外部条件对玉米淀粉粉尘爆炸特性的影响

为了探明外部条件对玉米淀粉粉尘爆炸特性参数的影响,利用20 L球形爆炸装置进行试验测试,探讨了点火能量及粉尘含水量对粉尘爆炸特性的影响,对比研究了CaCO_3和Al(OH)_3两种惰性介质的抑爆效果。结果表明:随点火能量增加,粉尘最大爆炸压力和最大升压速率呈线性上升,在高质量浓度下,粉尘爆炸压力受点火能量的影响更显著;添加CaCO_3和Al(OH)_3能够降低玉米淀粉的爆炸压力,相对于CaCO_3的物理抑爆,Al(OH)_3的物理-化学抑爆效果更佳;玉米淀粉粉尘的最大爆炸压力及爆炸升压速率随粉尘含水量降低而不断增大。

Effect of the external conditions on the explosion characteristic features of the corn starch dust

The paper is aimed at presenting its study results of the influence of the external conditions on the explosion characteristic features of the corn starch dust,which is expected to provide a guide for the industrial production safety and a trusted instruction for reducing the incidence of the said dust explosion accidents.For this purpose,the experiment system of 20 liter volume has been employed to study the effect of the external conditions on the explosion characteristic indexes of the corn starch dust.Through the said experiment,it would be possible for us to compare and discuss the influence of the corn starch dust with water content on the explosion behaviors of the dust,whose mass concentration should be between 250 g/m3 and 500 g/m3,with the particle size being less than 200 mesh (＜ 75 μm).In addition,we have also discussed the inhibiting effectiveness of CaCO3 and Al(OH) 3 in different concentration content sizes.As is known,the maximum explosion pressure and maximum pressure-rising rate are the two significant parameters in connection with the dust explosion.And,after all,the final experimental results show that the increase of ignition energy can improve the explosion energy and the combustion rate of the dust cloud.What is more,the maximum explosion pressure and the maximum pressure-rising rate tend to increase with the increase of the ignition energy,whereas the influence of the ignition energy on the explosion pressure of the corn starch dust proves quite obvious at the high concentrations.Furthermore,the explosion pressure of the corn starch dust tends to decrease noticeably,because by adding the inert CaCO3 and Al (OH) 3,the physical-chemical explosion suppression of Al(OH) 3 can be made more effective to suppress the physical explosion probability of CaCO3.Moreover,the explosion-suppressing efficiency can be reduced continuously with the increase of the amount of Al(OH)3.Since the explosion severity is significantly dependent on the moisture of the corn starch dust,the pre-humidification corn starch dust has similar effect of the explosion suppression as the inert media.The maximum explosion pressure and the maximum pressure-rising rate can both increase continuously as the water content of the dust corn starch decreases.Therefore,it can be concluded from the experimental results that it is of great significance to reduce the risk to be caused by the corn starch dust and increase the safety of production of such combustible dust so as to save human life and protect our material resources.