Effect of Elbow Structure on Gas-Solid Separation and Flow Field Adjacent to the Exit of the Swirl Burner

An elbow is often used as the solid-gas separator in coal- fired burners. In this paper, four different elbow structures are selected and their effects on the gas solid separation and flow field adjacent to the burner exit are numerically studied. The axial, circumferential velocity distributions, the particle trajectory and the secondary flow are presented and discussed. Based on the simulation results, the solid separation and particle concentration distributions in the radial direction and along circumference remarkably depended on the elbow structure. The secondary flow could be found near the elbow and it also depends on the elbow structure. By modifying the elbow structure, for example, using the guidance plate could improve the elbow performance.