Agricultural irrigation accounts for roughly 70% of freshwater consumption globally. A high concentration of sediment in rivers in northern China has led to irrigation issues, including failures with drip irrigation, sediment deposits, erosion, and farmland desertification. In an effort to resolve these issues, hydraulic engineers have used vortex-tube and vortex-settling basins to remove sediment from the water. The sediment-carrying flow enters the VSB, which uses a vortex flow where the sediment deposits to the floor and the water drains out. The size of the VSB grows proportionally to the task, which can affect stability. Support columns are one solution, but their use has led to reduced sediment trapping.
Researchers Yuan Wang, Yiyi Ma, and Lin Li propose using vanes at the bottom of the columns. In their study, “Reducing Sediment Deposition on Columned Vortex-Settling Basin Floor by Installing Vanes” in the Journal of Irrigation and Drainage Engineering, experiments were conducted under different inlet sediment concentrations and inflow discharges to examine the effectiveness of the vanes. The authors measured and compared sediment deposits, trapping efficiency, and water abstraction ratio of the VSB with and without the vane. Learn more about their approach for removing sediment for agricultural irrigation at https://doi.org/10.1061/(ASCE)IR.1943-4774.0001734. The abstract is below.
Abstract
Vortex-settling basins (VSBs) have been constructed with support columns under the deflector to enhance the structural stability of the deflector. This paper presents a retrofit for such columned VSBs by installing vanes at the bottom of the support columns to reduce the sediment deposition on the basin floor. Experiments were conducted for VSBs both with and without vanes, where the thickness and mass of sediment deposition, sediment trapping efficiency, and water abstraction ratio of the VSBs were measured and compared. The VSB with vanes exhibited a similar sediment trapping efficiency and water abstraction ratio to the original columned VSB. When the inflow is equal to or greater than the design discharge, the vanes showed a significant effect on reducing the mass of sediment deposition by an average of 11.71% and 22.25%, respectively, and the formed sandwave on the basin floor was smaller. When the inflow is less than the design discharge, the effect of the vanes was limited, with the mass of sediment deposition slightly reduced by 5.25% on average.
Read the paper in full in the ASCE Library: https://doi.org/10.1061/(ASCE)IR.1943-4774.0001734.
