A new plasmatron for metal cutting for welding: a comparative analysis

A new one-circuit plasmatron for metal cutting for welding with improved gas-dynamic characteristics is considered. The plasmatron design is created during the solution of the gas-dynamic problem of the non-uniform distribution of a plasma gas stream along the section of the plasmatron air-gas path. As a result of the analysis of various constructive variants of the air-gas path, such as the increased volume of the expansion chamber, the modification of the length, quantity and the form of gas rotating channels, the system of gas-dynamic filters in the expansion chamber, a complex system of gas rotating stabilization of a plasma arc is created. The system of gas-dynamic filters consists of a set of obstacles of various forms established in the expansion chamber, their functions represent uniform distribution of plasma gas streams along rotating channels. The results of computer modeling proving the design efficiency are presented. The comparative analysis of efficiency and safety parameters is presented. During the analysis of parameters of the cutting edge surface quality (deviations from perpendicularity, roughness size, the size of the heat-affected zone) it was established, that the new plasmatron performs metal cutting for welding of the 1st quality class. The improvement of safety parameters is also shown in the work of the new plasmatron.