Dynamic characteristics of bubbling fluidization through recurrence rate analysis of pressure fluctuations

Pressure fluctuations signals of a lab-scale fluidized bed (15 cm inner diameter and 2 m height) at different superficial gas velocities were measured. Recurrence plot (RP) and recurrence rate (RR), and the simplest variable of recurrence quantification analysis (RQA) were used to analyze the pressure signals. Different patterns observed in RP reflect different dynamic behavior of the system under study. It was also found that the variance of RR (sigma(2)(RR)) could reveal the peak dominant frequencies (PDF) of different dynamic systems: completely periodic, completely stochastic, Lorenz system, and fluidized bed. The results were compared with power spectral density. Additionally, the diagram of sigma(2)(RR) provides a new technique for prediction of transition velocity from bubbling to turbulent fluidization regime. (C) 2013 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.