Influence of Polymer Vapor Concentration on Temperature of Ar Induction Thermal Plasmas During Polymer Solid Powder Injections

Abstract

Influence of POM (polyoxymethylene), PE (polyethylene) and PMMA (polymethylmethacrylate) polymer solid powder injections on thermal plasmas was experimentally investigated for the fundamental study of ablation phenomena in a circuit breaker. For this purpose, the inductively coupled thermal plasma (ICTP) technique was used to sustain Ar thermal plasmas at atmospheric pressure at a high-power of 80kW. Spectroscopic observation was carried out to measure the radiation intensity of Ar I, H I and C I lines emitted from the thermal plasma. The excitation temperature of Ar atom was estimated from the relative ratio of the Ar spectral line intensities. The temperature around the center axis was found to decrease by the injection of polymer solid powders. The estimation method of polymer vapor concentrations in thermal plasmas was developed using the calculated emission coefficient ratios of the specified spectral lines. The radial distribution of polymer vapor concentrations was evaluated on the assumption of local thermal equilibrium. From the results, it was found that the polymer vapor was about 0.5-1.0% in the experiments, and that PMMA vapor seemed to have a higher plasma cooling efficiency than PE and POM.