Fluidized bed with a rotating distributor operated under defluidization conditions

Abstract The fluidization conditions of a rotating distributor applied to a 3-D bubbling fluidized bed was studied to assess its potential use as a counteracting measure of defluidization phenomena. The performance of the fluidized bed operating under nominal conditions was characterized for the rotating and the static distributor configuration. Different methods of analysis in the time and frequency domain were applied to establish the performance of the fluidized bed. The frequency domain analysis suggests some kind of local structuring of fluidized bed dynamics imposed by the distributor motion. The punctual injection of water over the surface of the bed lead to a high cohesive wet region that tend to settle down on top of the distributor giving rise to defluidization. The water-induced defluidization tests reflect an improvement of the fluidization quality with the distributor rotation.

[1]  Masayuki Horio,et al.  PARTICLE MOVEMENT ON A PERFORATED PLATE DISTRIBUTOR OF FLUIDIZED BED , 1980 .

[2]  Joachim Werther,et al.  An investigation of the mechanism of liquid injection into fluidized beds , 2005 .

[3]  Cor M. van den Bleek,et al.  Rapid detection of defluidization using the standard deviation of pressure fluctuations , 2004 .

[4]  Antonio Soria-Verdugo,et al.  Motion of a large object in a bubbling fluidized bed with a rotating distributor , 2011 .

[5]  Martin Rhodes,et al.  Using pulsed flow to overcome defluidization , 2005 .

[6]  H. J. M. Visser,et al.  Biomass Ash – Bed Material Interactions Leading to Agglomeration in FBC , 2003 .

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

[8]  Sandra Rocha,et al.  Prediction of minimum fluidization velocity of gas–solid fluidized beds by pressure fluctuation measurements — Analysis of the standard deviation methodology , 2007 .

[9]  Filip Johnsson,et al.  Characterization of fluidization regimes by time-series analysis of pressure fluctuations , 2000 .

[10]  Derek Wilkinson,et al.  Determination of minimum fluidization velocity by pressure fluctuation measurement , 1995 .

[11]  Anders Nordin,et al.  Bed Agglomeration Characteristics during Fluidized Bed Combustion of Biomass Fuels , 2000 .

[12]  Javier Bilbao,et al.  Defluidization modelling of pyrolysis of plastics in a conical spouted bed reactor , 2005 .

[13]  Cor M. van den Bleek,et al.  Response characteristics of probe-transducer systems for pressure measurements in gas-solid fluidized beds: how to prevent pitfalls in dynamic pressure measurements , 1999 .

[14]  Domingo Santana,et al.  Fluidization of Group B particles with a rotating distributor , 2008 .

[15]  A. E. Ghaly,et al.  Agglomeration of silica sand in a fluidized bed gasifier operating on wheat straw , 1993 .

[16]  D. Geldart.  Types of gas fluidization , 1973 .

[17]  J. Silvennoinen,et al.  A New Method to Inhibit Bed Agglomeration Problems in Fluidized Bed Boilers , 2003 .

[18]  Kim Dam-Johansen,et al.  Agglomeration in bio-fuel fired fluidized bed combustors , 2003 .

[19]  Somchart Soponronnarit,et al.  A novel cyclonic fluidized-bed combustor (ψ-FBC): Combustion and thermal efficiency, temperature distributions, combustion intensity, and emission of pollutants , 2006 .

[20]  Prabir Basu,et al.  Agglomeration of biomass fired fluidized bed gasifier and combustor , 2009 .

[21]  Cedric Briens,et al.  Effect of liquid properties on the agglomerating tendency of a wet gas–solid fluidized bed , 2005 .

[22]  Filip Johnsson,et al.  Non-intrusive determination of bubble and slug length scales in fluidized beds by decomposition of the power spectral density of pressure time series , 2002 .

[23]  Marc-Olivier Coppens,et al.  Structuring chaotic fluidized beds , 2003 .

[24]  Marc-Olivier Coppens,et al.  Imposing dynamic structures on fluidised beds , 2005 .

[25]  J. Drahoš,et al.  EVALUATION OF MINIMUM FLUIDIZING VELOCITY IN GAS FLUIDIZED BED FROM PRESSURE FLUCTUATIONS , 1985 .

[26]  P. Welch.  The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms , 1967 .

[27]  Cedric Briens,et al.  Digital X-ray Imaging Technique to Study the Horizontal Injection of Gas-Liquid Jets into Fluidized Beds , 2003 .

[28]  Srinath V. Ekkad,et al.  Influence of multiple gas inlet jets on fluidized bed hydrodynamics using Particle Image Velocimetry and Digital Image Analysis , 2011 .

[29]  Osvaldir Pereira Taranto,et al.  Identification of defluidization in fluidized bed coating using the Gaussian spectral pressure distribution , 2011 .

[30]  Freek Kapteijn,et al.  Agglomeration in fluidized beds at high temperatures: Mechanisms, detection and prevention , 2008 .

[31]  Domingo Santana,et al.  Bubble characteristics in a bubbling fluidized bed with a rotating distributor , 2009 .

[32]  A. P. Baskakov,et al.  A study of pressure fluctuations in a bubbling fluidized bed , 1986 .

[33]  Cedric Briens,et al.  On-line detection of bed fluidity in gas-solid fluidized beds with liquid injection by passive acoustic and vibrometric methods , 2011 .