玉米淀粉粉尘爆炸危险性研究

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。

Research on Explosion Risk of Corn Starch Dust

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.