FINITE-ELEMENT ANALYSIS AND T-10 OPTIMIZATION OF OZONE CONTACTORS

A finite element analysis (FEA) computer program was used to model the hydraulic characteristics and to predict the corresponding residence time distribution (RTD) curves for four full-scale ozone contactors wi th hydraulic capacities ranging from 14.5 to 394 m(3)/min (5.5 to 150 mgd). On average, model predictions for contactor efficiency (T-10/HDT ) were within 7.9% of actual test values. The Metropolitan Water Distr ict of Southern California (Metropolitan) is using the finite element program as a design tool to optimize the hydraulics of future ozone co ntactors. For one template model, results from several optimization ru ns are presented which confirm that T-10/dHDT increases with increasin g depth-to-length (D/L) ratio and which indicate that by adding two fe atures, vanes or wall foils, the T-10/dHDT is improved from 0.63 to 0. 68 or to 0.66, respectively. Results from the template model also indi cate that the T-10/dHDT is unchanged with the addition of a single con figuration of corner fillets.