Journal of the Society of Powder Technology, Japan
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
Search
Advanced search
OR
Browse
Search
Volume 25, Issue 7
Displaying 1-6 of 6 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • Developement of Ring Ball Mill Simulation Model
    Nobuyasu MEGURI, Kazunori SHOJI, Tadashi HASEGAWA
    1988 Volume 25 Issue 7 Pages 430-436
    Published: July 10, 1988
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.25.430
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The mathematical model previously developed for a ring ball mill based on specific rates of breakage, breakage distributions, and primary and secondary classification actions was further refined. In particular, empirical expressions are presented for both primary and secondary classification actions as a function of the mill and classifier geometry and operating conditions. In addition, the scale-up factor with the make-up feed rate determined in a pilot-scale mill was further developed for larger mills. Model simulations based on parameters measured in the Hardgrove mill with the present classification models and scale-up factors correctly predicted the circuit behavior of industrial-scale mill systems.
    Furthermore, some of the factors affecting the mill performance were investigated by the present simulation model. As a result, the feed size distribution and the total crushing load on balls were found to be dominant factors.
    View full abstract
    Download PDF (757K)
  • Simulation of a Maximum Storage Amount of Coal for Preventing Spontaneous Combustion and Degradation in Quality
    Hiroshi TAKAHASHI, Tatsuo TANAKA, Eiji OBATA, Takao TAKEUCHI
    1988 Volume 25 Issue 7 Pages 437-442
    Published: July 10, 1988
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.25.437
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The temperature increase curve due to the natural oxidation of a coal deposit was numerically simulated for a coal bed having a ‘spherical’ geometry. The maximum temperature occurred at the center of the bed when oxygen was fully supplied within the bed and near the surface when oxygen decreased due to the process of the reaction. The rate of temperature rise was significantly affected by the activation energy and frequency factor of the coal. Furthermore, the measurement of the moisture adsorbed on the oxidized coal samples showed that the loss in mass due to oxidation increased remarkably at temperatures above 120°C. In assuming the limiting temperature in coal storage to be 120°C, a maximum allowable amount of coal storage was estimated for various kinds of coal under the conditions of neither spontaneous combustion nor significant, loss in mass.
    View full abstract
    Download PDF (749K)
  • The Classification Mechanism of an Air Classifier Using Centrifugal Force (Part 2)
    Numerical Analysis of Factors Influencing Classification Accuracy
    Yuichi SATO, Takuo NAGAMINE, Yukiyoshi YAMADA
    1988 Volume 25 Issue 7 Pages 443-450
    Published: July 10, 1988
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.25.443
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Trajectories of particles thrown into a forced vortex-type centrifugal air classifier are numerically calculated, and the effects of the magnitude of blade interval, initial conditions of a particle, such as angular position and velocity, and particulate capture radius on classification accuracy are examined.
    It is found that partial classification efficiency is improved as the blade interval is reduced. A particle trajectory is influenced by the angular position and circumferential velocity of a particle at its injection into a classification chamber.
    View full abstract
    Download PDF (997K)
  • The Size Classification of Particles by an Air Elutriator under Reduced Pressure
    Isao AOKI, Takuzoh MATSUYAMA
    1988 Volume 25 Issue 7 Pages 451-455
    Published: July 10, 1988
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.25.451
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The gravitationl size classification of particles was carried out under reduced pressure using an air elutriator. This method was attemped to improve the performance paying attention to see if the effect of the slip factor in the ‘Cunningham correction’ increased with decreasing pressure.
    The performance under reduced pressure was much better that that under atmospheric pressure. It was found that the cut size varied according to the operating pressure. The cut size under reduced pressure could by estimated from the equation of the terminal velocity of a particle, including the Cunningham correction. The partial separation efficiency under reduced pressure agreed well with the calculated values.
    View full abstract
    Download PDF (628K)
  • Injection Molding of Ceramics (1)
    History, Processing and Rheology of Organic Additives
    Minoru TAKAHASHI, Suguru SUZUKI
    1988 Volume 25 Issue 7 Pages 456-461
    Published: July 10, 1988
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.25.456
    JOURNAL FREE ACCESS
    Download PDF (2033K)
  • Deformation and Failure of Granular Materials
    Hajime MATSUOKA
    1988 Volume 25 Issue 7 Pages 462-468
    Published: July 10, 1988
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.25.462
    JOURNAL FREE ACCESS
    Download PDF (2247K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top