MASS CONDUCTIVITY OF FLAT FIBROUS MATERIALS DURING THEIR CONVECTIVE DRYING

Abstract

The kinetics of drying dense woolen fabric under various temperature conditions was experimentally investigated. The mass-conducting properties of the fabric were determined depending on its moisture content and the temperature of the drying agent. Data on the thermophysical characteristics of drying objects, including mass conductivity coefficients, are necessary for calculating the kinetics of the drying process. Information on mass conductivity coefficients is not available for many materials, including fabrics, since their experimental determination is difficult. Experimental studies of the kinetics of convective drying of dense woolen fabric were carried out on a specially created installation under conditions excluding external diffusion resistance. To calculate the mass conductivity coefficients, a zonal method was used to determine the concentration dependence of the mass conductivity coefficient from the drying kinetics curves obtained at different temperatures. The nonlinear nature of the dependence of the mass conductivity coefficient on the moisture content of the material and the temperature of the drying agent is established. For the convenience of engineering calculations, the obtained data on the mass conductivity coefficients are approximated by formulas expressing their dependence on the moisture content of the material and temperature. The coefficients of mass conductivity calculated by the zonal method using experimental curves of drying kinetics are compared with the coefficients of mass conductivity calculated using the obtained dependence of the coefficients on the moisture content of the material and the temperature of the drying agent. The good quality of the approximation of the experimental curves obtained for the mass conductivity coefficient in this study and the applicability of the latter for calculations are shown. The obtained data on the kinetic coefficients of mass conductivity can be used to calculate the kinetics of the drying process of various dense woolen fabrics.