화학공학소재연구정보센터
Chemical Engineering & Technology, Vol.25, No.12, 1177-1181, 2002
Fluid dynamics in monolithic adsorbents: Phenomenological approach to equivalent particle dimensions
Due to the complex, often sponge-like structure of monolithic adsorbents it is difficult to define appropriate constituent units that characterize the hydrodynamics of the material, or to determine relevant shape and size distribution factors comparable to those for spherical particles in (particulate) fixed beds. Based on a phenomenological analysis of the friction factor (Reynolds number relation and the longitudinal dispersivity - Peclet number dependence for random sphere packings) we derive characteristic lengths (i.e., equivalent particle dimensions) for a monolith with regard to its hydraulic permeability and dispersion originating in stagnant zones. Equivalence to the hydrodynamic behavior in "reference" sphere packings is established by dimensionless scaling of the respective data for the monolithic structure. This phenomenological approach, which is simply based on liquid flow and stagnation in a porous medium, can successfully relate hydrodynamic properties of the monolith to that of particulate beds.