The temporal and cross‐sectional distributions of particles in a 127 mm diameter fluidized bed have been obtained using a new generation, high‐speed electrical capacitance tomography. Two planes of eight electrodes were used and mounted at 160 and 660 mm from the gas distributor which was a 3 mm thick porous plastic plate (maximum pore size of 50‐70 μm). 3 mm diameter, nearly‐spherical polyethylene granules made up the bed. Experiments at sampling frequencies of 200‐2000 cross‐sections per second and gas superficial velocities from just below the minimum fluidization to 83% above minimum fluidization velocities were used. The time series of the cross‐sectional average void fractions have been examined both directly and in amplitude and frequency space. The last two used probability density functions and power spectral densities. The information gathered shows that the fluidized bed was operating in the slugging mode, which is not surprising given the size of the particles. It has been found that an increase in the excess gas velocity above the minimum fluidization velocity resulted in an increase in the mean void fraction, an increase in the length and velocity of the slug bubbles as well as the bed height, and a slight decrease in the slug frequency. The results are presented in a level of detail suitable for comparison with later numerical simulation.

中文翻译：

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使用电容层析成像技术研究流化床行为

使用新一代高速电容层析成像技术已获得了直径为127 mm的流化床中颗粒的时间和截面分布。的八个电极的两个平面被用于和安装在160和从气体分配器这是3mm厚的多孔塑料板（最大孔径50-70的尺寸660毫米μ m）。床层直径为3毫米，几乎是球形的聚乙烯颗粒。实验使用的采样频率为每秒200-2000断面，气体表观速度从最小流化速度以下到最小流化速度以上的83％。横截面平均空隙率的时间序列已直接进行了检查，并且在幅度和频率空间中也进行了检查。最后两个使用概率密度函数和功率谱密度。收集到的信息表明，流化床以团块模式运行，考虑到颗粒的大小，这不足为奇。已经发现，超出最小流化速度的过量气体速度的增加导致平均空隙率的增加，团状气泡的长度和速度以及床高的增加，以及团状频率的略微降低。详细介绍了结果，适合与以后的数值模拟进行比较。