为使干法造粒过程中雾化液滴与粉体充分接触，改善粒径的均匀性，依据干法造粒试验样机简化物理模型，同时基于Euler - Lagrange法中的DPM模型建立雾化过程的数学模型，采用CFD软件分别对喷嘴内径均为1mm的平口喷嘴、压力式喷嘴、气流式喷嘴、气泡式喷嘴雾化流场进行数值模拟分析。模拟结果显示：气流式喷嘴、平口喷嘴、压力式喷嘴、气泡式喷嘴雾滴分散性依次递增，压力旋流式喷嘴雾滴平均粒径较之其它三种喷嘴更小且雾滴在造粒室内分散较均匀，更有利于雾滴与粉料的充分接触。因此，就雾化场雾滴分散性和雾滴粒径分布而言，宜选用压力旋流式雾化喷嘴作为干法造粒的雾化装置。%In order to make the atomized droplets fully contact with the powder in the process of dry granulation and to improve the uniformity of particle size, the mathematical model of the atomization process is established based on the DPM model in the Euler-Lagrange systems with the help of the simpliifed physical model for a test dry granulator. The atomization lfow ifelds of plain-oriifce-nozzle, pressure-swirl-nozzle, air-blast-nozzle, and effervescent-nozzle, all with the inner diameter of 1 mm, are numerically simulated using CFD software. And the particle diameter distributions of different nozzles are compared and analyzed. The simulation results show that the droplet dispersity increases with the order from air-blast-nozzle, plain-oriifce-nozzle, pressure-swirl-nozzle to effervescent-nozzle. But the droplets average particle size of pressure-swirl-nozzle is less than those of the other three kinds of nozzles and droplets inside the granulation chamber are dispersed more uniformly and thus more conducive to a good contact between droplets and powder. Therefore, in terms of the dispersity of atomized droplets and droplet size distribution, pressure-swirl-atomizer is the best for dry granulation atomization device.
展开▼
