紫菜过热蒸汽干燥特性研究

Study on the superheated steam drying characteristics of Porphyra haitanensis

将过热蒸汽干燥技术用于紫菜干燥加工中.首先确定紫菜烫漂护色的时间和温度,然后用过热蒸汽干燥技术对紫菜干燥特性进行研究,探讨不同物料铺设厚度、蒸汽温度、蒸汽流速及初始干基含水率对干燥特性的影响,根据逐步回归法和紫菜干燥过程中的水分比和时间变化规律,建立紫菜过热蒸汽干燥动力学数学模型.实验结果显示,紫菜过热蒸汽干燥最佳烫漂温度为85℃,时间为30 s.物料铺设厚度、蒸汽温度、蒸汽流速及初始干基含水率对物料干燥都有较明显影响.过热蒸汽干燥满足Page模型,预测值与实际值拟合程度良好.

Superheated steam drying technology was applied to dry Porphyra haitanensis. First,the time and temperature of Porphyra haitanensis color retention was measured. Based on superheated steam drying technology,Porphyra haitanensis drying characteristics were tested to explore the effects of different thickness,steam temperature,steam flow rate and initial dry basis moisture content on the drying characteristics. According to stepwise regression,water in Porphyra haitanensis drying process and time variation,the superheated steam drying dynamics mathematical model of Porphyra haitanensis was established. The experimental results showed that the best temperature and time of blanching was 85 ℃ and 30 s,which conformed to the general characteristics of the drying matter. The thickness,steam temperature,steam flow rate and initial dry basis moisture content had significant effects on drying. Superheated steam drying was matched to Page model. The predicted values had good fitting degree with the actual values.