Abstract: The extents of axial gas mixing for turbulent fluidization, fast fluidization and dilute phase transport regimes in a circulating fluidized bed testing unit of 90mm inside diameter and 8m height were measured and characterized by dynamic response technique consisting of tracer pulsed input, dual probe detection and computer on-line analysis system. Experimental results indicated that the extents of axial gas mixing were related to the bed voidage mainly determined by both the gas velocity and the solids circulating rate. A one dimensional pseudo-homogeneous dispersion model was used with the least squares method in time domain to fit in with the experimental data. As a result, a generalized correlation of the gas dispersion coefficient is obtained:

摘要： 在内径90mm、高8m的快速循环流化床试验装置上,用非理想脉冲示踪、双探头检测、计算机实时采样分析的方法,对湍流流态化、快速流态化和气力输送不同流动状态的气体混合程度分别进行了测量,结果表明均存在不同程度的轴向混合.轴向扩散系数主要与由气体速度和固体循环量决定的床层空隙度有关;用拟均相一维扩散模型对结果进行处理,时域拟合法求取模型参数,并将轴向扩散系数进行了关联,得到如下统一关联式D_e=0.1953ε~(-4.1197)