Developmental study of a new technique to classify submicron particles
Grant-in-Aid for Developmental Scientific Research (B).
|Research Institution||Nagoya Institute of Technology|
NAKABAYASHI Koichi Nagoya Institute of Technology, Mechanical Engineering, Professor, 工学部, 教授 (90024231)
若林 稔 株式会社神戸製鋼所機械, エンジニアリング事業部, 主任研究員
TSUCHIDA Yoichi Nagoya Institute of Technology, Mechanical Engineering, Associate Professor, 工学部, 助教授 (30144190)
MORINISHI Youhei Nagoya Institute of Technology, Mechanical Engineering, Lecturer, 工学部, 講師 (40222351)
|Project Fiscal Year
1991 – 1993
Completed(Fiscal Year 1993)
|Budget Amount *help
¥17,300,000 (Direct Cost : ¥17,300,000)
Fiscal Year 1993 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1992 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1991 : ¥16,100,000 (Direct Cost : ¥16,100,000)
|Keywords||Classification / Submicron Particle / Almost Rigidly Rotating Flow / Stewartson Layr / Ekman Layr / Interior Region / Particle Motion / Partial Classification Efficiency / 分級 / サブミクロン粒子 / 準剛体回転成層流 / ステワ-トソン層 / エクマン層 / 内部領域 / 粒子運動 / 部分分級効率 / ステワートソン層 / サブミクロン微粒子分級 / 分級性能 / せん断層|
We have studied a new classifier using the almost rigidly rotating through-flow between rigidly totating housing and rotor, and have obtained the following results.
1. Theoretical results
(1) In the interior region, the axial velocity depends on slopes and curvatures of the housing and rotor walls, while the azimuthal velocity depends only on the slopes.
(2) The ratio of the Ekman transport on the housing to that on the rotor is determinated by the ratio of the function of housing's slope to that of the rotor's.
2. Experimental results
(1) The condition of occurrence of a steady axisymmetric regime of the flow is epsilon(〕SY.ltorsim.〔)1.6E^<0.46>, Where epsilon and E are Rossby and Ekman numbers.
(2) Velocity distributions of the interior region agree with the theoretical results.
(3) The Stewartson layr constitutes of the inner layr with a strong axial flow and the outer layr with a weak reverse flow.
(4) We got excellent classification efficiency (sharpness index * 1.5) for the case where the feed is supplied only within the Ekman layr on the rotor.
3. Computational analysis
(1) A computational code to simulate the almost rigidly rotating through-flow between the coaxially rotating rotor and housing and a computational code to analyze motion of particles in the flow are constructed.
(2) In the analysis of the almost rigidly rotating through-flow between the rotating disk and cylindrical tank, we have numerically considered the mechanism of the present classification technique.
(3) Theoretical and experimental results are confirmed by the computational analysis.
(4) Almost all particles at the inlet go to Stewartson layr through Ekman layr.
(5) Coarse particles go to rigidly rotating region by the effect of centrifugal force at Stewartson layr.
(6) Particle classification efficiency are specified by a parameter Dp/^<0Eepsilon>0 (Dp ; diameter of particles, E ; Ekman number, epsilon ; Rossby number).
Research Output (19results)