Numerical simulation of particle motion in vibrated fluidized beds

Flow behavior of particles is simulated in a two-dimensional vibrated bubbling fluidized bed. The motion of particles is simulated by discrete element method (DEM). The distributions of velocity and concentration of particles are analyzed at the different amplitudes and frequencies of vibration. In the case with vertical vibration, the bed consists of three different regimes along bed height: a low particle concentration regime with a vibration gap near the bottom, a high concentration regime in the middle of the bed and a transition regime at the bed surface. The gas pressure losses are reduced with the vibration. The phase delay time between the time at the maximum pressure loss and the time at the maximum displacement of vibrated distributor in one cycle decreases with the increase of amplitudes. The contacting interaction between the vibrated distributor and particles increases as the distributor moves up, and trends to zero as the distributor moves down with the increase of frequency of vibration. The vibrating energy is transferred by collisions between the vibrated distributor and particles at the period of acceleration of the distributor.

Graphical AbstractThe collisional interaction of particles is simulated by discrete element method in a fluidized bed with vertical vibration. The averaged contact forces between the distributor and particles increase with the increase of frequency of vibration when the distributor moves up from the bottom to the top. At the high frequency of vibration, the averaged contact force closes to zero as the distributor moves down from the top to the bottom.Figure optionsDownload full-size imageDownload as PowerPoint slide