Experimental and Numerical Analysis of the Drying Characteristics of Modular Carpet Tiles

Abstract

Various backing materials developed for modular carpet tiles can be heat sensitive and may be damaged if exposed to high temperatures for prolonged periods. This paper presents a model to predict the drying characteristics of carpet tiles for a batch drying process. Drying characteristics are also determined experimentally in a controlled laboratory environment. The analytical framework consists of a three-layer lumped parameter configuration to calculate temperature and moisture profiles. The capillary movement of liquid water is not explicitly calculated in the model, but a sufficient amount of moisture in the solid is assumed to be available to maintain a constant rate drying period. The three-layer model comprises a moist top fiber layer, a middle layer also containing moisture, and a backing layer. To estimate the falling rate drying period, the middle layer is incorporated into the model. In the mathematical model, the top layer is initially saturated with water, but then dries out, providing greater resistance to mass transfer. Governing equations are obtained from mass and energy balances as well as relevant rate equations. A lumped parameter approach is applied to each layer. The energy balance for each layer provides a first-order ordinary differential equation with variable coefficients. A numerical routine is constructed to solve the governing equations.