Abstract Steam-jet granulation process consists in agglomeration mechanisms promoted by the wetting of fine particles and colliding them to generates the agglomerates, and in consolidation mechanisms of the agglomerates by drying stage. The aim of the present study was to evaluate the influence of the drying step on the properties of the agglomerates. Experiments were conducted using an original pilot system with different drying conditions (time and temperature). We demonstrated that the mechanisms induced by drying stage contribute to the final structure and characteristics of the agglomerates. On the other hand, the changes in drying temperature (70, 90, or 110 °C) did not significantly impact the structural properties. The rehydration properties of the agglomerates were found to depend on the changes in water content. During the first minutes of drying, a rapid decrease of the wetting time of the agglomerates was observed and associated with rapid lactose crystallization. For long drying times, the large decrease in water content induced a considerable increase in the glass transition temperature, leading to a delay in the plasticization effect of the water during rehydration. The drying stage is a key factor to control the stability and functional properties of agglomerates.

中文翻译：

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乳粉蒸汽喷射造粒过程中干燥步骤的影响

摘要 蒸汽喷射造粒过程包括由细颗粒润湿和碰撞产生团块促进的团聚机制，以及团块在干燥阶段的固结机制。本研究的目的是评估干燥步骤对附聚物性质的影响。使用具有不同干燥条件（时间和温度）的原始中试系统进行实验。我们证明了干燥阶段引起的机制有助于团聚体的最终结构和特性。另一方面，干燥温度（70、90 或 110 °C）的变化对结构性能没有显着影响。发现附聚物的再水合特性取决于水含量的变化。在干燥的最初几分钟内，观察到附聚物的润湿时间迅速减少并且与乳糖快速结晶有关。对于较长的干燥时间，水分含量的大幅降低会导致玻璃化转变温度的显着升高，从而导致再水化过程中水的增塑作用延迟。干燥阶段是控制附聚物稳定性和功能特性的关键因素。