CHARACTERIZATION OF EVAPORATION RATE, TEMPERATURE, VELOCITY AND HUMIDITY FIELDS IN A COLD CHAMBER

摘要

In a food factory some pathogenic bacteria can grow even at low temperature, especially Listeria Monocytogenes which resists to temperature around 0°C. Currently, two ways are used to prevent bacterial growth; product treatment (pasteurization, pH decrease) and cleaning but it's not sufficient to eliminate all microorganisms. This work takes part of a four-year research project called EcoSec (2013-2016) in France. The practical objective is to propose an ecological and economical way to destroy Listeria Monocytogenes by humidity reduction. The principle idea is based on the dehumidification of a plant. To achieve this objective, a method to predict the evaporation rate on wet surfaces was developed using experimental and numerical approaches (CFD, Computational Fluid Dynamics). The study was performed inside a cold room (volume 29m~3) in which temperature and velocity were controlled. The results show that the air humidity and its local velocity near the wet surface play a major role.