Abstract
Aim: The work comprised of a review of the impact of temperature on the values of explosiveness parameters. The aim of the publication is to determine essential explosiveness parameters, i.e. the maximum explosion pressure, maximum rate of explosion pressure rise of n-hexane vapours at elevated temperatures up to 50°C and 100°C. The knowledge of the parameters of combustible mixtures, and in particular lower flammability limit is important for the safety of the course of many industrial processes. When the temperature increases, the maximum explosion pressure and the maximum rate of pressure rise reducing its value, which proves that the explosion of hexane in such conditions becomes less rapid. According to theoretical estimations the lower explosion limit is reduced when temperature increases, which means that the use of hazardous substances with inflammable properties at elevated temperatures is associated with a higher risk of explosion.
Methodology: The testing was conducted in a spherical chamber in accordance with the following standards standards: PN-EN 15967:2011 The determination of the maximum explosion pressure and maximum rate of explosion pressure rise of gases and vapours and PN-EN 1839:2013 Determination of explosion limits of gases and vapours [1-2]. Measurements were made using B (bomb) method which helped to obtain the volume of excess pressure induced by ignition of the substance having appropriate concentration .
Results: The value of maximum explosion pressure and the maximum rate of pressure rise for hexane vapours at temperatures of 50°C and 100°C decreased with the growth of temperature, and has been determined for concentration of 1.675%mol and 1.870%mol of flammable substance respectively. The value of the lower explosive limit decreased as the temperature increased, and reached the value of 0.881%mol at the temperature of 50°C, and 0.800%mol at the temperature of 100°C. Maximum explosion pressure was reached and amounted to 7.160 bar and the rate of pressure rise was 396.28 bar/s, corresponding to the concentration of 1.87 mol% vapour of hexane at 50°C and 5.645 bar at the rate of 369.985 bar/s for concentration of 1.675 mol%
Conclusions: It is recommended to take into consideration the impact that temperature exerts on explosiveness parameters, in particular owing to the extension of the explosiveness scope under the impact of increases in temperature.
Keywords: parameters of vapour explosiveness, PN-EN 15967, PN-EN 1839
Type of article: original scientific article