On the Analysis the Packed Beds Structure at Low Aspect Ratios

WILSON ISMAEL SALVAT; NÉSTOR JAVIER MARIANI; OSVALDO MIGUEL MARTÍNEZ; GUILLERMO FERNADO BARRETO

Rio das Pedras, Rio de Janeiro, Brasil

Congreso; II Mercosur Congress on Chemical Engineering, IV Mercosur Congress on Process System Engineering; 2005

UFRJ, UERJ, IME, UFRRJ, UNS, UNL, SCMC, Petrobras, Oxiteno.

Structural properties of packed beds play an important role in the analysis of heat and mass transport processes, particularly, in multitubular catalytic reactors with low aspect ratios (a, tube to particle diameter ratio). Experimental information for aspect ratio ranging from 2 to 5 is scarce. Some authors (Zou and Yu, 1995) reported the existence of local overall void fraction minima and maxima in the mentioned range. Besides, the prediction of packed bed properties in this range is far from being satisfactory. The aim of this article is to analyse packed bed structure of monosized spheres in cylindrical containers with aspect ratios in the range of 2 to 5. With this purpose two approaches are employed. On one hand, experimental overall void fraction information from literature and a set of data obtained in our laboratory are analysed. On the other hand, a packed bed simulation software previously developed by our team is used. The results obtained with the software are contrasted with the experimental data in terms of overall void fractions. The detailed information from the software provides a feasible explanation for the behavior of overall void fraction vs. aspect ratio.