Simulation of Very Low Frequency Pulsed Fluidized Bed

Abstract

Achieving high fluidization quality and bed stability is a paramount challenge in pulsed fluidized beds. 2D hydrodynamics models were studied using the Eulerian-Eulerian method with KTGF. This study investigates the impact of rectangular pulsation superimposed on steady airflow, while maintaining a constant temporal average gas velocity, on fluidization quality. Numerical results indicated that superimposing pulsations on steady airflow and increasing the steady airflow velocity to three times the minimum fluidization velocity resulted in a decrease in the bed expansion ratio. This decrease was most notable particularly at a pulsation frequency of 0.05Hz, with a reducing of approximately by about 21%. By decreasing the velocity ratio from 9.52 to 6.52, the pressure drop increased by 27% and 4.5% at 0.05 Hz and 10 Hz, respectively. Additionally, the fluidization index increased by 32% and 2% under these conditions. The optimal range of pulsed airflow velocity fell between 2.76 and 1.17 times the steady airflow velocity and was most effective at 0.05 – 0.1 Hz.

Keywords

• combined airflow
• cfd simulation
• fluidization quality
• pulsed fluidized bed
• pulse frequency