Stereoscopic PIV studies on the swirling flow structure in a gas cyclone
Stereoscopic PIV studies on the swirling flow structure in a gas cyclone
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DOI：
10.1016/j.ces.2006.01.024
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发表时间：
2006-07
影响因子：
4.7
通讯作者：
Zhengliang Liu;Ying Zheng;L. Jia;Jinyu Jiao;Qikai Zhang
中科院分区：
文献类型：
--
作者：
Zhengliang Liu;Ying Zheng;L. Jia;Jinyu Jiao;Qikai Zhang
了解旋流器内的旋流过程对改进旋流器的设计具有重要意义。一旦充分了解三维强旋流，就可以通过优化旋流器设计来提高旋流器的压降和分离效率等性能。本文采用立体粒子图像测速技术（Stereo-PIV）对旋流进行了研究。在旋流器进气速度7.2 ~ 15.0m/s范围内，同时测量了旋流器圆柱形、锥形分离区和料斗区瞬时场切向、轴向和径向速度。旋流器圆柱段和圆锥段的时间平均流型表现为：由切向气体速度产生的典型朗肯涡，内准强迫涡和外准自由涡；轴向气速内部向上流动，外部向下流动；由于径向气速的存在，在靠近壁面的区域发生向心流动。在料斗内，锥形体与圆柱壁之间的环空区域形成二次纵向循环流。实验结果表明，分离后的颗粒可能会从料仓重新夹带到旋流器中，降低旋流器的分离效率。
Understanding the swirling flow in a gas cyclone is of great importance in improving the cyclone design. Once the three-dimensional strong swirling flow is fully understood, cyclone performance such as pressure drop and separation efficiency can be improved by optimizing the cyclone design. The swirling flow was investigated by the stereoscopic particle image velocimetry (Stereo-PIV) in this work. The instantaneous whole-field tangential, axial, and radial velocities were measured simultaneously in the cylindrical and conical separation zone, and in the dust hopper area of the cyclone with gas inlet velocity of 7.2–15.0m/s. The time-averaged flow pattern in the cylindrical and conical sections of the cyclone showed: a typical Rankine vortex with inner quasi-forced vortex and outer quasi-free vortex which is generated by tangential gas velocity; inner upward flow and outer downward flow of axial gas velocity; and centripetal flow in the region close to the wall due to the presence of radial gas velocity. In the dust hopper, a secondary longitudinal circular flow is formed in the annulus area between the conical body and the cylindrical wall. Experimental results indicate that the separated particles may be re-entrained into the cyclone from the bin to degrade the separation efficiency of the cyclone.