玉米淀粉粉尘爆炸危险性研究

Research on Explosion Risk of Corn Starch Dust

为研究玉米淀粉粉尘爆炸危险性,采用哈特曼管式爆炸测试装置和20 L球爆炸测试装置对200目(<75μm)以下的玉米淀粉粉尘爆炸危险性进行评估,基于静电火花和粉尘质量浓度对粉尘爆炸的影响,对玉米淀粉的静电火花最小点火能量、爆炸下限质量浓度、最大爆炸压力和爆炸指数进行了研究,根据试验结果对玉米淀粉爆炸危险性进行分级。试验结果表明:温度在25℃,喷粉压力为0.80 MPa,粉尘质量浓度在250～750 g/m3范围内,粉尘的最小点火能量随着粉尘质量浓度增加而降低,其最小点火能量在40～80 mJ之间;在点火能量为10 kJ时,粉尘爆炸下限质量浓度在50～60 g/m3之间;在粉尘质量浓度为750 g/m3时,爆炸压力达到最大,为0.66 MPa;在粉尘质量浓度为500 g/m3时,爆炸指数达到最大,为17.21 MPa.m/s,其粉尘爆炸危险性分级为Ⅰ级。

In the paper,the explosion risk of corn starch was assessed with the Hartmann tube and 20 L sphere explosion test units.These parameters were obtained for the sample of less than 200 mesh（75 μm） and the sensitivity degree of the corn starch to the electrostatic spark and the severity degree of explosion under a certain condition were obtained.Then the risk degree of explosion was graded.The experimental result indicates that the minimum ignition energy of the corn starch decreases with the increase of concentration with a range of 40-80 mJ under the conditions of temperature 25 ℃,powder spraying pressure 0.80 MPa,and concentration between 250 g/m3 and 750 g/m3.When the ignition energy is 10 kJ,the minimum explosive concentration is 50-60 g/m3;the dust explosion pressure and the dust explosion index increases with the dust concentration,but when the concentration exceeds 750 g/m3,the dust explosion pressure begins decrease and the concentration exceeds 500 g/m3,the dust explosion index begins decrease,the maximum explosion pressure is 0.66 MPa when the ignition energy is 10 kJ;the explosion index is 17.21 MPa·m/s and the classification of dust explosion hazards is Level I.