常规干燥中内径对落叶松空心圆柱干燥特性的影响

Effect of Inner Diameter on Drying Characteristics of Larch Center Bored Round Timber during Conventional Drying

研究日本落叶松在常规干燥过程中85%以上空心率对其干燥特性的影响.结果表明:经过312 h常规干燥,外径210 mm的空心圆柱含水率从41.8%降到6.8%,外径270 mm的空心圆柱含水率从46.6%降到7.3%;干燥过程中出现了少量表裂,但由于通过加大空心直径减小了柱材的异向收缩应力,干燥结束后表裂全部闭合;为避免干燥过程中发生表裂,建议在含水率26%以下使用较温和的干燥基准.

The effect of the hollow ratios more than 85 percent of Japanese larch round timbers on their drying characteristics during conventional drying was evaluated.After 312 hours conventional drying,the moisture content with 210 mm and 270 mm center bored round timbers decreased from 41.8%to 6.8%and from 46.6%to 7.3%,respectively.A small quantity of subtle surface checks occurred during drying,but the checks were closed at the end of drying because of the reduced differential shrinkage stress by increased center bored diameter.However,it is recommended to use a milder drying schedule below 26%moisture content in order to avoid the occurrence of checks during drying.