Optimization Of Deflector Perforation And Supports Of The Vortex Settling Basin For Suspended Sediment

Deflector is an important component of the vortex settling basin(VSB).In order to prevent the deflector from falling and destroying accidents,the deflector can be partially perforated to reduce the load on the deflector,and the column support system can also be installed under it.This paper combines theoretical analysis and series of model tests to obtain the optimal deflector perforation position,opening ratio,and the radial position,arrangement and body shape of the column support system for a similar separation performance of the VSB,which can provide basis and guidance for the optimal design of the promotion and application of the VSB.(1)The opening rate of the defelctor is fixed,and the separation performance of the VSB is different when the opening position is different.Only when perforated in the overflow area of the deflector,the load on the deflector is significantly greater than that of the traditional one.When the inflow discharge is 0.5 to 1 times the design discharge,the amount of sedimentation is increased in 9.57% to 60.73%,which is not conducive to the deflector stabilization;only perforated in Zone I(starting of the deflector)or Zone III(end of the deflector)the reduction is not significant;and perforated in Zone I and III at the same time,the amount of sedimentation decreases significantly,,the amount of sediment deposition on the deflector decreased by 44.72%,sediment trapping efficiency decreased by 3.72%,and the water consumption ratio increases0.77%.When opening rate at this area is 8.67%?13%,the separation performance of the VSB is similar to that original one without any openings.(2)When a single row column are arranged under the deflector,the radial position at 0.75 B was(B=the width of the deflector)exhibted little effect to the vortex characteristics and separation performance of the VSB than other radial positions.When the double-row columns are arranged under the deflector,the sediment trapping efficiency,the sediment flushing effiecieny,the mass of sediment deposition on the basin and water consumption ratio of the VSB under the type II column are similar to those with no column,VSB showing a higher separation performance compared with type H column.When type II columns are arranged side by side,the amount of siltation in the funnel room is smaller than columns arranged staggeredly.