螺旋曝气特性与流场分析  

Performance and flowanalysis of spiral aeration

作　　者：周涛[1] 孙建红[1] 孙智[1] 刘可[1] 

机构地区：[1]南京航空航天大学航空宇航学院,南京210016

出　　处：《东南大学学报（自然科学版）》2016年第5期1038-1044,共7页Journal of Southeast University：Natural Science Edition

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

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.To improve the efficiency in mass transfer of oxygen,a novel aeration method with spiral flowfield characteristics was presented. By making theoretical analysis on the spiral aeration,we find that the total contact area of gas-liquid two-phase is increased and the aeration efficiency is improved. Based on its principle analyses,a numerical calculation of spiral aeration tank flowfield was carried out by using Euler-Euler two-fluid model,and compared with that of traditional aeration tank（ vertical and horizontal aeration tanks）. Comparing results showthat the average mixing efficiency of a spiral aeration tank is about 23 times of a vertical aeration tank,and 10 times of a horizontal aeration tank. On the other hand,the analyses turn out that in a spiral aeration tank the path of the gas is helix,the vortex motion is stronger,the length of the path is longer,the total contact area is larger and the aeration efficiency is higher. The distributions of flowfield and gas holdup are more uniform in spiral aeration method.

关 键 词：螺旋曝气法 螺旋曝气池 混合效率 气含率 

分 类 号：TH17[机械工程—机械制造及自动化] V240.2[航空宇航科学与技术—飞行器设计]