Experimental and Theoretical Diffusion Modelling of Gas Filtration Processes

Abstract

This paper presents the study of structures of random fibre arrangement with very high irregularity and textiles made of fibres with a very high level of parallelism, arranged in layers. Studying of textile materials by the proposed aerodynamic method, namely, the gas filtration modeling, enables the differentiation of their internal structure. Therefore, it can be applied to modern analysis and comparison of use characteristics of any textiles.

Gas filtration modeling consists of blowing an air stream through a textile sample of a porous structure. The flow is ruled by Darcy’s law and Poieuille’a-Hagen’s law and by mass, momentum and energy conservation laws. The theoretical model of studies assumes dividing the sample thickness into layers in which, on the basis of pressure Δp_i and mass flux m measurements, we calculate: d_k-diameter of ducts; f-specific surface, K_i-Darcy coefficient, Re_i, Eu_i, Da_i – Reynolds, Euler and Darcy numbers. There are inlet and outlet convection zones. Local studies of the structure are also analysed in relation to the whole sample and averaged in the form of global values.

The test stand includes a measuring cassette, manometers, an air blower, meters of air stream mass (turbine and El-flow ones) and control valves. Homogeneous and multi-layer materials of thickness up to 50 mm can be tested. Measurements are carried out for samples arranged at different angles and with air streams of different magnitude, dividing the sample into layers Ag_i. It enables the evaluation of properties of textile products, their axial and circumferential irregularity as well as the determination of new physical modelling factors. The studies can also be used for comparative analysis of various textiles and evaluation of their suitability for different industrial applications.

Citation

Wawszczak, W. and Strzembosz, W. (2004), "Experimental and Theoretical Diffusion Modelling of Gas Filtration Processes", Research Journal of Textile and Apparel, Vol. 8 No. 1, pp. 38-42. https://doi.org/10.1108/RJTA-08-01-2004-B006