화학공학소재연구정보센터
Chemical Engineering Journal, Vol.185, 250-266, 2012
Heat transport in structured packings with two-phase co-current downflow
In this work structured packings such as OCFS (open cross flow structure), CCFS (closed cross flow structure), Knitted wire packing, and Aluminium Foams were characterized with respect to their heat transport performance in gas-liquid down flow covering all important flow regimes. A dedicated set-up was built to measure radial temperature profiles at different axial and azimuthal positions for a gas-organic liquid system flowing co-currently downwards in a cooled column with constant wall temperature. The effective bed conductivity and the wall heat transfer coefficient for various structured packings were estimated from a 2-D pseudo-homogeneous plug flow model used to correlate the measured temperature profiles. The measured heat transfer parameters can be explained with the different flow patterns of the packings. The structured packings - especially OCFS and CCFS - show heat transport parameters (up to 1000 W/(m(2) K)) that are superior over those of packed beds of Glass beads and at much lower energy dissipation. Due to the high radial transport in these structured packings, overall heat transfer is only limited by the wall heat transfer coefficient and therefore depends strongly on the turbulence generated between packing and wall. (c) 2011 Elsevier B.V. All rights reserved.