Showing papers in "Powder Technology in 1976"

TL;DR: In this paper, it is pointed out that powder behaviour depends on whether the powder can be considered cohesive or cohesionless. But the limitations that have been found in more fundamental studies on equipment are outlined.

TL;DR: In this paper, the importance of van der Waals and capillary interparticle forces with respect to particle weight is discussed and the need for detailed analysis of particle surfaces is shown.

TL;DR: In this article, the specific rates of breakage of particles in a tumbling ball mill are described by the equation S i = ax α i ( Q ( z ), where Q( z ) is the probability function which ranges from 1 to 0 as particle size increases.

TL;DR: In this article, the mixing of 2% sulphaphenazole (mean diameter 25 μm) with coarse directly compressible tablet vehicles has been studied using a sampling method and scanning electron microscopy.

TL;DR: This survey presents a general evaluation of the subject of powder mixing and a comprehensive classified list of 650 references to the topic and a selection of those of general background interest.

TL;DR: In this paper, the authors studied the heating of carbohydrates in an industrial scale horizontal drum with a diameter of 0.6 m. Strips were mounted on the inside wall and the drum was heated externally by steam.

TL;DR: In this article, a new measurement technique is developed in which three single measurements of the scattered light are used to determine the volume mean diameter, area mean diameter and variance of the particle distribution regardless of the nature of the distribution.

TL;DR: In this article, the movement of solids in a horizontal rotary drum was investigated, and residence time distribution measurements were performed in an industrial scale reactor, where potato starch, particle size range from 15 to 100 μm, was used as the solid material.

TL;DR: In this paper, the authors examined irregular particle movement in a failure zone developed in a simple shear cell, which was loaded with red and black material separated by a plane interface.

TL;DR: In this article, the authors examined the research and industrial requirements for a quantitative measure of the quality of mixtures of particulate solids and the criteria by which it may be assessed.

TL;DR: In this article, the authors studied the effect of the gap height between the distributor and the draught tube on the rate of particle circulation in an annular downcomer of up to 400 kg/m 2 s.

TL;DR: In this paper, a special application of vertical vibration was studied, by means of which a regular, recirculating particle stream may be induced in beds of granular materials, and the hydrodynamics of this particle flow as a function of the vibration parameters, amplitude and frequency, was investigated experimentally.

TL;DR: In this paper, it was shown that the convective solids transport occurring in large diameter gas fluidized beds can be predicted quantitatively on the basis of measured properties of the bubble phase.

TL;DR: The use of homogeneity assessment for mixer performance and for degree of mixing in pharmaceutical practice is described, and with cohesive materials, ordered mixing may be as important as randomisation for producing pharmaceutical mixtures.

TL;DR: In this article, the agglomeration behavior of silica sand, glass and calcium carbonate powders (average diam. 4 − 76 μm) in stirred suspensions was investigated.

TL;DR: In this paper, the mineralogical heterogeneity of the particle surface and sub-surface regions of natural hematite and the effect of desliming treatments was examined using scanning electron microscopy, energy dispersive analysis of X-rays and Auger spectroscopy techniques.

TL;DR: In this paper, a laser Doppler anemometer was used to find axial particle velocity profiles in two-phase gas-solids flows, and the loading ratios of up to 2.2 and air Reynolds numbers between 56,200 and 181,600 were investigated in a 5 cm nominal bore vertical glass tube.

TL;DR: In this article, the authors used the method of characteristics, as outlined by Sokolovski [8], to calculate the stress distribution in two-dimensional parallel-sided bins containing granular material under either a uniform or zero surcharge.

TL;DR: In this paper, an analytical solution for the stress function at the wall of a mass flow hopper is presented, which makes it possible to obtain analytical expressions for such parameters as the normal stress at wall and the flow factors for arching, in a converging channel.

TL;DR: In this paper, a set of equations describing the dynamic behavior of fibrous aerosol filters is developed in analogy with that used in deep bed filtration of solid liquid suspensions, which involves two correction functions, fλ and fP, which account for the effect of deposited matter on the local rate of deposition and on local pressure gradient, respectively.

TL;DR: In this paper, the pattern of solids circulation in various depth beds of silica sand fluidized in a square vessel, area 1.5 m2, has been obtained by adding both coloured tracers and plastic spheres to the system a known time prior to defluidization.

TL;DR: In this paper, the authors measured the breakage of maize in a small laboratory hammer mill, with a rigid blade used as hammer, and found that breakage was first-order and that the primary breakage distributions were insensitive to mill conditions or moisture content of the material.

TL;DR: Using mass, momentum and energy balances, a theory was developed which permits the calculation of the viscous and thermal attenuation of sonic waves in gas suspensions as mentioned in this paper, and the results agree well with the theory.