AbstractA study on the flow of power‐law fluids through a multi‐particle system including both fixed bed and fluidized bed is presented. Equations for the pressure drop, the minimum fluidization velocity, and the bed expansion are obtained by extending the Blake‐Kozeny's equation for the pressure drop through packed beds to power‐law fluids. Bed expansion equations are also obtained by extending the Richard‐son‐Zaki's theory for the drag force in a multiparticle suspension to power‐law fluids. These equations are compared with experimental data.