@techreport{oai:kanazawa-u.repo.nii.ac.jp:00043101,
 month = {Mar},
 note = {1)最適装置構造と操作条件の検討:
ノズル内、捕集プローブ近傍、開孔部内の流れを数値シミュレーションにより解析し、ノズル形状、ノズル出口周囲の形状、捕集プローブ形状、開孔部寸法、ノズル出口-プローブ間距離の影響を検討し、衝撃波形成位置と分離特性の関係を明らかにした。
2)装置試作と性能検討:
1)で検討・決定されたノズル構造、操作条件に基づいて装置を設計・試作し、大気エアロゾルをモデルエアロゾルとして粒子分離・濃縮、超音速流れ場中のガス状成分の挙動を含めた装置特性を検討した。
3)分級・濃縮装置の改良(ノズル、捕集板形状、管路形状の調整等)を行った。
4)本試作装置を用いたTiO_2ナノ粒子エアロゾルによる空気中有害ガス状物質(ホルムアルデヒド、VOC、PAHsなど)の高効率分解を行う装置を既存のTiO_2気相合成装置と光触媒用紫外線照射装置と組み合わせて試作し、基礎的な特性に検討を加えた。今後も検討を継続する。
5)総括
得られた結果から、目的とする粒子径範囲と粒子径に応じた装置形状の指針(矩形断面では200nm前後、円形断面では50nm前後のカット径、処理流量範囲の相違など)実用装置設計のための指針を得ることができた。また、製品化のための市場調査を行い、ナノ・粒子製造プロセスだけでなく、環境浄化装置としての展開も期待できることを明らかにした。, 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 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., 研究課題/領域番号:15560651, 研究期間(年度):2003-2004, 出典：「ナノ・エアロゾル粒子の高速分級・濃縮技術の開発」研究成果報告書　課題番号15560651
  (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)
　　　本文データは著者版報告書より作成},
 title = {ナノ・エアロゾル粒子の高速分級・濃縮技術の開発},
 year = {2005}
}