Study of Elutriation from a Vortexing Fluidized Bed

渦旋式流體化床中的淘淅研究

10.6358/JCYU.200503.0021

錢建嵩(Chien-Song Chyang)；李仲明(Chung-Ming Li)

流體化床 ； 渦旋式 ； 淘淅速率 ； Fluidized Bed ； Vortexing ； Elutriation Rate

中原學報

33卷1期（2005 / 03 / 01）

21 - 27

英文

本研究係於一內徑19公分高四公尺的壓克力冷模中進行，分別對傳統氣泡式流體化床(BFB)及渦旋式流體化床(VFB)做批式操作測試，空床氣速約0.9至1.8米/秒，床質爲屬於B群粒子的玻璃珠，大粒子的粒徑爲545微米，小粒子的粒徑爲115微米。本研究提出一關聯關係式用以預估渦旋式流體化床中的比淘淅速率常數，實驗數據與預估值相當吻合。依據實驗數據我們發現中間同心圓出口可有較低的淘淅速率，缺點是乾舷區的壓降較大。

A systematic investigation on the elutriation conducted in a cold model 0.19m diameter and 4.0m height was reported. Both bubbling fluidized bed (BFB) and vortexing fluidized bed (VFB) were studied by batch operation. The superficial velocity ranges from 0.9m/s to 1.8m/s. Glass beads classified in the B Group in Geldart's classification were used as the fluidized material. The diameter of the coarse particles was 545pm, and the diameter of fine particles used for the elutriation test was 115pm. An empirical correlation to predict the specific elutriation rate constant (K*) in VFB is founded in this study. The agreement between the calculated values and the experimental data is generally good. The results obtained from experimental data show that the concentric circle exhaust tube is the best design. The pressure drop within the freeboard at various superficial velocities is also reported.