Research on the explosion characteristics of chlorine dioxide gas

The explosion characteristics of chlorine dioxide gas have been studied for the first time in a cylindrical exploder with a shell capacity of 20 l. The experimental results have indicated that the lower concentration limit for the explosive decomposition of chlorine dioxide gas is 9.5% ([ClO2]/[air]), whereas there is no corresponding upper concentration limit. The maximum pressure of explosion relative to the initial pressure was measured as 0.024 MPa at 10% ClO2 and 0.641 MPa at 90% ClO2. The induction time (the time from the moment of sparking to explosion) at 10% ClO2 was 2195 ms, but at 90% ClO2 the induction time was just 8 ms. The explosion reaction mechanism of ClO2 is of a degenerate chain-branching type involving the formation of a stable intermediate (Cl2O3), from which the chain branching occurs.