論文名稱:

氣固旋轉流體化床顆粒流動特性與乾燥性質研究

Studies of flow behaviors and drying investigation in a rotating gas-solid fluidized bed

研究生:

羅國祐

指導教授:

楊士震

    學校名稱:

建國科技大學

系所名稱:

機械工程系暨製造科技研究所

          學號:

98017003

畢業學年度:

100

      出版年:

民101

關鍵字:

旋轉流體化床 rotating fluidized bed

離心力 centrifugal force

流體化 fluidization

乾燥 drying

摘要:

本研究建立旋轉氣固流體化床實驗設備，探討旋轉流化床粉體粒子流動行為與乾燥效應，配合高速攝影系統觀察旋轉流體化床粒子受到離心力、流體阻力與粒子間碰撞力交互作用所產生的複雜流動行為，實驗粉體物質使用不同粒徑大小之玻璃珠，實驗參數包括粒徑大小、旋轉速度與充填氣速，本研究分為二階段進行：首先探討旋轉流化床單一粒徑和雙成份混合粒徑粒子流體化行為，探討臨界流體化速度與壓力降關係，實驗結果並與Ergun方程式理論值比較；第二階段探討旋轉流化床濕顆粒乾燥效益，實驗結果顯示單一粒徑與雙成份混合粒子床體壓力降與臨界流化速度隨著粒徑與轉速的增加而增加；雙成份混合粒子床體壓力降與臨界流化速度隨著小粒子濃度的增加而降低；在乾燥效應分析上，單一粒徑與雙成份混合粒子床體粒子出口溫度降所需時間隨著轉速增加而降低；雙成份混合粒子出口溫度降所需時間隨著小粒子濃度降低而降低。

This study established a rotating gas-solid fluidized bed equipment to investigate the flow behaviors and drying efficiency of rotating granular powders. A high speed camera system is used to observe the complex flow behaviors due to the centrifugal force, the fluid drag force and the interaction forces between particles. The glass beads with different sizes are used as the granules in the experiment. The experimental parameters include the particle size, the rotation speed and the superficial gas velocity. This study is divided into two stages: firstly, the flow behaviors of rotating fluidized bed with mono-disperse and binary mixtures are performed to examine the relationship between pressure drop and critical fluidization velocity. The experimental results are compared with the theoretical value of Ergun equation. Secondly, the drying efficiency of wet particles is performed with different rotating conditions. The experimental results show that the pressure drop and critical fluidization velocity increased with the particle size and the rotating speed for both mono-disperse and binary mixtures. In the cases of binary mixtures, the pressure drop and critical fluidization velocity decreased with the concentration of small particles. The outlet temperature drop period decreased with the increase of rotating speed for both mono-disperse and binary mixtures. The outlet temperature drop period decreased with the decrease of concentration of small particles for the cases of binary mixtures.