Journal of the Society of Powder Technology, Japan

Effect of Surface Condition of Fabric Filter on Pressure Drop Evolution in Repeated Pulse-jet Cleaning

Yuping Yao, Masashi Wada, Ning Mao, Hidehiro Kamiya, Chikao Kanaoka

2008 Volume 45 Issue 1 Pages 4-11
Published: January 10, 2008
Released on J-STAGE: May 27, 2010

DOIhttps://doi.org/10.4164/sptj.45.4

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A standard testing method was applied to measure the evolutions of pressure drop during the dust collection by five fabric filters with different surface treatments on a base filtration material. The measurement was repeated until the number of pulse-jet cleaning reaches to 100. In general, the filtration cycle of a pulse jet cleaning filter consists of three stages, i. e., inner filtration, uniform dust layer formation and surface filtration. However, it was found that the inner filtration stage does not appear when the base filter is laminated with a membrane and entangled fiber layer. The present paper analyzed and discussed the effects of filter surface characteristics and base material structure on the pressure drop evolution during a filtration cycle in terms of the duration of three stages.

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Development of a Coarse Grain Simulation Methodology for Discrete Element Method in Gas-Solid Flows

Mikio Sakai, Seiichi Koshizuka

2008 Volume 45 Issue 1 Pages 12-22
Published: January 10, 2008
Released on J-STAGE: May 27, 2010

DOIhttps://doi.org/10.4164/sptj.45.12

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Discrete element method is an effective approach for evaluating the particle behavior in granular flows, whereas it is seldom used in investigating the design and the operation in industries. This is due to the fact that the number of particles is restricted by the limit of computer memories. Consequently the original discrete element method is difficult to be applied to the real-scale systems, where a large number of particles are dealt with. In this study, a new discrete element modeling for real-scale particle systems is proposed where a coarse grain represents a crowd of original particles. The new model, which is called coarse grain model, can be applied in general gas-solid flows by considering not only the drag force but also the contact force in the original particle system. In the present study, the coarse grain model is applied to a two-dimensional fluidized bed. The change in particle bed height, the bubble size and the minimum fluidization velocity are compared between the coarse grain model and the original particle system. The coarse grain simulation results show good agreement with those of the original particle system.

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Preparation of Transparent Nanocomposite Microspheres via Dispersion of High-Concentration TiO₂ and BaTiO₃ Nanoparticles in Acrylic Monomer

Masayoshi Takeda, Eishi Tanabe, Toru Iwaki, Akihiro Yabuki, Kikuo Okuy ...

2008 Volume 45 Issue 1 Pages 23-29
Published: January 10, 2008
Released on J-STAGE: May 27, 2010

DOIhttps://doi.org/10.4164/sptj.45.23

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Functional nanoparticle-dispersed composite polymer materials were prepared. Metal oxide nanoparticles such as BaTiO₃ (primary diameter: 20nm) and three sizes of TiO₂ (primary diameter: 7, 15, 20nm) were dispersed into acrylic monomer by means of beads mill filled with fine beads (50μm in diameter), and the nanoparticle-dispersed monomers were polymerized to obtain nanocomposite polymers by the suspension polymerization. The morphology, the nanoparticle dispersibility and the compressive strength of prepared polymer were evaluated. As a result, the TiO₂-dispersed acrylic polymer spheres were fairly uniform in size with the diameter of several micrometers, and had relatively high compressive strength of 257MPa. It was also confirmed from the transmission electron microscope that the nanoparticles were well-dispersed in the polymer matrix.

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The Powder Processing Technologies by Thermal Plasma Method

Keitaroh Nakamura, Kazuhiro Yubuta

2008 Volume 45 Issue 1 Pages 30-38
Published: January 10, 2008
Released on J-STAGE: May 27, 2010

DOIhttps://doi.org/10.4164/sptj.45.30

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Numerous techniques have been developed to synthesize powders with improved physical and chemical characteristics, and various production techniques are applied to the powder processing. Thermal plasma is one of the most attractive surface treatments in recent years. The thermal plasma produces a high temperature flame (about 10, 000K) to evaporate raw materials and quench the vapor rapidly outside the plasma flame so that nanoparticles form as a result of high supersaturation. The method has distinctive advantages over the conventional gas phase synthesis methods of nanoparticles. This paper reviews the synthesis of nanoparticles and the spheroidization of powder by radio frequency (RF) thermal plasma method.

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Crystal and Stability Properties of Clathrates for Drug Substances, and Application of Isothermal Microcalorimetry to Stability Studies

Hisashi Mimura

2008 Volume 45 Issue 1 Pages 47
Published: January 10, 2008
Released on J-STAGE: May 27, 2010

DOIhttps://doi.org/10.4164/sptj.45.47

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Research Life in Swiss Federal Institute of Technology Zurich

Kenji Iimura

2008 Volume 45 Issue 1 Pages 48-49
Published: January 10, 2008
Released on J-STAGE: May 27, 2010

DOIhttps://doi.org/10.4164/sptj.45.48

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Activity Report of Chubu Branch

Atsuya Towata

2008 Volume 45 Issue 1 Pages 50
Published: January 10, 2008
Released on J-STAGE: May 27, 2010

DOIhttps://doi.org/10.4164/sptj.45.50

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