汽蒸处理过程中木材内部水分的迁移动力初探

Water migration force inner wood during steam treatment process

为研究汽蒸处理过程中木材内部水分的迁移动力,在温度为100和140℃下,分别对厚度为2、4、6 cm的杨木试件进行汽蒸处理,并对处理前后试件的质量,以及处理过程中木材内部温度场进行研究;另外,在温度为110℃下,对木材内部压力场进行研究。结果表明:汽蒸处理后,木材含水率均有所下降,而且处理温度越高,含水率下降越多;当处理温度为100℃时,含水率下降量为23.0%;当处理温度为140℃时,含水率下降量达到78.27%;木材内部温度随着时间的增加而升高,最后趋于稳定,当环境温度为100、140℃时,木材内部最高温度分别为92、110℃;建立了不同处理温度、时间与试件含水率下降量的关系模型,以及木材内部水分减少量的理论模型,所建模型能够很好地模拟实际汽蒸处理过程。

Poplar with the thickness of 2, 4 and 6 cm was taken as wood samples pre-and post-treatment and the temperature field specimen in thins paper. The weight of were studied under the conditions of 100 and 140 ℃. What＇ s more, the pressure field inner wood was also studied at the temperature of 110 ℃. The results showed that the weight of samples decreased as the time went by, and the minimum value was 23.0% when the temperature was 100 ℃ , while the maximum value was 78.27% when the temperature was 140 ℃ ; the temperature inner wood increased at the beginning of pre-treatment process, and became constant at last, the maximum value were 92 and 110 ℃ when the treating temperature were 100 and 140 ℃, respectively. Lastly, the relationship among the moisture content variation, the treating time and the treating temperature was founded. What＇ s more, the theoretical model of the moisture decrement, which was corresponding to the practical value, was established to simulate the real production.