真空条件下木材表面水分蒸发速率模型及应用初探
A model of water evaporation rate from wood surface and its application under vacuum condition.
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摘要: 对真空条件下木材表面水分蒸发速率模型进行了理论推导，并以截面为20 mm×20 mm，长度分别为100、150、200、250、300 mm的桦木为试材，在干燥温度分别为60、75、90℃，绝对压力分别为0.02、0.04、0.06、0.07、0.08 MPa的真空干燥条件下，对试材内部水分移动速率进行研究。结果表明：木材表面水分移动速率大于内部水分移动速率，二者的比值在10～150之间变化。根据试验结果,得出了不同条件下各种规格试材的干燥速率与温度、绝对压力的关系式，并与理论推导得出的模型进行比较，得到木材表面水分蒸发速率与内部水分移动速率之比。最后根据不产生干燥缺陷的最大（极限）速比，得出木材真空干燥过程中不产生缺陷时的温度和绝对压力的关系式。Abstract: We developed a model of water evaporation rate from wood surface under vacuum condition using birch as material with cross-sectional area of 20 mm×20 mm and length of 100, 150, 200, 250 and 300 mm.The internal water moving rates of specimen were studied under the temperature of 60, 75 and 90℃ and absolute pressure of 0.02, 0.04, 0.06, 0.07 and 0.08 MPa. The results show that the surface water evaporation rates were much faster than the internal water moving rates, and the ratio of the former to the later varied from 10 to 150. In addition, the relations of the drying rate with temperature and absolute pressure under different conditions were deduced based on the experimental results. Compared with the model of surface water evaporation rate, we can obtain the ratio of the wood surface water evaporation rate to the internal water moving rates from the regression equation. Finally, the optimum formula between temperature and absolute pressure was deduced according to the maximal ratio of the surface water evaporation rate to the internal water moving rate, which could cause drying defects during vacuum drying.
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Keywords:
- water movement /
- drying rate /
- theoretical deduction /
- drying defect
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期刊类型引用(3)
1. 刘茸，陈娟. 森林培育对生态建设的重要性. 乡村科技. 2019(10): 52-53 . 
百度学术
2. 王成德，吴保国，刘建成，韩焱云. 基于智能选择算法的造林设计决策支持系统研建. 山东农业大学学报(自然科学版). 2018(02): 224-229 . 百度学术
3. 王建明，吴保国，梁其洋. 基于遗传算法的森林抚育间伐小班智能选择. 林业科学. 2017(09): 63-72 . 百度学术
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