Transport Processes in Spray Drying

这项研究旨在对喷雾干燥中影响干燥速度、颗粒形态和其他产品质量属性的因素有一个更好的、机械的理解。热线风速仪和示踪剂研究被用来确定实验室干燥器中喷雾包膜外区域的流动和混合模式。在第二个实验中，在悬浮液滴干燥过程中监测微量挥发性成分的损失率，同时通过视频技术监测形态变化。这项研究应该能够获得更好的风味和香气属性，并更好地控制喷雾干燥制成的食品--如速溶咖啡、茶和牛奶--的堆积密度。它还应该使喷雾干燥器中的操作条件的设计和选择更有见地，从而导致更具成本效益的操作和更可靠的产品质量。

This research is directed toward an improved, mechanistic understanding of the factors affecting drying rates, particle morphology, and other product-quality attributes in spray drying. Hot-wire anemometry and tracer studies are used to define flow and mixing patterns in the region outside the spray envelope in a laboratory dryer. In a second experiment rates of loss of a trace volatile component are monitored during drying of a suspended drop, with simultaneous monitoring of morphological change by video techniques. This research should make it possible to obtain superior flavor and aroma attributes and better bulk-density control of food products -- such as instant coffee, tea, and milk -- made by spray drying. It should, as well, enable more knowledgeable design and selection of operating conditions in spray dryers, leading to more cost-efficient operation, and more reliable product quality.