Spatially Resolved Tomographic Assessment of Axial Mixing in Structured and Random Packings

AbstractThe liquid axial dispersion inside modern structured packings (Sulzer Mellapak™ 500.Y, Raschig Super‐Pak 350Y) and one random packing of the 4th generation (Raschig Super‐Ring 0.3) was measured by means of computed tomography. As the gas velocity is known to have little effect on the liquid axial dispersion at low hydraulic load, all experiments were conducted without countercurrent gas flow at liquid loads of B = 10, 15, and 20 m3m−2h−1 in a column with an inner diameter of 100 mm. Injection of the X‐ray‐active tracer potassium iodide allows the identification of active and passive liquid accumulations inside the structured packing. Good agreement was found between the active liquid holdup from tomographic images and the total holdup calculated from the mean residence time for the structured packings.Combining X‐ray‐active tracers und computed tomography, the liquid holdup and interfacial area inside structured and random packings were analyzed. Different kinds of dispersion effects were detected depending on the packing geometry. image </p