RU2285358C2 - Device for generation of plasma stream - Google Patents

Abstract

FIELD: electronic industry, namely, ion and plasma technology, concerning electric discharges in gases and sources of radiation and cold plasma.

SUBSTANCE: device for generation of plasma flow contains nozzle with installed rod electrode, sharpened at the end, connected to source of plasma-generating substance, output electrode with through channel for creation of electric field on the side of output channel of nozzle. End of rod electrode of nozzle protrudes beyond limits of nozzle for distance, exceeding two diameters of aperture of output channel of nozzle, while distance between output aperture of nozzle and output electrode ranges from three to five diameters of aperture of nozzle channel.

EFFECT: decreased temperature of plasma stream and increased volume of plasma at atmospheric pressure and low power injected into charge.

1 cl, 3 dwg

Description

The present invention relates to techniques for electric discharges in gases, in particular to devices for generating plasma flows, and can be used in plasma technologies, substance atomizers, plasma chemical reactors, medicine - radiation sources and cold plasma.

A known device for generating plasma is a plasmatron (Badyanov B.N., Davydov V.A. Welding processes in electronic technology. M. VSh. 1988), containing a pointed cathode, anode - nozzle, which allows to obtain a high-temperature plasma stream at atmospheric pressure.

The closest technical solution, selected as a prototype, is a device for generating a plasma stream (certificate for utility model of the Russian Federation No. 8199), containing a nozzle with an electrode pointed at the end, having a device for connecting to a source of a plasma-forming substance, an output electrode to create an electric field from the output end of the nozzle.

However, this device has drawbacks in that, in this design, a high average mass temperature and a small volume of the plasma stream, which does not allow it to be used in plasma devices that allow receiving plasma flows with low average mass temperatures, for example, when working with biological fabrics with thermolabile and flammable (combustible) materials.

The problem solved by the invention is to reduce the average mass temperature of the plasma and increase the volume of the plasma stream.

The authors do not know that the goal was achieved at atmospheric pressure and low power invested in the discharge.

The specified technical result in the implementation of the invention is achieved by the fact that, in contrast to the known device for generating a plasma stream, comprising a nozzle with a rod electrode pointed at the end, having a device for connecting with a source of a plasma-forming substance, an output electrode with a through channel for creating an electric field from the side the outlet channel of the nozzle, the end of the rod electrode protrudes beyond the nozzle by a distance exceeding two diameters of the outlet Nala nozzle, and the distance between the outlet nozzle and the outlet electrode is from three to five times the channel diameter nozzle apertures.

The solution of this problem becomes possible on the basis of the phenomenon associated with the fact that, when these conditions are met, a dense plasma is formed at the end of the pointed electrode, which expands in the direction of flow in the form of a plasma formation, penetrating outside the output electrode into the atmospheric air by a distance of 6 8 millimeters with a transverse flow size of 5-6 millimeters.

A comparative analysis of the analogue, prototype and the claimed device revealed the following common signs:

- nozzle for supplying a plasma-forming substance;

- a rod electrode pointed at the end;

- output electrode with a through channel.

The analysis revealed the following distinguishing features:

- the rod electrode protrudes beyond the nozzle by a distance exceeding two diameters of the hole of the nozzle outlet channel;

- the distance between the nozzle exit hole and the output electrode is from three to five diameters of the nozzle channel opening.

These distinguishing features make up the criterion of "technical result", because thanks to them it is possible to significantly reduce the temperature and increase the volume of the plasma stream.

The invention is illustrated by drawings, where (Fig. 1) shows a device for generating a plasma stream, Fig. 2 is an electrical diagram, Fig. 3 is a measurement of the average mass temperature of a plasma flow.

The device consists of an output electrode 1, a nozzle 2, pointed at the end of the rod electrode 3 introduced into the channel 4, the end of the rod electrode extends beyond the nozzle by a distance (d) exceeding two diameters of the nozzle channel opening (D), the distance between the nozzle exit hole and the output electrode (s) is from three to five diameters of the nozzle channel opening (FIG. 1).

The device operates as follows.

The device is connected to a gas supply system 7 and a constant voltage source 6. When the working gas pressure is greater than atmospheric pressure, a voltage sufficient for breakdown of the interelectrode gap is applied to the electrodes of the device (rod electrode 3 and output electrode 1). At the exit of the nozzle 4, a discharge is ignited, a dense plasma is formed at the end of the pointed electrode, which expands in the direction of flow in the form of a plasma formation 5, penetrating outside the output electrode into atmospheric air at a distance of 6-8 millimeters with a transverse flow size of 5-6 millimeters (Figure 2).

Example. The output electrode 1 is made of copper. The diameter of the outlet is 2 millimeters. The rod electrode 3 is made of a tungsten wire with a diameter of 0.5 millimeters, is pointed at the end, inserted into the channel 4 of the nozzle 2. The diameter of the channel of the nozzle is 1 millimeter. The end of the pointed electrode protrudes beyond the nozzle end to a distance of 2.5 millimeters. The distance between the nozzle outlet and the output electrode is 4 millimeters. From the gas supply system 7 was supplied working gas - air. At a pressure above atmospheric, a constant voltage was applied to the electrodes (rod electrode 3 and output electrode 1). A discharge was ignited between the electrodes, the plasma of which drooped through the hole in the output electrode beyond the limits of the output electrode into atmospheric air. At a discharge current of 20 mA, the voltage at the electrodes was 500 V, and a discharge power of 10 W, the plasma flow length was 6 millimeters with a flow diameter of 5 millimeters. The temperature of the plasma stream at the output electrode is 60 ° C, at the plasma boundary 40 ° C (Figure 3).

Thus, the above information indicates the fulfillment of the following set of conditions when using the claimed invention:

- a tool embodying the claimed invention in its implementation, is intended for use in plasma technologies, substance atomizers, plasma chemical reactors, in the technique of electric discharges in gases, in medicine - radiation sources and cold plasma;

- for the claimed invention in the form described in the independent clause of the claims below, the possibility of its implementation using the means and methods described above or known prior to the priority date is confirmed;

- a tool embodying the claimed invention in its implementation, is able to ensure the achievement of the perceived technical result.

Therefore, the claimed invention meets the requirement of "industrial applicability" under applicable law.

Claims (1)

A device for generating a plasma stream, comprising a nozzle with a rod electrode pointed at the end, connected to a source of a plasma-forming substance, an output electrode with a through channel for creating an electric field on the side of the nozzle output channel, characterized in that the end of the rod electrode extends beyond the nozzle by a distance exceeding two diameters of the hole of the nozzle outlet channel, and the distance between the nozzle outlet and the output electrode is from three to five diameters from the orifice of the nozzle channel.

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