ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Homogeneous fluidized layers of spherical particles

J. Beňa, J. Ilavský, E. Kossaczký, and O. Zákutný

Slovak Technical University, Bratislava

Abstract: The expansion of homogenous fluidized layers of spherical particles was measured at low Archimedes' nos. 3.4 to 223. Evaluation of the results showed that in the case of homogeneous fluidized layers it is necessary to divide the region of flow, generally designated as laminar, into typical laminar and pseudolaminar. In the typical laminar region, in agreement with laws of hydraulics, the resistance does not depend on the d. of the liquid. Such a case occurs only if the particles, forming a homogeneous fluidized layer, at const. speed of free fall in a medium of unlimited viscosity, are affected by the resistance as expressed by Stokes' law, that is, at Archimedes' nos. lower than 7.2. If the Archimedes' nos. are higher than 7.2, the resistance during flow in a homogeneous fluidized layer is affected by the d. of the fluid, even at Reynold's nos. considerably lower than 0.4 to 1.0, regarded as an upper limit for the laminar region of flow. For that reason a region of flow was designated as pseudolaminar. For a typical laminar and pseudolaminar character of liquid flow in a homogeneous fluidized layer, the expansion of the layer can be expressed by the equation: 12.8 Re = Ar(Ar + 19)-0.11ε4.65, the validity of which is limited by the condition that: Re ≤ Rek = [(Ar + 34)/199.6]1/1.747. ε is the sp. vol. of the homogeneous fluidized layer.

Full paper in Portable Document Format: 133a170.pdf (in Slovak)

Chemical Papers 13 (3) 170–185 (1959)