Modeling for size reduction of agglomerates in nanoparticle fluidization

Matsuda, Satoru; Hatano, Hiroyuki; Muramoto, Tomoya; Tsutsumi, Atsushi

doi:10.1002/aic.10258

Cited by 75 publications

(66 citation statements)

References 18 publications

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“…Especially ABF type beds often require an assistance method to obtain proper fluidization; examples of such methods are electric fields, vibration, micro-jets, and sound waves. (Lepek et al, 2010;Matsuda et al, 2004;Quevedo et al, 2010;Zhu et al, 2004). Studies of nanoparticle fluidization are often limited to macroscopic properties (Huang et al, 2008;Tamadondar et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

An adhesive CFD‐DEM model for simulating nanoparticle agglomerate fluidization

et al. 2016

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Nanoparticle fluidization is an efficient technique to disperse and process nanoparticles. Previous studies show that nanoparticles are not fluidized individually, but as agglomerates with hierarchical fractal structures. In this study, an adhesive CFD-DEM (Computational Fluid Dynamics -Discrete Element Modelling) model is developed, in which we use the simple agglomerate as the discrete element, which are the building blocks of the larger complex agglomerates found in a fluidized bed. We show that both the particle contact model and drag force interaction in the conventional CFD-DEM model need modification for properly simulating fluidization of nanoparticle agglomerates. The contact model includes collision mechanisms of elastic-plastic, cohesive and viscoelastic forces, and the drag force is approximately corrected by a scale factor resulting from particle agglomeration. The model is tested for different cases, including the normal impact, response of angle, and fluidization. The simulation results are promising. With increasing particle cohesive force, the fluidized bed goes from a uniform fluid-like regime, to an agglomerate bubbling regime, and finally to defluidization. The current study provides a tool for gaining insights into the characteristics of nanoparticle fluidization.

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Section: Introductionmentioning

confidence: 99%

An adhesive CFD‐DEM model for simulating nanoparticle agglomerate fluidization

et al. 2016

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“…n the last two decades, the fluidization of nanoparticles has been one of the most important research interests in the area of nanoparticle handling and processing (Chaouki et al, 1985;Morooka et al, 1988;Iwadate and Horio, 1998;Wang et al, 1998Wang et al, , 2006Li et al, 1999;Li, 1999, 2000;Lu and Li, 2000;Matsuda et al, 2001Matsuda et al, , 2004Jung and Gidaspow, 2002;Yao et al, 2002;Watano et al, 2003;Mawatari et al, 2003a,b;Li and Tong, 2004;Nam et al, 2004;Zhu et al, 2004Zhu et al, , 2005Hakim et al, 2005;Yu et al, 2005;Jiradilok et al, 2006;Guo et al, 2006aGuo et al, ,b, 2007Gundogdu et al, 2007;Liu et al, 2007;Quevedo et al, 2007). Researchers have dealt with different aspects of nanoparticle fluidization, for example, the evaluation of agglomerate size via force and energy balance (Chaouki et al, 1985;Morooka et al, 1988;Iwadate and Horio, 1998;Li, 1999, 2000;Lu and Li, 2000;Mawatari et al, 2003a;Matsuda et al, 2004;Guo et al, 2007), hydrodynamic modelling of the phenomenon (Chaouki et al, 1985;Iwadate and Horio, 1998;Wang et al, 1998;Li et al, 1999;Jung and Gidaspow, 2002;…”

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confidence: 99%

An evaluation of the solid hold‐up distribution in a fluidized bed of nanoparticles using radioactive densitometry and fibre optics

2008

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An experimental study was conducted to assess the solid hold-up distribution in a fluidized bed of zirconia and aluminum nanoparticles. For this purpose, two different techniques, radioactive densitometry and fibre optic measurement, were used. The results showed that while the fluidization of these nanoparticles occurs in the agglomeration state, it performs homogeneously in terms of phase concentration. This matter is important especially when a polymerization reaction should take place uniformly on the surface of nanoparticles, where the monomer is the fluidizing gas. Both techniques presented uniform solid hold-up distribution over the cross-section, although the fibre optic method overestimated the overall solid concentration, which was obtained based on bed expansion results. The radioactive densitometry was, however, capable of properly predicting the phase concentration within the bed according to the bed expansion observation. Finally, the effect of bulk density on the fluidization of nanoparticles was discussed by comparing the fluidization of different types of particulate materials.On a mené uneétude expérimentale pourévaluer la distribution de rétention de solide dans un lit fluidisé de nano particules de zircon et d'aluminium.À cette fin, deux techniques différentes, la densimétrie radioactive et la mesure par fibres optiques, ontété utilisées. Les résultats montrent qu'alors que la fluidisation de ces nano particules survientà l'état d'agglomération, elle est relativement performante en termes de concentration de phase. Cet aspect est important, car une réaction de polymérisation devrait se produire uniformémentà la surface des nano particules, le monomèreétant le gaz fluidifiant. Les deux techniques ont mis enévidence une distribution de rétention de solide uniforme dans la section transversale, bien que la méthode par fibres optiques ait surestimé la concentration de solide globale, obtenueà partir des résultats d'expansion du lit. Cependant, la densimétrie radioactive est capable de prédire de manière correcte la concentration de phase dans le lit d'après l'observation de l'expansion de lit. Enfin, l'effet de la masse volumique apparente sur la fluidisation des nano particules est examiné en comparant la fluidisation de différents types de matériaux particulaires.

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“…FIGURE. 9 Comparison of the estimated agglomerate sizes and experimental data at B=3 mm for nanoparticles…”

Section: ˄3˅mentioning

confidence: 99%

“…In previous works, some focused on prediction of agglomerate sizes of micron size particles [5,[6][7][8], and another is for forced field, such as vibration filed [8][9][10] or sound field [11]. However, the work of estimating agglomerate sizes of non-magnetic nanoparticles prepared by liquid phase method in a magnetic fluidized bed (MFB) and a vibro-fluidized bed (VFB) by using energy balance model has not been reported so far.…”

Section: Introductionmentioning

confidence: 99%