Fluidization Characteristics of Nano Particles with the Assist of Stirrer

Fluidizationof ultrafine solidparticles iswidelyusedin a varietyofindustrial applicationsbecauseofitsunusualcapabilityofcontinuouspowderhandling, good mixing,large gassolidcontactarea,andveryhigh ratesofheatandmass transfer.As theparticlesizedecreases thecohesive forces betweenparticlesincreases.Therefore,fluidization of ultrafineparticles becomes much moredifficultas compared to thelargersizeparticlesanditneeds efficient method.In thepresentwork, the fluidizationexperimentswereconducted usingairas fluidizingmediaand SiO2, ZnO and Al2O3 nano particles, with a size ranging from 15 to 30 nmin2-dimensional fluidizedbedwiththe assist of stirrer.The fluidization behavior of the nanoparticle, including the fluidization regime, the minimum fluidization velocity, and the bed expansion are also investigated..The results showed that smoother fluidization was observed with increasing agitation speed, because the agglomeration and channeling were reduced by the mechanical agitation.Itwas found that with the assist of stirrer ,by increasing in the speed of stirrer initial bed voidage increased and terminal velocity and agglomerate diameter decreased.