1991 Fiscal Year Final Research Report Summary
Dynamic Microfiltration of Superfine Suspended Solids-Liquid Mixtures by Use of High-Speed Rotary Membrane Filter.
| Project/Area Number |
02650683
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
化学工学
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| Research Institution | Nagoya University |
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Principal Investigator |
MURASE Toshiro Nagaya Univ. Dept. of Chem. Eng. Professor, 工学部, 教授 (70023067)
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| Co-Investigator(Kenkyū-buntansha) |
IWATA Masashi Nagoya Univ. Dept. of Chem. Eng. Associate, 工学部, 助手 (10151747)
IRITANI Eiji Nagoya Univ. Dept. of Chem. Eng. Assoc. Professor, 工学部, 助教授 (60144119)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Superfine suspended solids / Dynamic filter / Dynamic Microfiltration |
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| Research Abstract |
To maintain a high flux level of filtrate through moving the deposit layer of filter cake, the operational mode of rotational dynamic filtration was studied. The efficient applications of a high-speed rotating ceramic filter were shown using several kinds of slurries covering high viscous liquid-solids system.
1) With a ceramic membrane of a much smaller pore size than the particle size of suspended solids, the dynamic microfiltration followed the principle of thin-cake filtration. A filtrate rate equation was derived for the thin-cake filtration process by introducing a dynamic filtration coefficient newly defined. On the basis of the fact that the dynamic coefficient depends on a controlling variable composed of the shear stress acting on membrane surface and the coefficient of constant pressure filtration, a basis for the design and evaluation of rotating microfiltration was proposed.
2) Based on the filtration rate equation, the time dependence of filtrate flux was examined for crossflow filtration operation. The filtration characteristics were related to a number of operational variables, in view of the fact that the final steady flux can be estimated as a function of both the membrane shear stress and the constant pressure filtration coefficient. A reliable data analysis was proposed for evaluating the filtration performance.
3) In the crossflow filtration of high viscous slurry, some limitations in increasing the filtration rate appeared though there being possibility of producing a high shear force due to the low fluidity of crossflowing slurry. For eliminating this difficulty of the reduction in filtration time, the relative motion between slurry and membrane, created by the high speed rotation of the latter, can be efficiently utilized to achieve a high flux filtration of viscous liquid-solids system.
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