Available online at www.sciencedirect.com Chemical Engineering and Processing 47 (2008) 1765–1770 Wire mesh tomography applied to trickle beds: A new way to study liquid maldistribution Juan-David Llamas a , C´ edric P´ erat a , Franc ¸ois Lesage a,∗ , Mathieu Weber a , Umberto D’Ortona b , Gabriel Wild c a Laboratoire des Sciences du G´ enie Chimique, Nancy-Universit´ e, CNRS, ENSIC B.P. 20451, 54001 Nancy, France b MSNM-CNRS IMT-La Jet´ ee, Technopˆ ole de Ch ˆ ateau-Gombert, 38 rue Fr´ ed´ eric Joliot-Curie, 13451 Marseille Cedex 20, France c D´ epartement de Chimie Physique des R´ eactions, Nancy-Universit´ e, CNRS, ENSIC, B.P. 20451,54001 Nancy, France Received 21 March 2007; received in revised form 23 August 2007; accepted 29 September 2007 Available online 5 October 2007 Abstract Two sets of wire mesh tomography sensors have been developed for the study of liquid maldistribution in trickle bed reactors. The technique, based on the one used by Prasser et al. [H.M. Prasser, A. B¨ ottger, J. Zschau, A new electrode-mesh tomograph for gas–liquid flows, Flow Meas. Instrum. 9 (1998) 111–119] in bubble columns, uses two horizontal planes of wires placed at fixed bed depths to measure the presence of a conductive liquid between them. Being only slightly invasive, the conceived wire mesh tomography device allows estimation of liquid concentration over a cross-sectional area of the column with a spatial resolution of 313 pixels. Examples of wire mesh tomography measurements inside a trickle bed reactor using different liquid distributors are presented here. Results are satisfying and wire mesh tomography appears to be a promising technique for the study of liquid maldistribution in trickle beds of non-porous particles. © 2007 Elsevier B.V. All rights reserved. Keywords: Trickle bed; Liquid distribution; Metrology 1. Introduction Trickle bed reactors are three-phase reactors in which gas and liquid flow cocurrently downwards through a fixed bed of catalyst particles. Because of their advantages in terms of cost and capacity, trickle bed reactors are widely used in industry, e.g. oil and gas or petrochemistry. Performance of this kind of reactors is highly influenced by the way in which the phases are distributed along the bed. A bad liquid distribution for instance, will lead to improper use of solid catalyst and can be at the origin of hot spot formation. Several factors affect liquid distribution in trickle beds and, even if a good initial distribution is highly important, it is well known that this does not guarantee a good distribution along the whole bed (e.g. Marcandelli et al. [2]). Following the evolution of liquid flow through the bed is then ∗ Corresponding author. E-mail address: francois.lesage@ensic.inpl-nancy.fr (F. Lesage). of great interest and could provide valuable information in the understanding of trickle bed reactors. Several techniques have been used to study liquid flow evolution in trickle bed reactors. Ravindra et al. [3] used a dye- adsorption method in a rectangular bed of 6.0 cm × 8.0 cm. After each run, the cross-section of the bed at several bed depths was photographed. The technique implies that the reactor has to be de-packed and the particles have to be washed after each run. Even if interesting results can be obtained using this method, the practical problems resulting of its application to bigger reactors are obvious. Other examples of techniques allowing cross-sectional imagining of the liquid flow in trickle beds are the tomographic measurements by photon attenuation (X- and -ray tomography) and magnetic resonance imagining. These techniques give access to the phase distribution in a section of the reactor with good spatial resolution and have the advan- tage of being non-invasive. Some application examples of these techniques can be found in Boyer et al. [4] for -ray tomogra- phy, Marchot et al. [5] for X-ray tomography and Nguyen et al. 0255-2701/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.cep.2007.09.017