单液滴干燥过程中阿拉伯胶乳液的干燥特性

喷雾干燥塔是一个完全封闭的设施,难以对干燥过程中的液滴取样分析。本试验以阿拉伯胶包埋油脂的水包油(O/W)型乳液为样液,采用单液滴干燥技术(SDD)模拟喷雾干燥条件,通过分析乳液液滴在干燥过程中的形态收缩和干燥动力学参数的变化,探究干燥气流速度和乳液中固形物含量对颗粒的表面形成机制的影响。结果表明,在0.70,0.90,1.10 m/s 3种干燥气流速度下乳液液滴的干燥行为差异很大。在1.10 m/s的干燥气流速度下,液滴水分蒸发最快,表壳形成最早,最终所得颗粒收缩率最小。乳液总固形物含量对液滴干燥行为的影响也较为明显。随着总固形物含量的增高,乳液液滴水分蒸发越慢,表壳形成越早,最终所得干燥颗粒形态越大。本试验对于干燥动力学模型的研究和喷雾干燥产品品质的改善具有指导性意义。

Drying Characteristics of Gum Arabic-encapsulated Emulsion during Single Droplet Drying

Spray drying tower is a completely enclosed facilities,it is difficult to sampling analysis during the drying process.Oil-in-water(O/W)emulsions with gum arabic as wall material were prepared in this experiment.Single droplet drying(SDD)was been proposed that can simulate the environment of spray-drying,to studying the effects of the air velocities and the solids content in the emulsion on the surface formation mechanism of the particles by analysing morphological shrinkage and drying kinetics parameters of droplet during drying process.The results show that the drying behavior of droplets varies greatly at three air velocities of 0.70,0.90,1.10 m/s.When air velocities was 1.10 m/s,the moisture of droplet evaporates fastest,crust form earliest,the produced particles have smaller shrink rate.The total solids content of the emulsion also has an obvious effect on the drying behavior of the droplets.With the increase of the solid content,the water evaporation of the emulsion droplets decelerate,the crust form earlier,and the morphology of the resulting particle was larger.The experimental has guiding significance for studying the drying dynamic model and improvement spray drying product quality.