涡流管制冷常压冷冻干燥怀山药技术分析-食品科学.PDFVIP

※工艺技术 食品科学 2015, Vol.36, No.20 7 涡流管制冷常压冷冻干燥怀山药技术分析 * 任丽影，任广跃 ，杨晓童，张 伟，段 续，张乐道，朱文学 （河南科技大学食品与生物工程学院，河南洛阳 471023 ） 摘  要：搭建一套涡流管制冷常压冷冻干燥装置，选用怀山药作为冻干实验材料，以涡流管为制冷源，对冻干规律 进行研究，分别考察涡流管进口压力、物料厚度、给热模式、物料形状等因素对干燥过程影响。结果表明：在干燥 处理过程中，物料性质及内部结构对干燥速率影响较大。通过适当减小物料厚度和采用对流辐射耦合变温给热模式 均可提高干燥速率。干燥室内温度略高于物料三相点温度时，涡流管制冷常压冷冻干燥过程仍可以进行。对怀山药 而言，当冷气流率0.4～0.5 、进口压力0.3 MPa时，制冷效率最佳。 关键词：常压冷冻干燥；涡流管；怀山药；干燥速率 Atmospheric Freeze-Drying of Chinese Yam Based on Vortex Tube Refrigeration * REN Liying, REN Guangyue , YANG Xiaotong, ZHANG Wei, DUAN Xu, ZHANG Ledao, ZHU Wenxue (College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China) Abstract: A set of atmospheric freeze-drying experimental equipment was established based on vortex tube refrigeration to dry Chinese yam. Effects of inlet pressure of vortex tube, thickness and shape of fresh sample, heating mode on the drying process were investigated in the experiment. Results showed that the properties and internal structure of the material had considerable influences on the drying rate during the drying process. Drying rate was improved through reducing the thickness of fresh material and using combination of convection and radiation. When the temperature of drying oven was slightly higher than the eutectic temperature of the material, the atmospheric freeze-drying process was still manipulated. The optimal refrigeration efficiency for Chinese yam was obtained when the inlet pressure was 0.3 MPa and the cold air μ flow rate was between 0.4 and 0.5. Key words: atmospheric freeze-drying; vortex tube; Chinese yam; drying rate 中图分类号：TS201.1 文