红锥干燥特性研究

Research on the Drying Characteristics of Castanopsis hystrix

[目的]为生产中制定红锥木材的干燥工艺奠定理论基础。[方法]在(100±2)℃的恒温干燥箱内进行红锥木材干燥试验,以试件重量、裂纹长度和宽度、最后全干重和含水率为指标评价干燥过程对红锥木材的影响。[结果]在100℃恒温干燥条件下,在试件干燥初期的干燥速度约为10.00%/h,干燥中期的干燥速度约为2.00%/h,干燥后期的干燥速度只有0.50%/h。红锥弦切板试件的初期开裂等级为3等,内裂等级为1等,截面变形等级为1等,扭曲等级为1等,干燥速度等级为3等,综合特性等级为3等。红锥的干燥初期温度为60℃,干燥初期干湿球温差为3～4℃,干燥终期温度为90℃。厚度为25 mm的红锥板材的强制循环干燥窑内干燥至10.00%所需的时间为10.25 d。[结论]该试验为红锥木材所制订的干燥基准在实际干燥中可用作参考。

[ Objective ] The research aimed to lay a theoretical foundation for formulating drying technology for Castanopsis hystrix lumber in pro- duction. [Method]The drying experiment of C. hystrix lumber was performed in drying oven at constant temperature of （100±2） ℃. With weight, crack length and width, final whole dry weight and water content of test piece as indexes, the effect of drying process on C. hystrix lum- ber was evaluated. [ Result]When the test piece was dried at constant temperature of 100℃, its drying speed was 10.00%/h in initial stage, 2.00%/h in intermedia stage and just 0.50%/h in later stage. The initial cracking grade, internal crack degree, cross-section disfigurement de- gree, twisting degree, drying speed degree and composite characteristic degree of test plain-sawed lumber of C. hystrix were Grade 3, 1, 1, 1, 3 and 3. The initial and final drying temperatures of C. hystrix were 60 and 90 ℃ and the temperature difference of dry-wet ball in initial drying stage was 3 -4 ℃. After the C. hystrix panel with thickness of 25 mm was dried in forced circulation drying oven for 10.25 d, its water content was decreased to 10.00%. [ Conclusion]The drying schedule formulated for C. hystrix lumber in this experiment could be used as reference for drying practice.