|
|
|
| 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.
|
|
Received: 05 August 2017
|
|
|
|
| [1]李婷,侯素珍,王平. 黄河内蒙古河段来沙组成对河道淤积影响研究[J]. 泥沙研究,2013(4):41-49. LI Ting, HOU Suzhen, WANG Ping. Impact of inco-ming sediment grain sizes on channel sedimentation in Inner Mongolia Reach of Upper Yellow River[J]. Journal of sediment research, 2013(4):41-49.(in Chinese)[2]赵琳琳,马太玲,于健,等.引黄灌区侧向取水口泥沙淤积和入渠特性[J]. 排灌机械工程学报,2014,32(8):685-690. ZHAO Linlin,MA Tailing,YU Jian,et al. Siltation features and into canal characteristics at water intake of lateral for Yellow River irrigation area[J]. Journal of drainage and irrigation machinery engineering, 2014,32(8):685-690.(in Chinese)[3]谷晓娟.污水处理厂污水和污泥气力提升系统的研究与应用[D]. 广州:华南理工大学,2013.[4]KATO H, MIYAZAWA T, TIMAYA S, et al. A study of an air-lift pump for solid particles[J]. Bulletin of JSME, 1975,18(117):286-294.[5]MAHROUS A F. Airlift pump with a gradually enlarged segment in the riser tube[J]. Journal of fluids enginee-ring, 2013,135(3):031301.[6]POUGATCH K, SALCUDEAN M. Numerical modelling of deep sea air-lift[J]. Ocean engineering, 2008,35(11/12):1173-1182.[7]XU Huibin, ZHONG Wenqi, JIN Baosheng, et al. Flow pattern and transition in gas-liquid-solid three phase spouted bed[J]. Powder technology, 2014,267(11):18-25.[8]胡东.水下矿物浆料气力提升理论模型与流动特性试验研究[D].武汉:武汉大学,2016.[9]魏纳,孟英峰,李皋,等.欠平衡钻井正气举过程井筒瞬态流动数值模拟[J]. 石油学报,2014,35(1):166-171. WEI Na, MENG Yingfeng, LI Gao, et al. Transient flow characteristics of gas lift in underbalanced drilling[J]. Acta petrolei sinica, 2014,35(1):166-171.(in Chinese)[10]LAWNICZAK F, FRANCOIS P, SCRIVENER O, et al. The efficiency of short airlift pumps operating at low submergence ratios[J]. The Canadian journal of chemical engineering, 1999,77(1):3-10.[11]SHABAN H, TAVOULARIS S. Identification of flow regime in vertical upward air-water pipe flow using differential pressure signals and elastic maps[J]. International journal of multiphase flow, 2014,61(5):62-67.[12]WANG Zhaohui, GAO Quanjie, LIAO Zhenfang, et al. Study on the mechanism and experiment of water treatment by electro-hydraulic power impulse technology[J]. Desalination and water treatment, 2014,52(37/38/39):6914-6919.[13]陈振瑜,李志彪,何利民,等.垂直管气液两相弹状流流动特性研究进展[J]. 管道技术与设备,2005(4):3-6. CHEN Zhenyu, LI Zhibiao, HE Limin, et a1. Advance in the investigation on the hydrodynamic characteristics of gas-liquid slug flow in vertical pipes[J]. Pipeline technique and equipment, 2005(4):3-6.(in Chinese)[14]MOHSEN Azadi, REZA Gheisari, MOHAMMAD REZA Ansaria. An experimental investigation on the effect of middle length and inclination angle of S-shaped channel on two-phase flow pattern[J]. Experimental thermal and fluid science, 2014,58:36-47. |
| [1] |
. ---[J]. Journal of Drainage and Irrigation Machinery Engin, 2019, 37(11): 936-940. |
|
|
|
|
