Transient distribution of metallic vapour concentration in a post-arc channel after current zero along the nozzle axis in a flat-type gas-blast quenching chamber

Abstract

A method for estimating metallic vapour concentration in a post-arc channel on the basis of a spectroscopic method was proposed. Using the method, the axial distribution of metallic vapour concentration in a post-arc channel was measured around the nozzle throat in a flat-type gas-blast quenching chamber. In the chamber iron was intentionally used as an electrode material since Fe spectral lines at wavelengths of 426.0 and 442.7 nm have very much higher radiation intensities than particles such as , F or Cu at temperatures below 6000 K. The proposed method was capable of determining the iron vapour concentration up to after current zero in the experiment. It was found that has a magnitude around % along the nozzle axis during the period from -60 to after current zero for 5 kA arcs.

Spectroscopic On-Line Monitoring of Cu/W Contacts Erosion in HVCBs Using Optical-Fibre Based Sensor and Chromatic Methodology

“…However, due to the self-absorption effect, the spectral lines were emerged with the strong continuum [17]. Conventionally, temperature and metal vapour density can be estimated via spectroscopic analysis when the arc plasma is proven to be LTE and optically thin [18,19,20]. Under the current breaking scenario, especially for currents above 10 kA, these assumptions are no longer valid.…”

The opening process of thermal plasma contacts in a post-arc channel after current zero in a flat-type gas-blast quenching chamber

“…First, we theoretically calculate ρ res of SF 6 gas contaminated with iron vapour as a function of temperature T and iron vapour concentration X Fe . Secondly, using this theoretical data, the axial distribution of ρ res of the postarc channel is estimated from T and X Fe given previously [15,16]. The results demonstrates that ρ res increases more rapidly at the nozzle throat than at other axial locations.…”

“…Having already detailed the experimental set-up in previous papers [15,16], we only describe it briefly here. Figure 1 shows the flat-type SF 6 gas-blast quenching chamber used in the experiment.…”

“…We have also described the iron vapour concentration X Fe in the post-arc channel in the quenching chamber [16]. A method for estimating X Fe in the post-arc channel was developed and enabled us to find the axial distribution of X Fe up to 100 µs after current zero.…”

Stable operation region and dynamic behavior of Ar pulse‐modulated induction thermal plasma with different molecular gases

“…Normally, the excitation temperature is calculated by using the inverse Abel transform; in this study, however, the excitation temperature is found from the apparent radiation intensity for the sake of simplicity. This temperature is governed mainly by the argon excitation temperature at the locations with the high-est radiation coefficient, where the excitation temperature too is highest [24].…”