浓度对橡胶粉尘爆炸特性的影响

Experimental study on the impact of the concentration on the explosion characteristic feaures of rubber

为了解橡胶粉尘的爆炸危险性,采用20 L球爆炸测试装置对常温常压下、粒径75μm以下的橡胶粉尘在质量浓度50~700 g/m3范围内的爆炸特性进行试验研究,测定其最大爆炸压力及爆炸指数随质量浓度的变化规律,进而对其爆炸危险性程度进行分级。结果表明:橡胶粉尘质量浓度为300 g/m3时,爆炸压力达到最大值0.49MPa;在橡胶粉尘质量浓度为250 g/m3时,爆炸指数达到最大值5.04MPa·m/s,根据ISO 6184粉尘爆炸烈度等级分级标准,其粉尘爆炸危险性分级为St-1级。

The present paper is aimed at investigating the explosion behaviors of the hazardous materials in relation to the aspects of dust concentration by choosing a kind of synthetic rubber dust from a driving wheel as the research object. For the said research purpose,we have chosen to trace the explosion features of the rubber dust by using the standard dust explosion test equipment,that is,the 20 L Spherical Explosion Testing System,PCI-1711 data acquisition equipment and the 2 kJ ignition energy initiator under the normal temperature and pressure whereas the experimental work has been divided into two main parts,with the firstpart mainly dealing with the explosion process and the second part identifying and determining the explosion parameters for the rubber dust of different concentrations,such as 50 g/m3,100 g/m3,200 g/m3,250 g/m3,300 g/m3,400 g/m3,500 g/m3,600g/m3,700 g/m3. For example,the explosion parameters under observation and investigation are supposed to include the maximum explosion pressure（ pmax） and the explosion index,the two principal parameters to be treated industrially as the combustible dusts,which can be gained from the sample in a volume of less than 75 μm. And,then,the test results can help to determine the risk degree of explosion through qualitative and quantitative analyses. Thus,the experimental results have shown that the dust explosion tends to be completed in a very brief moment before the explosives reach the maximum explosion pressure with the pressure strength pushed up promptly and then going to be released.To be exact,under the temperature of 25 ℃,the dust explosion pressure may tend to rise with the dust concentration until the concentration of the dust in the rubber may go up to as powerful as till 300 g/m3. And,till then,the dust explosion pressure would begin to drop,with the maximum explosion pressure being0. 49 MPa. Later,in the same way,the dust explosion index may also increase with the dust concentration,which may exceed 250g/m^3 in the rubber and then the dust explosion index may begin to decrease, with the maximum explosion index being 5. 04MPa·m/s. And,in so doing,the dust explosion hazards can be classified as Standard Level 1. Thus,it can be concluded from the experimental results that it is of great significance to guarantee the safe application of the above mentioned combustible materials.