Liquid Maldistribution in Random Packed Columns: Experimental Investigation of Influencing Factors

Abstract

Liquid Maldistribution in Random Packed Columns: Experimental Investigation of Influencing FactorsInvestigations on liquid maldistribution in random packings are conducted in a Ø1.2 m packed column at varying experimental and operating parameters -type of packing, packing height, liquid distributor, liquid load, and gas load. Used types of packing are metal Raflux-Rings 35-5 and 50-5, RVT Metal Saddle Rings 70-5 and plastic Hiflow -Rings 50-6. Graphical presentation in form of distribution spectra and further evaluation by means of a maldistribution factor provide insight into the influence of different parameters on maldistribution.

TUM–WelChem cell model for the prediction of liquid distribution in random packed columns

“…Experimental investigations show an increase of radial dispersion especially at high local liquid loads . This effect is dominant in the first few layers below the liquid distributor and for point source initial distribution.…”

“…Altogether, the liquid spread factors did show no significant deviations from the nonphysical method, especially on the macroscopic scale of the cell model. On the other hand, there was a much greater impact of fluid properties on the liquid loading and countercurrent gas flow effects, which are strongly linked to column fluid dynamics …”

“…Below loading conditions an increase of the gas load results in a more uniform liquid distribution. Above loading conditions, the wall flow and thus large scale maldistribution increases rapidly up to the flooding point …”

“…First of all, modeling of liquid distribution describes the flow and dispersion of liquid in random packing. It also includes the description of maldistribution phenomena, which have been characterized in numerous experimental investigations . Channeling describes the coalescence of liquid rivulets to bigger streams on the scale of single random packing elements, caused by surface tension .…”

Untersuchung der Phasendistribution in gepackten Kolonnen und Validierung eines Zellenmodells

“…Begründet ist dieser Vorteil in der annähernd idealen Durchmischung der flüssigen Phase auf jedem Boden innerhalb der Sprudelschicht [1]. Einbauten wie Böden, Packungen oder Füllkörper realisieren in diesen Anwendungen große Phasengrenzflächen.…”