螺旋曝气特性与流场分析

发布时间：2018-05-04 02:20

  本文选题：螺旋曝气法 + 螺旋曝气池　； 参考：《东南大学学报(自然科学版)》2016年05期

【摘要】：为了提高曝气效率,提出了一种具有螺旋流场特性的新型曝气方式.通过对螺旋曝气进行理论分析发现,该方法可以提高气液两相的总接触面积,进而增强曝气效率.同时采用EulerEuler双流体模型对螺旋曝气池流场进行了数值模拟,并与传统曝气方式(垂直曝气和水平曝气)进行对比分析.工程实例分析结果表明,当曝气总流量为7.48 kg/s时,螺旋曝气池全流域平均混合效率约为垂直曝气池的23倍,且为水平曝气池的10倍.此外,对螺旋曝气池中涡运动和湍流脉动等流动机理进行分析以及对气含率分布的考察发现,螺旋曝气中的气羽柱前行路径成螺旋状,涡运动和湍流脉动增强,使得气液总接触面积增大,流场更均匀,曝气效率更高.
[Abstract]:In order to improve aeration efficiency, a new aeration method with helical flow field characteristics was proposed. Through theoretical analysis of spiral aeration, it is found that this method can increase the total contact area of gas-liquid two phases and further enhance aeration efficiency. At the same time, the EulerEuler two-fluid model was used to simulate the flow field of spiral aeration tank, and compared with the traditional aeration mode (vertical aeration and horizontal aeration). The result of engineering example shows that when the total aeration flow is 7.48 kg/s, the average mixing efficiency of spiral aeration tank is about 23 times of that of vertical aeration tank and 10 times of that of horizontal aeration tank. In addition, the flow mechanism of vortex motion and turbulence pulsation in spiral aeration tank is analyzed and the gas holdup distribution is investigated. It is found that the forward path of the gas plume in spiral aeration becomes spiral, and the vortex motion and turbulence pulsation are enhanced. The gas-liquid contact area is increased, the flow field is more uniform, and the aeration efficiency is higher.
【作者单位】： 南京航空航天大学航空宇航学院;
【基金】：国家自然科学基金资助项目(21407077) 江苏省“六大人才高峰”资助项目(2012-JNHB-014) 江苏高校优势学科建设工程资助项目
【分类号】：X703
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本文编号：1841154