DEVELOPMENT OF A PLASMATRON WITH A SECTIONED CATHODE ASSEMBLY WITH ALLOWANCE FOR EXCESS PRESSURE
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Abstract
The results of numerical simulation of a plasmatron with a sectioned cathode node are shown, which showed that under the pressure of the plasmatron outlet, the partial pressure of oxygen-containing gases in the cathodic space significantly increases, which may adversely affect the emission
characteristics of the cathode material.
Therefore, failure to take into account the hydraulic resistance of the systems that are part of the complex into which the plasmatron is integrated, can lead to negative consequences, namely, significant erosion and reduced system life as a whole. Therefore, the level of excess pressure at the outlet of the plasmatron is one of the key parameters in the design of the plasma generators. In turn, it is shown that in existing traditional designs of plasma generators there is no power resource required to change the flow
characteristics.
For stable operation under conditions of excess pressure, it was proposed to use a P-13 type plasmatron, which showed that within the existing design limits were reached regarding the perfection of the geometric parameters of the cathode assembly. Reducing the harmful effects of oxygen-containing gases is only possible by increasing the flow of shielding gas or by using cathode materials with a higher poisoning threshold. Using the methods proposed in this work, design calculations of the plasmatron were made for the problems of gasification of raw materials with the possibility of a wider range of regulation of the parameters of the current load and the flow of protective and plasma-forming gases. Compared to the base structure, the anode assembly and cathode diameter were increased, the sections of supply of protective and plasma gases were increased, the design of the electrode
insert was changed. At the initial stage, the flow rate of the shielding gas was 0.001 kg/s, and the plasma-forming gas was 0.04 kg/s.
A hexagonal grid was used to sample the computational region enclosed in the cavity of the plasmatron model, including the determination of the surface layer and special regions of inlets and outlets.