1998 Fiscal Year Final Research Report Summary
Basic Research of a New System of Accurate Wet-Type Submicron Classification
| Project/Area Number |
09650185
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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 |
Fluid engineering
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
TSUCHIDA Yoichi Nagoya Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (30144190)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Centrifugal Classification / Wet-Type Classification / Almost Rigidly Rotating Flow / Stewartson Layer / Ekman Layer / Classification Performance / Particle Motion / Particle Dispersion |
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| Research Abstract |
The purpose of the present study is to develop a new centrifugal system which can very accurately classify even submicron particles suspended in a liquid (water) with a very low mass-concentration (ex. 1%) by applying an almost rigidly rotating through-flow produced within a highly rotating double-walled container. We have considered the classification performance of this new system by analysing the flow and the particle motion and by making the classification measurement of silica particles. Consequently, we have obtained the following main conclusions.
(1) The cut size decreases with decreasing Ekman number (increasing rotation rate) at a constant Rossby number (constant value of {through-flow rate / (rotation rate) ^0. ^5}), and decreases with decreasing Rossby number (decreasing through-flow rate) at a constant Ekman number (constant rotation rate). The experimental result of the Ekman-number- and Rossby-number-dependence roughly agrees with the theoretical one.
(2) The sharpness index approaches the value of the perfect classification with decreasing Ekman number at a constant Rossby number and with decreasing Rossby number at a constant Ekman number. The experimental result of the Ekman-number- and Rossby-number-dependence agrees with the theoretical one qualitatively, but does not quantitatively at all.
(3) The highest sharpness index value of 1.35 obtained experimentally is comparable to that of the recent accurate centrifugal classifiers, although the cut size is larger than the latter because of lower rotation rates (less than 1400rpm).
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