Abstract
Recently, with the development of the ozone generator, it has become possible to obtain high concentration of ozone up to 15vol.% in oxygen. In the previous study, the decomposing explosion properties and the flame propagation behavior of high concentration ozone in a closed vessel were clarified, but the minimum ignition energy was not. To ensure safe handling of ozone, its decomposing properties must be understood. In this study, the minimum ignition energy of an ozone/oxygen gas mixture of up to 15 vol.% of ozone in oxygen under atmospheric pressure in a closed vessel was investigated. A stainless steel cylinder (106mm i.d., 114mm in height, 1.0L in volume) was used as the explosion vessel. An electric spark by capacitor discharge was used for ignition. The energy was evaluated based on 0.5CV2. The experimental results are as in follows: 1) The minimum ignition energy at 15vol.% ozone in oxygen was 10mJ. 2) Higher concentrations of ozone showed lower minimum ignition energies. 3) The lowest minimum ignition energy of 14vol.% ozone in oxygen was observed with 3-4mm electrode distance. 4) It was confirmed that the quenching distance is approximately equivalent to the spark gap distance at the lowest ignition energy of the energy-versus-distance curve.
