Abstract： The pneumatic conveying process of Venturi powder injector was simulated by using the method of computational fluid dynamics -discrete element method （CFD -DEM） coupling，internal particle group was composed of five different diameters particles. The trajectories of particles were analyzed，part of particles gather together at the bottom of the absorption section. Most of the particles distribute in the middle and lower parts of pipelines in venturi powder ejector，small size particles are faster. The greater the particle size is， the more particle -particle collisions are and the less particle-wall collisions are. Analysis of the wall stress change due to the impact of particles was carried out by using the method of discrete element method-finite element analysis （DEM-FEA） coupling. It results that there is peak stress near the nozzle exit and the bottom of the absorbed section.

Keywords: Venturi ejector; computational fluid dynamics-discrete element method coupling; particle motion; discrete element method-finite element analysis coupling; stress analysis