LES-DEM investigation of the hydrodynamics and tube erosion in 3-d bubbling fluidized beds with different tube configurations

Immersed tubes have been widely adopted in the dense fluidizing apparatus due to its ability of restricting the bubble diameter and altering the gas-solid flow characteristics. However, different tube configuration results in different flow pattern. Based on the LES-DEM coupling approach, the current work numerically investigates the flow patterns and the erosion properties in the bubbling fluidized beds with different tube configurations. The results show that the presence of tube bundle results in the four typical circulations of solid phase spotted in the regions above and below the tube bundle. In addition, stronger restriction of the staggered tube bundle on the vertical transportation of solid phase can be observed as compared with the inline one, resulting in the more uniform transverse distribution of solid concentration. Different tube configuration gives rise to different gas-solid flow characteristics and then different erosion pattern appears around the tube surface.