Abstract: A new method to determine the characteristics of particle clusters in gas-solids circulating fluidized beds by using Phase Doppler Particle Analyzer (PDPA) was proposed. The influence of operating conditions on the structure of particle clusters in the dilute regime of circulating fluidized beds was investigated. Under the operating conditions in this study, both axial and radial distributions of the characteristics of particle clusters, such as time fraction, frequency, transient local voidage and axial average velocity, showed heterogeneous profiles. The radial profile was not affected greatly by solids circulation rate and showed a core-annulus structure. The axial profile changed much more significantly than the core-annulus structure when superficial gas velocity changed.

Key words: 颗粒团聚物, 相位多普勒粒子分析仪, 循环流化床

摘要： 提出了一种利用相位多普勒粒子分析仪（PDPA）来测量气固循环流化床中颗粒团聚物性质的方法，并运用此方法初步考察了操作条件对循环流化床稀相区中颗粒团聚物性质的影响.在本实验操作条件下，颗粒团聚物的时间分率、频率、内部空隙率以及轴向速度等性质都存在轴径向的不均匀分布，具有较明显的环核特征；固体循环速率对颗粒团聚物性质径向分布影响不大，表观气速的变化可引起其轴向分布规律发生显著改变，但其径向的环核特性仍然存在.

关键词: 颗粒团聚物, 相位多普勒粒子分析仪, 循环流化床