摘要
采用TG-DTG热重分析技术和材料介电参数测试系统研究了草果脱水过程和草果含水率与介电常数、介电损耗、损耗角正切及穿透深度的关系。结果表明,草果的热失重过程分为自由水脱除阶段和束缚水脱除阶段,其介电常数和介电损耗随着含水率的降低存在平缓下降和急剧下降的分段变化趋势。草果自由水存在时,介电常数和介电损耗平缓下降;当草果只剩束缚水时,介电常数和介电损耗急剧下降。物料含水率越大,微波能损耗越大,穿透深度越小;相反,物料含水率越小,微波能损耗越小,穿透深度越大。物料穿透深度D_p与含水率ω_t存在y=Ae^(-ax)+y_0,符合指数关系。
Relationship between water content of Amomum tsaoko and permittivity,dielectric loss,loss angle tangent and penetration depth was studied by TG-DTG and dielectric parameter test system. Research results showed that thermal weight loss process of Amomum tsaoko was divided into free water removal stage and bound water removal stage. When free water exists of Amomum tsaoko,dielectric constant and dielectric loss decreased slowly. While as Amomum tsaoko was only bound with water,dielectric constant and dielectric loss decreased rapidly. Plots of nonlinear surface fitting indicated that penetration depth increasing with water content descent of Amomum tsaoko. There was exponential relationship y=Ae^-ax＋y0 between penetration depth and water content.
作者
黄孟阳
刘鹏
杨玺
刘秉国
张明宇
HUANG Mengyang3, LIU Peng1,2, YANG Xi3, LIU Bingguo1,2, ZHANG Mingyu3(1. Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming Yunnan 650093, China ; 2. National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming Ytmnan 650093, China; 3. Yunnan Energy Research Institute Co. , Ltd, Chenggong Yunnan, 650550, China)
出处
《农业工程》
2018年第10期69-73,共5页
AGRICULTURAL ENGINEERING
基金
国家自然科学基金项目(项目编号:51564033)
云南省应用基础研究项目(项目编号:2016FA023)
关键词
草果
微波干燥
介电特性
穿透深度
Amomum tsaoko
microwave drying
dielectric properties
penetration depth
