Model for Calculation of Agglomerate Sizes of Nanoparticles in a Vibro‐fluidized Bed

Abstract

The behavior of SiO 2 nanoparticles and the effects of operating conditions on nanoparticle agglomerate sizes have been investigated under conditions created in a vibro-fluidized bed (VFB). The experimental results reveal that the vibrations imposed in the bed can suppress slugging and/or channeling, in contrast to conventional fluidization with upflow only. The vibrations imposed in the particle bed affect both the minimum fluidization velocity and the agglomerate size, both of which decrease with increases in the energy introduced to the bed by the vibrations. The effect of vibrations on the agglomeration in vibro-fluidized beds of nanoparticles depends on the critical vibration frequency corresponding to a minimum agglomerate size. Both the amplitude and the frequency of the applied vibrations have significant effects on the agglomerate size. The experimental results and the consequent analysis reveal that increasing levels of vibrations in the bed yields finer agglomerates. The Richardson-Zaki scaling law combined with Stokes law permits the prediction of agglomerate sizes and the extent of initial bed voidage. The average agglomerate sizes predicted are in good agreement with those determined experimentally.

Agglomerating Vibro-fluidization Behavior of Binary Nanoparticles Mixtures

“…Nam et al [5] developed a fractal analysis combined with a modified RichardsonZaki for prediction of agglomerate size of nanoparticle agglomerates. Wang et al [6] estimated agglomerate sizes of SiO 2 nanoparticles according to the Richardson-Zaki scaling law combined with Stokes law permits, and the average agglomerate sizes calculated were in agreement with those determined experimentally. Kaliyaperumal et al [2] determine the apparent minimum fluidization velocity from pressure drop signals by employing a novel technique, at the same time, using Richardson-Zaki equation to show agglomerate fluidization behavior.…”

An improved model for determining fractal structure of nano‐agglomerates

“…It was found that agglomerate structure properties are insensitive to the R-Z exponent, whereas the minimum fluidization velocity is sensitive to this parameter. [7] Present work Nam et al [14] Zhu et al [7] Wang et al [36] R974 …”

Fluidization of Mixed SiO2 and TiO2 Nanoparticles with FCC Coarse Particles

“…Many methods were developed to improve the fluidization behavior of nanoparticles, for example, adding coarse particles to the bed [9][10][11] and introducing a magnetic field [12][13][14], acoustic field [15,16], or vibrating field [17][18][19]. Contrasted with other methods, the advantage of adding coarse particles is that it is unnecessary to get additional equipment or devices.…”