Hydraulic characteristics such as pressure drop, fractional liquid hold-up and flooding point are of significant design importance in describing random and/or structured packing performance. For this reason, accurate modelling of these parameters over a wide operating and physical property range has to be ensured. In the past, various research groups developed many correlations. The significant combined databases of the Separation Research Program (SRP) at the University of Texas and the Montanuniversitaet Leoben (MUL) provide the perfect basis to evaluate available correlations. The databases include pressure drop, hold-up and flooding point data for 50 different random (2nd, 3rd and 4th generation) and structured packings (sheet and grid structured packings) for different test systems under absorption and distillation conditions.
Eight correlations (Billet and Schultes 1991 and 1999, Wolf 2014, Engel 1999, SRP 1997, Delft 1997, Verschoof 1999, Mackowiak 2003, Stichlmair 1989) were evaluated in an initial analysis. The best predictions were achieved with the model of Wolf 2014 and a modified model of Mackowiak 2003 by Wolf-Zoellner.
The objective of this work is to use the large database and extend the performance investigation to further well-known correlations available in literature (Spiegel and Maier 1992, Brunazzi 2002, Bozzano 2007, NNA-Model of Piché 2001, GPDC of Kister 2007, Robbins 1991, Jammula 2014). Based on this evaluation, the performance of the various correlations is compared and the application fields of the various models are revealed. In particular, the work shows the operating ranges as well as packing types for which the models provide reliable results but also the weaknesses of the various correlations.