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Volume 49, Issue 9
Special Issue of 49th Symposium on Powder Science and Technology
Displaying 1-6 of 6 articles from this issue
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Original Paper
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Shuji Matsusaka, Murino Kobayakawa, Yasuyuki Hosoh, Masatoshi Yasuda2012 Volume 49 Issue 9 Pages 658-662
Published: September 10, 2012
Released on J-STAGE: September 20, 2012
JOURNAL FREE ACCESSA novel micro-feeder for fine powders is developed using a vibration shear flow mechanism. This feeder consists of a cylindrical tube and a bottom, which are vibrated by piezoelectric vibrators. Particles in the tube are discharged through a narrow gap between the lower edge of the tube and the bottom surface. The frequency and maximum amplitude of the vibration applied were 320 Hz and 30μm, respectively. Micron, submicron, and nanoparticles were used in the experiments to study the effect of the particle size, amplitude and phase difference of the vibrations, gap distance, and inclination angle of the tube on the mass flow rate of the particles discharged from the tube. Furthermore, the stability of the mass flow rate was analyzed. The experimental results showed that the proposed method has high performance in micro-feeding of fine powders.View full abstractDownload PDF (581K) -
Shuji Matsusaka, Murino Kobayakawa, Takashi Yamamoto, Masatoshi Yasuda2012 Volume 49 Issue 9 Pages 663-668
Published: September 10, 2012
Released on J-STAGE: September 20, 2012
JOURNAL FREE ACCESSThis paper presents the detailed study of particle behavior in the vibration shear flow. Micron, submicron, and nanoparticles were discharged through a narrow gap whose walls were vibrated by two piezoelectric vibrators in a tangential direction at in-phase and anti-phase. The mass flow rates of the discharged particles were measured to evaluate the basic performance of the developed method. Then the flow behavior was observed using a high-speed microscope camera. The experimental results showed that the particles oscillated with a frequency of several hundred hertz in the narrow gap, and that the anti-phase vibration was more effective than the in-phase vibration for the disintegration of fine-particle agglomerates.View full abstractDownload PDF (1495K) -
Michitaka Suzuki, Tomohiro Tanaka, Kenji Iimura, Hiroshi Satone2012 Volume 49 Issue 9 Pages 669-674
Published: September 10, 2012
Released on J-STAGE: September 20, 2012
JOURNAL FREE ACCESSWe have developed a non-contact measuring method of mixing process in the mixer using a micro focus X-ray computer tomography. And its effectiveness was demonstrated from the experimental observation of mixing process of two kinds of particle with different X-ray transmission. The cross sectional image of particle packed bed in the cylindrical container rotation type mixer was obtained from the X-ray transmission images, and the image analysis of these cross sections was performed. From the brightness of each particle image, the particle materials can be detected and obtains the ratio of each particle on every section.
The degree of mixing was calculated from the measured distribution of each particle, and the effect of the separation plate in the mixer on the mixing performance of a cylindrical container rotation type mixer was studied. The actual mixing state in the mixer can be measured by non-contact, and the mixing degree in the mixing process from cross-sectional image analysis can estimate directly was shown.View full abstractDownload PDF (619K) -
Mitsuru Nikaido, Kazuhide Totani, Takuya Fukumura, Mitsumasa Osada, Ko ...2012 Volume 49 Issue 9 Pages 675-682
Published: September 10, 2012
Released on J-STAGE: September 20, 2012
JOURNAL FREE ACCESSIn the area of bioethanol production based on enzymatic saccharification and fermentation of wood raw materials, enzymatic saccharification methods have attracted attention because of small environmental loads. It is of great importance to establish a reliable preprocessing technique for wood raw materials for efficient enzymatic saccharification. We have developed converge mills-mechanochemical mills with high energy application-and revealed that they were capable of high-efficiency milling of wood raw materials in a short time. The multistage pre-milling processes in combination with hammer milling for pulverization and converge milling for amorphization （complex dry mechanochemical milling） were more efficient, and the enzymatic saccharification properties were remarkably improved. Another new development was the 6-liter semi-continuous type converge mill, which achieved milling performance equivalent to the conventional 1-liter batch type converge mill.View full abstractDownload PDF (1042K)
Review
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Fumio Saito2012 Volume 49 Issue 9 Pages 683-692
Published: September 10, 2012
Released on J-STAGE: June 04, 2015
JOURNAL RESTRICTED ACCESSThis paper introduces, first of all, the representative research results concerning single particle crushing of spherical and irregular shaped single particles made of different artificial materials and minerals by using several crushing devices. The topics on it are consisted of 1） size effect, 2） environmental effect, 3） loading rate effect on strength, fracture energy and new surface produced of the spherical particles, and 4） single particle fracture of irregular shaped particles under impact loading. Then the topics are focused on mechanochemistry of different materials caused by dry and wet grinding using mainly a planetary mill, and its application to material processing. The first part of them is mechanical activation of solid powder by grinding, and this activation enables us to assist solubility of chemical species from the milled material as well as sinterability of the milled product at relatively low temperature than as usual. Several examples of synthesis of functional materials are shown by only dry grinding a mixture, followed by separation of useful substances from minerals and waste materials. Finally, a novel method for generation of hydrogen as an energy source at high concentration and high yield from biomass has been introduced by its grinding and heating at low temperature.View full abstractDownload PDF (1330K) -
Hidetoshi Hirahara, Sumio Aisawa, Eiichi Narita2012 Volume 49 Issue 9 Pages 693-703
Published: September 10, 2012
Released on J-STAGE: June 04, 2015
JOURNAL RESTRICTED ACCESSThis review first surveies the characteristics （chemical composition, structure, synthesis and intercalation properties） of layered double hydroxide （LDH）, alternaotely known as anionic clay or hydrotalcite-like compound, and then provides the production methods of some eco-nanomaterials using LDH. Usually, LDH is characterized by its easy preparation under mild conditions, formation of nano-sized plate-like particles and unique properties such as high anion exchange capacity and good biocompatibility. In addition, the delamination of LDH has been achieved recently by chemical techniques to produce LDH nanosheets. Based on these features, the production examples of functional organic-inorganic nanohybrids, polymer-inorganic nanocomposites, and new carrier materials of drug delivery system from LDH are reviewed together with the recent results of our LDH research works.View full abstractDownload PDF (1564K)
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