水污染控制工程03 污水的物理处理（physical treatment of wastewater 03 in water pollution control engineering）

水污染控制工程03污水的物理处理（PHYSICALTREATMENTOFWASTEWATER03INWATERPOLLUTIONCONTROLENGINEERING）THETHIRDCHAPTERISTHEPHYSICALTREATMENTOFSEWAGESECTION1GRILLESANDSCREENSTHESECONDSECTIONISTHEBASICTHEORYOFSEDIMENTATIONTHIRDIDEALSETTLINGTANKFOURTHSECTIONGRITCHAMBERFIFTHSECTIONSETTLINGTANKSIXTHSECTIONREGULATINGTANKSECTION1GRILLESANDSCREENSSELECTTHEORIGINALSPACINGOFTHEGRIDBARSNOCLOGGINGOFPUMPANDWATERPROCESSINGEQUIPMENTATTHEPLANTANDSTATIONTHEGRILLEISMADEUPOFASETOFPARALLELMETALBARSANDFRAMES,WHICHAREINSTALLEDATTHEINLETOFTHEWATERINLETORTHEINLETOFTHEWATERCOLLECTINGSTATIONTOINTERCEPTTHELARGESUSPENDEDPARTICLESANDIMPURITIESINTHESEWAGEEFFECTSREMOVETHELARGERSUSPENDEDMATERIALTHATMAYCLOGTHEPUMPUNITANDTHEPIPEVALVE,ANDENSURETHENORMALOPERATIONOFTHESUBSEQUENTHANDLINGFACILITIESTHEAMOUNTOFPOLLUTANTSTRAPPEDINTHEGRILLEANDTHECONDITIONSOFTHEAREA,SEWAGEDITCHESTHETYPEOFTHESYSTEMISRELATEDTOTHEDISCHARGEOFTHESEWAGEANDTHESPACINGOFTHEGRIDBARS,SOMEDATATHATCANBEREFERENCEDWHENTHEBARSPACINGIS1625MM,THEGATESLAGREJECTIONIS010005M3/103M3SEWAGEWHENTHEBARSPACINGISABOUT40MM,THEGATESLAGREJECTIONIS003001M3/103M3SEWAGETHEMOISTURECONTENTOFTHEGATESLAGISABOUT80,ANDTHEDENSITYISABOUT960KG/M3METHODFORCLEANINGSLAGOFGRILLEGRILLEBARSECTIONSHAPEBYPASSCHANNELFLOWVELOCITYOFWATERSEWAGEBARRIERSTRIPSPACINGVELOCITYGRILLEBARSECTIONSHAPEBYPASSCHANNELFLOWVELOCITYOFWATERSEWAGEBARRIERSTRIPSPACINGVELOCITYGRILLEBARSECTIONSHAPEBYPASSCHANNELFLOWVELOCITYOFWATERSEWAGEBARRIERSTRIPSPACINGVELOCITYXGTYPEROTARYGRILLECLEANINGMACHINEROTARYSOLIDLIQUIDSEPARATORGLTYPEGRILLEDECONTAMINATIONMACHINERAKETYPEGRILLECLEANINGMACHINEFINEGRILLEOFAERATIONGRITTANKDESIGNANDCALCULATIONOFGRATINGCALCULATIONOFHEADLOSSH2THROUGHTHEGRILLEFORMULAH0CALCULATIONOFHEADLOSS,MVTHEVELOCITYOFTHESEWAGETHROUGHTHEGRILLE,M/SZETADRAGCOEFFICIENT,THEVALUEANDTHEGEOMETRYOFTHEBARSECTIONPLACEMENTANGLEOFTHEGRILLEGGRAVITATIONALACCELERATION,M/S2KTAKINGINTOACCOUNTTHECOEFFICIENTOFRESISTANCEINCREASEWHENTHEGRILLEISBLOCKEDBYCONTAMINANTS,AVAILABLEK336V132,USUALLYK3MUNICIPALSEWAGEGENERALLYTAKE0104MDESIGNANDCALCULATIONOFGRATINGBUILDINGDIMENSIONSOFGRATINGS1THECLEARANCENUMBEROFTHEGRILLENMEDIUMQVMAXMAXIMUMDESIGNSTREAMVOLUME,M3/SDBARSPACING,MHTHEDEPTHOFTHEGRID,MVTHESEWAGEFLOWSTHROUGHTHEGRILLESPEED,M/SBUILDINGDIMENSIONSOFGRATINGS4THETOTALCONSTRUCTIONLENGTHOFTHEGRIDLTYPEL1WATERINLETGRADUALLYWIDERPARTSLENGTH,MOFWHICHB1INLETCHANNELWIDTHMALPHA1THEINLETCHANNELBECOMESWIDERTHEEXPANSIONANGLEISGENERALLYALPHA120DEGREESL2THEGRILLEISCONNECTEDTOTHEOUTLETCHANNELTHELENGTHOFTHENARROWERPARTOFTHEJOINTL205L1H1THEDEPTHOFTHECHANNELBEFORETHEGRILLE,MEFFECTUSEDFORWASTEWATERTREATMENTORRECOVERYOFSHORTFIBERSFORMVIBRATIONSCREENHYDRAULICSCREENSTATIONARYSCREENLANDFILLINCINERATIONABOVE820DEGREESCELSIUSCOMPOSTTHESLAGISCRUSHEDANDTHENRETURNEDTOTHEWASTEWATERSINKSOLIDSINTOPRIMARYCLARIFIERDISPOSALMETHODFORPOLLUTANTTRAPPEDBYGRILLEANDSCREENMESHTHESECONDSECTIONISTHEBASICTHEORYOFSEDIMENTATIONSEDIMENTATIONISTHEUSEOFSUSPENDEDPARTICLESINWATERFORSETTLINGPROPERTIESATGRAVITYAPROCESSTHATPRODUCESASINKINGACTIONTOACHIEVESOLIDLIQUIDSEPARATIONFOURUSESOFPRECIPITATIONTREATMENTPROCESSACCORDINGTOTHECOHESIONANDCONCENTRATIONOFSUSPENDEDPARTICLESINWATER,PRECIPITATIONCANBEDIVIDEDINTOFOURTYPESFREEPRECIPITATIONANDITSTHEORETICALBASISBRANCHANALYSISTHEFALSESETTHEFORCEOFSUSPENDEDPARTICLESINWATERGRAVITY,BUOYANCYWHENGRAVITYISGREATERTHANBUOYANCY,ITSINKSWHENGRAVITYEQUALSBUOYANCY,RELATIVESTILLNESSWHENGRAVITYISLESSTHANBUOYANCY,FLOATUP1SUSPENDEDPARTICLESRECEIVEDINWATERFGFGISTHEPRECIPITATINGFORCE,ITISTHEGRAVITYOFPARTICLESANDTHEBUOYANCYOFWATERPOORFORMULAFGTHEPARTICLESINTHEWATEREXERTIONVTHEVOLUMEOFPARTICLESPPARTICLEDENSITYSPL,THEDENSITYOFWATERGGRAVITYACCELERATIONFORCEANALYSISOFSUSPENDEDPARTICLESINWATERAFORMULAFORSETTLINGVELOCITYOFFREESETTLINGOFSPHERICALPARTICLESWHENTHEEXTERNALFORCEOFTHEPARTICLEISBALANCED,THESETTLINGVELOCITYFORMULAFORSPHERICALPARTICLESWITHFREEPRECIPITATIONWHENTHEFLOWVELOCITYAROUNDTHESETTLEMENTOFSMALLPARTICLESIZE,SETTLINGVELOCITY,SMALLPARTICLESDURINGTHEHOURAROUNDALSO,THEVISCOUSRESISTANCEEFFECTOFPARTICLESAREMAINLYAFFECTEDBYWATER,THEINERTIAFORCECANBENEGLECTED,THEPARTICLEMOTIONISINLAMINARFLOWINLAMINARFLOW,THEEQUATIONOFMOTIONOFAFREEPARTICLEINSTILLWATERALSOKNOWNASSTOKESSLAWISFORMULATEDINTHELAMBDA24/REFORMULATHEKINETICVISCOSITYOFMUWATERFROMTHEABOVEFORMULA,THEPARTICLESEDIMENTATIONRATEUSISRELATEDTOTHEFOLLOWINGFACTORSWHENTHESISGREATERTHANPPL,PS,PLPOSITIVEGRANULESBYUSSINKWHENPSANDPLISEQUALTOUS0,ASTATEOFSUSPENDEDPARTICLESINTHEWATER,THEPARTICLESCANNOTBEUSEDTOPRECIPITATEANDREMOVESISLESSTHANPPL,PS,PLISNEGATIVE,USPARTICLESTOFLOATTHEMETHODTOREMOVETHEAVAILABLEFLOATUSISPROPORTIONALTOTHESQUAREOFTHEPARTICLEDIAMETERD,SOINCREASINGTHEPARTICLEDIAMETERISHELPFULTOIMPROVETHEPRECIPITATIONVELOCITYORFLOATINGVELOCITYANDIMPROVETHEREMOVALEFFICIENCYUSISINVERSELYPROPORTIONALTOMU,ANDDECREASESWITHTHEINCREASEOFWATERTEMPERATURETHATISTOSAY,THESETTLINGVELOCITYISAFFECTEDBYWATERTEMPERATURE,THEWATERTEMPERATURERISES,ANDTHESETTLINGVELOCITYINCREASESTHIRDIDEALSETTLINGTANKTHEWORKINGPRINCIPLEOFSEDIMENTATIONTANKIDEALSETTLINGTANKDIVIDEINTOIMPORTAREAS,PRECIPITATIONAREAS,EXPO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CAUSETHEAERATIONANDWATERTHESPIRALEFFECTOFSEWAGEINTHESUSPENDEDPARTICLECOLLISIONANDFRICTION,ANDBYTHEEROSIONOFRISINGBUBBLES,THEADHESIONOFORGANICPOLLUTANTSINTHESANDTOREMOVEHEAVYSANDATTHEBOTTOMOFTHEPOOLISPURE,ORGANICCONTENTISONLYABOUT5,LONGTERMHOLDDOESNOTDECAYAERATEDSANDSINKTHEHORIZONTALVELOCITYISUSUALLY008012M/STHERETENTIONTIMEOFSEWAGEINTHETANKIS46MINTHEMAXIMUMFLOWRATEINRAINYDAYSIS13MINASAPREAERATION,THERESIDENCETIMEIS1030MINTHEEFFECTIVEWATERDEPTHOFTHETANKIS23M,ANDTHERATIOOFTHEPOOLWIDTHTOTHETANKDEPTHIS115,ANDTHEASPECTRATIOOFTHETANKCANREACH5WHENTHEASPECTRATIOISGREATERTHAN5,THETRANSVERSEBAFFLESHOULDBECONSIDEREDTHEAERATIONGRITTANKADOPTSPERFORATEDTUBEAERATION,THEHOLEDIAMETERIS2560MM,THEDISTANCEFROMTHEBOTTOMOFTHETANKISABOUT0609M,ANDTHEREGULATINGVALVESHOULDBEPROVIDEDAERATEDGRITCHAMBERSHAPEASFARASPOSSIBLENOTTOINFLUENCEANDDEADINTHESANDTANKSHOULDBEINSTALLEDABOVETHEVERTICALBAFFLE,IMPORTANDEXPORTARRANGEMENT,SHOULDPREVENTTHEGENERATIONOFSHORTFLOWDESIGNPARAMETERSOFAERATEDGRITCHAMBERFIFTHSECTIONSETTLINGTANKSEDIMENTATIONTANKSEDIMENTATIONTANKTHREEKINDSOFFLOWREGIMEINSEDIMENTATIONTANKADVECTIONTYPEVERTICALFLOWTYPERADIALCHARACTERISTICSANDAPPLICABLECONDITIONSOFSEDIMENTATIONTANKPOOLTYPEADVANTAGESHORTCOMINGAPPLICABLECONDITIONADVECTIONTYPE1IMPACTLOADINGANDTEMPERATUREDEGREEOFADAPTATIONSTRONGFORCE2SIMPLECONSTRUCTION,LOWCOSTTHEUSEOFMULTIBUCKETSLUDGE,EACHBUCKETNEEDSSEPARATEMUDPIPE,EACHROWSLUDGE,HEAVYWORKLOAD,THEUSEOFMECHANICALMUD,MECHANICALEQUIPMENTANDDRIVINGPARTSAREIMMERSEDINWATER,EASYTORUST1SUITABLEFORAREASWITHHIGHUNDERGROUNDWATERLEVELANDPOORGEOLOGY2,SUITABLEFORLARGE,MEDIUMANDSMALLSEWAGETREATMENTPLANTSVERTICALFLOWTYPE1ROWSOFMUDCONVENIENT,SIMPLEMANAGEMENT2,SMALLFOOTPRINT1POOLDEPTH,DIFFICULTCONSTRUCTION2,THEABILITYTOADAPTTOSHOCKLOADINGANDTEMPERATURECHANGESISPOOR3HIGHERCOST4,THEPOOLDIAMETERSHOULDNOTBETOOLARGETHEUTILITYMODELISSUITABLEFORSMALLSEWAGETREATMENTPLANTSWITHLITTLEWATERTREATMENTRADIAL1,THEUSEOFMECHANICALSLUDGEDISCHARGE,BETTEROPERATION,MANAGEMENTISSIMPLETHE2ROWOFSLUDGEEQUIPMENTHASESTABLISHEDPRODUCTS1THEFLOWOFWATERISUNSTABLE2MECHANICALSLUDGEDISCHARGEEQUIPMENTISCOMPLEXANDREQUIRESHIGHERCONSTRUCTIONQUALITY1SUITABLEFORAREASWITHHIGHUNDERGROUNDWATERTABLE2,SUITABLEFORLARGEANDMEDIUMSIZEDSEWAGETREATMENTPLANTSTHESEDIMENTATIONTANKCONSISTSOFFIVEPARTSTHEFUNCTIONOFTHEINLETANDOUTLETISTOKEEPTHEFLOWINANDOUTSTABLESOASTOIMPROVETHESEDIMENTATIONEFFICIENCYTHESETTLINGZONEISTHEPRIMARYSITEFORPRECIPITATIONSTORAGE,CONCENTRATIONANDDISCHARGEOFSLUDGEINSLUDGESTORAGEAREATHEBUFFERPREVENTSWATERFROMFLOWINGAWAYFROMTHESLUDGEATTHEBOTTOMOFTHEPOOLTHESEDIMENTATIONTANKCONSISTSOFFIVEPARTSOPERATIONMODEOFSEDIMENTATIONTANK1DESIGNFLOWTHEDESIGNFLOWOFTHESEDIMENTATIONTANKISTHESAMEASTHEDESIGNFLOWOFTHEGRITCHAMBERINTHESEWAGETREATMENTSYSTEMOFCOMBINEDSEWERSYSTEM,WHENTHEWASTEWATERFLOWSINTOTHESEDIMENTATIONTANK,THEMAXIMUMFLOWSHOULDBETAKENASTHEDESIGNFLOWWHENTHEPUMPISLIFTED,THEMAXIMUMCOMBINEDFLOWOFTHEPUMPSHOULDBETAKENASTHEDESIGNFLOWINTHECOMBINEDSYSTEM,THEDESIGNFLOWSHOULDBECHECKEDACCORDINGTOTHERAINFALL,BUTTHESETTLINGTIMESHOULDBENOLESSTHAN30MIN2THENUMBEROFSETTLINGTANKSFORMUNICIPALWASTEWATERTREATMENTPLANTS,THENUMBEROFSETTLINGTANKSSHOULDNOTBELESSTHAN23EMPIRICALDESIGNPARAMETERSOFSEDIMENTATIONTANKSFORMUNICIPALSEWAGETREATMENTPLANTS,SUCHASNOSEWAGESEDIMENTATIONPERFORMANCEOFTHEMEASUREDDATA,YOUCANREFERTOTHETEXTBOOKTABLE108EMPIRICALPARAMETERSSELECTED4THERELATIONSHIPBETWEENEFFECTIVEWATERDEPTH,SETTLINGTIMEANDSURFACEHYDRAULICLOADOFSEDIMENTATIONTANKSEETABLE109GENERALDESIGNPRINCIPLESANDPARAMETERSOFSEDIMENTATIONTANKS5GEOMETRYSIZEOFSEDIMENTATIONTANKTHEHEIGHTOFTHETANKISNOLESSTHAN03MTHEBUFFERHEIGHTIS0305MTHEINCLINATIONOFTHEINCLINEDWALLOFTHEBUCKETBUCKETSHOULDNOTBELESSTHAN60THEBUCKETSHALLNOTBELESSTHAN55THEDIAMETEROFTHESLUDGEPIPEISNOTLESSTHAN200MM6SEDIMENTATIONTANKEFFLUENTSECTIONWEIRFLOWISGENERALLYUSEDANDKEPTLEVELATWEIRLEVELDISCHARGEWEIRLOADFORTHEINITIALSETTLEMENTTANKSHOULDBENOMORETHAN29L/SMFORTHETWOSEDIMENTATIONTANK,GENERALLYTAKE1529L/SMAMULTITANKOUTLETARRANGEMENTCANALSOBEADOPTEDTOIMPROVETHEEFFLUENTQUALITY7THECAPACITYOFTHEHOPPERGENERALLYCALCULATEDACCORDINGTONOMORETHAN2DOFTHEAMOUNTOFSLUDGEFORTHETWOSETTLINGTANK,THESTORAGETIMESHALLBENOMORETHAN2H8ROWSOFMUDTHESEDIMENTATIONTANKGENERALLYADOPTSHYDROSTATICPRESSUREMUDASFOLLOWSFIRST,THEHYDROSTATICPRESSURENUMERICALSEDIMENTATIONTANKSHALLNOTBELESSTHAN1471KPA15MH2OACTIVATEDSLUDGETWOSEDIMENTATIONTANKSHALLNOTBELESSTHAN883KPA09MH2OBIOFILMTWOSEDIMENTATIONTANKSHALLNOTBELESSTHAN1177KPA12MH2OGENERALDESIGNPRINCIPLESANDPARAMETERSOFSEDIMENTATIONTANKSADVECTIONSEDIMENTATIONTANKTHEWATERINLETISPROVIDEDWITHRECTIFICATIONMEASURESTOENSURETHATTHEINFLOWSEWAGEENTERSTHESEDIMENTATIONTANKEVENLYANDSTABLYTHEEFFLUENTAREAISPROVIDEDWITHAWEIRTOCONTROLTHEHEIGHTOFTHEWATERSURFACEINTHESEDIMENTATIONTANK,SOASTOENSURETHEUNIFORMDISTRIBUTIONOFTHEFLOWINTHESEDIMENTATIONTANKTHESEDIMENTATIONTANKSHOULDBEEQUALTOTHEDISCHARGEVOLUMEALONGTHEUNITLENGTHOFTHEENTIREWEIRFORTHEPRIMARYSETTLINGTANK,ITISGENERALLY250M3/MD,ANDTHETWOSETTLINGTANKIS130250M3/MDTHEMOSTCOMMONAPPLICATIONOFSAWTOOTHSHAPEDTRIANGULARWEIRISTHATTHEWATERSURFACESHOULDBEAT1/2OFTHETOOTHHEIGHTINORDERTOADAPTTOTHECHANGESOFTHEWATERFLOWORUNEVENSETTLEMENTOFTHESTRUCTURE,AREGULATINGDEVICEWHICHCANMAKETHEWEIRBOARDMOVEUPANDDOWNISREQUIREDATTHEWEIRMOUTH,SOASTOMAKETHEOUTLETWEIRLEVELASHIGHASPOSSIBLETHEWEIRSHALLBEPROVIDEDWITHABAFFLETOPREVENTFLOATINGOBJECTSORTOSETUPSCUMCOLLECTINGANDREMOVINGDEVICESMULTIBUCKETSEDIMENTATIONTANK,NOMECHANICALMUDSCRAPINGEQUIPMENTEACHSLUDGEHOPPERISPROVIDEDWITHASLUDGEDISCHARGINGPIPESEPARATELY,ANDEACHSLUDGEISSEPARATELYDISCHARGEDWITHOUTINTERFERENCE,THEREBYENSURINGTHECONCENTRATIONOFTHESLUDGESTRUCTUREANDWORKINGCHARACTERISTICSOFFLATFLOWSEDIMENTATIONTANKSTRUCTUREANDWORKINGCHARACTERISTICSOFFLATFLOWSEDIMENTATIONTANKTHESTRUCTUREANDWORKINGCHARACTERISTICSOFADVECTIONSEDIMENTATIONTANKINFLUENTTHESTRUCTUREANDWORKINGCHARACTERISTICSOFFLATFLOWSEDIMENTATIONTANKEFFLUENT3SEDIMENTATIONAREAEFFECTIVEVOLUMEV1OR4SEDIMENTATIONTANKLENGTHLMEDIUMVMAXIMUMDESIGNFLOWOFWATERFLATFLOWRATEOFMM/SGENERALLYNOTGREATERTHAN5MM/S5TOTALWIDTHOFSEDIMENTATIONTANKBDESIGNOFFLATFLOWSEDIMENTATIONTANK7SLUDGEVOLUMEFORDOMESTICSEWAGE,THETOTALSLUDGEAREAVOLUMEVFORMULASTHEAMOUNTOFSLUDGEPERPERSONPERDAY,L/D,MANCANREFERTOTHETEACHINGMATERIALTABLE108NDESIGNPOPULATION,PEOPLETSLUDGESTORAGETIME,DDESIGNOFFLATFLOWSEDIMENTATIONTANKDESIGNOFFLATFLOWSEDIMENTATIONTANK9CAPACITYOFSLUDGEHOPPERV1TYPES1THETOPAREAOFSLUDGEHOPPER,M2S2THEBOTTOMAREAOFTHESLUDGEHOPPER,M2TENSLUDGEHOPPERABOVETRAPEZOIDALPARTOFSLUDGECAPACITYPRODUCTV2TYPEL1TRAPEZOID,BOTTOMSIDELENGTH,ML2TRAPEZOIDALBOTTOMLENGTH,MRADIALFLOWSEDIMENTATIONTANKRADIALFLOWSEDIMENTATIONTANKISALARGESEDIMENTATIONTANKWITHADIAMETEROF100MANDADEPTHOF1530MAROUNDTHEPOOLTHEREARETHECENTRALWATERINLET,THESURROUNDINGWATER,ZHOUJINZHOUOUT,ROTATINGARMWITHWATERANDOTHERFORMSTHEBOTTOMOFTHESLUDGESEDIMENTATIONANDGENERALLYUSETHESCRAPERSCRAPING,THERADIALFLOWSEDIMENTATIONTANK,THECOMMONLYUSEDMUDSCRAPINGMACHINEHASCENTRALTRANSMISSIONMUDSCRAPERMACHINEANDSUCTIONMACHINEANDDRIVINGTYPEMUDSCRAPERANDSUCTIONMACHINEETCTHESTRUCTUREANDCHARACTERISTICSOFRADIALFLOWSEDIMENTATIONTANKFLOWTYPESINKLAKEPOOLSECTIONNOODLESCENTRALINLETPERIPHERALINFLOWTHECROSSSECTIONOFTHEINLETISLARGER,ANDTHEHOLEATTHEBOTTOMOFTHETANKISSMALLER,ANDTHEHEADLOSSINTHEWATERDISTRIBUTIONISCONCENTRATEDONTHEORIFICE,SOTHEWATERDISTRIBUTIONISRELATIVELYUNIFORMTHEWATERBAFFLEALONGTHEDEPTHBELOWTHEWATERSURFACEATTHEDEPTHOFABOUT2/3AWAYFROMTHEINLETORIFICE,ALONGERDISTANCE,WHICHHELPSTOFURTHERDIVIDETHEFLOWEVENLYDISTRIBUTEDINTHECROSSSECTIONOFTHEFLOWINTOTHECANAL,ANDTHEWASTEWATERINTOTHESEDIMENTATIONZONEVELOCITYISMUCHSMALLER,ISCONDUCIVETOTHESEDIMENTATIONOFSUSPENDEDPARTICLESPERIPHERALINFLUENTRADIALFLOWSEDIMENTATIONTANKTHESTRUCTURALCHARACTERISTICSOFTHEINFLOWZONEVERTICALFLOWSEDIMENTATIONTANKTHEWORKINGPRINCIPLEOFAVERTICALFLOWSEDIMENTATIONTANKTHEPLANEOFTHEVERTICALFLOWSEDIMENTATIONTANKCANBEROUND,SQUAREORPOLYGONALTHEDEPTH,WIDTHDIAMETERRATIOOFAVERTICALFLOWSEDIMENTATIONTANKISGENERALLYNOMORETHAN3,USUALLY2THECENTRALPIPEOFTHEVERTICALFLOWSEDIMENTATIONTANKISSHOWNINTHEFOLLOWINGFIGURESTRUCTUREOFVERTICALFLOWSEDIMENTATI