木材超声波-真空协同干燥的动力学研究  

Preliminary study of wood ultrasound-vacuum combined drying dynamics.

作　　者：何正斌[1] 郭月红[1] 伊松林[1] 张璧光[1] 

机构地区：[1]北京林业大学材料科学与技术学院

出　　处：《北京林业大学学报》2012年第2期133-136,共4页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(30871978)

摘　　要：结合超声波和真空干燥的优点,采取超声波--真空协同干燥方法,对核桃楸试件进行干燥。在不同干燥温度、绝对压力、超声波功率和频率的条件下,检测木材干燥过程中内部水分的有效扩散系数,并建立对应条件下的干燥动力学模型。结果表明:超声波--真空协同干燥过程中,木材内部水分有效扩散系数随着温度的升高而增大,而绝对压力对于水分有效扩散系数影响较小;干燥过程中,温度对干燥速率起着主要作用,相同温度、不同压力下木材的干燥速率随着时间的变化趋势一致;通过有效扩散系数和菲克单方向扩散方程得到的干燥模型和实际干燥动力学很接近。Combined with the advantages of ultrasound drying and vacuum drying, Juglans mandshurica Maxim was dried by ultrasound-vacuum combined drying method at different drying temperatures, absolute pressures, ultrasound power and frequency conditions. The water effective diffusion coefficient during drying process was measured, and the drying dynamics model was also established. The results showed that the value of the water effective diffusion coefficient increased along with the increasing temperature, while absolute pressure had little effects on the water effective diffusion coefficient during the ultrasound-vacuum drying process; temperature had significant effects on drying rates; the variation trends of drying rates versus time were approximate at the same temperature and different absolute pressure conditions; the drying model, which was established based on the effective diffusion coefficient equation and the Fick＇s unidirectional diffusional equation, was approximate to the practical drying dynamics.

关 键 词：超声波 木材真空干燥 水分有效扩散系数 干燥速率 

分 类 号：S781.71[农业科学—木材科学与技术]