Analysis of the dynamic response of falling-film evaporators considering fouling

Abstract Fouling is an unwished physical phenomenon that occurs in thermal treatments of foodstuffs. The dairy industry invests important quantities of time and economic resources to treat and reduce the fouling. The milk evaporation process experiences fouling formation under non-optimal operating conditions. This work proposes a set of dynamic models to analyze the fouling of falling-film evaporators by considering the operating variables: fouling thickness, film-thickness, temperature and mass fraction of solids. The dynamic models came from the mass and energy balances, involving thermo-compression and thermo-physical properties of foodstuff as functions of temperature and composition. The fouling is predicted by models that consider both the thermal conditions and the properties of the foodstuffs. The models are a set of ordinary differential equations, which are solved numerically by a developed computational package (DYFFEVA). The results were validated with experimental data from literature.