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林业科学 ›› 2006, Vol. 42 ›› Issue (3): 54-58.doi: 10.11707/j.1001-7488.20060311

• 论文及研究报告 • 上一篇    下一篇

小径木白桦锯材不同加热方式下含水率的变化

郭明辉 赵西平   

  1. 东北林业大学生物质材料科学与技术教育部重点实验室,哈尔滨150040
  • 收稿日期:2004-10-26 修回日期:1900-01-01 出版日期:2006-03-25 发布日期:2006-03-25

The Change of MC of Small-Diameter Birch Lumber with Different Heating Methods

Guo Minghui,Zhao Xiping   

  1. Key Laboratory of Bio-Based Material Science and Technology of Ministry of Education,Northeast Forestry University Harbin 150040
  • Received:2004-10-26 Revised:1900-01-01 Online:2006-03-25 Published:2006-03-25

摘要:

讨论小径木白桦锯材在连续加热和间歇加热方式下含水率的变化规律。结果表明:小径木白桦锯材的干燥速率在含水率15%以后明显降低,前期干燥过程锯材的干燥速率比后期的高2~3倍;间歇加热方式有利于内部水分向外扩散,间歇时间对干燥速率的影响很小;干燥过程中锯材厚度方向上的含水率梯度呈不对称分布,这与小径木的心材占较大比例有一定关系;间歇加热减少了锯材内含水率梯度的变化值,同时减少了应力的产生,从而提高了干燥质量。

关键词: 小径木, 白桦锯材, 加热方式, 含水率

Abstract:

In this paper, the change of moisture content (MC) of small-diameter birch lumber with the intermittent-heating and consecution-heats tests had been discussed. The result of research showed that: the drying rate of small-diameter lumber had fallen obviously after the MC getting 15%, and the rate of anaphase drying times 2~3 was prophase drying. The intermittent-heating was propitious to diffuseness of within water, but the time of intermission didn't have much effect on the drying rate. During drying, the MC grad along thickness wasn't symmetrical, which was interrelated with the more proportional heartwood of small-diameter lumber. The intermittent-heating cut the MC grads down, reduced the stress, and then improved drying quality.

Key words: small-diameter lumber, birch lumber, heating methods, moisture content(MC)