Temperature, Iron Vapor Concentration and Energy Density for Arc Jets of 10-50 kA AC Arcs in a Long Gap

Abstract

Arc jets that spout from electrodes as a result of high current fault arcs cause damage to the surrounding apparatus. This paper describes the results of spectroscopic observation of 10-50kA AC arc jet. The electrodes used were iron of 40mm in diameter. The temperature and the iron vapor concentration of the arc jet were determined by considering the self-absorption of two spectral lines of iron atom. As the arc current increased from 10kA to 50kA, the temperature gradually decreased from 14,000K to 10,000K, and the iron vapor concentration (molar rate) in the arc jet increased abruptly from 1% to 50%. The energy density was calculated and it was found that the energy density of the arc jet did not change greatly (8×105J/m3) as the arc current increased from 10kA to 50kA.