戊唑醇粉尘最小点火能试验研究

采用1.2 L哈特曼管爆炸装置分别对粒径小于54μm、74μm、150μm及大于150μm的戊唑醇粉尘进行测试。针对戊唑醇粉尘浓度及粒径范围对其最小点火能的影响,分别进行单因素试验,并对其危险性进行分级。结果表明,保持粒径小于150μm,环境温度为20℃,喷粉压力为0.7 MPa,在质量浓度100~1 300 g/m~3之间,戊唑醇粉尘的最佳敏感质量浓度ρ_m为983.71 g/m~3,此时的最小点火能为404.74 mJ。保持戊唑醇粉尘质量浓度为900 g/m~3,环境温度为20℃,喷粉压力为0.7 MPa不变,粒径小于54μm、74μm、150μm及大于150μm的戊唑醇粉尘的最小点火能分别为10 mJ、100 mJ、400 mJ和1 000 mJ以上。因此,判定戊唑醇粉尘最小点火能属于M2级,为特别着火敏感性。

Experimental study on the minimum energy-level ignition for the tebuconazole dust

This paper is aimed at presenting a systematic assessment of the parameters of the explosive characteristics of the tebuconazole dust.For the purpose,we have used a 1.2 L Hartman tube to conduct an independent single factor experiments on the effect of the dust concentration and the particle size of the dust on the minimum energy ignition and the degree or grade of the burst or the explosion risk of the said tebuconazole dust.As is known,in recent years,it has become a kind of the ever increasing frequency of the pesticide dust explosions.And,the tebuconazole,as one of the most widely spread pesticides calls for serious research attention on its explosive features.Technically speaking,the minimum ignition energy is known as a kind of important factor in deciding where and how often the dust explosion is likely to hit us.Since the dust concentration and the particle size are the two leading physical factors of the dust explosion,it proves of extremely important urgency to analyze the effects of the dust concentration and the particle size on the minimum ignition energy of such dusts.The experimental results we have gained indicate that the dust concentration is an extremely noticeable factor for the minimum ignition energy of dust,that is to say,there exists an optimum dust concentration,which can help to determine the value of the minimum ignition dust energy.Our test has enabled us to find that the sensitive concentration of the tebuconazole dust is equal to 900 g/m3,with the corresponding ignition energy being 400 mJ.And,the other corresponding parameters can be illustrated as follows:under the temperature of about 20 ℃,the powder spraying pressure stands about 0.7 MPa,with the particle size ranging between 0-150 μm,whereas the range of the dust concentrations remains from 100 g/m3 to 1 300 g/m3.We have also obtained the sensitive dust concentration of 983.71 g/m3 as a result of curve fitting test based on the experimental data,discovering that the best ignition energy should be 404.74 mJ while the derivative E'is 0.What is more,we have also confirmed that the particle size may have a significant effect on the minimum ignition energy,which tends to decrease with the decrease of the particle size.Furthermore,it has been found that,when the sensitive dust concentration is 900 g/m3,the tested results with the particle size should be equal to 0-54 μm,0-74 μm,and 0-150 μm.And,in case over 150 μm,there may yield the minimum ignition energy of 10 mJ,100 mJ,400 mJ and even over 1 000 mJ,respectively.Besides,according to the regulation of the VDI 2263,if the minimum ignition energy of the tebuconazole dust exceeds a level of M2,it would be highly sensitive for ignition,which implies that all the effective ignition sources should be avoided at that level.