The Impact of Pipe Inclination on Sediment Deposition at the Sedimentation Basin in the Yellow River

Abstract

【Objective】 This paper aims to study the optimal layout of inclined pipes in sedimentation basins in attempts to improve sediment removal efficiency in the Yellow River. 【Method】 Three different layouts of inclined pipes were compared: a single layer (Fs), and two double-layer layouts (Fv1, Fv2), in a gravity-operated sedimentation basin. Sediment distribution of three typical particle sizes in the upstream (Su), middle stream (Sm), and downstream (Sd) was measured. Sediment tests were conducted under a low (Qq) and a high (Qs) flow rate to compare the impact of pipe inclination on sedimentation in the three layouts. 【Result】 The large granular sediment settled prior to entering the inclined pipes, while the fine particle sediment (<75 µm) was effectively captured by the inclined pipe. These resulted in an outlet sediment content of 0.342~1.354 kg/m3 and a sand content of 0~0.018 kg/m3. Among the different inclined pipe layouts, Fv2 exhibited the lowest sediment and related sand, silt, and clay content at the outlet, followed by Fv1 and Fs. The Fv2 effectively controlled the outlet sediment content at 0.342~0.991 kg/m3, showing a reduction of 10.01%~20.95% and 26.82%~38.83%, compared to Fv1 and Fs, respectively. Furthermore, different Yellow River sections showed variations in sediment content, with the Su section exhibiting the lowest sediment and related sand, silt, and clay content. 【Conclusion】 The sediment treatment capacity varied significantly among the three inclined pipe layouts for different Yellow River sediments (P<0.05). The V-shaped inclined pipe layout was superior to the conventional layout, with the Fv2 (inclination angles of 60° and 45°) being most effective.

Keywords

• yellow river sediment
• sediment basin
• inclined pipe
• inclined pipe layout form