【作者】 张英； 姜斌； 黄国强； 徐世民； 李鑫钢；

【Author】 Zhang Ying, Jiang Bin, Huang Guoqiang, Xu Shimin, Li Xingang (School of Chemical Engineering, Tianjin University, Tianjin 300072; National Engineering Research Center of Distillation Technology, Tianjin University, Tianjin 300072)

【机构】 天津大学化工学院； 天津大学精馏技术国家工程研究中心；

【摘要】 以自行设计安装的二维砂箱,并首次采用乙炔作为示踪气体模拟了地下水曝气(air sparging,AS)。研究表明,在20-40目白色石英砂多孔介质体系中,AS总曝气压力基本不随气体流量变化,但气体影响半径和平均饱和度随流量增加而增加。在流量为0．15m3／h时, ROI为18cm,气体的平均饱和度为0．017;当流量增为 0.30m3／h时,ROI增大到37cm,平均饱和度增加为0．031。另外,曝气流量越大,水位上升越高,达到稳定所需时间越长。由乙炔示踪的AS气体分布研究中发现,在0．05m3／h曝气流量下,AS气体的分布稀疏而且分散;当曝气流量为0．15m3／h时,AS气体的分布均匀,形状近似为对称抛物形,抛物线中部区域气体的密度较高,浓度梯度较小,而抛物线边缘区域中气体的密度较低,浓度梯度较大;在0．30m3／h曝气流量条件下,气体的分布非常不均匀,较易形成优先流。更多还原

【Abstract】 This paper presents the results of a laboratory experimental study which investigated the injected gas flow patterns development within an self-designed two-dimensional aquifer simulation apparatus. In 20-40 mesh quartzose sands, an increase in gas flow rate would increase the radius of influence and the average gas saturation, but the injection pressure did not increased. When the gas rate was 0.15m3/h, the ROI measured 18cm, and the average gas saturation was 0.017. when the gas rate of 0.30m3/h was used, the ROI increased to 37cm and the average gas saturation increased to 0.031. Additionally, when higher injected gas flow rate was used, the water lever increased more and the time to reach stabilization was longer. Acetylene was used to trace the gas distributions during AS. It was found that a few thin and disperse gas channels formed inside the medium when the gas flow rate was 0.05 m3/h. when gas was injected at 0.15m3/h, the gas equably distributed and the whole gas plume formed a roughly symmetrical parabolic structure. The gas was denser and the concentration gradients was lower in the middle of parabolic plume at that flow rate, while the things were reverse at the edge of the plume. When added to the flow rate to 0.30m3/h, the gas plume was very asymmetrical and easily traveled along a path of least resistance.更多还原