CS232677B1 - Method of low temperature plasma production - Google Patents

Abstract

The invention relates to the field of plasma technology and solves the problem of increasing the temperature of the recombined plasma and increasing the service life of the cathode in a liquid-stabilized plasma generator. The essence of the invention lies in the fact that a liquid reducing the oxidative wear of the cathode is supplied to the cathode part of the stabilization system, and a liquid having a high binding energy is supplied to the remaining parts of the stabilization system. Liquids containing chemically bound carbon and nitrogen are used.

Description

BACKGROUND OF THE INVENTION The present invention relates to a method for producing low temperature plasma in a liquid-arc arc generator.

The prior art methods for producing low temperature plasma in arc-stabilized liquid generators use a single stabilizing fluid to protect the stabilization system from the thermal effects of the electric arc and the resulting plasma, to protect the cathode material from oxidation as well as to form the plasma itself. In particular, ionized water is used, which is supplied to the stabilization system by suitably spaced tangential inlets arranged both adjacent to the cathode and between the individual orifices of the stabilization system and discharged through slotted outlets arranged so as to form a vortex in the stabilization system. the thickness of which is sufficient to form plasma and to cool the stabilization system. The use of water as the only stabilizing fluid, providing all the required functions, is therefore a compromise that, while simplifying the construction and operation of the plasma generator, on the other hand limits the possibility of higher plasma temperatures, increases cathode wear and for some types of plasma coatings, especially for the area of oxide ceramics.

These disadvantages are overcome by the method of producing low temperature plasma in a liquid-arc arc generator according to the invention, which comprises supplying at least two types of stabilizing liquid to the generator stabilization system, wherein a liquid containing chemically bonded carbon or nitrogen is supplied to the cathode section. and having a boiling point different from that of the liquid supplied to the rest of the stabilizing system. The fluid supplied to the rest of the stabilization system may preferably have a higher binding energy than the fluid supplied to the cathode part of the stabilization system, the fluid supplied to the cathode part of the stabilization system may preferably flow downstream from the cathode to the anode. and the two liquids may be mixed in the stabilization system.

By using two or more stabilizing fluids according to the invention, less cathode oxidation is achieved while improving heat dissipation and facilitating the start of the generator due to an increase in the partial pressure of the carbon in the cathode portion of the stabilization system, thereby suppressing the loss of carbon cathode. The use of a liquid with higher contents of chemically bonded carbon and nitrogen then allows the use of metal cathodes. The remainder of the stabilization system utilizes liquids having higher VAA energy or suppressing the reducing character of the recombined plasma, thereby increasing the recombined plasma temperatures. Another improvement is the choice of the flow direction of the stabilizing fluids, which results in an increase in the stability of the forming arc while increasing the power of the generator.

The process for producing the low temperature plasma according to the invention is explained in the following by means of several exemplary embodiments.

He did

In a graphite cathode plasma generator, styrene (vinylbenzene CsHs. CH = CH? - CTIsj), which has a boiling point of 145 ° C and is insoluble in the liquid supplied to the rest of the stabilization system, is water (Η) Ο) boiling point 100 ° C. Both fluids flow from the cathode to the anode and do not mix with each other, significantly increasing the lifetime of the cathode while increasing the plasma current.

Example 2

In a graphite electrode plasma generator, nitrobenzene (C6H5NO2) having a boiling point of 211 ° C and insoluble in the liquid fed to the rest of the stabilizing system, which is water (H 2 O) at a boiling point of 100 ° C, is fed to the cathode part of the stabilization system. The two liquids flow from the cathode to the anode while mixing in the stabilization system. The effect is similar to the previous example.

Example 1 and d 3

In a tungsten-thorium cathode plasma generator, the cathode part of the stabilization system is fed with toluidine (CeHa. CH3. NH2 - C7H9N) having a boiling point of 201 ° C and soluble in the liquid fed to the rest of the stabilization system, toluene. (C 6 H 8 CH 2 -C 7 H 8) having a boiling point of 111 ° G. By directing the stream of toluidine from cathode to anode and toluene in the opposite direction, the stability of the arc increased and the number of recombined particles increased.

Example 4

In a graphite cathode plasma generator, ethanol (CH 2, CH 2) is fed to the cathode portion of the stabilization system.

. OH - C2H6O}, which has a boiling point of 78 ° C and is soluble in the liquid fed to the rest of the stabilization system, which is picoline (methylpyridine C5H4. N. CH3 - C6H7N), boiling at 144 ° C. This combination greatly improved the startability of the generator.

S G

In practice, other types of stabs have also proven useful, with an increase in life-sustaining liquids, such as cathode methylates of 30 to 35%, with concomitant ZOH (CH3OH. CH4O), ethyl nitrate (C2H5 - increase in recombined plasma temperature by approx.

NOs) and the like. In all reported, 20 percent.

Claims (6)

OBJECT OF THE INVENTION A method for producing low temperature plasma in a liquid-arc arc generator, characterized in that at least two types of stabilizing liquid are supplied to the generator stabilization system, wherein a liquid containing chemically bonded carbon or nitrogen and having a boiling point different from liquids supplied to the rest of the stabilization system. 2. The method of producing low temperature plasma according to claim 1, wherein the liquid fed to the cathode portion of the stabilizing system has a lower binding energy than the liquid fed to the rest of the stabilizing system and having a higher binding energy than water. 3. The method of producing low temperature plasma according to claim 1, wherein the liquid supplied to the cathode portion of the stabilization system flows in the direction from the cathode to the anode, while the liquid supplied to the rest of the stabilization system flows from the anode towards the cathode. 4. The method of producing low temperature plasma according to claim 1, wherein the liquid supplied to the cathode portion of the stabilizing system comprises chemically bound carbon in an amount of 37 to 93% by weight. 5. The method of producing low temperature plasma according to claim 1, wherein the liquid supplied to the cathode portion of the stabilization system comprises chemically bound carbon in an amount of 25 to 80% by weight. and chemically bound nitrogen in an amount of 10 to 25% by weight. 6. The method of producing low temperature plasma according to claim 1, wherein the liquid supplied to the cathode portion of the stabilizing system comprises chemically bonded carbon in an amount of 50 to 93% by weight, and the liquid supplied to the rest of the stabilizing system contains chemically bonded carbon in an amount of 25 to 93 80 wt. and chemically bound nitrogen in an amount of 10 to 25 wt.