摘要
该文以马尾松为试验材料 ,通过对水分扩散系数和浮压系数的试验研究 ,总结出木材在真空 浮压干燥过程中吸着水迁移的基本规律 .试验分析表明 ,真空 浮压干燥过程中 ,含水率梯度不是水分移动的主要驱动力 .在纤维饱和点以下时 ,木材内部吸着水的迁移可分为 :水蒸汽压力梯度下的扩散迁移和由于干燥介质压力的波动而引起的浮动压力下的迁移两个部分 .由数据分析可见 ,当介质温度一定时 ,木材水分扩散系数随绝对压力的减小和压力变化速率的加大而增加 。
Using masson pine (Pinus massoniaha) as specimen, experiments based on the research of water diffusion coefficient and floating coefficient have been carried out to reveal the fundamental principle of absorbed water movement in wood drying under vacuum-floating pressure. The results show that moisture gradient is not the dominant driving force of moisture movement in the process. When the moisture content is below the fibre saturation point, the movement of absorbed water is subdivided into two parts: one is diffusion transfer due to the vapor pressure gradient, the other is moisture movement caused by the pressure fluctuation due to the variation of medium. When the temperature of the medium is constant, the analysis of data presents that the diffusion coefficient of moisture increases with the reduction of absolute pressure and the rise of changing rate of pressure, among which the effect of the latter makes a big difference compared with that of the former.
出处
《北京林业大学学报》
EI
CAS
CSCD
北大核心
2003年第6期60-63,共4页
Journal of Beijing Forestry University
基金
国家自然科学基金资助项目"木材浮压干燥过程的传热传质"( 5 98760 0 5 )
关键词
木材干燥
真空
浮压
吸着水迁移
纤维饱和点
Diffusion
Drying
Moisture
Pressure
Vacuum applications
Water absorption
