Showing papers in "Powder Technology in 1988"

TL;DR: In this paper, an analytical model based on the experimental results of binary mixtures and the experimental theory of mixtures is developed to estimate the porosity of multicomponent mixtures.

TL;DR: In this paper, the authors observed changes in the mechanical properties of the microcrystalline cellulose and the tensile strength of its compacts due to the way in which water is sorbed into the cellulose structure.

TL;DR: In this paper, the first-order particulate distribution function is determined and constitutive equations for the kinetic parts of the particulate stress tensor and fluctuation energy flux vector are formulated.

TL;DR: In this paper, the effects of feed properties on the granulation of iron ore sinter feed have been studied using simplified sinter mixes and a measure of granulation effectiveness, x 0.5, has been defined as the particle size at which half the particles act as adhering particles and half as nuclei particles.

TL;DR: In this paper, the effect of magnesium stearate was shown to be dependent on a number of factors, including particle size (surface area), flowability and mechanism of consolidation.

TL;DR: In this paper, a fluidized-bed drier end-point indication system was developed based on the temperaturedifference technique, which was shown to control the end point of drying to within narrow limits of final moisture content, largely independent of variations in relative humidity.

TL;DR: In this article, it was shown that an optimum impact energy can be determined for the breakage of an ore particle of a given size to a specified product size, and that the optimum usage of impact energy is often obtained by the use of a number of breakage steps for the size reduction of a particle.

TL;DR: In this article, the authors evaluated the dryer wall-to-particle heat transfer coefficient for drying operations from the knowledge of fundamental particle mixing in a bed of granular material agitated by a moving blade.

TL;DR: Tetrahedral tessellation is applied to an existing, computer-generated, random packing of nearly equal spheres as discussed by the authors, where the objective is to identify the tetrahedral pores and then determine the geometrical characteristics of the pore space.

TL;DR: In this article, the tensile strength of five different powders (i.e., iron oxide, β copper phthalocyanine, calcium carbonate, disodium cromoglycate and glass) was measured.

TL;DR: In this article, the rheological properties of concentrated coal and quartz were determined in a cup-and-bob viscometer in the laminar flow region, using a ridged bob and cup.

TL;DR: In this paper, the effect of systematic variation of all the relevant variables on the bubbling point of gas-fluidized beds are shown to be in agreement with the predictions of a general fluid dynamic stability criterion for fluidisation.

TL;DR: In this paper, a parametric approach using a first-order autoregressive model of the time series is proposed to distinguish between dilute and dense-phase flows, and the values of choking velocity are determined from the dependence of local static pressure drop on gas velocity.

TL;DR: In this article, a new method of analysis of the signal acquired from capacitance probes has been developed, where the trace from a single probe is analyzed to obtain the probability density function of signal.

TL;DR: In this paper, the transition between the stabilized and frozen regimes was determined for pure and admixed systems by determining the conditions when a lead weight placed on the top surface of the bed would remain supported.

TL;DR: The fit of the modified beta function to narrow log-normal distributions was also excellent but it declined significantly as the distribution spread increased as mentioned in this paper, indicating that for real particle populations, having a finite size range, and not necessarily a perfectly smooth size distribution, the modified Beta function can replace all three functions, thus providing a way to present and compare the different size distribution patterns in terms of a single mathematical expression.

TL;DR: In this article, the authors studied the flocculation properties of polyacrylamides on sodium kaolinite under controlled conditions of ionic strength, temperature and agitation, and examined the mechanisms of floccuration as a function of the charge of the polymer and clay.

TL;DR: In this article, a new model, based on that of Gibilaro and Rowe but accounting for the particular characteristics of the solids used, has been developed and reasonable agreement with experimental data has been obtained.

TL;DR: In this article, the authors investigated the mechanism of coating a coarse powder by a fine adhesive powder in a rotary-type mixer with rocking motion and found that the shearing and friction forces generated by the rotational movement of the mixer turned out to exert a strong and positive effect on the rate of coating.

TL;DR: In this paper, a simple physical model was developed to predict the flux of particles entrained above the transport disengaging height (TDH), which is essentially constant and does not require any empirical correlation.

TL;DR: In this article, a system to sample gas from bubbles in a fluidized bed was designed, built and tested, which consisted of a dual-stem static-pressure probe (DSPP) to detect a rising bubble and a gas-sampling probe situated a small distance above the DSPP, together with a computer and hardware interface.

TL;DR: A Richardson plot of an arbitrarily rugged line can be constructed by "coating" it with a "blanket" of increasing thickness and calculating its length from the blanket's area divided by its thickness as discussed by the authors.

TL;DR: In this article, the dynamics of batch sedimentation of polydispersed suspensions was studied assuming that underbatch sedimentation, polydpersed particles in a suspension segregate and group themselves into several zones of constant composition.

TL;DR: In this paper, an assessment of the utility of a cone penetrometer technique for measurement of the cohesive caking strength of a powder was made, and results from a shear cell were compared with those from a penetrationrometer using five different types of powder.

TL;DR: In this article, the breakage of anthracite in tumbling ball mills exhibits an unusual behavior of acceleration at fine levels of grinding by using the selection function and the primary breakage distribution parameters to predict the size distribution of Anthracite using the kinetics of grinding approach.

TL;DR: In this article, the surface-enhanced spin-lattice relaxation rate is a function of proton frequency, fluid, temperature and surface chemistry, and a threefold increase in the sensitivity of the surface area determination is noted when the frequency is decreased from 300 to 20 MHz.

TL;DR: In this paper, the influence of particle size distribution on the viscosity and maximum coal concentration in coal-water mixtures was investigated and a simple correlation method was proposed to arrange the apparent visco-temporal data for coal water mixtures.

TL;DR: In this paper, an experimental study of the conveying of coal as a plug at low air velocity in a horizontal pipe and 45° inclined pipe was completed, where the authors measured the pressure drop and the plug velocity at various air velocities and plug lengths within the range of study.

TL;DR: In this article, a rotating cylinder with blades was used for the batch mode operation, and binary mixtures of spherical and non-spherical particles were classified continuously according to shape. The performance of the classifier run in batch and continuous modes were compared with each other and the superiority of the continuous operation to the batch operation was shown for the rate of shape separation.