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

Abstract

MemberArc 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 10-50 kA AC arc jet. The electrodes used were iron of 40 mm 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 10 kA to 50 kA, the temperature gradually decreased from 14,000 K to 10,000 K, 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 × 10 5 J/m 3 ) as the arc current increased from 10 kA to 50 kA.

Two-dimensional temperature distribution of air arc commutating to arc runner

“…Spectroscopic observation techniques have often been used to estimate the metallic vapor concentration and conductivity in arc columns [24][25][26]. Sakuta et al, for example, pioneered the measurement of arc temperature and Cu vapor concentration from the radiation intensities of the NC diatomic molecular spectral line and a Cu spectral line from a dc 30 A air arc between Cu electrodes and found the Cu vapor concentration to be approximately 0.5% [25].…”