X-ray imaging for flow characterization and investigation of invasive probe interference in travelling fluidized bed

Abstract X-ray imaging was employed to visualize the internal flow structures of the travelling fluidized bed (TFB), operating in the bubbling and turbulent flow regimes. The degree of interference of a 4-mm diameter intrusive probe inserted in the gas-fluidized bed was investigated by comparing the time-average voidage in a region of the bed operated with and without the probe being present. Transition from bubbling to the turbulent fluidization regime was visually inspected from images obtained by the X-ray system and quantitatively characterized in terms of statistical parameters associated with grayscale intensity probability distribution functions (PDF). Voidage data obtained by different measurement techniques are compared with time-average voidages obtained by X-rays and borescopic imaging. The hydrodynamic data provided by this study extend the benchmark database produced from the experiments performed on the TFB for validation of CFD and other models.

[1]  L. T. DeCarlo.  On the meaning and use of kurtosis. , 1997 .

[2]  John F. Davidson,et al.  Slug flow in fluidised beds , 1967 .

[3]  J. Yates,et al.  X-Ray Analysis of Fluidized Beds and Other Multiphase Systems , 2002 .

[4]  Claude E. Shannon,et al.  The mathematical theory of communication , 1950 .

[5]  P. Lettieri,et al.  New Generation X-Ray Imaging for Multiphase Systems , 2013 .

[6]  C. E. SHANNON,et al.  A mathematical theory of communication , 1948, MOCO.

[7]  Yuri A. Sergeev,et al.  EXPERIMENTAL OBSERVATIONS OF VOIDAGE DISTRIBUTION AROUND BUBBLES IN A FLUIDIZED BED , 1994 .

[8]  Feng Duan,et al.  SHANNON ENTROPY ANALYSIS OF DYNAMIC BEHAVIOR OF GELDART GROUP B AND GELDART GROUP D PARTICLES IN A FLUIDIZED BED , 2013 .

[9]  Joachim Werther,et al.  Measurement techniques in fluidized beds , 1999 .

[10]  S. Simons,et al.  Experimental methods in fluidization research , 1994 .

[11]  Sang-Done Kim,et al.  Particle flow behavior in three-phase fluidized beds , 1999 .

[12]  Filip Johnsson,et al.  Time-series analysis of pressure fluctuations in gas–solid fluidized beds – A review , 2011 .

[13]  Hsiaotao Bi,et al.  Effect of measurement method on the velocities used to demarcate the onset of turbulent fluidization , 1995 .

[14]  Hsiaotao Bi,et al.  Characterization of dynamic behaviour in gas–solid turbulent fluidized bed using chaos and wavelet analyses , 2003 .

[15]  J. Chaouki,et al.  Investigation of particle velocity in FCC gas-fluidized beds based on different measurement techniques , 2015 .

[16]  J. Chaouki,et al.  Traveling column for comparison of invasive and non-invasive fluidization voidage measurement techniques , 2013 .