NEW APPROACH TO EVALUATE THE PERFORMANCE OF HIGH LOADING RATE DISSOLVED AIR FLOTATION IN SEAWATER

摘要

More Dissolved Air Flotation (DAF) systems are becoming important process of seawaterdesalination plants as a pre-treatment process. To enhance DAF performance to achieve highloading rate more than 30 m/h, more accurate analysis and detailed optimization of flow patternin DAF tanks is required. In this study, a flow profile visualization method in three-dimensionsusing Acoustic Doppler Velocimeter (ADV) and MATLAB is presented. Flow patterns incontact zone/separation zone/effluent chamber are compared based on the analysis results fromthe DAF’s pilot tank. The experimental result using ADV is confirmed by theoretical velocities.Flow patterns are determined by combination of tank geometry and hydraulic conditions.Treatment performance of DAF process can be enhanced by modification of flow patterns.