On Bubble–Jet Interactions in Fluidized Beds

The dynamics of bubble growth near a jet in 2D rectangular gas–solid fluidized beds were investigated in this work, by a high-speed camera and measuring pressure fluctuations. The investigation utilizes a unique dual-sparger design to observe the interplay between bubbles and jets, providing detailed insights into their effects on hydrodynamics. Time domain observations revealed that a single bubble induces a greater pressure difference than a jet, leading to sustained low-pressure conditions and particle suction when a jet is introduced. Pressure signals exhibit distinctive negative peaks representing the presence of a jet and positive peaks indicating the transition from jet to bubble. The coexistence of the jet impedes maximum bubble growth within the bed. Frequency analysis highlights a bubble frequency of approximately 4 Hz and a jet frequency of around 7.5 Hz, underscoring the intricate dynamics of bubble–jet interactions. These findings contribute to a nuanced understanding of fluidized bed behavior, supported by independent verification of observed phenomena.