Measurements of current, voltage and amplitude of electric field of dusty high-frequency capacitor discharge have been carried out. Increase in the current proceeding in discharge at its dustiness by substances with potential ionization less than 7 V was established. Electromagnetic wave parameters extending in dusty high-frequency capacitor discharge were calculated. The absence of characteristics change in discharge electromagnetic field at degrees of its dustiness v<10? was show

Lutsenko, Yu. Yu.

Venderevskaya, Yu. V.

Vlasov, Viktor Alekseevich

Electronic archive of Tomsk Polytechnic University

10. Ryzhov V.V., Yastremskiy A.G. Distribution of electron beam energy in nitrogen plasma // Fizika Plazmy. – 1978. – V. 4. – Issue 6. –P. 1262–1266.11. Ryzhov V.V., Yastremskiy A.G. Features of generation of lowtemperature plasma at ionization of gas mixtures by electron beam //Zhurnal Tekhnicheskoy Fiziki. – 1979. – V. 49. – № 10. –P. 2141–2145.12. Baranchikov E.I., Belenkiy G.S., Denisenko V.P. et al. SO2 oxidation in the air under the influence of highcurrent beam of relativistic electrons // Reports of USSR AS. – 1990. – V. 315. – № 1. –P. 120–123.13. Novoselov Yu.N., Suslov A.I., Kuznetsov D.L. Electron pulse beaminfluence on carbon disulfide impurity in the air // ZhurnalTekhnicheskoy Fiziki. – 2003. – V. 73. – № 6. – P. 123–129.14. Remnev G.E., Furman E.G., Pushkarev A.I. et al. Pulse highcurrent accelerator with matching transformer // Pribory i TekhnikaEksperimenta. – 2004. – № 3. – P. 130–134.15. Pushkarev A.I., Remnev G.E., Vlasov V.A., Sosnovskiy S.A.,Ezhov V.V. Plasmachemical processes initiated by pulse electronbeam in gas mixture of SF6 and N2 // Bulletin of The Tomsk Polytechnic University. – 2004. – V. 307. – № 6. – P. 59–62.16. Vlasov V.A., Pushkarev A.I., Remnev G.E., Sosnovskiy S.A., EzhovV.V., Guzeeva T.I. Experimental investigation and mathematical simulation of fluoride compound reduction by pulse electron beam //Bulletin of The Tomsk Polytechnic University. – 2004. – V. 307. –№ 5. – P. 89–93.17. Pat. 2228239 RF. IPC7 С22В 5/00, С21В 13/00. The technique ofhalogenide direct reduction / G.E. Remnev, A.I. Pushkarev,M.A. Pushkarev, V.A. Krasilnikov, T.I. Guzeeva. Stated 04.02.2002,Published 10.05.2004, Bulletin № 13.18. Remnev G.E., Pushkarev A.I., Pushkarev M.A., Reznitchenko M.F.Highcurrent pulsed electron beam application for silicon reduction// Proc. of 3rd Intern. Symp. on pulsed power and plasma applications. – China, 2002. – P. 152–154.19. Remnev G., Pushkarev A. Chain plasmachemical synthesis of superdispersed silicon dioxide // Proc. of 4th Intern. Symp. on pulsedpower and plasma applications. – Japan, 2003. – P. 180–184.20. Saraeva V.V. Radiolysis of hydrocarbons in liquid phase. Modern stateof the question. – Moscow: Moscow University Press, 1986. – 256 p.21. Mansurov Z.A. Sooting in combustion actions (survey) // FizikaGoreniya i Vzryva. – 2005. – V. 41. – № 6. – P. 137–156.Received on 7.12.2006Mathematics and mechanics. Physics73Gas discharges in plasma technology are usually used only as a source of plasma jet. However, substanceprocessing in gas discharge directly has a number of advantages in comparison with substance processing inplasma jet. First of all, higher temperature of plasmaand lower axial temperature gradient are typical for gasdischarge. Presence of electric fields and higher concentration of electrons in discharge area make plasmacatalytic properties more defined.It is more optimal to use highfrequency dischargesof capacitive type to carry out processes in discharge area. Discharges of this type have large volume of discharge plasma at low level of power supplied to discharge.Walls of plasmachemical reactor and intensification ofprocesses occurring in plasma may be refined by amplitude modulation.In this work electrophysical characteristics of highfrequency capacitive discharge dusty by dielectric andconducting materials were measured. The diagram of experimental setap is given in Fig. 1. Highfrequency capacitive discharge with a ring electrode with the diameterof 48 mm was used. Presence of the second groundedelectrode, as experience has shown, does not substantially influence [1] the characteristics and modes of capacitive discharge combustion. The discharge was excited inquartz tube with the diameter of 36 mm. Discharge combustion was carried out in the air at atmospheric pressure. Discharge power varied from 1 to 3 kW. Electromagnetic field frequency amounted to 40 MHz. Dispersion ofmaterials which were used for discharge dust amountedto 20...60 mkm. Powder was supplied to central discharge area by pneumatic feeder. Consumption of plasma forming gas amounted to 0,6 m3/h.Voltagecurrent characteristics of discharge in freeconsumption mode and in the case of discharge plasmadustiness by dielectric and conducting particles weremeasured. The degree of discharge plasma dustiness determined as a ratio of spray substance volume to totalvolume of discharge chamber changed from 0 to 10–4.Discharge dustiness degree was measured by determiUDC 537.9FEATURES OF HIGHFREQUENCY CAPACITOR DISCHARGE COMBUSTION PROCESS IN MEDIA WITH DISPERSE PHASEYu.Yu. Lutsenko, V.A. Vlasov, Yu.V. VenderevskayaTomsk Polytechnic UniversityEmail: luts@mail.ruMeasurements of current, voltage and amplitude of electric field of dusty highfrequency capacitor discharge have been carried out. Increase in the current proceeding in discharge at its dustiness by substances with potential ionization less than 7 V was established. Electromagnetic wave parameters extending in dusty highfrequency capacitor discharge were calculated. The absence of characteristicschange in discharge electromagnetic field at degrees of its dustiness ν<102 was shown.ning the change of sprayed powder weight for a certainperiod of operation of experimental device. Voltage wasmeasured by voltmeter V352/1 furnished with additional capacitance divider. Current was measured by Rogowski loop.Fig. 1. Diagram of experimental setap: 1) tube for powdersupply; 2) feeder; 3) capacitive probeAs a result of measuring the increase of highfrequency current in discharge at its dustiness with such substances as Al2O3, Na2SO3, Ca(CH3COO)2 was stated. Atdischarge dustiness with substances having ionizationpotentials higher than ionization potential [2] of calcium, discharge characteristic change is not observed.In particular, at discharge dustiness with Ni, Fe currentchange in discharge is in the range of measurement errors. The results of current change measurements indischarge at its dustiness with substances with differentionization potentials are given in Fig. 2. The value of ionization potential is put on Xaxis and the ratio of current in dusty discharge to the current in free discharge isput on Yaxis.Fig. 2. Dependence of current in a discharge on a value of ionization potentialLet us note that current increase in a discharge is accompanied by proper decrease of voltage at highvoltage electrode. So, at discharge dustiness with aluminumoxide current increases by 15 %, voltage decreases simultaneously by 15 %. Therefore, discharge power at itsdustiness does not change. The degree of dustiness anddispersion of dusting material influence insignificantlyon discharge plasma resistance.The results of experiments showed high resistance ofhighfrequency capacitive discharge to dustiness bothby dielectric and conducting material. Let us note thatdischarge resistance to dustiness is mainly determinedby change at dustiness of its electrodynamic characteristics.In this connection radial component of electric fieldof highfrequency capacitive discharge was measured aswell. Measurements were carried out by capacitive probe; a signal from it was delivered to oscillograph input.Capacitive probe represented copper finger with the diameter of 1 mm and length of 3...5 mm. The results ofmeasurements are given in Fig. 3. It follows from theresults of measurements that the changes in axial distribution of radial component of electric field of capacitive discharge at its dustiness are insignificant. Only slightincrease of electric field amplitude along discharge axisin the case of its dustiness by conducting material is observed.Fig. 3. Electric field distribution along the axis of highfrequency capacitive discharge: 1) freely combusting discharge;2) discharge dusted with nickel (ν=104)Let us examine the process of electromagnetic wavepropagation along the channel of highfrequency capacitive discharge. As it is shown in paper [1] the character of electromagnetic field of highfrequency capacitive discharge is similar to the character of electromagnetic field of highfrequency torch discharge except theregion abutting directly on highfrequency electrode.Therefore it might be supposed that combustion ofhighfrequency capacitive discharge is realized due todissipation of energy of «direct» and «reflected» crossmagnetic waves as in the case of highfrequency torchdischarge. Electromagnetic field decay in discharge plasma and correspondingly, a part of energy consumed formaintenance of discharge combustion process is determined by the value of decay constant of electromagnet01002003004005006007000 50 100 150 200E r,ȼ/ɦ21Z, ɦɦ5 6  7  8 U, ɷȼ0,81,01,2I / I090,6§213Bulletin of the Томsк Pоlytеchnic University. 2007. V. 311. № 274ic wave. The decay constant in its turn may be determined from the expression for wave number. Wave numberof crossmagnetic wave propagating along the channelof discharge [3] has the following form:where a is the radius of discharge channel; ε'=ε/ε0 is therelative value of complex permittivity of discharge plasma; α is the decay constant; β is the phase coefficient.Complex permittivity ε of discharge dusted plasmamay be determined [4] by the formula of LorentzLorentz:Here: ε1, ε2 are the complex permittivity of dustingmaterial and plasma respectively; ν is the ratio of dusting material to general volume of dusted plasma. Theresults of calculation of decay constant of electromagnetic wave propagating in plasma of highfrequency capacitive discharge with power of 1 kW depending on degree of its dustiness are given in Fig. 4.As it is seen from Fig. 4 the change of decay constantof electromagnetic field of capacitive discharge is observed only at degrees of dustiness ν>10–2. Similar degreesof dustiness can not be implemented in practice. Realdegrees of discharge dustiness, in particular using pneumatic feeder amount to ν<10–4.Fig. 4. Dependence of decay constant of electromagnetic wavein discharge plasma on degree of its dustiness: 1) Al2O3(dielectric); 2) Ni (metal)Thus, the results of calculations allow stating thatcombustion of highfrequency capacitive discharge isstable at its dustiness by dielectric and conducting materials at ν<10–2 that is confirmed by the results of experimental measurements.-4 -3 -2 -1 0lgȞ102030Į,ɦ-1121 222 1 2( )1 .1 ( )3vvε εε εε ε ε⎡ ⎤⎢ ⎥−= +⎢ ⎥−⎢ ⎥+ −⎣ ⎦2 222( ) ,5h jaα β ε= + ≈ − ′Mathematics and mechanics. Physics75REFERENCES1. Lutsenko Yu.Yu. Features of electromagnetic field of highfrequency capacitive discharge of string type combusting at atmosphericpressure // Zhurnal Tekhnicheskoy Fiziki. – 2005. – № 11. –P. 124–127.2. Energy of chemical bond opening. Ionization potential and electronaffinity. Reference book ed. by. V.N. Kondratieva. – Moscow, 1974.– 350 p.3. Kachanov A.V., Trekhov E.S., Fetisov E.P. Electrodynamic model ofhighfrequency torch discharge // Zhurnal Tekhnicheskoy Fiziki. –1970. – V. 40. – № 2. – P. 340–345.4. Netushil A.V., Zhukhovitskiy B.Ya., Kudin V.N., Parini E.P. Highfrequency heat of dielectric and semiconductors. – MoscowLeningrad: Gosenergoizdat, 1959. – 480 p.Received on 7.12.2006

Features of high-frequency capacitor discharge combustion process in media with disperse phase

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