Reduction in Pressure Rise Due to Internal Arcing Using Melting and Vaporization of Metal

When an arc is ignited between the electrodes in a closed chamber, the internal pressure rises. In this paper, the reduction in the pressure rise due to internal arcing using the melting and vaporization of a de-energized metal plate was investigated experimentally. The results showed that allowing a Cu or Fe plate placed near the electrodes to be melted and vaporized by the arc, the reduction in the pressure rise increased as the amount of mass loss of the plate increased. The decrease level of the maximum pressure rise was more than 20% on average in our experiments. On the basis of these experimental results, the energy balance in the closed chamber was estimated in order to clarify the mechanism behind the reduction in the pressure rise. The dominant cause of the reduction in the pressure rise for the Cu plate was the increase in energy consumption by the melting and vaporization of the plate. For the Fe plate, it was the increase in the energy of consumption by the arc radiation.