ABSTRACT
KUNIAKI GOTOH* Department of Applied Chemistry, Okayama University, Tsushima-naka 3-1-1, Okayama 700-8530, Japan
The phenomenon causing removal is called resuspension. The resuspension phenomenon has been studied as one of the phenomena related to an aerosol pipe flow. Many experimental and theoretical studies have been reported (these are well summarized by Ziskind eta!. [1]). As it is expected that the adhesion force
betweentheparticleandthesolidsurfaceandtheforceinducedbythefluidare relatedtoresuspension,itisassumedthatparticlesareresuspendedwhenthe forceinducedbytheflowexceedstheadhesionforce[2].Accordingtothis model,aparticlehavingsmalleradhesionforcethantheforceinducedbytheflow shouldberesuspendedatonce.Asshownlater,however,thenumberofresuspendedparticlesgraduallyincreaseswithtime,eveniftheflowissteady.Thus, anothermodelassumingthattheflowfluctuationdictatesthemagnitudeofthe forceinducedbythef1owisproposed.Asthecausesforfluctuation,burstingmotionoff1uidparticlesinthevicinityofthesurface[3]orthevelocityfluctuation causedbyturbulence[4,5]areassumed.However,theintensityofthebursting motionortheflowfluctuationhasnotbeenunderstoodyet.Becauseofthis,the modelfortheresuspensionphenomenonhasnotbeenestablishedyet.
