Experimental study on sediment transport in river channel based on pneumatic lifting technology
CHEN Qiuliang1, WU Shijing1, LI Xiaoyong1, WANG Aihua2*
1.Key Laboratory of Hubei Province for Waterjet Theory & New Technology, Wuhan University, Wuhan, Hubei 430072, China; 2.Comprehensive Engineering training Center of Wuhan University, Wuhan, Hubei 430072, China
Abstract：In order to examine the effectiveness of pneumatic lifting technology in river dredging processes, a sediment transport test platform using the pneumatic lifting technology was set up based on the usual condition of 70% dimensionless immersion depth. At 0-4.5 m/s air inlet velocities, a series of pneumatic lift experiments were carried out to identify the air inlet velocity for the optimum lif-ting efficiency. Meanwhile, the flow patterns at different air inlet velocities, especially at 0.6 and 1.0 m/s, were analyzed based on the image processing function in Matlab. As a result, the solid particle motion characteristics near the optimum lifting efficiency were obtained. It is shown that the solid particle flow patterns and mention characteristics are directly affected by the air inlet velocity. In a fixed immersion depth, the sand lifting efficiency is determined by the air inlet velocity. By studying the flow patterns at various air inlet velocities, the reasons for the formation of different flow patterns have been clarified. When the inlet velocity is 1.0 m/s, the gas phase is fully dispersed into uniformly-sized small bubbles, and strong momentum exchanges take place in gas, liquid and solid phases. Consequently, most of the kinetic energy of the gas phase is transferred into the solid and liquid phases, and the lifting efficiency is the highest. At the same time, the flow pattern is also the optimum for airlift. Establishing the relationship between the dredging efficiency and the air inlet velocity by experimentation, the feasibility of pneumatic lifting technology in river channel dredging has been confirmed.
陈秋良, 巫世晶, 李小勇, 王爱华*. 基于气力提升技术的河道泥沙输送试验研究[J]. 排灌机械工程学报, 2018, 36(5): 397-403.
CHEN Qiuliang, WU Shijing, LI Xiaoyong, WANG Aihua*. Experimental study on sediment transport in river channel based on pneumatic lifting technology. Journal of Drainage and Irrigation Machinery Engin, 2018, 36(5): 397-403.
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