Showing papers in "Powder Technology in 2000"

TL;DR: In this paper, the effect of rolling resistance at contact points is taken into account to simulate the formation of shear bands in a column-like structure during hardening process and its collapse in the softening process.

TL;DR: In this article, three types of particle interactions are reviewed: van der Waals forces, liquid bridge forces and sintering, and the observed effects of these three types on fluidization behavior are described and explained in terms of simple models.

TL;DR: In this article, a simulation of gas/particle flow behavior in the riser section of a circulating fluidized bed (CFB) was simulated using a computational fluid dynamics (CFD) package by Fluent.

TL;DR: A review of electrical tomography methods for investigating, monitoring and controlling gas and liquid solids systems is presented in this article, where the physical laws governing the electrical measurements and issues associated with image reconstruction are described in detail.

TL;DR: In this paper, the authors used the discrete element method (DEM) in the simulation of static packings to investigate the behavior of granular materials by modeling the forces on the particle level.

TL;DR: In this article, a numerical model for gas-solids two-phase flow with heat transfer in pneumatic transport pipes is presented, where the gas phase is modeled as a continuum and the solids phase is modelled by the distinct element method.

TL;DR: In this article, the suitability of different test methods for spheres, tablets and extrudates, respectively, are discussed, and it is concluded that the crushing test is a satisfactory method for spheres.

TL;DR: In this article, the rebound behavior of 5 mm aluminium oxide spheres impacting a soda-lime glass anvil and an aluminium alloy anvil was measured with a strobe and single-frame digital camera, for a range of impact angles from normal to very near glancing.

TL;DR: In this article, the authors report the first fully three-dimensional (3D) particle dynamics simulations of granular dynamics in two standard industrial tumbling blender geometries: the double-cone and the V-blender.

TL;DR: In this article, three cases studies of discrete element methods (DEM) simulations are presented; dragline excavators, mixing in tumblers and charge motion in centrifugal mills.

TL;DR: In this article, the capacitance-probe measurements of instantaneous local solid concentrations in a 15 cm diameter fast fluidized beds (FFB) were used to investigate the effect of particle size and gas velocity on the formation of clusters.

TL;DR: In this paper, a hard-sphere discrete particle model of a gas-fluidized bed was used in order to simulate segregation phenomena in systems consisting of particles of different sizes.

TL;DR: In this article, the parameters of impact interaction between the working bodies and the material to be treated have been calculated for a series of comminuting devices, i.e., different types of ball mills, disintegrator, etc.

TL;DR: In this article, a statistical approach to the scattered light signals from a conventional detector array is shown to improve the sensitivity to a few large particles relative to the main size distribution, which offers even more promising applications for on-line process control.

TL;DR: In this paper, the authors presented a numerical study of the gas-solid flow in a bed by a Combined Continuum and Discrete Model (CCDM), where they simulated the motion of 10,000 spherical particles of 4 mm diameter caused by lateral gas blasting into a bed with its thickness equal to the diameter of particles.

TL;DR: In this article, the results of numerical simulations of quasi-static shear deformation of a polydisperse system of soft elastic spheres with interface friction and adhesion are presented.

TL;DR: In this paper, a set of Distinct Element (DEM) simulations of the filling and the discharge of a plane rectangular silo have been performed with variable values of particle mechanical parameters.

TL;DR: In this paper, a numerical simulation of mono-sized spherical particle flows with a small amount of water in a centrifugal tumbling granulator was made by using discrete element method (DEM).

TL;DR: In this paper, a fluidized/spouted bed coater is used to process fine particles without agglomeration and what kinds of functions are desired for particulate dosage forms.

TL;DR: In this paper, a new Monte Carlo method for solving the population balance problem with multiple growth processes is presented, which samples a constant number of particles regardless of whether the actual growth process results in increase or decrease of the particle concentration.

TL;DR: In this article, the attrition behavior of two different limestones during calcination and sulphation in fluidized beds has been investigated by a combination of experimental techniques, which shed light on the interactions between sorbent attrition and the change of particle mechanical and morphological properties associated with the progress of chemical reactions.

TL;DR: In this article, the authors used fast response pressure transducers and the dynamic gas disengagement (DGD) technique to study variations in gas holdups, bubble population and their rise velocities.

TL;DR: In this paper, a reflective-type optical fiber probe was used to determine local voidages for conditions corresponding to dense suspension upflow and fast fluidization in a riser of diameter 76.2 mm and height 6.1 m.

TL;DR: In this article, a quasi-three-dimensional numerical simulation method for axisymmetric gas-solid flows was proposed to reduce the computational load, in which the circumferential components were neglected and the particle motion was calculated threedimensionalally and was traced discretely by solving Newton's equation of motion for each particle.

TL;DR: In this paper, the effect of particle shape on the angle of internal friction of fine powders was investigated by triaxial compression test, and it was found that the angle increased with increasing angularity of particles and decreasing initial voidage of the specimen.

TL;DR: In this paper, a Lagrangian approach was used to simulate two-dimensional gas-solid flow in a circulating fluidized bed with a total solids concentration of 3% in the riser.

TL;DR: In this paper, a numerical study of the micromechanics of impact of a sub-millimetre sized crystalline agglomerate with a target wall has been carried out using granular dynamics (or discrete element) simulations.

TL;DR: In this article, the generalized kinetic equation was applied to the calculations of ab initio rate constants of specific mechanochemical processes in comminuting devices and the obtained theoretical values have been compared with experimental results.

TL;DR: In this article, a modified spontaneous emulsion solvent diffusion (modified-SESD) method was applied to polylactide (PLA) and poly( dl -lactides-co-glycolide) (PLGA) polymers with different molecular weights, copolymer ratios (L / G ratios) and original sources, and to find the optimal composition of binary organic solvents.

TL;DR: In this article, a high-frequency (140 kHz) acoustic emission (AE) sensor with narrow-band receptors was developed and applied in monitoring the particle fluidization in a fluidized bed granulator.