The mass-transfer processes in fiberglass were studied in the course of drying the saturated glass fabric sample. Experiments were carried out using an Avance DRX Bruker spectrometer equipped with a micro tomography device. Experimental signal intensities of fluids flowing at different velocities were obtained. A one-dimensional mathematical model was applied to calculate mass-transfer coefficients from experimental data. Dependencies Nu(Re) at the Reynolds number varied between 0 and 400 were obtained at different fluid velocities. The data obtained were compared to correlation dependencies for woven Pt/Pd gauzes and for rows of parallel cylinders. Numeric experiments of gas flow filtration at low Reynolds numbers (Re < 1) were carried out using the CFD FLUENT software package. Fibrous material was represented as porous system consisting of bunches of parallel cylinders with varied distances between the cylinders. Dependence Nu(Re) was calculated at various parameters of system. (c) 2005 Elsevier B.V. All rights reserved.