摘要
根据干燥动力学理论,分别设定95、100、105℃为热风对流干燥参数和80、160、240 W为微波干燥参数,对植物纤维发泡材料的热风对流和微波干燥的干燥特性进行了研究,并对干燥动力学特性进行数学模型拟合。研究表明,当绝对含水率≤100%,植物纤维发泡材料的热风对流干燥出现传热传质困难,干燥效率降低。而微波干燥速率稳定,干燥曲线呈近似直线线性关系。植物纤维发泡材料的干燥动力学模型可由多项式模型来表示。
Drying is the most energy and time consuming step in the manufacture of ultra-low density plant fibre-based foaming nat （ULD mat） because of its high initial moisture content （MC）. The drying characteristics of the ULD mat was examined under 6 drying conditions： convective hot-air drying at 3 temperatures （95, 100 and 105 ℃） and microwave drying under 3 microwave powers （80, 160 and 240 Watt）. Three drying models, including diffusion model, Page model and the forth-order polynomial equa-tion, were fitted to describe the moisture ratio （moisture at given time to initial moisture） in relation to drying time. The results indi-cated that the time needed for drying the mat from 600% to 10% （dry base） decreased by 24% and fi0% With increasing temperature from 95 to 105℃ for the convective hot-air drying and power from 80 to 240 Watt for the microwave drying, respectively. The microwave drying had an even drying rate, while the convective hot-air drying showed 3 distinctive stages： fast drying stage from 600% to 250% MC, slowing-down stage from 250% to 100% MC and slow drying stage from 100% to 10% MC. The forth-order polynomial model fitted the data better than did the diffusion and Page models in terms of R2, while the coefficients in the forth-order polynomial model can be expressed as the second-order polynomial equation of drying parameters, i. e. , temperature for the convective hot-air drying and power for the microwave drying. The results should provide data and basis for the design of industrial manufacture line. Key words： ultra-low density; plant fiber; drying characteristics; kinetic model; convictive hot-air drying; microwave drying
出处
《福建林学院学报》
CSCD
北大核心
2012年第2期177-182,共6页
Journal of Fujian College of Forestry
基金
国家自然科学基金资助项目(30871982)
"十一五"国家科技支撑计划项目(2008BADA9B01)
关键词
超低密度
植物纤维
干燥特性
动力学模型
热风对流干燥
微波干燥
ultra-low density
plant fiber
drying characteristics
kinetic model
convictive hot-air drying
microwave drying
作者简介
刘景宏（1972-），男，副教授，博士研究生，从事木材科学与技术研究。
谢拥群（1960-），男，教授，博士生导师。从事木材科学与技术研究。E-mail：fjxieyq@hotmail．com。
