrevitytheirSEMimagesarenotincludedinthispaper,butcanbefoundin“HandbookofPharmaceuticalexcipients”.2.1.NearinfraredspectroscopyAcetaminophenhomogeneitywasquantifiedusingnearinfraredspectroscopy.Acalibrationcurvewasconstructedforapowdermixturecontaining(inaverage)35%avicelPH102,62%lactoseand3%acetaminophen.Nearinfrared(NIR)spectroscopycanbeausefultooltocharacterizeacetaminophen.SamplesarepreparedbykeepingtheratioofAviceltolactoserandomizedinordertominimizeeffectsofimperfectblendingofexcipientsduringtheactualexperimentsontheaccuracyoftheresults.TheRapidContentAnalyzerinstrumentmanufacturedbyFOSSNIRSystems(SilverSpring,MD)andVisionsoftware(version2.1)isusedfortheanalysis.Thesamplesarepreparedbyweighing1gofmixtureintoseparateopticalscintillationvials;(KimbleGlassInc.Vineland,NJ)usingabalancewithanaccuracyof±0.01mg.Near-IRspectraarecollectedbyscanningintherange1116–2482nminthereflectancemode.Partialleastsquare(PLS)regressionisusedincalibrationmodeldevelopmentusingthesecondderivativemathematicalpretreatmenttominimizetheparticlesizeeffects.AsshowninFig.1,excellentagreementisachievedbetweenthec