全文总字数：8341字

摘 要：: 在刨花板生产过程中，铺装机可实现刨花板的不间断生产。刨花气流铺装机最大的技术难点在于对气流场特性的把控，箱体几何结构对气流铺装机内部流场有重要影响，而目前主要是通过反复试验进行研究，研究周期长，加工成本较高。通过计算流体力学方法对气流铺装机气流场进行几何和物理建模，对耦合刨花板气流铺装机气流场和刨花颗粒的气固两相流场进行数值模拟计算，通过调整箱体几何参数，分析气流场变化特性，从而把控箱体几何结构对气流铺装机内部流场特性的影响。模拟结果表明: 箱体坎肩后移与坎肩前移相比，气流回旋所造成的紊流现象较小，但箱体尾部压力增大明显; 当箱体去除坎肩后紊流影响进一步减小，但整个箱体内的压力剧烈增大，可能会导致抽风口的破坏; 当箱体坎肩后移和去除坎肩时，刨花颗粒在底面的沉积都更为均匀，铺装质量得到提高，且坎肩后移的箱体从抽风口逃逸的刨花颗粒少于去除坎肩的箱体。综合各因素，在实际设计气流铺装机箱体时，需要设置坎肩且箱体坎肩应适当后移，坎肩距离小于2570 mm，从而降低紊流影响，提高板坯铺装质量。文献综述

关键词：气流铺装机；箱体几何结构; 数值模拟; 流场特性

Literature Review

Abstract: In the production of particleboard，the particleboard forming machine plays a vital role in the uninterrupted production of particleboard．Particle mat forming is an important section in the particleboard production．The performance of the particle mat forming not only affects the thickness tolerance，mechanical properties，structural symmetry and surface quality of the board，but also plays a decisive role in the diversification of the board product specifications to realize special functions．The most difficult technical problem of the airflow forming machine is to control the characteristics of the airflow field，and the box geometry has an important effect on the internal flow field of the airflow forming machine．It is urgent to investigate the influence of the box geometry on the flow field characteristics of the airflow forming machine． In this study，the flow field of particleboard airflow forming machine was modeled physically and geometrically by the computational fluid dynamics method，and the numerical simulation of gas-solid two-phase flow field of particleboard airflow forming machine coupled with the particles movement was carried out．The correctness of the calculation model was verified by comparing the characteristic point velocity obtained from the experiment and simulation．By adjusting the box geometric parameters，the changing characteristics of the flow field were analyzed，so as to control the influence of the box geometric structure on the flow field characteristics inside the airflow forming machine．The simulation results showed that，compared with the forward movement of the cantilevered shoulder，the turbulence caused by the airflow was smaller when the cantilevered shoulder of the formed box moved backward，but the pressure at the end of the box increased obviously．When the shoulder of forming box was removed，the effect of turbulence was further reduced，but the pressure in the whole forming box increased sharply，which may lead to the damage of the suction outlet．When the shoulder of forming box was moved backward or removed，the deposition of particles on the underside was more uniform，resulting in the improvement of forming quality．The particles escaping from the air outlet of the box with the shoulder moved backward were less than those with the shoulder re-moved．In combination with various factors，to actually design the airflow forming body，it was necessary to set up the vest shoulder correctly and the forming body sill should be properly moved backward．The distance between the shoulders of the box body was less than 2 570 mm，so as to reduce the turbulence effect，improve the quality of particle forming and provide the actual particleboard production with solid theoretical basis．

Key words: airflow forming machine; box geometry structure; numerical simulation; flow field characteristic

1 研究目的及意义

研究目的：在刨花板生产中，气流铺装机扮演着非常重要的角色，并且是实现刨花板连续不间断生产的必不可少的设备。改革开放以后，随着板式家具生产线的引进，我国刨花板行业发展迅速，中国的刨花板经历了上升期，下降期再到上升期的反复过程。在二十世纪九十年代期间，我国刨花板产业集中度低，小型企业比重大，生产设备落后，技术水平差，再加上许多厂家只追求产量，不注重刨花板质量，这导致了我国生产的刨花板普遍质量较差，且存在甲醛超标的问题。为提高企业的市场竞争力，许多刨花板企业引进国外先进生产线，中国的刨花板质量有了明显提高。国内外对刨花板需求量不断增多和国家出台优惠政策推动了人造板行业的发展，为刨花板行业发展奠定了良好的基础。刨花板气流铺装机的原理就是利用气流的分选作用对施胶刨花进行铺装。刨花撒落在铺装机 内部气流场中得到加速，进一步受到分选，较大的 粗重刨花落在距进风口较近的地方，较小的细轻刨 花则落在较远的地方，在运输带上形成具有渐变结构的板坯。箱体几何结构对气流铺装机内部流场有重要影响，而目前主要是通过反复试验进行研究，研究周期长，加工成本较高。通过计算流体力学方法对气流铺装机气流场进行几何和物理建模，对耦合刨花板气流 铺装机气流场和刨花颗粒的气固两相流场进行数值模拟计算，通过调整箱体几何参数，分析气流场变化特性，以及对板坯质量的影响，从而把控箱体几何结构对板坯质量的影响。

研究意义：目前，国内还鲜见自主研发的分级式刨花板气 流铺装机投入使用，现阶段仅少数公司进行自主研发刨花板气流铺装机。因此，我国人造板铺装设备的开发和技术研究还处于起步阶段。国内外对于气流铺装机的研究较少，为满足市场对刨花板不断提高的铺装质量要求，对于气流铺装机技术的研究迫在眉睫。 近年来，为缩短试验周期，降低成本，在林业行业中已逐渐开始采用数值模拟技术开展研究。 笔者通过计算流体力学对刨花板气流铺装机气流场进行几何和物理建模，并对耦合气流场和刨花颗粒的气固两相流场进行数值模拟计算，研究箱体几何结构对板坯质量的影响， 为气流铺装机箱体结构设计及后续的优化设计提供理论依据。