Add Nano Particle Fluidization Of The Components

The fluidization behaviors of SiO₂,TiO₂ and ZnO nano-particles by adding coarse particles were investigated experimentally.Since plug, channeling and agglomerate can be oberseved with increasing superficial gas velocity in a conventional fluidized bed for these three nano-particles. However,the fluidization characteristic was improved by adding coarse particles,such as FCC,ordinary Al₂O₃ and heat-resistant Al₂O₃.The effects of the size and adding amount of these three additive particles on the fluidization behavior of nano-particles were investigated.The experimental results were also checked by using Richardson-Zaki equation.(1)The fluidization characteristic of SiO₂ nano-particles was greatly improved by adding 30%FCC.The minimum fluidized velocity decreased and the rate of bed expansion increased with increasing adding amount of FCC particles.SiO₂ nano-particles can also be fluidized by adding 40%ordinary Al₂O₃.The fluidization characteristic of SiO₂ nano-particles was not well improved until the adding amount of heat-resistant Al₂O₃ reach to 50%.(2)The fluidization characteristic of TiO₂ nano-particles was greatly improved by adding 30%FCC,ordinary Al₂O₃ and heat-resistant Al₂O₃ separately.And the fluidization quality of the mixture systems was improved with increasing adding amount of additive particles.(3)The fluidization quality is the best for these three additive particles size of 180-200 mesh under the same adding amount.R-Z equation analysis shows that the terminal velocity increases and bed expansion index of the mixture systems become large with increasing adding amount and decreasing size of additive particles.The result also shows that the fluidization characteristic of the mixture system is best by adding FCC particles.(4)The properties of FCC,ordinary Al₂O₃ and heat-resistant Al₂O₃ are all not well compatible with that of ZnO nano-particles.Plug and channeling could be observed in the bed at lower superficial gas velocity. The pressure drop and bed height fluctuated violently at higher superficial gas velocity,and the surface of the bed became extremely unstable.The fluidization characteristics of ZnO nano-particles can be improved by adding FCC,ordinary Al₂O₃ and heat-resistant Al₂O₃,but not very well.