Power Spectral Density Analysis of Pressure Signal in an 18 m Circulation Fluidized Bed Riser

Studies on the gas-solids flow characteristics using power spectral density based on the pressure data from different axial locations in a riser of diameter in 80 mm and height in 18 m. Results show that the pressure signal fluctuation is mainly affected by gas-solid interaction, which included gas-solid friction, particle-particle collision and particle-particle aggregation. With the increase of solid circulating rate, frequency of particle interactions including particle-particle collision and particle-particle arrogation becomes strong and the pressure fluctuation also increases. It can be seen that the pressure signal fluctuation intensity decreased gradually with the increase of axial position in the riser. The phenomenon of low frequency with high power nearly disappears in the fully developed zone near the top of the riser. Based on the results, it can be concluded that the gas-solids interaction is stronger at the bottom of riser. On the other hand, the gas-solid interaction is more homogeneous, and the pressure fluctuation is relatively weak in the fully developed zone. © 2018, Editorial Office of Acta Petrolei Sinica(Petroleum Processing Section). All right reserved.