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Your search keyword '"Fukasawa, Tomonori"' showing total 93 results
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93 results on '"Fukasawa, Tomonori"'

64. Effects of Surface Finish of Nonwoven Fabric Bag Filters on Filter Efficiency.

Author

Fukasawa, Tomonori, Kanaoka, Chikao, Ishigami, Toru, and Fukui, Kunihiro

Subjects
*SURFACE finishing, *AIR filters, *NONWOVEN textiles, *POLYTEF, *MEMBRANE filters, *PRESSURE drop (Fluid dynamics), *PERMEABILITY
Abstract

The effects of the surface finish of the bag filter for industrial use on the spatial distributions of the fiber mass, air permeability, and thickness were examined using a nonwoven fabric filter made of polytetrafluoroethylene (PTFE) with no surface finish and two nonwoven fabric filters made of PTFE with different surface finishes, i.e., resin finish and membrane finish. The surface finish had no impact on the non‐uniformity in air permeability distribution. However, the air permeability of the filters was reduced with the use of a surface finish. In addition, the specific filtration resistance of the filter media increased by approximately 1.2 times in the case of the resin finish and 4.2 times for the membrane finish. Hence, the influence of the membrane finish on the filter efficiency is extremely strong. [ABSTRACT FROM AUTHOR]

Published
2022
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65. Synthesis of NiCuZn ferrite nanoparticles from metallic nitrate solutions using the microwave direct denitration method and evaluation of its properties.

Author

Karisma, Achmad Dwitama, Shinokawa, Yoshihiro, Fukasawa, Tomonori, Ishigami, Toru, and Fukui, Kunihiro

Subjects
FERRITES, COPPER ferrite, FERROMAGNETIC materials, EVALUATION methodology, MICROWAVES, NANOPARTICLES, NITRATES
Abstract

NiCuZn ferrite nanoparticles having the chemical composition Ni0.5Cu0.1Zn0.4Fe2O4 were synthesized by the microwave direct denitration (MDD) method from a mixture of metal nitrate hydrate solutions. A single-phase of NiCuZn ferrite powder with an average particle diameter of about 30 nm could be obtained using this method at reaction temperatures higher than 900 °C. This diameter was less than one-fifth of that obtained by the conventional solid-state reaction (SSR) method. Therefore, the NiCuZn ferrite synthesized by MDD method had a higher sinterability than the SSR method. It was categorized as a soft ferromagnetic material and its saturation magnetization was three times more than of the SSR. Its coercivity was about half of that by the SSR method. For the NiCuZn ferrite sintered with Bi2O3 additive, the saturation magnetization obtained from the MDD method was about 80% of that of the SSR method, while the coercivity was almost identical. [ABSTRACT FROM AUTHOR]

Published
2021
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82. Existence Form of Potassium Components in Woody Biomass Combustion Ashes and Estimation Method of Its Enrichment Degree

Author

Maeda, Norio, Fukasawa, Tomonori, Katakura, Takaaki, Ito, Munechika, Ishigami, Toru, Huang, An-Ni, and Fukui, Kunihiro

Abstract

Woody biomass is a growing renewable energy source, and the emitted combustion ash may serve as valuable materials. In this study, the relationship between the potassium concentration in combustion ash and the particle size was investigated for several types of biomass ashes with different morphologies. The form of the potassium components in the ash was also analyzed to examine this relationship. From the results, a method to estimate the degree of potassium enrichment was proposed. The potassium concentration first decreases rapidly with an increasing mass median diameter and then continues to decrease gradually, although this relationship depends upon the properties of the combustion ash. It was also found that almost all of the potassium component in the ash existed as relatively small particles composed of crystallized hydro-soluble potassium compounds, such as KCl, K2SO4, etc., although the particle size and crystalline phases varied according to the type of power plants. The classification process was implemented in an actual biomass power plant and demonstrated to produce combustion ash with enriched potassium. The enrichment factor calculated from the size distributions of the potassium component particles and other components qualitatively agreed with the enrichment factor obtained experimentally for all types of ashes. Ash with a potassium concentration above 300 mg/g could be successfully acquired on an industrial scale by collecting the finer ash selectively, using size classification equipment constructed at the biomass power plant.

Published
2024
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93. Direct numerical simulation and experimental validation of flow resistivity of nonwoven fabric filter.

Author

Rozy, Mohammad Irwan F., Ueda, Masaki, Fukasawa, Tomonori, Ishigami, Toru, and Fukui, Kunihiro

Subjects
NONWOVEN textiles, COMPUTED tomography, COMPUTATIONAL fluid dynamics, COMPUTER simulation, FILTERS & filtration, DARCY'S law
Abstract

We numerically study and then experimentally validate the flow resistivity of commercial nonwoven fabric filters used for a bag filter system. To represent a realistic flow field inside the filters during simulation, a numerical method that coordinates the filter structure obtained by X‐ray computed tomography imaging with computational fluid dynamics using the immersed boundary method is developed. The effects of superficial velocity, porosity of the filter domain, and type of filter on pressure drop are investigated and analyzed based on Darcy's law. The predictions from our numerical method are quantitatively in good agreement with the experimental measurements. We demonstrate that the Kozeny constants of the filters can be estimated by utilizing the solid volume fraction. These results demonstrate that our simulation method can be used to clarify the effects of porosity, fiber arrangement, and fiber shape on the pressure drop. Finally, its application to water droplet permeation is demonstrated. [ABSTRACT FROM AUTHOR]

Published
2020
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