In this contribution, new results of our experiment a I Study of the creeping flow of fluids of different rheological behaviour through fixed beds of spherical and non-spherical particles are presented. It was verified that for engineering estimation of the viscoelastic pressure drop excess. simple forms of the correction function of the effective Deborah number can be Used. Analysing the extensive set of experimental data, the procedure for determination of these Deborah number functions, which are based on an effective liquid characteristic time. has been proposed. (C) 2008 Elsevier B.V. All rights reserved.