| Project/Area Number |
08455353
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Tokyo Institute of Technology |
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Principal Investigator |
OGAWA Kohei Tokyo Institute of Technology, Dept.of Chem.Eng., Professor, 工学部・化学工学科, 教授 (00016635)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIKAWA Shiro Tokyo Institute of Technology, International Cooperation Center for Science and, 理工学国際交流センター, 助教授 (40220602)
KURODA Chiaki Tokyo Institute of Technology, International Cooperation Center for Science and, 理工学国際交流センター, 教授 (80114867)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥5,400,000 (Direct Cost: ¥5,400,000)
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| Keywords | agitated vessel / agitated vessel with aeration / mixedness / information entropy / impulse response method / 撹拌槽 / 通気撹拌槽 / 通気撹拌 / 乱流 |
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| Research Abstract |
Though there many investigations on the mixing phenomena in an agitated vessel, the detail of mixing mechanism has not been made clear. In the multi-phase mixing in an agitated vessel which is very significant in the industry, there remain many unsolved problems, especially the mixing mechanism of gas-liquid in an agitated vessel has not been clarified at all.
It has been known that there remains concentration distribution of absorbed gas in liquid even after enough time lapsed. There is possibility that this concentration distribution leads the decrease of quality of product. In order to except this concentration distribution, it is indispensable to obtain enough information about mixing process in an agitated vessel. From the experimental restrict the experiment based on impulse response method that the tracer is injected into liquid or the gas is changed step wisely by the tracer gas has been done. However, even the effect of circulation flow or fluctuating flow on the mixing phenomena has not been made clear.
In this investigation, at first, the mixing process in an agitated vessel with aeration is paid attention. The mixing process in an agitated vessel with aeration was investigated experimentally by injecting the injecting nitrogen gas by the tracer gas carbon dioxide gas impulsively into the vessel under normal steady operational condition. On the basis of the change in concentration of absorbed tracer gas in water with time, which is measured by using an electrode conductivity probe, the change in the mixedness based on the information entropy with time was calculated. Based on the results it is clarified that the mixing process consists of three steps ; the first step is associated with rise of gas from the nozzle to the impeller, the second step is associated with one circulation of discharge flow from the impeller, and the third step is associated with the circulation flow and fluctuating flow.
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