Bed expansion in turbulent bed contactor: Experiments and prediction

Abstract

In this work, turbulent bed contractor (TBC) hydrodynamics have been studied in terms of bed expansion (Hd/Hst) using a particular approach to predict this important property for the design of such equipment. The study is based on 1604 sets of experimental data on the bed expansion, obtained by varying the operating variables (gas velocity, liquid spray, packing characteristics, static bed height, and free opening of the supporting grid). The prediction of the bed expansion necessitates the estimation of gas and liquid holdups. To achieve this, we employed a variety of correlations derived from existing literature, comprising six equations for gas holdup and twenty equations for liquid holdup estimation. Out of a total of 120 cases, bed expansion was estimated, and the accuracy of the model was evaluated by calculating the mean absolute error in percentage (MAPE), root mean square error (RMSE), correlation coefficient (ρXY), and explained variance (VECV). This study identified suitable correlations for gas and liquid holdups, leading to predictions with acceptable errors. Furthermore, statistical analysis was employed in a subsequent phase of the study to determine the most appropriate correlations for predicting bed expansion among those proposed by various authors.

Keywords

• three phase fluidization
• turbulent bed contactor
• bed expansion
• gas holdup
• liquid holdup