Local phase holdups in gas-solids fluidization and transport

Authors

  • Hsiaotao T. Bi,

    Corresponding author
    1. Dept. of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
    • Dept. of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
    Search for more papers by this author
  • Peng-Cheng Su

    1. Dept. of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
    Search for more papers by this author

Abstract

A two-phase structural model consisting of a dense phase and a dilute phase with allowance for the dense-phase expansion and the solids holdup in the dilute phase was developed and successfully applied to the analysis of local voidage fluctuation signals. Such a model can be used to derive local-phase holdups and voidage in each phase in both bubbling/slugging/turbulent fluidized beds and circulating fluidized-bed risers without ambiguity in defining criteria for dividing phases used by previous researchers. Such a model can also explain the existence of a maximum standard deviation at a local voidage around 0.7, and why a maximum peak is observed in the radial profiles of standard deviation of local voidage fluctuations in high-velocity fluidized-bed columns.

Ancillary