Journal of the Society of Powder Technology, Japan
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
Volume 16, Issue 8
Displaying 1-4 of 4 articles from this issue
  • Ken-ichi KANATANI
    1979 Volume 16 Issue 8 Pages 445-452
    Published: August 10, 1979
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    Continuum mechanical foundation for the flow of granular materials is established. The material is assumed to consist of cohesionless rigid spheres of uniform size and weight. Macroscopic laws are deduced from microscopic considerations of interparticle friction by means of statistical inference. The field is described by the theory of polar fluids. Various characteristics of granular materials such as the critical stress condition and the angle of repose are mathematically deduced from the theory. The effects of couple-stress in the Couette flow between two parallel plates is also studied and the ‘boundary layer’ is shown to exist.
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  • Hideharu HIROSUE, Eiichi ABE, Akira YOKOTA
    1979 Volume 16 Issue 8 Pages 453-459
    Published: August 10, 1979
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    This paper deals with filtration and drying characteristics of red mud which is a waste from Bayer process to produce alumina.
    First, the equilibrium porosity and the local specific filtration resistance of red mud slurry were measured at various compressive pressures and experimental equations were obtained. The Ruth's coefficient in a case of constant pressure filtration was calculated on the basis of the modern filtration theory and the Ruth's theory, respectively, and the both calculated values were compared with experimental data.
    Secondly, shrinkage characteristics and drying rate of the sample bed prepared by forming wet red mud into a cylindrical shape were measured. The results indicated that the shrinkage characteristics could be estimated from the data of the true density of red mud, the moisture content of the sample bed and the specific volume of the dried sample bed. Furthermore, it was clarified that drying rates were affected by the solute material in the red mud slurry deposited at and near drying surface.
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  • 2nd Report: On the Stress Distribution and Deformation in the Case with 1mm of Clearance between the Punch and the Side of the Box
    Takaaki NAGAO, Kenji CHIJIIWA, Yotaro HATAMURA, Koji TAKEUCHI, Nobuyuk ...
    1979 Volume 16 Issue 8 Pages 460-472
    Published: August 10, 1979
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    A series of compression tests of silica sands have been carried out in a square box. Silica sands have been filled and smoothed in the box and compressed by a punch 2mm shorter in width than the box, and the distributions of pressure, friction stress, internal stress, deformation, strain etc. have been measured under loading and unloading. The pickups, i. e. the pressure cell, the friction cell, the inclination cell and the internal stress cell have been developed by the authors to measure them. The mean pressure on the punch surface has been raised up to 111kgf/cm2. The following conclusions have been obtained:
    (1) Thed eveloped pickups have shown good performance. It has turned out thatt here is a problem on the measurement of internal stress with sharp gradient.
    (2) The pressure distribution is lower in the middle and higher by 20% on the both ends below the lower surface of the punch. The direction of friction turns reversely at some parts on it. The pressure distributes almost uniformly (40-50% of the mean pressure on the punch surface) on the side of the box. It is higher in the middle and lower on the both side on the bottom.
    (3) The internal stress cell is transmitted almost vertically except near the both sides.
    (4) The vertical displacement can be explained by the square law (σ∝ε2). It distributes horizontally uniform and vertically exponential. The strain is maximum at the ends of punch and decreases near the bottom. The strain distribution is not uniform.
    (5) On the way of unloading, the stress decreases not proportional to the mean pressure on the punch surface but slowly in the beginning of unloading. The principal axes rotate in some region. The residual stress remains on the bottom and the sides. The recovery of deformation is about 3% under unloading.
    (6) The use of a simple slip-line solution as a rough approximation can be justified in some cases.
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  • Hiroaki Masuda
    1979 Volume 16 Issue 8 Pages 491-495
    Published: August 10, 1979
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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