简介：Thebed-loadmovementandtheevolutionoftheChangjiang(Yangtze)EstuaryarestudiedbyusingthegeographicinformationsystemandtheremotesensingimageprocessingsoftwareAnalysisontheerosionandsiltationoftherivermouthisperformedfortheperiod1988-2000.Thepossiblelocationandthicknessofthefuturedepositionareasintheestuarinechannelsarepredicted.

简介：Thefluidized-bedpolymerizationprocesshasbeeninusefordecades.Fromthemanufacturer'sperspectiveitisdesirabletoimprovetechnologywithoutmajormodificationofthereactorsystem.Therefore,inordertomeetthedemandfornewproductsormoreefficientreactoroperation,manufacturersprefertoimprovethecatalystsysteminthemostcosteffectivemanner.Usingpolypropyleneproductionasanexample,somerecentadvancesinfluidized-bedpolymerizationtechnologyarepresented.

简介：

简介：Mathematicalmodelsforpulsedfluidizationaresystematicallydiscussed.SeveralundeterminedconstitutiverelationshipsareincludedintheGeneralTwo-FluidModel(GTFM),theadjustableparametersofwhicharealwayschosenatwilltosomeextent.AlthoughtherearenoadjustableparametersintheBasicTwo-FluidModel(BTFM),itseigenvaluesarecomplexnumbersanditisill-posedforinitial-valueproblems.TheLocalEquilibriumModel(LEM),afurthersimplificationofBTFM,isdiscussedatlength.Althoughthemodelisverysimple,itishighlycapableofsimulatingcomplexprocessesinpulsedfluidizationoverabroadrangeofoperatingparameters,anditsnumericalresultswellfitexperimentalresultsinboththevariationofbedheightandthedistributionofparticleconcentrationasfluidizingvelocityvaries.

简介：Theslurry-bedhydrocrackingofKaramayVGOwithwater-solubledispersedcatalystwasstudiedandthecatalystafterbeingseparatedfromthereactionproductswasanalyzedbyusingLRS,XRDandXPStoidentifythecrystalstructureofthecatalyst.Inthispaper,thecatalyticfunctionsofmolybdenum,nickelandironwerestudiedrespectivelyduringtheslurry-phasehydrocrackingwhileusingdiphenylmethaneasthemodelcompoundandVGOfromKaramaycrudeasthefeedstock.Thetestresultsshowedthat,duringtheslurry-phasehydrocrackingofheavyoil,themetalsulfidesenteredintochemicalreactionswiththefreeradicalintermediateH·formedonthecatalystsurface.Thefree-radicalintermediateH·formedonthecatalystsurfacecouldreactwiththefree-radicalsofbigmoleculesandcouldsuppresscokedeposition.

简介：ResearchwascarriedoutattheUniversityofKarlsruheinthelast10yearstomodifyexistingformulasandimproveourknowledgeonthedeterminationofthestabilityofstreambedsconsistingofgravelsandstones.StreamsinthemiddlemountainregionwithtypicalslopesofI=0.05%to0.8%aswellasthosewithdistinctstep-poolstructuresandslopesofI＞4%andI≤10%wereinvestigated.MostoftheexperimentswereconductedintheTheodor-RehbockLaboratory.However,someoftheresultsthathadbeenobtainedunderlaboratoryconditionscouldbeverrifiedwithexistingfielddata.Inthefollowing,theresultsandformulasofpracticalimportancewillbeintroducedanddiscussed.

简介：Inthiswork,syngasmethanationoverNi-W/TiO2-SiO2catalystwasstudiedinafluidized-bedreactor(FBR)anditsperformancewascomparedwithafixed-bedreactor(FIXBR).Theeffectsofmainoperatingvariablesincludingfeedstockgasesspacevelocity,cokecontent,bedtemperatureandsulfur-tolerantstabilityof100hlifewereinvestigated.ThestructureofthecatalystswascharacterizedbyXRD,N2adsorptiondesorptionandTEM.Itisfoundthatundersamespacevelocityfrom5000h1to25000h1FBRgaveahigherCH4yield,lowercokecontent,andlowerbedtemperaturethanthoseobtainedinFIXBR.Ni-W/TiO2-SiO2catalystpossessedexcellentsulfur-tolerantstabilityonthefeedstockgaseslessthan500ppmH2SinFBR.ThecarbondepositsformedonthespentcatalystwereintheformofcarbonfibersinFBR,whileintheformofdenseaccumulationdistributionappearanceinFIXBR.

简介：3阶段的水动力学反的使流体化的床为不同液体和煤气的速度用低密度粒子试验性地被学习。水动力学特征学习了包括压力落下，最小的液体和气体使液化速度和阶段劫盗。用床压力坡度决定的最小的液体使液化速度，随气体的增加减少速度。液体劫盗沿着床高度增加的阶段劫盗表演的轴的侧面，而稳固的劫盗减少，击倒床。然而，煤气的劫盗在床上是几乎一致的。

简介：Gas-solidtwo-phaseflowinacirculatingfluidizedbed(CFB)isaffectedbyoperatingconditions(e.g.,superficialgasvelocity,solidsinventory),materialpropertiesandgeometricfactors,suchastheentryandexitconfiguration.Inparticular,thesuspensionsection,whichislocatedbetweentheriserbottomandthesolidsrecycleinlet,affectsthehydrodynamicsintherisersignificantly.However,thesuspensionsectionhasreceivedlessattentioncomparedwithothergeometricfactors.Mostcomputationalfluiddynamics(CFD)simulations,especiallytwo-dimensionalsimulationsdonottakethisfactorintoaccount.Weperformedthree-dimensional,full-loopCFDsimulationswithadragcoefficientthatwasdeterminedbytheenergy-minimizationmulti-scalemodel,andinvestigatedtheflowbehavioroftwoCFBswithdifferentsuspension-sectionlengths.ThesimulationresuitsrevealedthattheaxialprofilesofvoidageintheriserwithalongersuspensionsectionaremorelikelyS-shaped,whereasthosewithshortersuspensionsectionsdecayexponentially.ThedependencesofsolidsfluxonsolidsinventorydifferinthetwoCFBs.Ashortersuspensionsectionmayresultinasmoothtransitionfromdilutetodensetransportwithoutintermediateaccumulativechoki-ng,whereasaIongersuspensionsectionmayleadtoachokingtransition.Thesesimulationresultsarequalitativelyconsistentwiththeflowbehaviorsdescribedinliterature.

简介：Athree-dimensionalgeometricmodeloftheoxidativecouplingofmethane(OCM)packed-bedreactorloadedwithNa2WO4-Mn/SiO2particulatecatalystwassetup,andanimprovedStanschkineticmodelwasestablishedtocalculatetheOCMreactionsusingthecomputationalfluiddynamicsmethodandFluentsoftware.Thesimulationconditionswerecompletelythesamewiththeexperimentalconditionsthatthevolumevelocityofthereactantwas80mL/minunderstandardstate,theratioofCH4/O2was3,thetemperatureandpressurewere800°Cand1atm,respectively.Thecontourofthecharacteristicsparametersinthecatalystbedwasanalyzed,suchasthespeciesmassfractions,temperature,theheatfluxonsidewallsurface,pressure,fluiddensityandvelocity.TheresultsshowedthatthecalculatedvaluesmatchedwellwiththeexperimentalvaluesontheconversionofCH4andtheselectivitytoproducts(C2H6,C2H4,CO2,CO)inthereactoroutletwithanerrorrangeof±2%.ThemassfractionsofCH4andO2decreasedfrom0.6and0.4inthecatalystbedinletto0.436and0.142intheoutlet,wherethemassfractionsofC2H6,C2H4,COandCO2were0.035,0.061,0.032and0.106,respectively.Duetotheexistenceoflaminarboundarylayer,thecontoursofeachcomponentbentupwardsinthevicinityoftheboundarylayer.ThisOCMreactionwasvolumeincreasereactionandthetotalmolesofproductsweregreaterthanthoseofreactants.Theflowfieldinthecatalystbedmaintainedconstanttemperatureandpressure.Thefluiddensitydecreasedgraduallyfrom2.28kg/m3intheinletofthecatalystbedto2.22kg/m3intheoutletofthecatalystbed,whilethevelocityincreasedfrom0.108m/sto0.115m/s.

简介：单个粒子的动态行为在在一张煤气的使流体化的床上的粒子混合物的混合/分离的过程期间被分析。分析基于从分离粒子模拟产生的结果，与轨道和对单个粒子起作用的力量的焦点。典型粒子被选择代表三种粒子运动：开始在床并且最后的底部部分的一个漂浮物粒子在床的最高的部分使流体化；开始在床并且最后的最高的部分的一个投弃货物粒子在底部呆在床的使流体化de的层；并且间歇地正在加入顶的一个投弃货物粒子使流体化并且底部使流体化de的层。一个粒子的运动在宏观或全球的规模是混乱的，但是能很好以它的相互作用在显微镜的规模被解释的结果表演与另外的粒子，particlefluid相互作用力量，和本地流动结构强迫，接触调节。他们也为建立一个合适的方法连接在不同时间和长度规模产生并且当模特儿的信息加亮需要。

简介：Ａｎａｌｙｓｉｓｏｎｍｅｃｈａｎｉｓｍｏｆａｘｉａｌｄｒｉｆｔｉｎｇｏｆｃｙｌｉｎｄｅｒｗｏｒｋｐｉｅｃｅｏｎｗｅｌｄｉｎｇｒｏｌｌｅｒｂｅｄ￥ＳＨＥＮＦｅｎｇｇａｎｇ；ＰＡＮＸｉｄｅ；ＸＵＥＪｉｎａｎｄＷＡＨＧＺｈｅｎｇ（ＷｅｌｄｉｎｇＲｅｓｅａｒ...

简介：这篇论文论述实验室斜槽的结果流动速度上的银行植被和石子床的相互作用上的试验性的学习(首先在最大的速度的地点上，Umax)并且雷纳兹压力分布。结果表明在水表面下面的最大的速度的剧降直到在Umax之间的35%流动深度和差别，在水表面的速度面对墙上的植被是可观的。木头法律的地区从墙从多达15%流动深度和它不取决于的y/h=2改变距离。没有植被盖子，在在有墙上的植被盖子的一张石子床上的外部层的速度侧面的偏差比在一张石子床上的流动的盒子大得多。墙上的植被的存在把一致流动改变到不一致的流动。这个事实能被越过斜槽在不同距离在每侧面认为非线性的雷纳兹是压力分发和最大的速度的地点解释。在距离的雷纳兹压力分布从墙的0.02m有否定价值并且离开墙，他们改变在更高的地点与顶与特定的凸的形式拿积极价值的符号。为这研究的vonKarman经常的κ的一般水准等于0.16。基于κ=0.16，Clauser的方法和雷纳兹压力为决心是兼容的砍速度。

简介：Chinaisrichincoalbedmethane.Accordinglatestsurvey,coalbedmethanegasreserveswithaburyingdepthoffewerthan2000mamountto3600billibeingequalto45billiontonsofstandardcoalor35tonsofstandardoil.totheurymgonm3,billionNDRChasissuedthe11thFive-YearProgramforEx-ploitationandUtilizationofCoalBedMethaneinAugust.Itisplannedthattheproductionofmethanegaswillcomeupto10billionm3,andanindustrialsystemofexploitingand

简介：Withtherevisionofemissionstandards,deepdesulphurizationandDeNOXisneededincirculatingfluidizedbed(CFB)boilers.Theoperationofthefirstsetof300-MWCFBboilerpluslimestone/gypsumwetfluegasdesulphurization(FGD)systemintheworldshowsthatdeepdesulphurizationandDeNOXofCFBboilershashigherSO2removalefficiencyatalowerCa/Sratiocomparedwithtraditionalinnerdesulphurizationmode.Itcanmeettheincreasinglyrigidemissionstandards,andissuitableformorefuels.DeepdesulphurizationandDeNOXcanalsoachieveahighly-efficienthigh-temperatureCFBboilerthatcannotonlyachieveinnerdesulphurizationandlowNOXemission,butbenefitslow-grade,highsulfurcontentfuelsaswell.ResearchofdeepdesulphurizationandDeNOXwillbeadevelopingdirectionforCFBboilers.

简介：Adsorptionisoneofthewidelyusedprocessesinthechemicalindustryenvironmentalapplication.Ascomparedtomathematicalmodelsproposedtodescribebatchadsorptionintermsofisothermandkineticbehavior,insufficientmodelsareavailabletodescribeandpredictfixed-bedorcolumnadsorption,thoughthelatteroneisthemainoptioninpracticalapplication.Thepresentreviewfirstprovidesabriefsummaryonbasicconceptsandmathematicmodelstodescribethemasstransferandisothermbehaviorofbatchadsorption,whichdominatethecolumnadsorptionbehaviorinnature.Afterwards,thewidelyusedmodelsdevelopedtopredictthebreakthroughcurve,i.e.,thegeneralratemodels,lineardrivingforce(LDF)model,wavepropagationtheorymodel,constantpatternmodel,Clarkmodel,Thomasmodel,Bohart-Adamsmodel,Yoon-Nelsonmodel,Wangmodel,Wolborskamodel,andmodifieddose-responsemodel,arebrieflyintroducedfromthemechanismandmathematicalviewpoint.Theirbasiccharacteristics,includingtheadvantagesandinheritshortcomings,arealsodiscussed.Thisreviewcouldhelpthoseinterestedincolumnadsorptiontoreasonablychooseordevelopanaccurateandconvenientmodelfortheirstudyandpracticalapplication.

简介：Inthispaper,multifractalanalysistogetherwithwavelettransformmodulusmaxima(WTMM)methodisusedtoanalyzethefluctuatingsignalsofcirculatingfluidizedbed(CFB).Singularityspectrumshowsthatthegas-particleflowinCFBhasmultifractalcharacter.Motionbehavioroftheparticle-fluidsystemofCFBcanbedescribedbysingularityspectrum.Intermittencyindexcanbeusedtodeterminethetransitionofflowregimefromfastfluidizationtopneumaticconveying.

简介：Thestudyofbed-loadtransportisofgreatsignificancebothintheoryandinpractice.Thispaperdiscussesthesaltationofbed-loadsolidgrainsinflowingwater.Experimentsandtheoreticanalysishavebeenmadebymeansofhigh-speedphotographingandadvanceddataprocessingtechniquewithacombinedmethodbasedonmechanicalandstatisticaltheories.Itindicatesthatthesaltationisthemainformofthebed-loadtransportunderordinaryflowingconditions.Inthemeantime,takingsuecessivesaltationasthemod-elofbed-loadtransport,systematicanalysishasbeenmadewithregardtothekinematicpropertiesandmechanismofsaltation.ThestatisticalanalysisshowsthattheprobabilitydensityfunctionsoftherelativeheightandlengthofsaltationareinconformitywithΓ-typedistribution,whiletheprobabilitydensityfunc-tionsoftherelativevelocitiesofsaltationareinconformitywiththeGaussiandistribution.

简介：

简介：TuyerecokeprobingwasconductedattheBaosteelCorexPlantinordertogainabetterunderstandingofthestructureofthecharbedinthemeltergasifier(MG).Afterscreening,thespecimenswereobservedbyanopticalmicroscopetodeterminethemechanismofthecharbedformation.X-raydiffraction(XRD)wasusedtoclarifythedegreeofgraphitizationandinferthermalhistoryofcoke.Theresultsshowthattheamountofpowdercomingfromlumpcoalintheburdenismuchmorethanthatfromcoke.Basedonthis,measuresforimprovingthecharbed'spermeabilityareproposed.