The effect of reduced oxygen levels on the electrostatic ignition sensitivity of dusts

Abstract

When handling powders with low values of minimum ignition energy (MIE), it is often necessary to employ additional protective measures such as explosion venting, suppression, containment or inerting. Inerting generally involves reducing the oxygen concentration to around 5% v/v; however, it has been shown with gases that more modest reductions in the oxygen content can still have a significant effect on the MIE. Therefore, a test program was carried out to assess the impact of reduced oxygen levels on the MIE of a series of sensitive powders. In addition, this work was also used to investigate whether testing of such sensitive materials in the standard equipment but with reduced oxygen levels could enable the prediction of MIEs <1 mJ at standard atmospheric oxygen levels.