文献类型：期刊文献

英文题名：Drying kinetics of poplar lumber during periodic hot-press drying

作者：Zhou, Fan[1] Gao, Xin[1] Fu, Zongying[1] Zhou, Yongdong[1]

第一作者：周凡

通信作者：Zhou, F[1]|[a00052d20f1f335f2c02c]周凡;

机构：[1]Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China

年份：2018

卷号：36

期号：14

起止页码：1767-1780

外文期刊名：DRYING TECHNOLOGY

收录：;EI(收录号：20180604759779);Scopus(收录号：2-s2.0-85041576796);WOS:【SCI-EXPANDED(收录号:WOS:000450556100010)】；

基金：This study was supported by the National Forestry Industry Research Special Funds for Public Welfare Projects from State Forestry Administration of China (201404502).

语种：英文

外文关键词：Contact-state; high-press-state; kinetics; periodic hot-press drying; poplar lumber

摘要：The drying kinetics of poplar lumber was experimentally investigated as a function of drying temperature (115, 135, 160, 185 and 205 degrees C) during a periodic hot-press-drying process. Poplar lumber was dried under contact (compression ratio of 10%) and high-press states (compression ratio of 44%). Compared with the contact-state, the high-press-state showed higher drying rate and higher efficiency of removing free water than bound water in wood. Eight mathematical models from the literature were established to analyze the drying behavior. The Weibull model, with an average determination coefficient R-2 of 0.9958, fitted well for all applied drying conditions. The scale parameter decreased with increasing drying temperature and was lower for high-press-state drying compared with that for contact-state drying. Moisture diffusivity and activation energy were calculated according to the Weibull model. Diffusivity increased with increasing drying temperature, with the average value of 1.734 x 10(-6) and 3.313 x 10(-6) m(2)/s and activation energy of 34.79 and 32.85 kJ/mol for contact-state drying and high-press-state drying, respectively. Hot-press drying created an M-shaped curve of density distribution, with high density at the two surface regions gradually decreasing toward the core region. The contact state-dried wood showed increased density near the wood surface. Both average density and peak density improved in the case of high-press-state-dried wood. Furthermore, the hydrophilic index of wood for high-press-state drying was lower than that of the contact-state drying, and the opposite was true regarding crystallinity index. The hygroscopicity of high-press-dried poplar decreased with lower equilibrium moisture content and higher moisture excluding efficiency, compared with contact-state-dried poplar. The rapid, high-quality drying of poplar lumber through periodic hot-press was more potentially achieved by the high-press-state compared with contact-state drying.