CFD Simulation of UV Disinfection Reactor for Applesauce with a Low UV Absorption Coefficient

In this study, a Computational Fluid Dynamics (CFD) model was developed to evaluate ultraviolet disinfection applesauce reactor. To simulate UV reactors, three sets of equations, including hydrodynamics, radiation and species mass conservation were solved simultaneously. The Realizable k-e turbulence model and the discrete ordinate method were used to find the UV radiation profile through the reactor. Using the Chick-Watson kinetic model and the Eulerian framework, inactivation of applesauce microorganisms was simulated in the UV reactor. Simulation results for water disinfection in the UV reactor were evaluated by the reported experimental data. Simulation was extended for non-Newtonian fluid such as applesauce. Results show that the UV reactor is less effective in eliminating microorganisms from applesauce than from water because applesauce has a higher UV absorption rate. In order to achieve higher disinfection of the UV reactor for non-Newtonian fluids with high absorption, this study examined different parameters and makes suggestions for appropriate reactor design. Different designs for disinfection reactor were studied, due to higher UV absorption coefficient of applesauce, CFD simulations show that the inactivation of microorganisms in applesauce is less than water, consequently thin film or small radius reactors are appropriate design.