Vibrated Bulk Density Research Articles

Measurement of Vibrated Bulk Density of Coke Particle Blends Using Image Texture Analysis

A rapid and nondestructive machine vision sensor was developed for predicting the vibrated bulk density (VBD) of petroleum coke particles based on image texture analysis. It could be used for making corrective adjustments to a paste plant operation to reduce green anode variability (e.g., changes in binder demand). Wavelet texture analysis (WTA) and gray level co-occurrence matrix (GLCM) algorithms were used jointly for extracting the surface textural features of coke aggregates from images. These were correlated with the VBD using partial least-squares (PLS) regression. Coke samples of several sizes and from different sources were used to test the sensor. Variations in the coke surface texture introduced by coke size and source allowed for making good predictions of the VBD of individual coke samples and mixtures of them (blends involving two sources and different sizes). Promising results were also obtained for coke blends collected from an industrial-baked carbon anode manufacturer.

Packing density of irregular shape particles: DEM simulations applied to anode-grade coke aggregates

Particle packing problem exists in variety of applications such as transportation, packaging, agricultural and pharmaceutical industries. Particles have not always regular shapes and this makes the packing problem more complex. Understanding the packing characteristics and enhancing the packing density of granular systems is of interest for different industries. In the present work, packing density of an irregular shape particulate system is investigated. The approach is applied on anode-grade calcined coke aggregates with the aim of improving the Vibrated Bulk Density (VBD) of the aggregate recipe which is currently used in industry. A three-dimensional imaging technique is coupled with Discrete Element Method (DEM) simulations to model the coke particles. To study the packing of an industrial aggregate recipe, a sample with only the largest fraction of coke particles were created by DEM. Then, the pore size distribution of this sample was obtained. New aggregate recipes were created according to the results of the pore size distribution. Results showed that the modified recipes with even a lower number of size fractions hold higher vibrated bulk densities than the standard industrial sample. The voids tracking method used in this study is an effective tool to study the packing density of granular systems.

Simulation of vibrated bulk density of anode-grade coke particles using discrete element method

Packing density is an important quality parameter of calcined cokes used in aluminum industry to produce carbon anodes. Vibrated bulk density (VBD) test is a well established method to measure the packing density of coke samples. In the present work, Discrete Element Method (DEM) is coupled with a three-dimensional imaging technique to investigate the possibility of using DEM to simulate the packing behavior of calcined cokes. As the method verified, effects of shape, friction coefficient, size and size distribution of the particles on the VBD of cokes are also investigated. DEM simulations, in accordance with the experiments, show that vibrated bulk density of coke samples decreases as the content of coarse particles in the mixture increases. Moreover, it is shown that friction coefficient has a negative effect on the VBD value and this effect is more pronounced for the samples with lower sphericity. High friction coefficient restricts the movement and rearrangements of the particles and thus vibrational forces cannot effectively rearrange the particles and fill the porosities. Lower sphericity of coke samples not only induces a higher initial porosity level in the samples but it also increases the chance of formation of locks and particle bridges which result in lower VBD. Results also show that sphericity and friction coefficient have a synergic effect on the VBD of coke so that, for the samples with lower average sphericity the rate of decrease in VBD is higher with increasing the friction coefficient.

Tensile modulus modeling of carbon‐filled nylon 6,6 and polycarbonate‐based resins

AbstractElectrically and thermally conductive resins can be produced by adding conductive fillers to insulating polymers. Mechanical properties, such as tensile modulus, are also important. This research focused on performing compounding runs followed by injection molding and tensile testing of carbon‐filled nylon 6,6 and polycarbonate‐based resins. The three carbon fillers investigated included an electrically conductive carbon black, synthetic graphite particles, and a milled pitch–based carbon fiber. For each polymer, resins were produced and tested that contained varying amounts of these single‐carbon fillers. In addition, combinations of fillers were investigated by conducting a full 23 factorial design and a complete replicate in each polymer. These tensile modulus experimental results were then compared to results predicted by several different models. For the composites containing only one filler type, the Nielsen model with the modified Ψ term provided the best prediction of the actual experimental values. For the composites containing more than one filler type, a new parameter, which includes the vibrated bulk density (VBD) of the fillers, was incorporated into the Nielsen model with the modified Ψ term. This model with the new VBD parameter provided the best estimate of experimental tensile modulus for composites containing multiple‐filler types. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1716–1728, 2003

97/05213 Vibrated bulk density (VBD) measurement of calcined coke and binder control in prebaked anode paste: a case study: Duchesneau, L. et al. Light Met. (Warrendale, PA), 1997, 497–503

97/05213 Vibrated bulk density (VBD) measurement of calcined coke and binder control in prebaked anode paste: a case study: Duchesneau, L. et al. Light Met. (Warrendale, PA), 1997, 497–503