About the applicability of commonly used pressure-flow models to plane single-layer filters of activated carbon fabric

The pressure drop through plane single-layer filters of activated carbon fa bric was determined experimentally with air and water as working fluids, fo r mean flow velocities covering the laminar and turbulent regimes in the up stream flow, and under various operating conditions. Observational evidence is given that common approaches consisting of linearly relating the pressu re drop coefficient and the reciprocal of the particle Reynolds number with constant coefficients are inappropriate to fully describe the hydrodynamic behaviour of such systems. These coefficients were found to strongly depen d on the nature of the circulating fluid and on the upstream flow regime as a result mainly of the property of fabrics to deform. Significant discrepa ncies are to be expected between their value in actual service conditions a nd those estimated from standard measurement procedures with the fabric at rest and in the absence of any flow, as is usually done in practice, with d irect practical consequences. Data analysis using the pressure-flow models of Goodings (1964, Textile Research Journal, 34(8), 713-724.) and Comiti an d Renaud (1989, Chemical Engineering Science, 44(7), 1539-1545.) corroborat ed the tentative conclusions that were reached as regards the effects of ch anges in the structure of fabrics with fibre deflection onto the hydrodynam ic behaviour of single-layer fabric filters. (C) 2000 Elsevier Science Ltd. All rights reserved.