蒸汽预热处理过程中橡木干燥时水分横向迁移的机理。

Moisture transverse moving mechanism during presteamed oak lumber drying.

机构信息

Department of Wood Science and Engineering, Beihua University, Room 113, Yifu building, No. 3999, Binjiang East Road, Jilin City, Jilin Province, 132013, P.R. China.

Department of Housing Environmental Design, and Research Institute of Human Ecology, College of Human Ecology, Chonbuk National University, Room 504, Building No. 7-1, 567 Baekje - daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, Republic of Korea.

出版信息

Sci Rep. 2019 Dec 3;9(1):18228. doi: 10.1038/s41598-019-54430-5.

DOI:10.1038/s41598-019-54430-5

PMID:31796789

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6890683/

Abstract

Effect of steaming at 100 °C, 80 °C and 60 °C dry-bulb temperature and 0 °C wet-bulb depression for 4 hours prior to drying on the drying rate and drying deformation of 25.4 mm thick oak lumbers during kiln drying was explored in this study. The results showed that presteaming delayed the drying time by at least 19 percent, and increased the crooks and bows of the lumbers. The mechanism that presteaming delayed the drying time is attributed to the smaller and fewer moisture transverse pathways inside the surface layers of presteamed lumbers. These pathways decrease the moving rates of the bound water and the water vapor from the inner part to the surface layers of presteamed lumbers during the middle and last stage of drying because of reduced distance between the microfibrils and increased crystallinity.

摘要

本研究探讨了在干燥前分别以 100°C、80°C 和 60°C 干球温度和 0°C 湿球温度蒸 4 小时，然后再进行干燥对 25.4mm 厚的橡木方材干燥速率和干燥变形的影响。结果表明，预蒸至少延迟了 19%的干燥时间，并增加了方材的翘曲和弯曲。预蒸延迟干燥时间的机制归因于预蒸方材表面层内的水分横向路径更小且更少。由于微纤维之间的距离减小和结晶度增加，这些路径在干燥的中后期降低了束缚水和水蒸气从内部向预蒸方材表面层移动的速度。