Particle velocity and flow development in a long and high-flux circulating fluidized bed riser
Particle velocity and flow development in a long and high-flux circulating fluidized bed riser
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DOI：
10.1016/s0009-2509(01)00200-7
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发表时间：
2001-09
影响因子：
4.7
通讯作者：
J. Pärssinen;J.-X Zhu
中科院分区：
文献类型：
--
作者：
J. Pärssinen;J.-X Zhu
在一个10米高，76毫米内径。在高通量提升管中，颗粒速度的径向分布用五个光纤探针在七个轴向水平上测定，固体循环速率（固体通量）高达550 kg/m2 s，表观气体速度高达10 m/s。这项研究显示了一个更全面的一套径向配置文件下更高的通量比以往任何文献。根据颗粒速度和浓度的径向分布，可将轴向流动发展分为四个阶段。与低通量操作（<200 kg/m2 s）相比，在高通量操作（>300 kg/m2 s）下，颗粒速度的径向分布明显不均匀。在高颗粒流量下，表观气速对径向速度分布的影响大于颗粒流量。净固体向下流动只发生在底部有限条件下的壁面附近。
In a 10 m tall and 76 mm i.d. high-flux riser, radial profiles of particle velocities were determined with a five-fiber optic probe on seven axial levels, with solids circulation rate (solids flux) up to 550 kg/m2s and superficial gas velocity up to 10 m/s . This study shows a more comprehensive set of radial profiles under higher fluxes than any previous literature. Four axial stages of flow development were distinguished based on radial distributions of particle velocity and concentration. Compared to low-flux operations (<200 kg/m2s ), the radial profiles of particle velocity are significantly less uniform at high-flux operations (>300 kg/m2s ). The superficial gas velocity has more influence on the radial velocity profiles than the solids flux at high solids flux. Net solids downflow only occurs near the wall under limited conditions in the bottom section.