화학공학소재연구정보센터
Chemical Engineering Science, Vol.168, 480-494, 2017
Hydrodynamics of descending gas-liquid flows in solid foams: Liquid holdup, multiphase pressure drop and radial dispersion
In this contribution we report on spatially resolved analysis of multiphase hydrodynamics in solid foam packed trickle bed reactors. For the investigation we used ultrafast X-ray computed tomography and fast response pressure transducers. The SiSiC foams' pore density, the liquid distribution system as well as gas and liquid flow rates were varied. The transient behavior of the liquid holdup at trickle and pulse flow as well as after drainage were examined and correlations for static and dynamic holdups were derived. The correlations are based on Edtvds, Reynolds and Galileo number, using porosity and specific area for the definition of the hydraulic diameter. The correlations are applicable to a wide range of foam morphologies, pore densities and operating conditions reported in the literature. The axial pressure gradients in the solid foams showed significantly lower pressure drop compared to particle packings of similar specific surface area. The evolution of liquid spreading was analyzed qualitatively and quantitatively with various irrigation patterns. In addition, an approach for the determination of radial liquid dispersion coefficients in solid foams is presented. (C) 2017 Elsevier Ltd. All rights reserved.