THEORY OF 2-PHASE COCURRENT DOWNFLOW IN NETWORKS OF PASSAGES

Soluble substances and heat are often transferred between liquid and gas on a commercial scale by means of coarse porous media such as packed beds. Two-phase cocurrent downflow in packed beds finds wide application in devices such as trickle-bed reactors. The first step in understanding the mechanisms of transfer is to understand how the two fluid phases are distributed and flow within the pore space, or "void", of the packing. This paper shows that fluid distribution and flow in packed beds can be understood in terms of well-defined flow processes at the level of individual passages and junctions. It reports further that, by considering interactions in the network, understanding can be formulated as a theory that explains observed flow regimes and transitions between them, and from which predictions of macroscopic behavior, including hysteresis and pulsing, can be computed.