An in-depth numerical simulation analysis of the hydrodynamic characteristics of internally-reinforced spouted beds

Due to the lack of gas-solid radial mixing in conventional spouted bed (CSB), particles are prone to accumulation and the formation of flow dead zones. To address the limitations of CSBs, this study, for the first time, the combination optimization of the two strengthening internal components of multi-jets and draft tube was carried out, and two new types of internal strengthening structural spouted beds were proposed: the Integral Multi-jets Draft-tube Spout-fluidized Bed (IMDSFB), and the Integral Multi-jets Open-hole Draft-tube Spout-fluidized Bed (IMODSFB). At the same time, the hydrodynamic characteristics of IMDSFB and IMODSFB are studied by numerical simulation for the first time and compared with the draft tube spouted bed (DTSB) and CSB. Results indicate that compared to CSB, the spouting heights of the DTSB, IMDSFB, and IMODSFB were enhanced by 2.92%, 14.75%, and 7.94%, respectively, and the dead zone of the DTSB, IMDSFB, and IMODSFB decreased by 14%, 1%, and 5%, respectively. Compared to the CSB and DTSB, the addition of novel internal components notably improved the radial velocities of both gas and particles, as well as the gas-solid slip velocity, while reducing flow dead zones within the bed. Furthermore, the gas turbulence kinetic energy in the novel spout-fluidized beds was higher, with increased fluctuations of gas velocity in the spouting region. The granular temperature in the IMDSFB and IMODSFB was higher than in the CSB and DTSB, indicating enhanced particle fluctuations within the bed. These improvements contribute to more efficient gas-solid phase interactions, thereby enhancing the overall performance of the spouted bed. • New spouted beds were proposed by introducing multi-jets and draft tube. • Internally reinforced spouted beds increased the spouting height. • The new spouted fluidized bed reduces flow dead zone in the bed. • Gas-solid contact is improved by internally reinforced spouted beds.