简介:Ahigh-density,high-fluxcirculatingfluidizedbed(CFB)riser(100mminIDand10.614minheight)wasappliedinawiderangeofoperatingconditions(withsolidfluxesupto400kg/m2sandsuperficialgasvelocitiesupto12m/s)toexamineitsradialnon-uniformitydynamics.Thesolidsholdupwasdeterminedthroughtheuseofafiber-opticprobeat11axiallevels.Theresultsindicatedthatunderalloperatingconditions,thehighsuperficialgasvelocityandlowsolidfluxesmaintainedalowradialnon-uniformityindex(RNI).Thehigh-density/fluxCFBriserhadseveraluniquecharacteristics,sothatthepeakoftheradialsolidsholdupprofileoccurredatapositionwithr/R=0.8.TheRNIandsolidsholdupatthecross-sectionalpositionhadagoodlogarithmicrelationshipatthelow-densitycondition(withameansolidsholdupof<0.2),andtheRNIdecreasedwhenthemeansolidsholdupexceeded0.2.InvestigationofthedynamicsofstratifiedinjectionrevealedthatthefeedratiohadanimportanteffectonGsandonsolidsholdupdistribution.Anovel"<"shapedaxialsolidsholdupprofilewasfound.Gsdecreasedsharplywhentheup-flowfeedratioexceeded0.5,andRNIwaslowestwhentheup-flowfeedratiowas1.