Experimental investigation of bubbling in particle beds with high solid holdup

粒子ベッドの浮き上がる気泡運動の実験的研究

Cheng, S.*; 平原 大輔*; 田中 鷹平*; 権代 陽嗣*; Zhang, B.*; 松元 達也*; 守田 幸路*; 福田 研二*; 山野 秀将   ; 鈴木 徹; 飛田 吉春

Cheng, S.*; Hirahara, Daisuke*; Tanaka, Yohei*; Gondai, Yoji*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*; Fukuda, Kenji*; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu

水を液体として用い観察タンクの底から窒素を発生させバブルを作る実験が2次元(2D)3次元(3D)それぞれの状態で個別に行われた。粒子ベッド高さ(30mmから200mm),粒子直径(0.4mmから6mm)そして、粒子タイプ(アクリルビーズ,ガラス,アルミ,ジルコニウム)等で粒子ベッドに変化を持たせた。これらの実験でイメージ解析によって初めて3種類のバブル特性が観察され、さらに表面バブル頻度、2D, 3D状態の表面バブルサイズなどのバブル挙動の定量的な詳細分析で検証された。

The current experiments were conducted under two dimensional (2D) and three dimensional (3D) conditions separately, in which water was used as liquid phase, and bubbles were generated by injecting nitrogen gas from the bottom of the viewing tank. Various particle-bed parameters were varied, including particle-bed height (from 30 mm to 200 mm), particle diameter (from 0.4 mm to 6 mm) and particle type (beads made of acrylic, glass, alumina and zirconia). Under these experimental conditions, three kinds of bubbling behavior were observed for the first time using digital image analysis methods that were further verified by quantitative detailed analysis of bubbling properties including surface bubbling frequency and surface bubble size under both 2D and 3D conditions.