1996 Fiscal Year Final Research Report Summary
Hydrodynamic Analysis on a Slurry Bubble Column Using Ultrasonic Technique
| Project/Area Number |
07650890
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
化学工学一般
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| Research Institution | Shizuoka University |
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Principal Investigator |
UCHIDA Shigeo Shizuoka University Department of Chemical Engineering Professor, 工学部, 教授 (10023194)
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| Co-Investigator(Kenkyū-buntansha) |
MAEZAWA Akinori Shizuoka University, Graduated School of Electronic Science and Technology Assoc, 大学院電子科学研究科, 助手 (20209365)
OKAMURA Seichi Shizuoka University, Department of Electronics Engineering Professor, 工学部, 教授 (20022014)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Slurry Bubble Column / Ultrasonic / Holdup / flow scheme / Transmission time |
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| Research Abstract |
In this work, an ultrasonic method has been developed to analyze the hydrodynamics in a slurry bubble column. To establish the ultrasonic technique, the relationships among velocity difference in term of transmission time difference of ultrasound, the ultrasonic attenuation and the dispersed phase holdups in gas-liquid and liquid-solid systems have been derived. Comparison between the theory and the experimental results showed a good agreement. Based on those relations, a model for simultaneous measurement of gas and solid holdups in three-phase systems has been proposed by utilizing the velocity changes of two ultrasonic pulses with different frequencies or the velocity change and the attenuation of one ultrasonic pulse.
The method gas been applied to investigate the axial as well as radial distributions of gas and solid holdups in a slurry bubble column for various operating variables. The macroscopic flow scheme model in the slurry bubble column has been proposed based on the structu
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re of the bubble distribution. The relationships among the gas bubble distribution, the flow scheme and the particle concentration distribution have been investigated for various operating variables including the gas and the liquid velocities, the amount of solid loading and particle diameter. The mechanism of radial migration of solid particles in the slurry bubble column has been discussed.
To describe the radial distribution of the gas bubble and the solid particles in the slurry bubble column, a bubble-wake-particle diffusion model has been proposed. The model has been developed by combining the bubble-wake model and the particle/bubble diffusion model and by taking into account of the bubble-particles and wake-particles interactions, the particles diffusion and the lateral lift force. The calculated particles distribution profiles have been aompared with the measured ones by the ultrasonic method, and showed that the model can describe well the trend of the distributions observed experimentally. Less
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