Heat flux estimation in thin-layer drying

摘要

A method is developed in order to determine the drying curves for sludge thin-layer drying. Since mass balance is very difficult to measure for thin-layer drying, these curves are obtained through energy blance. An experimental device is built up, in order both to provide and to estimate the heat flux density at the interface between a hot metallic plate and the drying sample. An analytical direct model is made using the quadripole foralism, and the system transfer function is calculated. The inverse problem is solved using the beck's sequential function specification nethod, and the corresponding drying curve is deduced by a simple energy balance. Real expeirment results are presented.