CFD modelling of cyclonic-DAF (dissolved air flotation) reactor for algae removal

Abstract

The purpose of this study is to simulate the Cyclonic-DAF tanks using CFD techniques for the optimal design. CFD simulations were performed on two different Cyclonic-DAF reactor shapes either having or not having a cone shaped settled sludge removal unit in the bottom area of the inlet in the Cyclonic-DAF reaction tank. An average flow of less than 10% within the Cyclonic-DAF was rarely found in both shapes while areas of less than 20% were only slightly found near the central concentrate waste pipe. Areas having an average flow of less than 50% were found around the concentrate waste pipe and were observed at a rate of less than 5% of the total volume. Efficiency test results of different Cyclonic-DAF (CDAF) tank height to diameter ratios set at 1:1, 1:35:1, 1.6:1, and 1.85:1 indicated similar efficiencies with turbidity at 91.9% and chlorophyll-a at 94.7%. Keywords: Algae removal, Dissolved air flotation, DAF, Cyclonic-DAF, Computational fluid dynamics (CFD)