Study On Numerical Simulation And Optimization Of An Ozone Contactor

Along with people’s improved sense of health and paying more attention to the quality of drinking water, the traditional water disinfection treatment process is difficult to achieve the new potable water quality standards. As efficient oxidant and antiseptic, ozone has been the best option for advanced treatment of drinking water. The article aims at enhancing the ozone disinfection efficiency of ozone contactor, utilizes business software FLUENT related to Computational Fluid Dynamics (CFD) as the calculation platform, and the inner configuration of ozone contactor is optimized designed.In the dissertation, the concept of effective hydraulic residence time (T10) was provided for evaluating the disinfection efficiency of ozone contactor. Tio represented the true residence time of disinfectants in ozone contactor. According to Froude analogous rule, a1/25scale of full-scale prototype was established, and three different types of optimization methods were used to obtain the accumulated retention time distribution function through simulating the area weighted averaged concentration over flowtime at outlet. Finally, the species transport model and the experimental results of full-scale prototype in Jin Junwei’s dissertation are compared, and the two results inosculate well where the difference-value less than9%. The results indicate that the species transport model can simulate the effective hydraulic residence time accurately and efficiently.To improve the disinfection efficiency, the ozone contactor prototype was optimized and designed. The current flow and rentention time distribution fuction were simulated with species transport model in six kinds of different contactors. The value T10/T and current flow indicate that increasing the number of reaction rooms can improve the current flow and hydraulic efficiency. When the length scale of first room, secongd room and third room is1:2:3, the hydraulic efficiency gets better. After the optimization of design by inserting perforated plates, installing plan plates and guide plates, the hydraulic efficiency in ozone contactors increase by23%～40%, and the current flow become more uniform.To further verify the feasibility of the structural optimization of ozone contactor, the freeface and two phase (gas and liquid) flow were simulated in three kinds of contactors. The results show that the velocity distribution is improved, and short currents and circle currents decrease. The ozone phase and mass concentration distribution also get uniform, and disperse throughout the entire contactor area. As a result, the research considers and commends the sixth scheme as the best one for the optimization of design in ozone contactor.