ANALYTICAL METHOD AND APPARATUS OF MOLTEN METAL BY PLASMA EMISSION SPECTROCHEMICAL ANALYSIS METHOD FOR LONG-DISTANCE CARRIAGE OF FINE PARTICLE

摘要

PURPOSE:To analyze rapidly, precisely, and directly components in molten metal without any sampling operation by subjecting the surface of the molten metal to a spark discharge to form fine particles by evaporation, and carrying the particles to an analyzer. CONSTITUTION:Sparks are discharged between a counter electrode 8 and the surface 13 of molten metal to form by evaporation fine particles of molten metal which are entrained by a gaseous Ar stream sent in from a gas supply apparatus 39 and introduced into a plasma torch 29 through an introducing pipe 3 and a carried gas distributing apparatus 24. The interval of electrodes between the counter electrode and the molten metal is fixed by operating a lifting device 20 with the detection signal from a detector 38 of the surface level of the molten metal. After finishing an analysis, by changing over a three-way selector valve and simultaneously operating the lifting device 20, a fine particle forming probe 1 is pulled up from the molten metal 13 and the gaseous Ar is blown into a carrying pipe 22 at a high flow rate from a gas supply apparatus 41 in the direction reverse to that during the analysis to peel off and remove the fine particles deposited on the inner walls of the carrying pipe 22, the fine particle introducing pipe 3, and the electric discharge chamber.