Hydrodynamics of shallow fluidized bed of coarse particles
Hydrodynamics of shallow fluidized bed of coarse particles
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DOI：
10.1016/j.cej.2005.09.002
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发表时间：
2005-11
影响因子：
15.1
通讯作者：
Danica V. Brzić;D. Ahchieva;E. Piskova;S. Heinrich;Ž. Grbavčić
中科院分区：
文献类型：
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作者：
Danica V. Brzić;D. Ahchieva;E. Piskova;S. Heinrich;Ž. Grbavčić
本研究的目的是对粗颗粒浅层沸腾床的流体力学特性进行实验研究。空气是流态化的液体。使用直径为1 mm和1.8 mm的γ-Al_2O_3颗粒，密度为1080千克的−_3(均为Geldart D)。实验在矩形截面面积为100 mm×100 mm的柱中进行，温度分别为20℃和500℃，测量了绝对压力和差压波动。用标准差分析和幅谱分析确定了流态化的流态化模式。在表观速度0-4.5ms−-1范围内，发现了三种不同的流态化区域：单一气泡区、快速生长气泡区和湍流流态化。确定了与床层结构有关的这些区域的一般质量特征。通过实验确定了不同制度之间的转换速度，并与文献中的关联式进行了比较。提出了预测粗颗粒系统湍流流态化起始速度的新关联式：REC=0.326Ar0.52。
The aim of the present study is experimental investigation of hydrodynamics of shallow fluidized bed of coarse particles. Air was fluidizing fluid. γ-Al2O3particles of 1mm and 1.8mm in diameter and density of 1080kgm−3(both Geldart D) were used. Experiments were carried out in a column with rectangular cross-section area of 100mm×100mm, at temperatures of 20°C and 500°C. Measurements of absolute and differential pressure fluctuations were employed. Standard deviation and amplitude spectra analysis were used to determine fluidization regimes. In the range of superficial velocities 0–4.5ms−1, three different regimes were found: single bubble regime, rapidly growing bubble regime and turbulent fluidization. General qualitative characteristics of those regimes regarding bed structure were ascertained. Transition velocities between regimes were experimentally determined and compared with literature correlations. A new correlation for prediction the velocity at the beginning of turbulent fluidization in the coarse particle systems was proposed as follows: Rec=0.326Ar0.52.