Scale and variance of radial liquid maldistribution in trickle beds

Radial distribution of liquid flow rate in a trickle bed with an inner diameter of 0.283 m was measured for various bed heights under varying flow conditions. The total variance of flow distribution was partitioned into large-scale and small-scale components, and the statistical method was used to analyze the experimental data and determine the scale of liquid maldistribution. The scale of nonuniform radial distribution varied from 0.02 to 0.3 m as indicated by diagrams of the power spectral density function (PSDF). Both scale and variance of small-scale maldistribution decrease as gas and liquid flow rates are increased, suggesting that maldistribution is mainly governed by gas-liquid interaction. On the contrary, large-scale liquid maldistribution (wall flow and central flow) was dominantly controlled by solid-liquid interaction. The experimental results also showed close relationship between some hydrodynamic phenomena and liquid distribution. (C) 1998 Elsevier Science Ltd. All rights reserved.