Abstract

SANCHEZ-LOPEZ, J. L.; RUIZ-MARTINEZ, R. S.; ALONSO-MARTINEZ, F.  and  ANCHEYTA-JUAREZ, J.. Study of bed expansion-contraction phenomenon in ebullated-bed reactors based on dimensional analysis and model theory. Rev. Mex. Ing. Quím [online]. 2008, vol.7, n.2, pp.113-122. ISSN 1665-2738.

The hydrodynamics scale-up approach reported by Safoniuk et al. (1999) for three-phase fluidized beds has been evaluated when applied for high pressure and temperature systems. The aforementioned method, which is based on dimensional analysis concepts and model theory, suggests the use of a set of five dimensionless groups that must be matched to ensure hydrodynamic similarity between two separate experimental units that differ both geometrically and in the operating conditions. With the aid of these concepts, in the present work experiments have been carried out with a system operated at atmospheric pressure to simulate the hydrodynamics of an ebullated-bed system operated under severe conditions. The bed porosity and the bed expansion-contraction phenomena have been compared for both systems. On a statistical basis, a good agreement between the bed porosities of both units was observed.

Keywords : ebullated-bed; hydrodynamics; scale-up; similarity; high pressure.