Drying rates in the convective drying of craft paper

Abstract

The drying of craft paper at forced air conditions is provided. The aim of this research is to analyze the influence of the drying air operating conditions on the process behaviour. The experimental apparatus consists of a metallic box where hot air was canalized over both surfaces of the paper sample. Drying rate curves were built for different drying air temperatures and velocities and the classical methodology of the two drying periods was used in the curves analysis. Thus, for the constant rate period, a thermal balance was adjusted according to the equivalence between the heat transferred and the heat involved in the evaporation process. For the falling rate period, a proposal of a capillary flow type (lineal reduction of the constant rate) was verified.