Title of article :
Discrete particle simulations of an electric-field enhanced fluidized bed
Author/Authors :
F. Kleijn van Willigen، نويسنده , , F. and Demirbas، نويسنده , , B. and Deen، نويسنده , , N.G. and Kuipers، نويسنده , , J.A.M. and van Ommen، نويسنده , , J.R.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Abstract :
Reducing the size of gas bubbles can significantly improve the performance of gas–solid fluidized reactors. However, such a control of bubbles is difficult to realize without measures that either use a lot of energy or deteriorate the fluidization behavior. In this paper, we present the results of discrete particle simulations of an electric-field enhanced fluidized bed, and compare these results to experimental data.
mulations show a significant effect on the size of bubbles, both with horizontal and vertical electric-fields applied. When the field strength is increased to values higher than those used in the experiments, the particles are found to form strings in the direction of the electric field. At very high field strengths, defluidization is observed, consistent with the experiments.
h the analysis of the bubble behavior, it is concluded that moderate strength electric fields distribute gas more evenly at the bottom of the bed. As the bubbles rise through the bed, the coalescence rate is lower because of the guiding paths, or resistance, the particles form due to the field. This results in a smaller average bubble size in the higher region of the bed. The simulations presented here show how and why the electric fields reduce bubble size in electric-field enhanced fluidized beds.
Keywords :
CFD , Discrete particle model , Bubble size reduction , Fluidization , Electric-field enhanced fluidized beds , Dipole force
Journal title :
Powder Technology
Journal title :
Powder Technology