【摘要】 为了获得循环流化床床内颗粒团的行为特性,利用高速数字摄像与激光相结合的图像拍摄系统,以玻璃珠为床料,在一截面为200 mm×200 mm、高为4 m的冷态循环流化床实验台上获得了循环流化床内颗粒团形成、运动及破碎过程的动态连续图像。通过对数字图像的分析,床内颗粒团可以依据结构形态分成抛物体状、U形颗粒团、松散型颗粒团、致密型颗粒团、贴壁带状颗粒团以及小颗粒团等几类,并获得了不同位置上这些颗粒团的一些特性参数如:形状、大小和存在时间等.在分析床内颗粒团的形成及破碎过程的同时发现颗粒团在过渡区和稀相区内具有不同的运动特性.更多还原

【Abstract】 To understand the behaviors of the cluster in circulating fluidized bed(CFB) riser,experiments were carried to acquire the image sequences of the formation,movement and decomposition of the glass beads clusters on a cold circulating fluidized bed riser with 200 mm×200 mm square cross-section and 4 m height by the video system consisting of a high-speed digital video camera and a green laser sheet.Based on the captured images,the clusters may be sorted by the structure and shape into paraboloid-shaped cluster,U-shaped cluster,incompact cluster,compact cluster,near-wall banding cluster and small cluster.Simultaneity,the properties of the clusters such as structure,velocity and existing life are obtained.In additional,different movement characteristics of the clusters in the transition zone and the dilute zone are shown while analyzing the processes of the formation and decomposition of the cluster.更多还原