Liquid Distribution in Trickle Beds. An Experimental Study Using Computer-Assisted Tomography

Liquid distribution in trickle beds with a quiescent gaseous phase was visualized by using computer-assisted tomography (CAT). The model system was made up of a column packed with uniform, nonporous glass spheres, distilled water, or a mixture of water and ethanol for a lower surface tension. Flow patterns at the bed scale were recorded as a function of various parameters—liquid flow rate, the size of the particles, the type of liquid inlet distributor used, and surface tension. The flow pattern was shown to depend strongly on whether the bed had been prewetted by flooding the column with liquid or was initially dry. Furthermore, the flow pattern at a given liquid flow rate depended on whether it was obtained by decreasing or increasing the liquid flow rate to the present state.