Abstract There is a paucity of riser data for industrial scale units, particularly with regard to the solids fraction. This is especially true for detailed spatially distributed values. To alleviate this problem, NETL installed a 0.445 m tall electrical capacitance volume tomography (ECVT) sensor 9.66 m from the gas distributor of its industrial size (15.45 m high and 0.3 m diameter) circulating fluidized bed (CFB) cold model. A series of tests were conducted to investigate the gas-solid flow behavior using high density polyethylene (PPE) solids. Static electricity was successfully minimized using Larostat and humidification. Time averaged radial solid fractions profiles are presented and discussed. The time and spatially averaged solid fractions measured by the ECVT agree well with estimates from the pressure drop. The annular thickness was measured and found to increase with increases in the solids flow rate and decrease with increases in the gas velocity. Comparisons of the annular thickness and solids fraction as determined from the ECVT unit were compared to existing correlations. The average error ranged from 13% to 275% which is not surprising since the literature correlations were developed from data on much smaller units and for significantly different particles.

中文翻译：

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用电容体积断层扫描 (ECVT) 研究工业规模循环流化床立管中的核心环流

摘要 工业规模装置的提升管数据很少，特别是关于固体部分的数据。对于详细的空间分布值尤其如此。为了缓解这个问题，NETL 在距离其工业规模（15.45 m 高和 0.3 m 直径）循环流化床 (CFB) 冷模型的气体分配器 9.66 m 处安装了一个 0.445 m 高的电容体积断层扫描 (ECVT) 传感器。进行了一系列测试以研究使用高密度聚乙烯 (PPE) 固体的气固流动行为。使用 Larostat 和加湿成功地减少了静电。呈现和讨论了时间平均径向固体分数分布。ECVT 测量的时间和空间平均固体分数与压降的估计值非常吻合。测量环形厚度，发现随着固体流速的增加而增加，随着气体速度的增加而减少。从 ECVT 装置确定的环厚度和固体分数的比较与现有的相关性进行了比较。平均误差范围在 13% 到 275% 之间，这并不奇怪，因为文献相关性是根据小得多的单位和显着不同粒子的数据得出的。