不同玉米淀粉粉尘的燃烧与爆炸特性研究

Research on the Combustion and Explosion Characteristics of Different Cornstarch Dusts

粉尘具有可燃性,在玉米淀粉的生产、加工和使用过程中容易发生粉尘爆炸事故。为探究无色玉米淀粉和彩色玉米淀粉燃烧和爆炸危险性的不同,利用热重分析探究燃烧过程特征温度和质量损失变化,采用20 L球型爆炸实验研究二者爆炸特性参数。结果表明:无色玉米淀粉在氧化过程的挥发分燃烧阶段质量损失率较大,释放的能量更多。在400~600 g/m^(3)粉尘浓度范围内,粒径对爆炸压力的影响较大,粒径较小的彩色玉米淀粉的最大爆炸压力高于无色玉米淀粉。在600~1 000 g/m^(3)浓度范围内,粉尘颗粒所含碳元素含量与碳氮比占主导地位,碳氮比更高的无色玉米淀粉的最大爆炸压力高于彩色玉米淀粉。无色玉米淀粉粉尘爆炸燃烧时间普遍少于彩色玉米淀粉,爆炸指数更高,与氧气反应速率更快,爆炸危险性更高。

Dust is combustible,and dust explosion accidents are likely to occur during the production,processing and use of Corn starch.In order to explore the difference in combustion and explosion hazards between colorless cornstarch and colored cornstarch,thermo-gravimetric analysis is used to explore the changes of characteristic temperature and mass loss in the combustion process,and the 20 L spherical explosion test is used to study the explosion characteristics parameters of the two.Results show that colorless cornstarch has a higher mass loss rate and more energy release in the volatile combustion stage of the oxidation process,that in the range of 400~600 g/m^(3) dust concentration,the particle size had a greater influence on the explosion pressure,and the maximum explosion pressure of colored cornstarch with smaller particle sizes is higher than that of colorless cornstarch,that in the range of 600~1000 g/m^(3) concentration,the carbon content and carbon-nitrogen ratio of dust particles are dominant,and the maximum explosion pressure of colorless cornstarch with a higher carbon-nitrogen ratio is higher than that of colored cornstarch,and that the combustion time of colorless cornstarch dust explosion is generally shorter than that of colored cornstarch,and has the higher explosion index,the faster reaction rate with oxygen and the higher explosion risk.