速生杨木粉尘最小点火能的实验研究

为防止木材加工中木质粉尘燃爆事故的发生，以纤维板生产中常见的原材料速生杨木粉尘作为研究对象，在分析粉尘粒径分布、元素分析、工业分析及形貌特征的基础上，采用1.2 L哈特曼管对3种不同粒径（0~50，＞50~96，＞96~180 μm）速生杨木粉尘进行最小点火能实验，探究点火延迟时间、喷粉压力、质量浓度和粒径分布对速生杨木粉尘最小点火能的影响及变化规律。研究结果表明:在质量浓度为500 g/m3时，分别增加点火延迟时间和喷粉压力，最小点火能都先减小后增大；最佳点火延迟时间和最佳喷粉压力分别为120 ms和120 kPa；粒径对最佳点火延迟时间和最佳喷粉压力无显著影响。在点火延迟和喷粉压力分别为120 ms和120 kPa条件下，最小点火能随质量浓度的增加先减小后增大。粉尘粒径与最小点火能呈正相关性，3种样品的最小点火能分别为1~3，1~3和7~13 mJ，对应的敏感质量浓度分别为500 ，750和1 250 g/m3，属于特别着火敏感性粉尘。

Experimental study on minimum ignition energy of fast grown poplar dust

In order to prevent the accidents of wood dust combustion and explosion during the wood processing, taking the dust of fast grown poplar which is the common raw material in the production of fibreboard as the research object, on the basis of analyzing the particle size distribution, ultimate analysis, proximate analysis and topographic characteristics of dust, the experiments of the minimum ignition energy were carried out on the dust of fast grown poplar with three different particle sizes (0-50 μm, 50-96 μm and 96-180 μm) by using a 1.2 L Hartmann tube, and the influence and change laws of ignition delay time, dust spray pressure, mass concentration and particle size distribution on the minimum ignition energy of fast grown poplar dust were investigated. The results showed that when the mass concentration was 500 g/m3, both the minimum ignition energy decreased first and then increased when increasing the ignition delay time and dust spray pressure respectively. The optimum ignition delay time and dust spray pressure was 120 ms and 120 kPa respectively. The particle size had no obvious influence on the optimum ignition delay time and dust spray pressure. When the ignition delay time and dust spray pressure was 120 ms and 120 kPa respectively, the minimum ignition energy decreased first and then increased with the increase of mass concentration. The particle size of dust was positively correlated with the minimum ignition energy, the minimum ignition energy of three types of sample was 1-3 mJ, 1-3 mJ and 7-13 mJ respectively, and the corresponding sensitive mass concentration was 500 g/m3, 750 g/m3 and 1 250 g/m3 respectively, which belonged to the special ignition sensitive dust.