Design Criterion Of Structure Size And Experimental Study On Optimization Of Overflow Weir On The Circular Rings Desilting And Sediment Ejection Basin

Circular rings desilting and sediment ejection basin are new secondary sediment treatment facilities, Provide a new idea for the separation of water and sand. In this paper, through the study of basic data of hydraulics and other related, experimental data and previously done by people as the basis, Analysis of Circular rings desilting and sediment ejection basin structure size related factors, Initially proposed the design criterion of plane inner diameter and the depth elevation. The design criterion of plane inner diameter : According to the project needs to deal with the smallest particle of sediment, through the rational formula to calculate the corresponding stop flow or non-depositing velocity, finally take the velocity to calculation the inner diameter of circular rings desilting and sediment ejection basin. The design criterion of the depth elevation: According to the maximum particle size of sediment which settlement in desilting basin, by using the dynamic formula of the starting particle size corresponding to the start velocity, and through the start velocity to calculate the cone slope, finally Through this inverted cone slope obtained the corresponding depth of desilting basin.According to the original and circular rings desilting and sediment ejection basin on the basis of theory and experiment data, ring the sediment subsidence is inversely proportional to the ring velocity; The longer the overflow weir, the smaller the average flow velocity, the overflow weir length is circular rings desilting and sediment ejection basin is conducive to the important case of desanding. To reduce average velocity inside ring, increase the overflow weir length, the original circular rings desilting and sediment ejection basin physical model was used to structural optimization: the original smooth circle of overflow weir is adjusted to labyrinth weir, to increase their overflow weir length, reduce the ring inside the flow velocity, and improve the efficiency of the desilting. The results showed that: the labyrinth weir overflow weir length is longer than the original weir increased 1.48 times, velocity decrease significantly, is beneficial to sediment subsidence ring.