Spectral Characteristics of the Glow of Coal Flames during the Exposure to Laser Pulses

Abstract

The results of measuring the characteristics of the glow of coal flames at the initial moments of ignition under the action of laser pulses of a neodymium laser (1064 nm, 120 μs) are presented. In microparticles of coal grades DG, G, Zh, and K, when the corresponding critical energy densities are exceeded during a laser pulse, the surface ignites and flame propagates at a speed of V~50 m/s. The emission spectra of flames are contributed by the emission of emitted hot coal particles, excited H2* and H2O* molecules, as well as the flame emission arising from the oxidation of carbon (CO*) and carbon monoxide (CO2*) by atmospheric oxygen. Keywords: coal, laser, ignition, flame, volatile substances, degree of coalification, coke residue.