Showing papers in "Powder Technology in 2001"

TL;DR: In this article, the authors present a review of the current understanding of the three key areas of wet granulation processes: wetting and nucleation, consolidation and growth, and breakage and attrition.

TL;DR: In this paper, a mathematical model was developed to predict the transitions between different forms of transverse motion of free-flowing bed materials in rotating cylinders: sliding, surging, slumping and cascading.

TL;DR: Dry particle coating is used to create new generation materials by combining different powders having different physical and chemical properties to form composites, which show new functionality or improve the characteristics of known materials as discussed by the authors.

TL;DR: This work studies systems where the predominant mode of cohesion is due to interstitial liquid (capillary cohesion), and proposes two discrete characterization criteria, based on the physical picture of liquid-induced particle-level cohesion, which seem to work well in both static and flowing systems.

TL;DR: A new, digital approach to particle packing is described, which can avoid many of the difficulties suffered by conventional methods and can simulate some physical phenomena such as size segregation.

TL;DR: In this paper, an attempt was made to quantify the boundaries and validate the granule growth regime map for liquid-bound granules recently proposed by Iveson and Litster (AlChE J. 44 (1998) 1510).

TL;DR: In this paper, the impact and rebound behavior of 5-mm aluminium oxide spheres impacting a soda-lime glass anvil was investigated for impact angles from normal to very near glancing incidence, and the results showed very close agreement with the numerical work of Maw et al. which takes into account the effects of sticking, microslip and tangential compliance.

TL;DR: In this article, a review on both theoretical and experimental studies on the application of electrostatic forces in filtration and discusses the needs for further studies on particle loading is presented.

TL;DR: A brief review of current techniques in solid flow measurement and recent contributions of the multiphase flow approach to gas/solid flow systems and fluidization can be found in this paper.

TL;DR: In this paper, the packing of uniform spheres has been studied by means of Discrete Element Method with special reference to variables affecting the packing dynamics, with the results analyzed in terms of packing density, radial distribution function (RDF), and coordination number.

TL;DR: In this article, the authors investigated the relationship between dimensionless spray flux, process variables and the coverage of binder fluid on the powder surface in wet granulation and showed that changes in dimensionless spraying flux correlate with a measurable difference in powder surface coverage.

TL;DR: In this paper, a new phenomenological compacting equation is proposed, which is ln (1/(1−D))=A P +B where P is the applied pressure, D is the relative density of the compact, A is a parameter related to densification of compact by plastic deformation, and B is a powder density at the start of compaction.

TL;DR: In this article, the diffusivity of the solid particles in a 152mm ID gas-solid fluidized bed was determined at different regimes of fluidization at different velocities from 0.5 to 2.8 m/s for sand and 0.44 to 0.9 m/m for FCC (in both bubbling and turbulent regimes).

TL;DR: In this paper, the authors presented a computational method combining smoothed particle hydrodynamics and the discrete element method (DEM) to model flows containing a viscous fluid and macroscopic solid particles.

TL;DR: In this article, the impact behavior of a steel ball was modeled by a nonlinear differential equation and the contact parameters to be used in the discrete element method were directly extracted from the model.

TL;DR: In this article, Magnetic Resonance Imaging (MRI) volume-visualisation in combination with image analysis techniques are used to characterise the structure within the interparticle space of unconsolidated and consolidated packed beds of ballotini for column-to-particle diameter ratios of 9, 14 and 19.

TL;DR: In this article, a high-speed digital video imaging technique is used to gain an insight into the impact behavior of individual agglomerates against a target plate, and several breakage patterns are observed.

TL;DR: In this article, the authors review the mechanical properties of agglomerates in the context of continuum solid and fluid mechanics and fracture mechanics, focusing on practical measurements of tensile strength, yield strength, hardness and fracture toughness.

TL;DR: In this paper, the main effect of liberation by electrical pulses manifests in the generation of a higher percentage of the coarse monomineral particles and in the general increase of liberated material with dimensions of particles, which can be efficiently treated by separating equipment.

TL;DR: The influence of interparticle adhesion on the formation and properties of aggregates is reviewed in this article, where it is shown that strongly adhesive fine particles lead to fluffy structures which contain fewer contacts and which are therefore weak, even though each individual contact may be stronger.

TL;DR: In this paper, the authors describe possibilities to separate particles with difficult dust properties from gases, which are related to extreme values of particle size and shape and to the flowability, the adhesion properties or the reactivity of the particles.

TL;DR: In this article, the solid flow nonuniformities which develop in lean phase upward flow in a vertical pneumatic conveying line following a horizontal-tovertical elbow were investigated.

TL;DR: In this paper, the effect of seeding in batch cooling crystallization is discussed on the basis of original experimental data on potassium alum-water system obtained for both controlled and natural cooling modes.

TL;DR: In this paper, the effect of adding non-volatile liquids with different viscosity and surface tension to a cold model gas-solid fluidized bed was studied, in general, to result in a transition to group A behaviour and eventually to group C behaviour.

TL;DR: In this article, a vibro-fluidized bed was constructed for the fluidization of fine BN powder, which exhibits the characteristics of a Geldart C type powder, with significant cohesive behavior.

TL;DR: In this article, a method combining computational fluid dynamics with a mathematical model for the particle dynamics has been applied to simulate experimental data from the synthesis of TiO 2 -particles in diffusion flames.

TL;DR: In this paper, two kinds of inserts (conical insert and BINSERT®) are used in the silo to change the flow fields of a silo during filling and discharging of two-dimensional plane silos.

TL;DR: In this paper, the authors validate two-dimensional Lagrangian-Eulerian simulations of gas-solid fluidized beds by comparing these with dedicated experimental data obtained with polystyrene Geldart type D particles of 1.545 mm size.

TL;DR: In this article, the axial density profile of a rotating fluidized bed is investigated and a correlation between axial densities and gas velocities is obtained. But, this correlation is only applied to literature data and good agreement is not obtained.

TL;DR: In this article, the mathematical relationship between the inlet and outlet particle-size distributions of a roller milling operation is described, and the breakage function linking the two is defined.