本文主要在探討Group C 粒子( 高筋麵粉﹑矽藻土﹑高嶺土﹑輕質碳酸鈣
﹑砂﹑氮化矽﹑.alpha.－氧化鋁和鎢)在聲波振動流體化床中的行為。實
驗在一內徑24milimeter, 高約１meter的壓克力管中進行。利用波形產生
器輸出頻率260 Hertz和振幅8 Voltage(root mean square)的方波來推動
揚聲器, 以其所發出的聲波作為流體化床的振動源。由在振動膨脹床的範
圍內, 床的壓力降與粒子接觸點 (床膨脹) 間的關係,即可估計出粒子間
作用力的大小及 Group C／A 的分界。由吾人實驗結果指出, 在聲波振動
作用下, 粒子床有較大的床壓降及床膨脹, 即對流體化品質有所改善。當
靜床高較低時, 振動床內的流體化品質愈佳, 且流體化的情況和靜床高有
關。同時將Jaraiz et al. (1992)的理論加以修正, 吾人提出 C／A 轉移
數Ic/a; 利用此數, 吾人即可預測出Group C／A在低密度(＜4 gram per
cubic meter)的分界範圍(L2H2), 並與文獻上的其它結果加以比較。此
外, 吾人也將本研究所使用的Group C 粒子, 依其在振動床中的行為再細
分為三類。

The behavior of Group C powder (flour, diatomaceous earth,
kaolin, calcium carbonate, sand, silicon nitride, aluminum
oxide and tungsten) was studied in the sound waveｓ vibrated
fluidized beds (SVFB). Experiments were done in a transparent
plexiglas tube (24 milimeter I.D. by 1 meter high). A speaker
supplied by a function generator with square waves ( frequency
260 Hertz, amplitude 8 Voltage(Vrms) ) was used to generate
sound as the source of vibration of fluidized beds. From bed
pressure drop versus coordination number (bed expansion) data
of vibrated and expanded beds, the interparticle force and the
boundary between Group C and Group A could be estimated. The
results showed that the powder bed had larger bed pressure drop
and bed expansion during vibration of sound, the quality of
fluidization was improved. The lower static bed height was, the
better quality of fluidization was. The behavior of
fluidization was dependent on the static bed height. Based on
the modified theory of Jaraizet et al.(1992), the C/A
transition number Ic/a was proposed. By using this number, the
Group C/A boundary at lower density ( ＜4 gram per cubic meter
) (L2H2) could be predicted and compared further with other
results in the literature. In addition, the Group C powder used
in this study could be classified into three sub-groups
according to their behavior in the vibrated beds.