Using flow perturbations to enhance mixing of dry powders in V-blenders

Brone, Dean; Wightman, Carolyn; Connor, Kevin; Alexander, Albert; Muzzio, Fernando J.; Robinson, P.

doi:10.1016/s0032-5910(96)03231-7

Cited by 44 publications

(18 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental techniques used in this study have been described in detail elsewhere (Wightman et al, 1995;1996;Brone et al, 1997); only a brief description is presented here. Custom-made disposable aluminum mixing vessels (American Aluminum Co., Mountainside, NJ) that were 76 mm in diameter, 153 mm long, and had a 90-degree angle between shells were used in all the experiments reported here.…”

Section: Methodsmentioning

confidence: 99%

“…In a previous communication, Brone et al (1997) showed that the main barrier to mixing in a V-blender is the axial flow of particles across the vertical plane of symmetry perpendicular to the axis of rotation; once particles cross the plane they are mixed relatively quickly within each shell. Due to the symmetric design of the V-blender, there is no inherent convective mechanism for the particles to cross the center of the vessel.…”

Section: Aiche Journalmentioning

confidence: 99%

See 1 more Smart Citation

Quantitative characterization of mixing of dry powders in V‐blenders

1998

Self Cite

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Section: Aiche Journalmentioning

confidence: 99%

Quantitative characterization of mixing of dry powders in V‐blenders

1998

Self Cite

View full text Add to dashboard Cite

“…Due to computational limitations, simulations are restricted to a much smaller number of particles than in previously communicated laboratory experiments (Wightman and Muzzio, 1997;Wightman et al, 1996). Hence, to allow closer comparison, additional experiments were carried out using modified conditions.…”

Section: Conditions/parametersmentioning

confidence: 99%

“…Powder processing has been recently characterized by chemical engineers as having a legacy of neglect (Ennis et al, 1994). Awareness of this neglect has motivated a recent resurgence of both experimental investigations (McCarthy et al, 1996;Hill and Kakalios, 1995;Brone et al, 1997) and theoretical approaches (Johnson et al, 1990;Edwards and Mounfield, 1996). It has become fashionable in a sense to study powders, not only because of their complexity but also because there is a growing need in industry to reliably manufacture high-quality products.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Simulation of flow and mixing of particles in a rotating and rocking cylinder

et al. 1998

Self Cite

View full text Add to dashboard Cite

Granular material in a cylindrical vessel undergoing rotational and rocking motions is modeled using a discrete element method. Rotational motion supplemented by rocking is compared to purely rotational motion via linear density profiles, velocity fields, and axial concentration profiles. The rocking motion, which imparts a time-dependent flow perturbation to purely rotational motion, dramatically enhanced mixing in laborat o y studies. Simulation results appear to agree well with experimental results and observations. IntroductionMany technical fields deal with mixing of granular materials, including chemical, agricultural, ceramic, mechanical, civil and soil engineering, the life sciences, physics, and pharmacy. Although researchers in these fields consider a wide range of physical characteristics and flow regimes, they share a common interest: the need to understand and characterize bulkflow powder behavior. Powder processing has been recently characterized by chemical engineers as having a legacy of neglect (Ennis et al., 1994). Awareness of this neglect has motivated a recent resurgence of both experimental investigations (McCarthy et al., 1996;Hill and Kakalios, 1995;Brone et al., 1997) and theoretical approaches (Johnson et al., 1990;Edwards and Mounfield, 1996). It has become fashionable in a sense to study powders, not only because of their complexity but also because there is a growing need in industry to reliably manufacture high-quality products.Although practitioners have attempted to handle powder problems using empirical approaches, more detailed studies of the physics of powders are required. Some researchers have suggested that granular materials might be a different state of matter (Jaeger et al., 1996). Interest in the physics of powders has increased dramatically in the past decade, starting with the analysis of sand piles (Baxter et al., 1989(Baxter et al., , 1993Bak and Chen, 1991), prompted by analogies with self-organized critical systems (Bak et al., 1988). Fundamental questions concerning how and why granular materials behave alternaCorrespondence concerning this article should be addressed to F. J. Muzrio tively like a liquid when flowing down an inclined chute and like a solid when forming a sloping surface remain to be answered (Glanz, 1995). A growing research community is currently investigating microscopic theories (Jaeger et al., 1996;Jaeger and Nagel, 1992;Evesque and Stefani, 1991;Evesque et al., 1992; Mehta, 19941, as well as unit operations typically found in industry, such as blending, sampling, discharge, fluidization, and granulation. The kinetic theory developed for fast-flowing low-density solids has achieved some success in modeling Couette flows and flows down inclined planes, but industrial systems are often more complex. Civil and soil engineers are mainly interested in strain effects (failure) produced by external forces and the effect of time on the development of strain. The chemical engineering community, on the other hand, has focused primarily on mixing and tran...

show abstract

Computational and experimental investigation of flow and particle settling in a roller bottle bioreactor

Muzzio

Unger

Liu

et al. 1999

Biotechnol. Bioeng.

View full text Add to dashboard Cite

It is shown that cell settling is a key factor affecting the performance of roller bottle bioreactors. The two‐dimensional cross‐sectional flow at the center of a roller bottle is simulated using a finite difference method, and the settling behavior of cells is simulated using particle dynamics algorithms and validated experimentally using fluorescent particles. The settling behavior of particles in the roller bottle flow is studied using both steady and time dependent rotation rates. Under steady flow conditions the flow is divided into two regions: one where the particles settle to the wall and one where the particles remain suspended indefinitely. The relative size of these two regions depends on the ratio of the settling velocity to the rotation rate of the bottle. For unsteady flows generated by periodic changes of the bottle rotation direction, the settling of cells is accelerated significantly, leading to complete deposition in just a few turns of the bottle. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 63: 185–196, 1999.

show abstract

Using flow perturbations to enhance mixing of dry powders in V-blenders

Cited by 44 publications

References 11 publications

Quantitative characterization of mixing of dry powders in V‐blenders

Quantitative characterization of mixing of dry powders in V‐blenders

Simulation of flow and mixing of particles in a rotating and rocking cylinder

Computational and experimental investigation of flow and particle settling in a roller bottle bioreactor

Contact Info

Product

Resources

About