气流磨制备高氯酸铵粉体过程静电分布的CFD-DEM模拟OA

To address the safety hazard of electrostatic accumulation during the preparation of ammonium perchlorate(AP)powder by air jet milling,in this article,a numerical simulation method coupling computational fluid dynamics(CFD)and discrete element method(DEM)was used to conduct electrostatic simulation research.The gas-solid two-phase flow,particle fragmentation,and electrostatic distribution characteristics in the air jet mill were systematically investigated under six different air flow velocity conditions.The CFD simulation results showed that the contraction of the flow cross-section at the throat of the Laval nozzle formed a pressure difference,which served as the main driving force to suck the particles into the grinding chamber and complete the fragmentation.At the same time,the high-speed vortex structures generated in the flow field could effectively carry the particles,prolong their residence time and enhance the collision frequency between particles and between particles and wall surfaces,thereby significantly improving the fragmentation efficiency.The software Event Driven Execution Manager(EDEM)simulation results further revealed that the particle velocity,fragmentation degree,and charge quantity all significantly increased with the increase in the inlet air flow velocity.The charge quantity generated by the frictional electrification of the particles increased by nearly an order of magnitude.Through the analysis of the static electricity distribution,the results showed that the flow field vortices had a concentrating effect on the charge transport and distribution.The potential in the vortex core area is the highest,and the potential at all test points increased monotonically with the increase in flow velocity.