Pulsed fluidization - a DEM study of a fascinating phenomenon

Abstract An investigation of pulsed fluidization by discrete element method simulation is presented. The particles used were 0.5 mm in diameter and 2650 kg/m3 in density. The pulsed gas flow consisted of a fluctuating component superimposed on a constant component. The effect of gas pulsation was assessed through examination of bed pressure drop and bubble patterns for a wide range of conditions. The influence on fluidized bed behaviour of frequency and amplitude of pulsation, superficial gas velocity of the base flow, and the nature (type) of pulsation was studied. Transition from chaos to ordered behaviour and formation of regular bubble patterns were reproduced. It was found that regular bubble patterns arise from periodical formation of horizontally aligned voids near the distributor plate.

[1]  Y. Tsuji,et al.  Discrete particle simulation of two-dimensional fluidized bed , 1993 .

[2]  J. Kuipers,et al.  Discrete particle simulation of bubble and slug formation in a two-dimensional gas-fluidised bed: A hard-sphere approach. , 1996 .

[3]  M. Coppens,et al.  Application of chaos analysis to multiphase reactors , 2002 .

[4]  Kurt Liffman,et al.  Onset of cohesive behaviour in gas fluidized beds: a numerical study using DEM simulation , 2001 .

[5]  Kurt Liffman,et al.  Study of mixing in gas-fluidized beds using a DEM model , 2001 .

[6]  Masayuki Horio,et al.  Particle and bubble movements around tubes immersed in fluidized beds : a numerical study , 1999 .

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

[8]  Cor M. van den Bleek,et al.  Deterministic chaos: a new tool in fluidized bed design and operation , 1993 .

[9]  Masayuki Horio,et al.  Numerical simulation of cohesive powder behavior in a fluidized bed , 1998 .

[10]  Masayuki Horio,et al.  Numerical simulation of metallic solid bridging particles in a fluidized bed at high temperature , 2000 .

[11]  Kurt Liffman,et al.  Use of discrete element method simulation in studying fluidization characteristics: influence of interparticle force , 2001 .

[12]  Masayuki Horio,et al.  Numerical analysis of particle mixing characteristics in a single helical ribbon agitator using DEM simulation , 2000 .

[13]  M. Baird,et al.  Fluidisation in a pulsed gas flow , 1971 .

[14]  Daw,et al.  Chaotic characteristics of a complex gas-solids flow. , 1990, Physical review. A, Atomic, molecular, and optical physics.