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Inert Particles (inert + particle)
Selected AbstractsEffect of Volume Fraction of Material on Separation by Density Difference in a Liquid-Fluidized Bed of Inert ParticlesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2010Y. Tatemoto Abstract A liquid-fluidized bed was used to separate a pure material from a mixture. A quantity of relatively large sized material was immersed in an inert-particle fluidized bed and the behavior of materials was examined for different liquid velocities. In particular, the volume fraction of the material was varied and its effect on the separation characteristics was examined. The material floats on the inert-particle fluidized bed when the density of the material is lower than the apparent density of the bed, regardless of the volume fraction of the material. The apparent density of the bed can be adjusted by changing the liquid velocity. The materials in the upper portion of the bed affect the properties of the bed below them, i.e., the void fraction decreases and the apparent density increases in the inert-particle suspension when materials are present in the upper portion of the bed. Therefore, the materials float on the bed although the apparent density of the inert-particle suspension obtained from the case without material is less than the density of the material at a relatively high volume fraction of material. This phenomenon occurs more easily for lighter and smaller materials. This means that small inert particles and low liquid velocities are the optimum operating conditions for the separation. [source] Voltammetric Sizing of Inert ParticlesCHEMPHYSCHEM, Issue 7 2005Trevor J. Davies Abstract The average size of inert particles is determined using a simple electrochemical procedure. Alumina particles are deposited on an edge-plane graphite electrode, and a cyclic voltammogram is recorded. The scan rate employed varies between 0.2 and 2 V,s,1. At these scan rates the diffusion layer thickness is greater than the size of the alumina particles, minimizing the influence of the particles, height on the observed voltammetry. The average size of the particles is determined via comparison of the experimental voltammograms with simulations. [source] In Situ X-Ray Radiography and Tomography Observations of the Solidification of Aqueous Alumina Particle Suspensions,Part I: Initial InstantsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2009Sylvain Deville This paper investigates by in situ high-resolution X-ray radiography and tomography the behavior of colloidal suspensions of alumina partic les during directional solidification by freezing. The combination of these techniques provided both qualitative and quantitative information about the propagation kinetic of the solid/liquid interface, the particle redistribution between the crystals and a particle-enriched phase, and the three-dimensional organization of the ice crystals. In this first part of two companion papers, the precursor phenomena leading to directional crystallization during the first instants of solidification are studied. Mullins,Sekerka instabilities are not necessary to explain the dynamic evolution of the interface pattern. Particle redistribution during these first instants is dependent on the type of crystals growing into the suspension. The insights gained into the mechanisms of solidification of colloidal suspensions may be valuable for the materials processing routes derived for this type of directional solidification (freeze-casting), and of general interest for those interested in the interactions between solidification fronts and inert particles. [source] A Simple Experimental Technique to Measure Tortuosity in Packed BedsTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2006J. M. P. Q. Delgado Abstract In this article, a simple and inexpensive experimental technique easy to build in laboratory, for the measurement of tortuosity of a packed bed of inert particles, is described. Experimental values of the tortuosity were obtained with four different packed beds of sand. The experimental results obtained are in good agreement with the theoretical values of tortuosity in a porous media; and the data reported showed the tortuosity to increase with decrease in the void fraction of the packed bed as expected. On décrit dans cet article une technique expérimentale simple et peu coûteuse facile à concevoir en laboratoire, pour la mesure de la tortuosité d'un lit garni de particules inertes. Des valeurs expérimentales de tortuosité ont été obtenues avec quatre lits différents garnis de sable. Les résultats expérimentaux obtenus montrent un bon accord avec les valeurs théoriques de la tortuosité dans un milieu poreux; et les données signalées montrent que la tortuosité augmente avec la diminution de la fraction de vide du lit garni tel qu'attendu. [source] Terrestrial and airborne non-bacterial ice nucleiATMOSPHERIC SCIENCE LETTERS, Issue 4 2009S. K. Henderson-Begg Abstract To freeze above ,36.5 °C, water requires the presence of an ice nucleus (IN). These can be inert particles or living or dead biological material. As they are the most efficient, inducing freezing at up to ,1.8 °C, bacteria are the most widely studied biological IN. Here, we show that there is a huge repository of IN in lichens which comprise a large biomass and are able to become airborne. The lichen IN are similar to those we have detected in urban air, exhibiting heat sensitivity but resistance to lysozyme. This suggests many airborne IN are non-bacterial and that eukaryotic IN may be more important to atmospheric processes than previously thought. Copyright © 2009 Royal Meteorological Society [source] Effect of Volume Fraction of Material on Separation by Density Difference in a Liquid-Fluidized Bed of Inert ParticlesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2010Y. Tatemoto Abstract A liquid-fluidized bed was used to separate a pure material from a mixture. A quantity of relatively large sized material was immersed in an inert-particle fluidized bed and the behavior of materials was examined for different liquid velocities. In particular, the volume fraction of the material was varied and its effect on the separation characteristics was examined. The material floats on the inert-particle fluidized bed when the density of the material is lower than the apparent density of the bed, regardless of the volume fraction of the material. The apparent density of the bed can be adjusted by changing the liquid velocity. The materials in the upper portion of the bed affect the properties of the bed below them, i.e., the void fraction decreases and the apparent density increases in the inert-particle suspension when materials are present in the upper portion of the bed. Therefore, the materials float on the bed although the apparent density of the inert-particle suspension obtained from the case without material is less than the density of the material at a relatively high volume fraction of material. This phenomenon occurs more easily for lighter and smaller materials. This means that small inert particles and low liquid velocities are the optimum operating conditions for the separation. [source] Voltammetric Sizing of Inert ParticlesCHEMPHYSCHEM, Issue 7 2005Trevor J. Davies Abstract The average size of inert particles is determined using a simple electrochemical procedure. Alumina particles are deposited on an edge-plane graphite electrode, and a cyclic voltammogram is recorded. The scan rate employed varies between 0.2 and 2 V,s,1. At these scan rates the diffusion layer thickness is greater than the size of the alumina particles, minimizing the influence of the particles, height on the observed voltammetry. The average size of the particles is determined via comparison of the experimental voltammograms with simulations. [source] | ||||||||||