Dynamic and Steady-State Characterization of the Liquid Spray Zone in an Externally Heated Gas–Solid Fluidized Bed

Abstract

In industrial fluidized beds with liquid spray, dynamic and steady-state characteristics of the liquid spray zones are of significant importance for operation optimization and products control. In this study, a conductivity probe array, two thermocouple arrays, and a pressure sensing system are applied to an externally heated gas–solid fluidized bed with a side-wall liquid spray. Nonstationary and nonlinear characteristics are exhibited in the Hilbert spectra of the conductivity probe signals, and the fluctuation energy distribution shifts to higher frequencies with the liquid spray velocity, related to the liquid-induced higher-frequency bubble motion. The variation coefficient analysis of temperature data is a reliable approach to characterizing the liquid spray zone boundary. The liquid spray zone is enlarged and extends downward along the wall with the liquid spray velocity and shrinks with the gas velocity. Moreover, the liquid spray zone is enlarged and extends downward along the wall with the nozzl...