Study On Dispersion Behavior Of Sepiolite Particles In A Spiral Nozzle

Sepiolite is easy to agglomerate in the process of entering the classification device from the round tube,which reduces the classification accuracy.For this problem,this paper chooses spiral nozzle to disperse sepiolite particles,and explores the feasibility and dispersion effect after using spiral nozzle.CFD-DEM method is used to study dispersion state of sepiolite particles after ejected by the spiral nozzle under different parametersthe,which provides theoretical guidance for the application of the spiral nozzle in sepiolite particle ejection.This paper mainly includes the following contents:Establishment of gas-solid two-phase calculation model for sepiolite particles.Firstly,several numerical simulation methods of gas-solid two-phase flow are introduced,and the cfd-dem coupling method is selected as the simulation mean in this study after comparing various methods;Analyzed the control equation of gassolid two-phase flow of sepiolite particles theoretically,and selected the discretization method and solution method of the gas-phase control equation;Explored the mechanical model of sepiolite particles after entering the airflow field.Numerical simulation of dispersion behavior of sepiolite particles in spiral nozzle jet.The coupling of FLUENT and EDEM is realized through single-phase physical field API,and the fluid domain model is established and meshed;The sepiolite particle model is established,including sepiolite particle agglomeration model and sepiolite multi particle size particle model;The flow field in the fluid domain inside the spiral nozzle was analyzed,and the movement and dispersion behavior of sepiolite particles with different particle sizes in the fluid domain were observed.Effects of different parameters on the dispersion behavior of sepiolite particles.Different process parameters and structural parameters,gas flow incidence velocity,screw pitch and internal contraction angle of spiral nozzle,are selected.CFD-DEM method was used to simulate the flow field in the spiral nozzle,and the motion and dispersion behavior of sepiolite particles in the nozzle under different parameters.Experimental study on dispersion behavior of sepiolite particles.The experimental platform of sepiolite particle spray with spiral nozzle was built,and the overall state of particles ejected from the spiral nozzle was photographed with a highspeed camera.The dispersion of sepiolite particles under different time,different air velocity and different structure of spiral nozzle was catched,the simulation results are in good agreement with the experimental results.The dispersion behavior of sepiolite particles in the spray process of spiral nozzle was analyzed by the numerical simulation and experimental methods.The results showed that the use of spiral nozzle in the spray process of sepiolite particles could reduce the production of aggregates;The dispersion of sepiolite particles is affected by many factors,such as air flow,nozzle structure and so on.By exploring the dispersion behavior of sepiolite particles under different parameters,this paper provides theoretical guidance for the application of spiral nozzle in sepiolite powder injection.