Bubble Behaviors in a Dense Gas-Solids Fluidized Bed: Analysis of Pressure Fluctuation

The pressure signals were analyzed by time-domain and frequency-domain methods, including standard deviation, autocorrelation function, and power spectral density function, to investigate the bubble behavior and determine the regime transition. Results indicated that the autocorrelation function of pressure signals derived from bubbles was periodic fluctuation. The periodic nature of the autocorrelation function disappeared and the dominant frequency increased when the transition from bubbling to the turbulent regime occurred. The decrease of static bed height facilitated the explosion of bubbles, which accelerated the transition from the bubbling to the turbulent regime. The fluidization index was used as an indicator for the bubble state in the dense fluidized bed.

Automated summary

The pressure signals were analyzed using time-domain and frequency-domain methods to study bubble behavior and determine regime transition. The results showed that the autocorrelation function of pressure signals from bubbles exhibited periodic fluctuation, which disappeared and the dominant frequency increased during the transition from bubbling to the turbulent regime. The decrease in static bed height facilitated the explosion of bubbles and accelerated the transition. The fluidization index was used as an indicator for the bubble state in the dense fluidized bed.