粉体工学会誌
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
48 巻, 12 号
Special Issue of 2011 Spring Annual Meeting and Forum
選択された号の論文の5件中1~5を表示しています
  • 井門 孝博, 乾 真規, 田中 敏嗣, 辻 拓也
    2011 年 48 巻 12 号 p. 822-828
    発行日: 2011/12/10
    公開日: 2012/01/07
    ジャーナル フリー
    It is important to develop a numerical simulation method to predict the behavior of droplets in granular media, which concerns wide range of natural phenomena and industrial particulate processes. Mainly empirical methods have been applied to complex granular problems including liquid transport by granular motion such as liquid transport by granular convection, liquid bridge formation between particles, breakup of a liquid bridge and so on. Effective numerical simulation method will enable us to design products more effectively. In this study we examined the applicability of MPS (Moving Particle Semi-implicit) method to the wetting behavior of droplet on a solid plane and between particles. We performed the numerical simulations of a droplet motion on an inclined plane and between a couple of particles by using the MPS method contains surface tension and wetting model, and made validation using the corresponding experiments.
  • 石原 真吾, 曽田 力央, 加納 純也, 齋藤 文良, 山根 圭司
    2011 年 48 巻 12 号 p. 829-833
    発行日: 2011/12/10
    公開日: 2012/01/07
    ジャーナル フリー
    We have investigated on size reduction process in an autogenous (AG) grinding a solid in a tumbling mill with 12.1 cm in inner diameter and 14.7 cm in length. The model solid samples were two kinds of cubic shaped sugar particles, having 15 mm x 15 mm x 15 mm. The size reduction process of these samples was monitored by using DEM simulation as well as the experiment, both of which were conducted in ambient condition. As a result, the motion of the samples simulated has been shown by surface grinding model, and this grinding behavior explains fairly well the phenomena observed by the experiment. The fine particle production ratio observed by the experiment is in agreement quantitatively with that shown by the DEM simulation. Consequently, we have confirmed that the AG grinding process of the solid samples in the mill can be promoted by surface grinding under the present condition.
  • 天野 寛之, 渡邉 啓晶, 池野 栄宣
    2011 年 48 巻 12 号 p. 834-839
    発行日: 2011/12/10
    公開日: 2012/01/07
    ジャーナル フリー
    We examined the effect of pleat shape and length of cartridge filter on the dust removal performance. By introducing the parameter taking account of installation space, we found that the existence of optimum design point of P / H (ratio of pleats pitch P to height H) ranged from 0.15 to 0.25. Moreover, the removal performance tests for the various length of the cartridge revealed that the amount of gas under the same pressure drop was not proportional to the length of the cartridge. From concerning accessing the amount of gas processed per unit volume of equipment, it was found that optimum length exist and it depends on the pulse air consumption. In addition, we examined the effects of the distance between pulse jet nozzle and the top of cartridge filter Hp and the inner cylinders diameter of the cartridge filter D on the dust removal performance. We found that the existence of optimum design point of D / Hp was in 0.4 - 0.5 for cartridge length 540 mm, air pressure 0.5 MPa, air consumption 4.5 LN / piece.
  • 竹田 尚広, 西村 祐介, 小澤 和三, 山本 徹也, 福井 国博, 吉田 英人
    2011 年 48 巻 12 号 p. 840-846
    発行日: 2011/12/10
    公開日: 2012/01/07
    ジャーナル フリー
    The purpose of this study is to improve particle separation performance by use of the modified type dry-cyclone. By use of the apex cone at the inlet of dust box, it is possible to decrease the fluid velocity component in the dust box and to reduce the re-entrainment of particles from the dust box.
    It is found that the optimum apex cone angle is 70 deg. The particle collection efficiency is improved by use of the additional flow injection near the upper plate and inlet guide plate. It is also newly found that the intake of free air at the cyclone inlet part increases particle separation efficienrcy under low pressure drop condition.
  • 辻 拓也, 成田 栄嗣, 田中 敏嗣
    2011 年 48 巻 12 号 p. 847-858
    発行日: 2011/12/10
    公開日: 2012/01/07
    ジャーナル フリー
    The behavior of flows in engineering applications such as a fluidized bed and a pneumatic conveyer is highly complex and a reliable numerical model has been desired. The flows are usually with solid walls that give considerable effects on flow field. To enhance the prediction capability of a model, it is important to include its effect properly. Observation of microscopic flow near walls shall enhance our understandings on flow behavior and model improvements. In the present study, direct simulations were performed to investigate the effect of walls on a flow field in the microscopic level. The effects of void fraction, particle Reynolds number and particle diameter were discussed. A prediction performance of existing correlation equations usually used in model calculations was also investigated. It is found that, by using Ergun and Beetstra equations, there is a large discrepancy in the region within 1 particle diameter from a wall.
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