木材含水率分级干燥及其节能分析

木材干燥是木材加工生产中不可缺少的一道重要工序，也是耗能最大的工序。现在能源短缺，燃料价格上涨，节省能源尤其重要。加强对木材干燥过程节能减排降耗的研究，寻求高效环保的节能技术是目前国内外学者广泛关注的课题之一。在分析木材干燥能耗的基础上，从3个方面探讨了木材含水率分级干燥的必要性:1)生材含水率不同导致每一块板材的干燥特性不同；2)与水分移动有关的木材性质（物理力学性质等）的差异；3)木材中各种状态水分的干燥能耗。进而对木材含水率分级干燥过程进行了分析，提出了木材含水率分级干燥的概念，并对分级干燥理论进行了分析。探究了含水率分级干燥对木材干燥质量、干燥效率和干燥过程节能减排的影响，采用含水率分级技术实现木材的精细干燥，可以达到缩短干燥周期，降低能耗，提高干燥质量的目的。最后，提出应根据干燥材的用途要求，在节能经济的基础上，制定合适的含水率分级标准的应用设想。

Moisture Content Classification and Energy Saving in Wood Drying

Wood drying is indispensable and important working procedure in lumber production.It is also the biggest energy consumption process.Nowadays,due to the energy shortage and higher fuel price,Energy saving becomes an particularly important issue.It is of great interest to study the energy saving,emission reduction and consumption reduction of wood drying process,and to seek efficient and environmentally friendly energy saving technologies.On the basis of analyzing the energy consumption of wood drying,the necessity of moisture content classification in wood drying was discussed from three aspects:1) different drying characteristics caused by the differences in different moisture contents between different lumbers; 2) differences in wood properties (physical and mechanical properties,etc.) related to the movement of water; 3) differences in drying energy consumption for various moisture states in wood.The process of classification and drying process of wood moisture content was analyzed.Firstly,the concept of wood moisture classification drying was put forward,and the classification drying theory was analyzed.Effects of moisture content classification drying on wood drying quality were examined.Drying efficiency and energy-saving and emission-reduction process were introduced.The fine drying of wood was realized by adopting the moisture content classification technology,and the wood drying technology was improved,and the energy consumption of wood drying process was reduced.Finally,several assumptions were presented,about the application that setting up appropriate grading standards for moisture content according to the requirements of the use of dry materials and on the basis of energy saving and economy.