Concentric-baffle rotating bed (CRB) is a novel HIGEE device, whose performance has been experimentally studied in distillation process. The CRB structure optimization has also been obtained from comparison among the several CRB variants. The CRB is a stagewise contactor, and thus, its mass transfer performance can be expressed by the overall efficiency, which can be easily used to convert theoretical stages to real stages. Therefore, the prediction of the overall efficiency is an important step in CRB design. In our study, it is found that the CRB exhibits a highly similar flow and contact pattern to the sieve tray column. Then, on this basis, a semi-theoretical model predicting the overall efficiency of the CRB is developed, which involve calculations of mass transfer coefficients, effective interfacial area, number of mass transfer units, Murphree point efficiency, and Murphree stage efficiency. The proposed model was validated by comparison of predicted efficiencies with the experimental data obtained in the optimized CRB. It shows that the proposed model can provide a good prediction in the industrially relevant operating area around the highest efficiency point, i.e. with the F-factor lower than 4.0. Further comparison shows that the proposed model can give a much better prediction than several models available in the literature, which are widely used for the tray column. The proposed model is more fundamental and only involves one adjustable empirical parameter for the average diameter of liquid droplets, but it is still a great preliminary model for the CRB and other contactors with similar gas and liquid flow regimes. The validity of the proposed model requires further testing by more data from different sources. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.