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Abstract

The article presents the results of experimental studies of a double-chamber linear circuit DC electric arc plasmatron in experimental and industrial conditions. The electric arc plasmatron of the VORTEX-200 linear circuit with a rated power of 200 kW is designed for plasma ignition of a pulverized-coal torch, its stabilization and oil-free ignition of pulverized-coal boilers of thermal power plants.The linear circuit plasmatron contains two water-cooled casings isolated from each other, one of which has a hollow cylindrical electrode - a cathode having swirlers of the plasma-forming gas at both ends, and the other has an output electrode - an anode-diffuser having a channel with a cylindrical segment at one end and the exit nozzle in the form of a diffuser at the other end.The power of the plasmatron, depending on the process parameters, can vary from 80 to 230 kW. The plasmatron has a stable powerful air plasma torch. Tests of such plasmatrons showed their high reliability and possibility of their operation in difficult conditions of thermal power plants (high level of dust and humidity, high temperatures near the boilers). Measured volt-ampere characteristics of the plasmatron enabled us to determine the region of stable arc combustion from 350 to 475 A. Parameters of the plasmatron operation at its nominal power of 200 kW and the flow rate of the plasma-forming gas of 1000 l/min are attained at currents not exceeding 450 A. The use of mechanical ignition of the plasmatron with a needle from a refractory material, instead of breakdown the inter electrode gap by an oscillator, increased the reliability of its operation.The device for axial scanning of binding of the cathode spot of the arc, which allows us to increase the surface of cathode erosion many times,was developed. The use of azimuthal and axial scanning of the cathode spot of the arc of the plasma torch makes it possible to increase the service life of the cathode up to 200 hours with a service life of the massive anode exceeding 500 hours.

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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