US3375392A - Plasma generator utilizing a ribbonshaped stream of gas - Google Patents

Plasma generator utilizing a ribbonshaped stream of gas Download PDF

Info

Publication number
US3375392A
US3375392A US634005A US63400567A US3375392A US 3375392 A US3375392 A US 3375392A US 634005 A US634005 A US 634005A US 63400567 A US63400567 A US 63400567A US 3375392 A US3375392 A US 3375392A
Authority
US
United States
Prior art keywords
gas
nozzle
chamber
plasmatron
plasma generator
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US634005A
Other languages
English (en)
Inventor
Brzozowski Wojciech
Reda Janusz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from PL103947A external-priority patent/PL49407B1/pl
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3375392A publication Critical patent/US3375392A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc

Definitions

  • Plasmatron Owing to the considerable thermal capacity of nitrogen, nitrogen-operated devices of the type known by the trademark Plasmatron constitute high-power plasma generators. Depending on the manner of operation, i.e. with non-transferred or transferred arc, such Plasmatrons may produce temperatures of the order of 10,000 or 20,000 C., respectively. They serve mainly for metallurgical purposes, cutting metals, and spraying with particularly hard-to-melt powders as well as for chemical analysis and synthesis. Modern Plasmatrons operate on the principle of vortex gas flow, a fact which affords a higher flow stability than that obtainable in the previously used axial-flow Plasmatrons.
  • the Plasmatrons known at present are characterized by a complicated design, and they usually incorporate a ceramic piece located between the anode and the cathode, this piece being provided with small vortex grooves which serve to impart a whirling motion to the gas. Fitting such ceramic pieces tightly in position is difficult; moreover, they are subject to frequent fractures as a result of rapid changes in temperature.
  • the cathode of known Plasmatrons represents a body, generally made of copper, which terminates in a holder for a tungsten point. This cathode is internally cooled with water, the mounting of its end on the ceramic piece preventing the holder for the tungsten point from being cooled additionally by a gas flow. This is determined for the service life of the cathode.
  • the vortex grooves of the ceramic piece have a considerable cross-section, thus causing an increase in the gas mass rate of flow, as well as difiiculties in obtaining high-temperature plasma, coupled with the necessity of substituting a short Plasmatron nozzle for a long one when changing the operation from the transferred-arc to the non-t-ransferred-arc mode Moreover, the vortex grooves of oval or circular crosssection make it impossible to obtain a uniform flow of whirling gas and a uniform distribution of pressure, thus causing the arc to strike at locations of reduced pressure, offset from the cathode axis, which tends to damage the cathode.
  • the Plasmatron according to our invention is free from any of the disadvantages referred to above; furthermore, it is simple and durable in design.
  • Whirling motion of the supplied nitrogen is achieved by the provision of a metallic slotted gas nozzle positioned tangentially to the Plasmatron gas chamber.
  • a rectangular slot at the nozzle outlet ejects a flat ribbon of nitrogen situated in a plane perpendicular to the gas-flow axis, thus creating optimum aerodynamic conditions of flow, with minimum pressure along the axis of the tungsten piece. This ensures proper ignition of the Plasmatron from the center of the tungsten piece.
  • the metallic nozzle and the slot are of reduced size compared with those of an equivalent nozzle of ceramic material, a fact which affords a decreased rate of mass flow and, in consequence, a higher temperature of the plasma with given electric parameters.
  • the decrease obtained in the rate of mass flow enables also the same Plasmatron nozzle to be used for operation with both non-transferred and transferred arc as more fully described hereinafter.
  • FIG. 1 represents the Plasmatron in longitudinal section
  • FIG. 2 is a transverse section along line II-II of FIG. 1;
  • FIG. 3 represents the gas nozzle as viewed on the line III+III of FIG. 2;
  • FIG. 4 shows water circuits in the nozzle body seen in section along line IVIV of FIG. 2.
  • S represents a DC supply unit
  • R is an electric resistance
  • M is an external anode
  • switch Z When operating the Plasmatron with the nontransferred-arc mode (dot-dash lines), switch Z is in horizontal position to disconnect the auxiliary anode M, switch Z being opened.
  • switch Z When operating the device with the transferredarc mode (full lines) switch Z is situated in vertical position, switch Z being closed to provide a resistive path for the energization of a main anode 14, 15 to which an arc lit between anode M and a cathode (described below) is subsequently transferred. Nitrogen is fed to the Plasmatron through a flexible hose 1 leading to a gas nozzle 2 terminating in a slot 2 (see FIG.
  • the chamber contains a tungsten piece 4 soldered into a copper holder 5. Tangential feeding of nitrogen at a pressure of 6 to 7 atmospheres creates a vortical flow in the space between the conical end of the chamber 3 and the conical holder 5 situated in that chamber. Cooling water is introduced by a flexible hose 6 through the length of which runs a power cable 7. Flexible hose 6 terminates in a threaded nipple 8 which receives, by a soldered joint, the cable 7. Nipple 8 of flexible hose 6 is screwed into a cathode body 9 which terminates in a pipe 10 feeding water to the interior of holder 5.
  • the cathode body 9 and flexible hose 6 are secured to a cathode sleeve 11- by means of a nut 12.
  • the water after leaving holder 5, flows through an insulating spacer 13 into a support 14 for an ejection nozzlelS forming part of the anode.
  • Water flowing through the body 14 sweeps past the Plasmatron ejection nozzle 15, next enters a pipe 16, and finally, via a threaded nipple 17, flows into a flexible hose 18 discharging the water to a drain (not shown).
  • the flexible hose 18 surrounds a power cable 19 which is soldered into nipple 17.
  • the Plasmatron ejection nozzle 15 is secured to the support 14 by means of a nut 20 and is sealed by two rubber gaskets 21.
  • the cathode assembly 4, 5, 9-12 is sealed by two gaskets 22.
  • the ejection-nozzle support 14 is separated from the cathode sleeve 11 by spacer 13.
  • Flexible hose 1, supplying nitrogen, and water pipe 16 pass through a plate 23 which is traversed by three tubes 24, 25 and 26.
  • Insulating spacer 13 is screened by a nickel-brassplate coating 27 protecting it against the radiation of the electric arc.
  • the Plasmatron is provided with a housing, which consists of a casing 28 for the ejection-nozzle support 14, a conical ring 29, a casing 30 protecting the flexible hoses, and an insulating shield 31 lining the inner surface of the latter.
  • slot 2' is bounded by an outer edge 2b, which is substantially tangent to the outer periphery of chamber 3, and by an inner edge 20 on a line that is substantially tangent to the inner periphery of that chamber, i.e. to the annular extension 13' of spacer 13 surrounding the central electrode (cathode) 4, the two edges 2b, form a diverging discharge end for the nozzle 2 so that, as will be readily apparent from FIG. 2, the gas issues therefrom within the plane II-II in a fiat, thin ribbon occupying substantially the full width of the annular chamber 3 in which it whirls in a clockwise sense as viewed in that figure, spiraling with progressively decreasing pressure toward the axially extending outlet 34 (FIG. 1).
  • the cooling water introduced via conduit 6 and removed via conduit 18 flows through a passage 35 (FIG. 4) in spacer 13 before reaching a cavity 36 formed in the two-piece annular anode body 14, 15, this cavity extending around part of the chamber 3 and the outlet 34 for an effective cooling of the anode surfaces heated by the exiting gas.
  • a plasma generator having a central electrode and an annular electrode coaxially surrounding saidoentral electrode and defining therewith an annular' gas chamber, said annular electrode forming an axial outlet communicating with said chamber beyond and in line with said central electrode, the combination therewith of inlet means for admitting a gas with whirling motion to said chamber, said inlet means including a nozzle entering said chamber tangentially from without, said nozzle being provided with a narrow slot having its dimensions of width and length in a radial plane of said annular electrode transverse to the axis thereof and having a height substantially less than its width in a direction perpendicular to said plane whereby a fiat ribbon of gas is discharged in said radial plane from said nozzle into said chamber, said slot having a discharge end dimensioned to make the Width of said ribbon equal to more than half the width of said annular chamber.
  • annular electrode is provided with a channel in said plane receiving said nozzle and with a larger axially extending bore terminating at said channel, said nozzle having a lateral aperture which opens into said channel, said inlet means including a conduit extending within said bore to said aperture for communication with said slot.
  • annular electrode is hollow and forms a cavity around part of said chamber and said outlet, further comprising conduit means for circulating a cooling fluid through said cavity.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Plasma Technology (AREA)
  • Coating By Spraying Or Casting (AREA)
  • Nozzles (AREA)
US634005A 1964-03-07 1967-04-26 Plasma generator utilizing a ribbonshaped stream of gas Expired - Lifetime US3375392A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PL103947A PL49407B1 (fi) 1964-03-07

Publications (1)

Publication Number Publication Date
US3375392A true US3375392A (en) 1968-03-26

Family

ID=19941693

Family Applications (1)

Application Number Title Priority Date Filing Date
US634005A Expired - Lifetime US3375392A (en) 1964-03-07 1967-04-26 Plasma generator utilizing a ribbonshaped stream of gas

Country Status (5)

Country Link
US (1) US3375392A (fi)
BE (1) BE660672A (fi)
FR (1) FR1428278A (fi)
GB (1) GB1096820A (fi)
NL (1) NL6502885A (fi)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3463957A (en) * 1965-04-09 1969-08-26 Inst Badan Jadrowych Arc plasma torch with same liquid cooling means for electrodes
US3480805A (en) * 1965-09-08 1969-11-25 English Electric Co Ltd Magnetohydrodynamic apparatus
US3674978A (en) * 1970-04-24 1972-07-04 Messer Griesheim Gmbh Torch, especially for plasma cutting
US3811029A (en) * 1972-02-17 1974-05-14 M Krutyansky Plasmatrons of steel-melting plasmaarc furnaces
US3818174A (en) * 1972-11-09 1974-06-18 Technology Applic Services Cor Long arc column forming plasma generator
US3869593A (en) * 1971-12-09 1975-03-04 British Titan Ltd Heating device
US3944778A (en) * 1974-05-14 1976-03-16 David Grigorievich Bykhovsky Electrode assembly of plasmatron
US4055741A (en) * 1975-12-08 1977-10-25 David Grigorievich Bykhovsky Plasma arc torch
US4058698A (en) * 1974-04-02 1977-11-15 David Grigorievich Bykhovsky Method and apparatus for DC reverse polarity plasma-arc working of electrically conductive materials
US4059743A (en) * 1974-10-28 1977-11-22 Eduard Migranovich Esibian Plasma arc cutting torch
US4107507A (en) * 1973-06-06 1978-08-15 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Arc welding process and apparatus
US5235155A (en) * 1989-10-23 1993-08-10 Brother Kogyo Kabushiki Kaisha Plasma cutting device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008056278A1 (de) 2008-10-25 2010-04-29 Kjellberg Finsterwalde Plasma Und Maschinen Gmbh System zur thermischen Bearbeitung von Werkstücken

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3463957A (en) * 1965-04-09 1969-08-26 Inst Badan Jadrowych Arc plasma torch with same liquid cooling means for electrodes
US3480805A (en) * 1965-09-08 1969-11-25 English Electric Co Ltd Magnetohydrodynamic apparatus
US3674978A (en) * 1970-04-24 1972-07-04 Messer Griesheim Gmbh Torch, especially for plasma cutting
US3869593A (en) * 1971-12-09 1975-03-04 British Titan Ltd Heating device
US3811029A (en) * 1972-02-17 1974-05-14 M Krutyansky Plasmatrons of steel-melting plasmaarc furnaces
US3818174A (en) * 1972-11-09 1974-06-18 Technology Applic Services Cor Long arc column forming plasma generator
US4107507A (en) * 1973-06-06 1978-08-15 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Arc welding process and apparatus
US4058698A (en) * 1974-04-02 1977-11-15 David Grigorievich Bykhovsky Method and apparatus for DC reverse polarity plasma-arc working of electrically conductive materials
US3944778A (en) * 1974-05-14 1976-03-16 David Grigorievich Bykhovsky Electrode assembly of plasmatron
US4059743A (en) * 1974-10-28 1977-11-22 Eduard Migranovich Esibian Plasma arc cutting torch
US4055741A (en) * 1975-12-08 1977-10-25 David Grigorievich Bykhovsky Plasma arc torch
US5235155A (en) * 1989-10-23 1993-08-10 Brother Kogyo Kabushiki Kaisha Plasma cutting device

Also Published As

Publication number Publication date
FR1428278A (fr) 1966-02-11
GB1096820A (en) 1967-12-29
BE660672A (fi) 1965-07-01
NL6502885A (fi) 1965-09-08

Similar Documents

Publication Publication Date Title
US3387110A (en) Apparatus for uniform feeding of powder into a plasma spray gun
US2960594A (en) Plasma flame generator
EP2689640B1 (en) Plasma torch
US5147998A (en) High enthalpy plasma torch
US3375392A (en) Plasma generator utilizing a ribbonshaped stream of gas
US3145287A (en) Plasma flame generator and spray gun
KR930005953B1 (ko) 개량 플라즈마 아아크 토오치 시동방법
CA1234689A (en) Plasma gun
US3042830A (en) Method and apparatus for effecting gas-stabilized electric arc reactions
KR0137957B1 (ko) 아아크 토치용 개스 냉각 캐소드
CN102388681A (zh) 用于电弧等离子喷枪的冷却管、电极容纳部和电极以及由它们组成的装置和包括这些部件的电弧等离子喷枪
JPS6340300A (ja) プラズマ発生装置及び精確に制御されたプラズマを発生させる方法
GB990533A (en) Electrical spraying apparatus and methods
US3114826A (en) High-temperature spray apparatus
US4596918A (en) Electric arc plasma torch
JPH08339893A (ja) 直流アークプラズマトーチ
US3390292A (en) Fluid coolant system for a plasma-jet generator
US2973426A (en) Electric-arc torch
EP0515975B1 (en) High enthalpy plasma torch
US3597650A (en) Arc radiation sources
US3472995A (en) Electric arc torches
US3139509A (en) Electric arc torch
US3590219A (en) Electric arc gas heater
RU2614533C1 (ru) Электродуговой плазмотрон
US3106633A (en) Arc torch device