Investigation of the characteristics of an indirect plasma torch

Abstract

The main task of creating plasma technologies is to improve the operation parameters of its main element - the plasma torch, which is achieved by designing and constructing its main nodes. The paper analyzes the principles of designing a plasma torch and investigates the characteristics of an arc discharge plasma torch. The possibilities of increasing the thermal stability of the anode structure are considered; the speed and trajectory of powder particles are studied; the axial introduction of the powder through the cathode and the thermal stability of the cathode are studied. Using the finite element method, the effect of the anode shape on the service life of the plasma torch is studied by estimating the heat release power under the condition above the melting temperature of copper (anode). The optimal anode geometry for effective cooling of the unit with radial inlet and outlet of the coolant is determined. The influence of the thermal load on the cathode part of the plasma torch is studied, the thermophysical characteristics of the cathode on the operational characteristics of the plasma torch during the thermal load are taken. The dynamics of the particle by axial injection of the powder through the cathode is calculated, and the dynamics of the heating of the powder particle is determined. The output of the carrier gas is stabilized by a swirler and has great dynamics and is located in the high-temperature part of the arc. The trajectory of the movement of a powder particle in the nozzle area is calculated, which corresponds to the average value of the velocity ≈450-500 m/s. It is found that an increase in the cathode diameter from 3 to 5 mm reduces the thermal load by 50%.