Abstract Spray drying is a fundamental process in several industries. As many factors affect the particulate product property in complex manners, optimal operating conditions have been determined through trial and error. In a spray dryer, numerous sprayed droplets form a tear-shaped droplet aggregate (droplet group), in which each droplet evaporates at a different rate. Owing to the complicated evaporation behavior of a droplet group, a detailed mechanism of dried particle generation has yet to be sufficiently elucidated. The objective of this study is to investigate the effects of the operating conditions of spray drying processes on the evaporation rate of a droplet group. Numerical simulations were performed under various conditions to calculate the evaporation rates of a droplet group in a spray drying process. A method for estimating the evaporation rate of a droplet group based on the operating conditions, using the thermal efficiency and Nusselt number, is proposed.

中文翻译：

---

喷雾干燥过程中水滴群蒸发率的估算

摘要 喷雾干燥是多个行业的基本过程。由于许多因素以复杂的方式影响颗粒产品的特性，因此通过反复试验确定了最佳操作条件。在喷雾干燥机中，无数喷射的液滴形成泪滴状的液滴聚集体（液滴群），其中每个液滴以不同的速率蒸发。由于液滴群的复杂蒸发行为，干燥颗粒产生的详细机制尚未得到充分阐明。本研究的目的是研究喷雾干燥过程的操作条件对液滴组蒸发率的影响。在各种条件下进行数值模拟以计算喷雾干燥过程中液滴群的蒸发率。