Material characterization and inter/intra-particle validation for DEM simulation of urea coating process  

作　　者：Salma A.Nouh KuZilati KuShaari Lau Kok Keong Shafirah Samsuri 

机构地区：[1]Chemical Engineering Department,Universiti Teknologi PETRONAS,32610 Seri Iskandar,Perak Darul Ridzuan,Malaysia

出　　处：《Particuology》2024年第5期32-48,共17页颗粒学报（英文版）

摘　　要：Particle coating is a common operation in the controlled-release fertilizer (CRF) industry,where a coating layer is appliedto the urea cores.A discrete element method (DEM) computer simulation was applied to model the coating process for the urea granules using measured model parameters.The accuracy of DEM input parameters for the coating material properties and the physical and mechanical characterizations of urea granules are crucial to the study of particle coating processes.Thus,to enhance the simulation accuracy,information on the material properties (urea granules) is required.In this study,the elasticity parameters,shear modulus ,coefficient of restitution (CoR),and coefficient of rolling and static friction (CoRF) and (CoSF) of urea granules are estimated experimentally in addition to the physical characteristics.The sensitivity of the angle of repose of the urea bed was investigated at different coefficients of friction.According to the obtained experimental value of the angle of repose,values of 0.2 and 0.3 for CoRF and CoSF,respectively,were adjusted to obtain consistent urea granules’ motion for simulation and the experiment.Moreover,the spray droplet sizes and velocity distributions were estimated using the video-imaging process technique.Based on this experimental characterization,elasticity parameters and spray properties were integrated into DEM simulation software as input data to perform numerical analysis of the coating process to compare simulation and experimental results,which show uniformity at three different pan speeds with a maximum deviation of 0.033 at 5 rpm.Also,consistency between DEM and experiment results was achieved in terms of average coating thickness (μm) of the selected samples and average intra-particle thickness variation ( CoV intra ).These results revealed that the coating film thickness is proportional to the rotation speed for the experiment and simulation.To enhance the inter-particle coating uniformity,the effects of the most significant parameters such as pan s

关 键 词：Contact model Discrete element method Urea fertilizer Coating process 

分 类 号：TQ441.41[化学工程—化学肥料工业]