Experimental study of large-scale pulsations of a fluidized bed

In experimental investigations of the hydrodynamics of fluidized beds, study of large- and small-scale pulsations of the most important characteristics of the fluidized bed: voidage, hydraulic resistance, velocities of the gaseous and solid phases, etc., is of considerable interest. The character of these pulsations is determined by the heterogeneity of the structure of the fluidized bed, due to the presence of channels, bubbles, stagnant zones, and circulation currents. The object of the present work was experimental study of fluctuations of the height h of the surface of a fluidized bed, with simultaneous recording of the corresponding fluctuations of the hydraulic resistance ΔP of the bed. The existence of a direct connection between large-scale pulsations of the hydraulic resistance ΔP of the fluidized bed and large-scale pulsations of the bed height h is demonstrated in the paper. It is proved on this basis that large-scale pulsations of h and ΔP can be described by equations of the same type. The coefficients of the equation are determined from experimental data on pulsations, and its solutions for different fluidization regimes are analyzed