入口旋流对均一粒径液滴喷雾干燥塔影响的数值模拟

均一粒径液滴喷雾干燥塔（MDSD）在生产均匀尺寸颗粒产品中发挥着较大优势，进一步优化其干燥过程操作尤为重要。集成离散相（DPM）和反应工程法（REA）干燥方法，通过耦合分散室和主干燥室模型，本研究开发了完整的MDSD三维计算流体力学模型。并系统探究了在干燥过程中分散气旋流、热空气旋流以及二者共同旋流对颗粒运动和最终干燥效果的影响。模拟结果表明，在30°入射角下加入旋流效果最优。同时引入分散室和干燥室旋流后发现，同向旋流比反向旋流带来的干燥效果提升2%，更比无旋流操作下的干燥效果提升30%。欲达到同样的干燥效果，引入同向旋流，塔身可缩短近12%。

Numerical simulation of mono-disperse droplet spray dryer under influence of swirling flow

Monodisperse droplet spray dryer (MDSD) has demonstrated great advantages in the production of uniform sized particle products. The drying performance of such facility is improved. By resorting to the discrete phase model (DPM) and the reaction engineering approach (REA) based on drying model, a 3D CFD model is developed to describe a complete MDSD consisting of a small droplet pre-dispersion chamber and a big drying chamber. The model allows to investigate the influence of introducing swirling flows in the pre-dispersion chamber and the drying chamber on particle trajectory and drying dynamics. It is shown that the introduction of the swirling flow at an air inlet angle of 30° can offer decent performance. When both chambers have swirling flows, the co-current scheme is 2% better than the counter-current scheme in terms of reaching lower particle moisture content. Compared with the case without any swirling flow, the particle moisture content can be 30% lower. To achieve the same moisture content, with the introduction of the swirling flow, the dryer can be shortened by nearly 12%.