Einfluss von Randspalt und Randabweiser auf die Fluiddynamik einer Messzelle zur HETP-Bestimmung

The scale-up of columns equipped with structured packings is a time and cost intensive process. In order to improve scale-up efficiency, a measurement cell for structured packings has been developed. This makes it possible to investigate characteristic sections of packed columns, such as bulk and wall area on a small scale. The study shows the influence of commonly installed wall wipers and the distance between wall and packing on the fluid dynamics in the measuring cell.     

Quantifizierung der Trenneffizienz einer strukturierten Packung mittels numerischer Simulation

The numerical simulation of the distillation and absorption/desorption process is made possible by coupling a transient two‐phase simulation in a structured packing with a model for the simulation of the species transfer. The two‐phase flow is modeled by the volume of fluid (VoF) method. The simulation of the locally resolved species transfer is conducted using the generalised continuous species transfer (GCST) model. The simulation data are evaluated for the separation efficiency of the tested packing by calculating the HETP value.     

Tomographische Untersuchung der Fluiddynamik viskoser Systeme in Packungskolonnen

Fluid dynamics in structured packings is investigated by X‐ray tomography. The focus is set on the influence of liquid viscosity varied between 5 and 50 mPa s. Film flow is the dominant flow pattern, but there are also contact‐point liquid patterns representing liquid accumulated at contact points between adjacent packing sheets. The holdup fractions of both flow patterns are quantified, and the average surface‐to‐volume ratio is determined. Furthermore, the wetting ratio of the structured packing is examined for different viscosities and liquid loads.     

Miniaturisierte Messzellenversuche als potenzielles Auslegungswerkzeug für Kolonnen mit strukturierten Packungen

Structured‐packing columns are widely used equipment for distillation and absorption processes in the chemical industry. For a highly promising design approach using miniaturized experimental setups, the design and evaluation of two developed miniaturized experimental setups is presented. The miniaturized experimental setups are meant to define characteristic parameters of fluid dynamics. Results of the liquid holdup from both setups are compared against existing correlations and measurements in a pilot plant.     

Methodik zur Entwicklung additiv gefertigter Packungsstrukturen im Bereich der thermischen Trenntechnik

The methodical procedure for the development of additive manufactured, innovative packing structures in laboratory scale is described with the focus on the methodology of development strategies. Packing structures, based on crystal lattices, with flexible dimensioning are created with the VBA‐tool in Autodesk Inventor®. For the characterisation CFD simulations are used to examine the dry specific pressure drop and the liquid distribution. For additive manufacturing of the packing with the shell, selective laser sintering as additive manufacturing method and polyamide 12 as material were selected.