Explosion characteristics tests for micrometer-sized Ag dust cloud with a concentration of 0.8 g/L

Abstract

A dust explosion is triggered by the rapid combustion of burnable particulate matter suspended in air. Two blank tests and three Ag-dust-cloud explosion tests were performed in a 20-L spherical steel chamber using a 5 kJ pyrotechnic igniter as the energy source in each test. In the explosion tests, no apparent increase in pressure above that found in the blank tests was observed for Ag dust cloud with a concentration of 0.8 g/L. In addition, fine solid particles remaining after the tests showed no evidence of a combustion reaction at the end of the tests. In this research, the thermal decomposition of Ag powders was measured using a differential scanning calorimeter, and the thermal analysis technique to estimate hazards in relation to the samples was employed. The change in enthalpies (H) of the Ag powders were approximately 180, 93, and 53 J/g, and the onset temperatures (T0) were approximately 211.76, 201.41, and 240.46 °C for P3032, P3012, and P3072, respectively. These results support the conclusion that Ag samples with concentrations below 0.8 g/L do not pose a dust explosion hazard.