Distribution of chlorine sanitizer in a flume tank: Numerical predictions and experimental validation

Abstract

Fresh produce are typically washed in a flume washer to detach and inactivate bacteria from produce surface and the typical sanitizer employed by produce processors is chlorinated water. The distribution of free chlorine in a flume washer was simulated and validated using experimental data. The influences of free chlorine injection velocity and the presence of soluble organic matter on the spatial distribution of free chlorine were investigated. At lower injection velocity, the chlorine was more concentrated near the bottom of the flume compared to the middle of the flume. The presence of soluble organic matter depleted the free chlorine in the flume. The experimental data on free chlorine concentrations were in reasonable agreement with the numerically predicted free chlorine concentrations under laminar flow conditions. Turbulent fluid flow in an industry-scale flume washer was also simulated. At lower main flow velocity (0.1 m/s) and higher free chlorine injection velocity (0.5 m/s), and when the injection direction was perpendicular to slanted side faces of the flume, the distribution of free chlorine was more uniform compared to other injection strategies.