An experimental assessment of fluid–solid drag models based on the pressure drop in bidisperse fixed beds

Experimental data on binary fixed beds were gathered from the literature and produced by us through experiments in a vertical column fed with liquid water. Then, we used the fluid pressure drop data to compare the performance of the existing models that can predict the fluid-solid drag force for polydisperse systems. The results show that the models behave quite similarly and do not offer significant advantages compared to the Ergun equation, aside from being able to yield the force values for the different particle types. The accuracy of the predictions does not appear to be influenced by the Reynolds number and the particle diameter ratio but seems generally better for equivolumetric mixtures. This work highlights that more research is needed in this field and provides additional experimental data that were lacking for certain operational conditions and may be useful for future works.