2004 Fiscal Year Final Research Report Summary
Development of Technology for Separation and Enrichment of Nano-Aerosol Particles
| Project/Area Number |
15560651
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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 |
Properties in chemical engineering process/Transfer operation/Unit operation
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| Research Institution | Kanazawa University |
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Principal Investigator |
FURUUCHI Masami Kanazawa University, Graduate School of Natural Science and Technology, Associate Professor, 自然科学研究科, 助教授 (70165463)
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| Co-Investigator(Kenkyū-buntansha) |
HATA Mitsuhiko Kanazawa University, Graduate School of Natural Science and Technology, Research Associate, 自然科学研究科, 助手 (00334756)
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| Project Period (FY) |
2003 – 2004
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| Keywords | nano particles / ambient control / inertial separation / supersonic flow / concentration / gaseous compounds / 超音波 |
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| Research Abstract |
1)Determination of optimal geometry of supersonic virtual impactor as a nano-particle separator and concentrator : A supersonic dichotomous sampler with a Laval nozzle was numerically investigated into its performance either as a separator or a shape of nozzle cross-section (rectangular and circular), clearance between nozzle exit and particle collection probe inlet, and probe geometry on the separation characteristics were simulatively investigated. The effect of sheath flow along the nozzle wall and center on the separation characteristics and the particle wall loss were also analyzed. The supersonic dichotomous sampler was designed to make the flow as similar to the stagnation flow, which provided a distinct standing shock wave between the nozzle exit and the collection probe inlet. The smaller distance from the collection probe inlet to the standing shock wave was related to the cutoff size of particle. The sheath air flow improved the separation sharpness and reduced the particle
… More
wall loss.
2)Devising of equipment and investigation into performance : The devise designed as the result of the investigation 1) was equipped and the separation performance and behavior of gaseous PAHs were investigated using the ambient air. Influence of humidity was shown to be significant for gaseous PAHs compounds with higher water solubility.
3)Improvements of nano-particle separator and concentrator : The devise was modified and improved based on the results 2). The nozzle geometry and probe geometry were adjusted.
4)Summary : According to obtained results, the guideline for the design of supersonic impactor was proposed. The cutoff size of the rectangular nozzle is 200-300nm under the ambient pressure condition while the circular nozzle has 50-80nm of the minimal cutoff size. Gaseous PAH compounds and organic carbon was shown to be effectively collected in the downstream of supersonic flow due to the highly saturated condition. The water vapor was condensed in the supersonic flow and gaseous PAH compounds such as Nap, Ace, Phe, which have higher water solubility were collected on the water droplet. Combining the deposition or condensation of gaseous compounds in the supersaturated condition and deposition to water droplets, the gaseous compounds can be effectively collected using the preset technique. Less
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Research Products
(10 results)
