US3183337A - Electrical plasma-jet spray torch and method - Google Patents

Electrical plasma-jet spray torch and method Download PDF

Info

Publication number
US3183337A
US3183337A US126402A US12640261A US3183337A US 3183337 A US3183337 A US 3183337A US 126402 A US126402 A US 126402A US 12640261 A US12640261 A US 12640261A US 3183337 A US3183337 A US 3183337A
Authority
US
United States
Prior art keywords
gas
passage
nozzle passage
arc
back electrode
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
US126402A
Other languages
English (en)
Inventor
John W Winzeler
James F Tucker
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.)
Giannini Scientific Corp
Original Assignee
Giannini Scientific Corp
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 to NL279638D priority Critical patent/NL279638A/xx
Application filed by Giannini Scientific Corp filed Critical Giannini Scientific Corp
Priority to US126402A priority patent/US3183337A/en
Priority to FR896746A priority patent/FR1352815A/fr
Priority to GB22718/62A priority patent/GB990533A/en
Application granted granted Critical
Publication of US3183337A publication Critical patent/US3183337A/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
    • H05H1/42—Plasma torches using an arc with provisions for introducing materials into the plasma, e.g. powder, liquid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
    • B05B7/22—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed electrically, magnetically or electromagnetically, e.g. by arc
    • B05B7/222—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed electrically, magnetically or electromagnetically, e.g. by arc using an arc
    • B05B7/226—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed electrically, magnetically or electromagnetically, e.g. by arc using an arc the material being originally a particulate material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/20—Control lever and linkage systems
    • Y10T74/20576—Elements
    • Y10T74/20582—Levers

Definitions

  • FIG. 4A I ELECTRICAL PLASMA-JET SPRAY TORCH AND METHOD Filed June13. 1961 J. W. WINZELER ETAL 2 Sheets-Sheet 1 FIG. 4A
  • An object of the invention is to provide a method and apparatus for effecting spraying onto a substrate of mate rials, including metals, ceramics and mixtures thereof, which melt at temperatures ranging from several hundred degrees F. to thirty thousand degrees F.
  • a further object is to provide a method and apparatus for effecting spray-sintering or alloying of materials, and which is characterized by extremely high deposition rates.
  • a further object is to provide an apparatus and method for effecting discharge of plasma at an angle, including a ninety-degree angle, to the axis of a plasma-jet torch, without rendering the plasma density dis-uniform and without resulting in deposition of powder in the torch.
  • An additional object is to provide a method and apparatus for adjusting the rear electrode of an electrical plasma-jet torch in relation to the powder-introduction port in the front electrode thereof, thereby permitting a single torch to be employed for different gases and for difierent materials having widely-varying melting points.
  • FIGURE 1 is a central sectional view illustrating an electrical plasma-jet spray torch constructed in accordance with the present invention
  • FIGURE 2 is a transverse section taken on line 2-2 of FIGURE 1;
  • FIGURE 3 is a transverse section taken on line 3-3 of FIGURE 1;
  • FIGURES 4A, 4B and 4C are fragmentary sectional views illustrating various electrode adjustments to adapt the torch for different materials and different gases;
  • FIGURE 5 is a central sectional view schematically illustrating an electrical plasma-jet spray torch constructed in accordance with a second embodiment of the invention, wherein the plasma is ejected at approximately a forty-five degree angle to the axis of the torch;
  • FIGURE 6 is a sectional view on line 6-6 of FIG- URE 5;
  • FIGURE 7 is a fragmentary sectional View corresponding generally to FIGURE 5 but illustrating a torch wherein the plasma-jet is ejected at approximately a ninety-degree angle to the torch axis.
  • the spray torch is illustrated to comprise a unitary casing and handle 10 formed of a suitable insulating plastic.
  • the handle portion of element It) is hollow and is sufficiently large to receive conduits leading from suitable sources of current, water, gas and spray material.
  • the casing is provided with a suitable metal shield 11 between the plasma jet 12 and the handle, such shield serving to protect from the intense heat of the plasma jet the hand of the operator holding the apparatus.
  • the apparatus further comprises an insulating body 13, preferably formed of a suitable plastic such as a phenolic, having a central flange portion 14 the cylindrical outer wall of which abuts the interior cylindrical wall of casing 10.
  • a front housing element 15 Abutted against the forward surface of flange portion 14 is a front housing element 15 having a generally annular shape.
  • Such element may be formed of brass or other suitable electrical conductor.
  • Abutted against the rear surface of flange portion 14 is the rim of a generally cup-shaped rear housing element 16 which is also formed of brass or other suitable conductor.
  • the stem portion 19 of the front electrode extends inwardly toward the rear housing element, having a flanged portion 29 which abuts the inner surface 21 of the phenolic body 13.
  • Such inner surface 21 is cylindrical in shape and defines the outer portion of a vortex chamber 23 into which gas is introduced tangentially as will be stated hereinafter.
  • the front portion of such vortex chamber is defined by stem 19, including its flange 20, whereas the rear portion of the chamber is defined by a disc 24 formed of a suitable insulating material.
  • the vortex chamber 23 communicates with, and is coaxial with, a nozzle passage 25 which is bored centrally through the nozzle electrode.
  • nozzle passage 25 permits discharge of gas from the vortex chamber 23 to the ambient atmosphere and in the form of the plasma jet 12, it being understood that the temperature of the plasma jet depends upon several factors including the location and magnitude of an electric are 26 which is maintained between the interior wall of nozzle passage 25 and the tip of a rear electrode assembly next to be described.
  • the rear electrode assembly comprises an externallythreaded adjustment shaft or rod 28 formed of copper or other suitable conductor, such shaft or rod being threaded into an internally-threaded bore through a stem portion 29 of the rear housing element 16.
  • Soldered coaxially at the extreme front end of the threaded shaft 28 is a rear electrode rod 30 preferably formed of thoriated tungsten.
  • the rod 3% has a diameter substantially smaller than the nozzle passage 25 with which it is coaxial, so that the vertically-flowing gas may pass forwardly from chamber 23 to create the plasma jet 12.
  • An insulating adjustment knob 31 is non-rotatably connected through a knob 31 operates through the shaft 28 to move the tip of electrode rod 39 either forwardly or rearwardly.
  • a lock knob 33 preferably formed of a suitable insulating plastic, is internally threaded to mate with the outer end of adjustment shaft 28, and is also bored to slidably receive the rod 32.
  • An inner or stem portion 34 of knob 33 extends slidably through casing 10 and abuts the outer surface of rear housing 16.
  • the threads of shaft 28 may be caused to have a somewhat different or varying pitch (or other characteristic) in comparison to the internal threads of stem portion 29, so that the shaft 23 may not be rotated except with difficulty.
  • Such an arrangement maintains the threads of elements 2% and 29 in close abutment at all times, and insures against arcing therebetween. It follows that adjustment of the shaft 28 and thus of rear electrode rod 3i? is rendered possible during operation of the torch.
  • the stem portion 29 of the rear housing extends through a bore in body 13, and also through a somewhat smaller opening in disc 24, to the vortex chamber 23.
  • a counterbore 36 is provided around the stem 29, inwardly adjacent disc 24, and communicates through passages 37 with a coolant chamber 38 which is defined by the interior surfaces of the rear housing element 16 and by the rear radial surface of body 13.
  • a second coolant chamber 39 is defined around the nozzle passage by stem 1% '(ineluding its flange 2%), by the front edge or rim of body l3, and by the interior surface of front housing 15.
  • the main coolant chambers 33 and 39 communicate with each other through a passage 41 which extends through body 13 radially-outwardly of vortex chamber 23.
  • the passages 3'7 permit circulation of water from the rear coolant chamber 38 to the annulus formed by counterbore 36, so that the forward portion of stem 29 is cooled.
  • a suitable source (or sources) of both current and water is indicated schematically at 43.
  • Such source is connected through waterconducting cables 44 and (such as insulating plastic water conduits containing large electrical conductors) to the front and rear housing elements 15 and 16, respectively.
  • Water is thus fed from source 43 to coolant chamber 39 in the front electrode, from which it flows through passage 41 to rear coolant chamber 3% and the associated counterbore 36, after which it discharges through the cable 45'to a suitable drain.
  • the electrical circuit comprises current and water source 43, cable 44, front housing element 15, front electrode 18, arc 26, rear electrode rod 30, adjustment shaft 28, rear housing element l6, and cable 45 back to source 43.
  • the current source is normally a DC. source adapted to deliver very large currents at relatively low voltages.
  • the polarity of the source is normally such that nozzle electrode 18 is positive, and rear electrode rod 30 is negative.
  • a suitable source 46 of gas under pressure is schematically indicated in FIGURE 1, being connected through a conduit 47 to a passage 48 (FIGURE 2) which extends through body 13 and is tangential to the gas vortex chamber 23. Gas is thus introduced from source 46 into the chamber, where it whirls at substantial velocity and then passes forwardly through nozzle passage 25 in a vortical or helical manner around electrode rod 30.
  • Powder sources 50 and 51 are connected, respectively, to conduits 52 and 53 which extend through the handle portion of casing It) to passages or ports 54 and 55 (FIG- URE 3) in front electrode 18. Passages 5d and 55 compassage to effect gas-constriction of the arc and to result erally in a single plane perpendicular to the axis of passage 25.
  • Such plane is spaced a short distance from the forward radial surface of electrode 13, the distance being insufficient to result in deposition of spray material in the outer or forward end of passage 25.
  • the passages 54 and 55, at least at their points adjacent passage 25, are substantially radial to the axis thereof.
  • the passages 54 and 55 are close to each other, or separated by only a small angle as shown in FIGURE 3. This minimizes turbulence, and prevents splitting of the plasma jet.
  • Each of the powder sources 59 and 51 includes a suitable source of propellant gas, and means to mix such gas with the powder, so that the powder is propelled by the gas through the associated conduit and into nozzle passage 25.
  • the propellant gas in each source may be introduced into a chamber containing spray powder, so that a portion of the powder becomes entrained in the gas and is carried thereby to the nozzle Cir passage.
  • wire-feed devices may be employed to introduce consumable wires of spray material into the plasma jet, through passages 54 and 55.
  • the remaining component of the torch comprises a spark plug element 57 which is threaded or force-fit into phenolic body 13, being illustrated as inclined toward the inner surface of nozzle electrode 18.
  • a lock nut 58 is threaded over the outer portion of spark plug 57 and is adapted to maintain the same in the desired adjusted position.
  • the spark plug cooperates with front electrode 18 in generating a spark in vortex chamber 23, so that the gas therein becomes ionized and may be employed to initiate an are between electrode rod 30 and the wall of nozzle passage 25.
  • Electric circuitry for accomplishing this result is described and claimed in co-pending application Serial No. 39,709, filed June 29, 1960, for Low- Voltage System for Initiating an Electric Arc, inventor John W. Winzeler.
  • the method comprises providing a high-current low-voltage electric are entirely within a nozzle passage, passing gas through such passage to effect gas-construction of the arc and to result in generation of a plasma jet, and injecting spray material into the jet at a point downstream from the downstream footpoint of the are, such material being injected along a plurality of paths.
  • spray material is introduced into the arc, that is to say upstream from the downstream footpoint of the arc, various undesired results occur, including vaporization of the spray material as distinguished from melting thereof.
  • the flow velocity of powder-propellant gas may be greatly reduced, so that the powder is not blown through the jet but instead is heated as desired. It is to be understood (as indicated previously) that more than two powder-introduction ports may be employed, the number varying with factors including the desired number of spray components to be introduced.
  • a plurality of powder sources 5b and 51, or any desired number, are employed as previously indicated.
  • One reason for this is that it has been discovered that if powder is introduced from a single source into an annulus surrounding the nozzle passage, such annulus communicating through a plurality of passages with the nozzle passage, substantially all of the powder will pass through only one of such passages.
  • special powderpassage configurations are employed in the vicinity of the nozzle passage, it is preferred that separate powder sources be employed for thevarious powder-introduction passages or ports, such as 54 and 55.
  • a separate powder is supplied by a each of the sources 5% and 51 or by additional sources, not shown. It has previously been the practice, with modern plasma-jet torches of the constricted-arc type, to effect alloying or sintering by mixing powdered ingredients and then introducing them from a single source into the plasma-jet. Applicants have discovered that improved. alloying or sintering is achieved, with less difli- It has been found that if the culty, by causing the mixture to occur in the jet itself instead of in the powder hoppers. Various metals may thus be alloyed or sintered, as well as mixtures of metals and ceramics or the like (cermets).
  • the rear electrode 30 of the torch is adjusted in relation to the plane of the powder-introduction passages or ports 54 and 55, and in accordance with the following two factors: (a) the gas which is introduced into the vortex chamber 23, and (b) the melting point or points of the powder introduced through passages 54 and 55.
  • the downstream footpoint of the are 26 is caused to rest immediately adjacent the upstream edges of the passages 54 and 55, that is to say in the plane (perpendicular to the axis of passage 25) of such upstream edges.
  • the above may be accomplished, regardless of the gas which is employed, by loosening the lock knob or nut 33 and then rotating knob 31 to adjust the axial position of back electrode 30 in relation to the above-indicated plane.
  • the arc gas is argon
  • the back electrode is adjusted until its tip is relatively close to such plane, as indicated in FIGURES l and 4A.
  • the arc gas is a gas such as nitrogen
  • the electrode is retracted to the position indicated in FIGURE 4C, the are 26 then being longer because of the characteristics of the gas.
  • helium, hydrogen or other gases, or various mixtures of gases may also be employed.
  • the method also comprises adjusting the back electrode 30 rearwardly sufiiciently far that the downstream footpoint is located a substantial distance upstream from the passages 54 and 55, for example at the point indicated in FIGURE 43.
  • This permits the introduction through such passages 54 and 55, etc., of low melting-point materials such as zinc, lead and even soft solder.
  • materials such as tungsten carbide, hafnium carbide, zirconium and alumina may be sprayed.
  • materials melting as low as 200 to 300 degrees F. may be sprayed, while at the other end of the scale the torch will spray any material which melts at a temperature lower than its disintegration temperature. Stated otherwise, the torch range is from 200 or 300 degrees F. up to 30,000 degrees F.
  • the are 26 is constricted and stabilized by the vortically-flowing gas, and furthermore that the downstream footpoint of the are 26 is rotated by the vortically-fiowing gas instead of burning in at one point of the wall of the nozzle passage. Also, and very importantly, the vortical gas fiow renders much less critical, as compared to axial flow, the requirement that the electrode rod 30 be concentric with nozzle passage 25.
  • the argon, nitrogen, or other suitable gas (preferably inert) is introduced tangentially into vortex chamber 23 from the gas source 46, through conduit 47.
  • the gas then flows vortically and forwardly around back electrode rod 30 and around the are 26 to effect constriction and stabilization of the latter along the axis of the passage 25.
  • the downstream portion of the arc bends radiallyoutwardly and enters the nozzle passage rearwardly of the plane of passages 54 and 55, as indicated in FIGURES l and 4.
  • a typical torch for this purpose (and which may also be employed for the specific examples stated below) has a nozzle passage 25 the diameter of which is one-quarter inch, and a back electrode rod 30 the diameter of which is one-eighth inch.
  • Each of the powder-introduction passages 54 and 55 may have a diameter of one-tenth to one-eighth inch.
  • the are current is set at 600 amperes, the arc voltage being about 25 volts.
  • argon argon propellant gas
  • passage 48 Approximately 0.3 c.f.m. argon propellant gas is used with each of the powder sources 50 and 51.
  • powderpropellant gas is passed through chambers containing the powdered aluminum oxide, so that the powder becomes entrained in the gas and is thus injected into the plasma jet 12. The oxide is thus melted and deposits on the substrate S.
  • the same torch may be employed to spray tungsten, the current being 500 amperes at about 26 or 27 volts.
  • the flow of arc gas (introduced through passage 48) may be increased slightly, so that it is between 1.1 and 1.2 c.f.m.
  • the flow of propellant gas employed with each powder source 50 and 51 may be increased slightly, to 0.4 or 0.5 c.f.rn.
  • the axial position of back electrode 30 is so adjusted that the downstream footpoint of the arc is located rearwardly adjacent the plane of passages 54 and 55, as shown in FIGURE 1 and in FIGURES 4A and 4C.
  • a cermet composed of aluminum oxide and tungsten may be sprayed.
  • Aluminum oxide is delivered from one of the powder sources 5'0, and tungsten from the other powder source 51.
  • the current may be intermediate, for example 550 amperes.
  • the rate of propellant gas flow may also be intermediate that of the two previous specific examples, namely 0.35 c.f.m.
  • FIGURES 5 and 6 illustrate a plasma-jet spray torch system which may be substantially identical to that described relative to FIGURES 1-4, except that the electrodes are adapted to cause the arc and the plasma jet to extend at an angle oblique to the back electrode.
  • Corresponding reference numerals have been applied to parts corresponding to those of FIGURES 14, whereas modified components have been given reference numerals corresponding to those of FIGURES 14 but followed in each instance by the letter a.
  • the nozzle passage illustrated in FIGURE 5 is denoted 25a, having a frustoconical portion which is coaxial with the torch axis, and having a cylindrical portion which extends from the small end of the frustoconical portion at an oblique angle relative thereto.
  • the rear electrode 30a is also illustrated as being conical, and projects into the nozzle passage 25a coaxially with the frustoconical portion thereof.
  • the front or nozzle electrode 18a also contains powder-introduction passages such as are indicated at 55a, only one such passage and the corresponding powder source 51 being illustrated.
  • the back electrode 30:: is so adjusted that the downstream footpoint of arc 26 strikes in the cylindrical (oblique) portion of nozzle passage 25a.
  • the arc itself strikes around a corner, having its upstream footpoint at the tip of a stick-shaped back electrode disposed axially of the torch, and its downstream footpoint striking to the wall of a passage portion which is oblique to the torch axis.
  • the arc itself turns the corner so that there is no need to deflect the plasma.
  • adjustment of the back electrode 30a may be employed to cause the downstream arc footpoint to be moved upstream from the passages 55a, etc, for purposes previously described relative to FIG- URE 43.
  • the arc gas still follows a vortical or helical path when it flows through the cylindrical (oblique) portion of nozzle passage 25a.
  • the part of the arc in such cylindrical portion is vortex stabilized, and the downstream footpoint of the arc is rotated as desired and in order to prevent its burning into the wall of the nozzle passage.
  • FIGURES -6 is highly useful in spraying relatively inaccessible surfaces such as at the interiors of rocket nozzles, the interiors of various containers, etc.
  • An interior surface of one such object is indicated at S in FIGURE 5.
  • FIGURE 7 illustrates schematically a torch which (except as will be stated) may be identical to that of FIG- URES l6, but which need not incorporate the adjustable rear electrode.
  • the nozzle passage contains a first cylindrical portion which is coaxial with the back electrode and a second cylindrical portion which is approximately at a right angle relative to the first cylindrical portion.
  • the back electrode 3% extends axially of the torch, and has a generally spherical tip 60 the center of which is coaxial with the downstream (second) cylindrical portion of nozzle passage 25b.
  • Powder passages, such as at are provided through the nozzle electrode 18b to inject powder into the downstream (second) cylindrical portion of the nozzle passage.
  • the spacing between the spherical or ball-shaped electrode end and the powderintroduction ports is made such that the arc 26 will strike the nozzle wall at a point upstream from such powderintroduction ports, for the desired gas (such as argon).
  • the gas is introduced tangentially into vortex chamber 23, such gas flowing vortically or helically around back electrode dill) and in the upstream or first portion of the nozzle passage.
  • the gas continues to flow vertically or helically after it has turned the right-angled corner into the downstream or second portion of the nozzle passage, so that the are 26 is stabilized by the gas.
  • the downstream footpoint of the arc 26 is rotated as desired.
  • a plasma jet 12b which extends generally at right angles to the torch axis, and which may be employed to coat a substrate such as is indicated at S.
  • the end wall of the upstream cylindrical portion of the nozzle passage is generally spherical, being concentric with the ball 60.
  • FIGURES 5 and 7 Only one powder source is illustrated in FIGURES 5 and 7, it is to be understood that a plurality are employed for the reasons stated previously relative to the embodiment of FIGURES 1-4. It is emphasized that, in the embodiment of FIGURE 7 as in that of FIGURES 5-6, the arc itself strikes at an angle to the axis of the torch, which is a situation distinctly different from that which occurs when only plasma is deflected after being generated by an arc.
  • a back electrode providing a nozzle electrode having a nozzle passage therethrough, said nozzle passage having at least a downstream portion which extends at an angle to the axis of said back electrode, maintaining a high-current low-voltage electric arc generally longitudinally of said passage between said back electrode and a predetermined portion of the wall of said passage, said predetermined portion of said passage wall being located in said downstream portion of said nozzle passage whereby said are extends at an angle to said back electrode, effecting flow of gas through said passage and out the outlet end thereof in a manner effecting stabilization and gas-constriction of said are to a smaller cross- .scctional area than it would normally occupy in space, :said are heating said gas to create a plasma jet downstream from said predetermined portion, injecting into said plasma jet through a first material-injection port and at an axial location downstream from said predetermined portion a spray powder adapted to be melted by said plasma jet, and injecting into said plasma jet at generally said axial location and through a second material-
  • An electrical plasma-jet spray torch which-comprises a metal nozzle electrode having a nozzle passage therethrough, a metal back electrode having an elongated portion disposed in said nozzle passage radially inwardly from the wall of said nozzle passage, said nozzle passage having at least a portion which extends at an oblique angle to the axis of said back electrode, the tip of said elongated portion of said back electrode being spaced a substantial distance from the outlet end of said nozzle passage, means to effect flow of gas through said nozzle passage around said elongated portion and thence out the outlet end of said nozzle passage, means to maintain a high-current low-voltage electric arc in said nozzle passage between said tip and the wall of said oblique portion of said nozzle passage at a region upstream from said outlet end thereof, whereby said arc is caused to strike around a corner in said nozzle passage, said are effecting heating of said gas to create a plasma jet which passes out said outlet end of said nozzle passage, means to introduce spray material into
  • An electrical plasma-jet spray torch which comprises a metal nozzle electrode having a nozzle passage therethrough, a metal back electrode having an elongated portion disposed in said nozzle passage radially inwardly from the wall of said nozzle passage, the tip of said back electrode portion being spaced a substantial distance from the outlet end of said nozzle passage, means to effect flow of gas through said nozzle passage around said elongated portion of said back electrode and thence.
  • An electrical plasma-jet torch adapted to discharge plasma at an angle to the longitudinal axis of the torch, which comprises wall means to define a nozzle passage, an elongated back electrode disposed at substantially a right angle to at least a portion of said nozzle passage, said back electrode having an arcing portion at one end thereof and generally on the axis of said nozzle passage, means to maintain an electric are from said arcing portion of said back electrode through at least part of said portion of said nozzle passage, said are striking to the wall of said nozzle passage portion, and means to effect flow of gas along said back electrode and thence through said nozzle passage, said gas being heated by said are to create a plasma jet which emanates from the torch at an angle to said back electrode.
  • An electrical plasma-jet torch adapted to discharge plasma at an angle to the longitudinal axis of the torch, which comprises wall means to define a nozzle passage, an elongated back electrode disposed at an angle to at least a portion of said nozzle passage, said back electrode having a generally spherical arcing portion at one end thereof, said spherical arcing portion of said back electrode being disposed coaxially of a passage which extends at a right angle to said nozzle passage and communicates therewith at said arcing portion, the end of said last-named passage being generally concentric With the surface of said arcing portion, means to maintain an electric arc from said arcing portion of said back electrode through at least part of said portion of said nozzle passage, said arc striking to the wall of said nozzle passage portion, and means to effect fiow of gas along said back electrode and thence through said nozzle passage, said gas being heated by said are to create a plasma jet which emanates from the torch at an angle to said back electrode.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Electromagnetism (AREA)
  • Nozzles (AREA)
  • Plasma Technology (AREA)
US126402A 1961-06-13 1961-06-13 Electrical plasma-jet spray torch and method Expired - Lifetime US3183337A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NL279638D NL279638A (sv) 1961-06-13
US126402A US3183337A (en) 1961-06-13 1961-06-13 Electrical plasma-jet spray torch and method
FR896746A FR1352815A (fr) 1961-06-13 1962-05-07 Pistolet électrique à jet de plasma et procédés y relatifs
GB22718/62A GB990533A (en) 1961-06-13 1962-06-13 Electrical spraying apparatus and methods

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US126402A US3183337A (en) 1961-06-13 1961-06-13 Electrical plasma-jet spray torch and method

Publications (1)

Publication Number Publication Date
US3183337A true US3183337A (en) 1965-05-11

Family

ID=22424620

Family Applications (1)

Application Number Title Priority Date Filing Date
US126402A Expired - Lifetime US3183337A (en) 1961-06-13 1961-06-13 Electrical plasma-jet spray torch and method

Country Status (3)

Country Link
US (1) US3183337A (sv)
GB (1) GB990533A (sv)
NL (1) NL279638A (sv)

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3280295A (en) * 1962-07-27 1966-10-18 Air Liquide Device for projecting pulverulent materials by means of a plasma torch
US3378391A (en) * 1962-12-20 1968-04-16 Giannini Scient Corp Method for coating plastics onto a substrate employing a plasma
US3425864A (en) * 1965-07-21 1969-02-04 Templeton Coal Co Method for making electric resistance heaters
US3529226A (en) * 1966-12-19 1970-09-15 Skinner Precision Ind Inc Tachometer speed control for a linear induction motor
US3591759A (en) * 1969-06-04 1971-07-06 Sealectro Corp Method of depositing heat fusible material and apparatus therefor
US3707615A (en) * 1971-11-12 1972-12-26 Metco Inc Nozzle for a plasma generator
US3751295A (en) * 1970-11-05 1973-08-07 Atomic Energy Commission Plasma arc sprayed modified alumina high emittance coatings for noble metals
US3753666A (en) * 1967-12-04 1973-08-21 Trw Inc Noble metals having a high emittance coating of iron titanate
US3839618A (en) * 1972-01-03 1974-10-01 Geotel Inc Method and apparatus for effecting high-energy dynamic coating of substrates
US3854993A (en) * 1971-12-08 1974-12-17 Monsanto Res Corp Microwave circulator
US3914573A (en) * 1971-05-17 1975-10-21 Geotel Inc Coating heat softened particles by projection in a plasma stream of Mach 1 to Mach 3 velocity
US3947617A (en) * 1974-07-08 1976-03-30 Eppco Coated container
US3958097A (en) * 1974-05-30 1976-05-18 Metco, Inc. Plasma flame-spraying process employing supersonic gaseous streams
US3962486A (en) * 1974-01-02 1976-06-08 Eppco Novel process for applying thermoset resinous coatings
EP0171793A2 (de) * 1984-08-17 1986-02-19 Plasmainvent AG Plasmaspritzbrenner mit gekühlter Elektrode und Brennerdüse
EP0195409A2 (en) * 1985-03-21 1986-09-24 United Overlay Systems Plasma transfer welded arc torch
EP0271032A2 (de) * 1986-12-11 1988-06-15 Castolin S.A. Verfahren zur Aufbringung einer Innenbeschichtung in Rohre od. dgl. Hohlräume engen Querschnittes sowie Plasmaspritzbrenner dafür
DE4228064A1 (de) * 1992-08-24 1994-03-03 Plasma Technik Ag Plasmaspritzgerät
US5374802A (en) * 1992-12-31 1994-12-20 Osram Sylvania Inc. Vortex arc generator and method of controlling the length of the arc
EP0766502A1 (en) * 1995-09-28 1997-04-02 Sulzer Metco (Irvine) Inc. Single cathode plasma gun with powder feed along central axis of exit barrel
US6137078A (en) * 1998-12-21 2000-10-24 Sulzer Metco Ag Nozzle for use in a torch head of a plasma torch apparatus
US6271497B1 (en) * 1999-04-09 2001-08-07 Tatras, Inc. Plasma torch head and method for making the same
WO2006003374A3 (en) * 2004-06-30 2006-08-24 Boc Group Plc Method and apparatus for heating a gas stream
US9211603B2 (en) 2012-01-31 2015-12-15 The Esab Group, Inc. Plasma gouging torch and angled nozzle therefor

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5518178A (en) * 1994-03-02 1996-05-21 Sermatech International Inc. Thermal spray nozzle method for producing rough thermal spray coatings and coatings produced
US5858469A (en) * 1995-11-30 1999-01-12 Sermatech International, Inc. Method and apparatus for applying coatings using a nozzle assembly having passageways of differing diameter

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1002721A (en) * 1910-08-09 1911-09-05 Hub Machine Welding & Contracting Co Electric-arc furnace-heater.
US2806124A (en) * 1955-07-26 1957-09-10 Union Carbide Corp Arc torch and process
US2858411A (en) * 1955-10-11 1958-10-28 Union Carbide Corp Arc torch and process
US2973426A (en) * 1956-06-05 1961-02-28 Joseph J Casey Electric-arc torch
US2982845A (en) * 1958-07-11 1961-05-02 Union Carbide Corp Electric arc spraying
US3104310A (en) * 1959-08-24 1963-09-17 Nat Res Dev High temperature torches

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1002721A (en) * 1910-08-09 1911-09-05 Hub Machine Welding & Contracting Co Electric-arc furnace-heater.
US2806124A (en) * 1955-07-26 1957-09-10 Union Carbide Corp Arc torch and process
US2858411A (en) * 1955-10-11 1958-10-28 Union Carbide Corp Arc torch and process
US2973426A (en) * 1956-06-05 1961-02-28 Joseph J Casey Electric-arc torch
US2982845A (en) * 1958-07-11 1961-05-02 Union Carbide Corp Electric arc spraying
US3104310A (en) * 1959-08-24 1963-09-17 Nat Res Dev High temperature torches

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3280295A (en) * 1962-07-27 1966-10-18 Air Liquide Device for projecting pulverulent materials by means of a plasma torch
US3378391A (en) * 1962-12-20 1968-04-16 Giannini Scient Corp Method for coating plastics onto a substrate employing a plasma
US3425864A (en) * 1965-07-21 1969-02-04 Templeton Coal Co Method for making electric resistance heaters
US3529226A (en) * 1966-12-19 1970-09-15 Skinner Precision Ind Inc Tachometer speed control for a linear induction motor
US3753666A (en) * 1967-12-04 1973-08-21 Trw Inc Noble metals having a high emittance coating of iron titanate
US3591759A (en) * 1969-06-04 1971-07-06 Sealectro Corp Method of depositing heat fusible material and apparatus therefor
US3751295A (en) * 1970-11-05 1973-08-07 Atomic Energy Commission Plasma arc sprayed modified alumina high emittance coatings for noble metals
US3914573A (en) * 1971-05-17 1975-10-21 Geotel Inc Coating heat softened particles by projection in a plasma stream of Mach 1 to Mach 3 velocity
US3707615A (en) * 1971-11-12 1972-12-26 Metco Inc Nozzle for a plasma generator
DE2254504A1 (de) * 1971-11-12 1973-05-17 Metco Inc Winkelduesenelektrode fuer plasmageneratoren
FR2159271A1 (sv) * 1971-11-12 1973-06-22 Metco Inc
US3854993A (en) * 1971-12-08 1974-12-17 Monsanto Res Corp Microwave circulator
US3839618A (en) * 1972-01-03 1974-10-01 Geotel Inc Method and apparatus for effecting high-energy dynamic coating of substrates
US3962486A (en) * 1974-01-02 1976-06-08 Eppco Novel process for applying thermoset resinous coatings
US3958097A (en) * 1974-05-30 1976-05-18 Metco, Inc. Plasma flame-spraying process employing supersonic gaseous streams
US3947617A (en) * 1974-07-08 1976-03-30 Eppco Coated container
EP0171793A2 (de) * 1984-08-17 1986-02-19 Plasmainvent AG Plasmaspritzbrenner mit gekühlter Elektrode und Brennerdüse
DE3430383A1 (de) * 1984-08-17 1986-02-27 Plasmainvent AG, Zug Plasmaspritzbrenner fuer innenbeschichtungen
EP0171793A3 (en) * 1984-08-17 1987-09-23 Plasmainvent Ag Plasma spray torch for internal coatings
EP0195409A2 (en) * 1985-03-21 1986-09-24 United Overlay Systems Plasma transfer welded arc torch
EP0195409A3 (en) * 1985-03-21 1987-05-06 United Overlay Systems Plasma transfer welded arc torch
EP0271032A3 (en) * 1986-12-11 1990-01-10 Castolin S.A. Method for depositing an inner coating in tubes or similar hollow spaces with a small diameter, and plasma spray gun therefor
DE3642375A1 (de) * 1986-12-11 1988-06-23 Castolin Sa Verfahren zur aufbringung einer innenbeschichtung in rohre od. dgl. hohlraeume engen querschnittes sowie plasmaspritzbrenner dafuer
EP0271032A2 (de) * 1986-12-11 1988-06-15 Castolin S.A. Verfahren zur Aufbringung einer Innenbeschichtung in Rohre od. dgl. Hohlräume engen Querschnittes sowie Plasmaspritzbrenner dafür
DE4228064A1 (de) * 1992-08-24 1994-03-03 Plasma Technik Ag Plasmaspritzgerät
US5374802A (en) * 1992-12-31 1994-12-20 Osram Sylvania Inc. Vortex arc generator and method of controlling the length of the arc
EP0766502A1 (en) * 1995-09-28 1997-04-02 Sulzer Metco (Irvine) Inc. Single cathode plasma gun with powder feed along central axis of exit barrel
US6137078A (en) * 1998-12-21 2000-10-24 Sulzer Metco Ag Nozzle for use in a torch head of a plasma torch apparatus
US6271497B1 (en) * 1999-04-09 2001-08-07 Tatras, Inc. Plasma torch head and method for making the same
WO2006003374A3 (en) * 2004-06-30 2006-08-24 Boc Group Plc Method and apparatus for heating a gas stream
US9211603B2 (en) 2012-01-31 2015-12-15 The Esab Group, Inc. Plasma gouging torch and angled nozzle therefor

Also Published As

Publication number Publication date
NL279638A (sv)
GB990533A (en) 1965-04-28

Similar Documents

Publication Publication Date Title
US3183337A (en) Electrical plasma-jet spray torch and method
US3312566A (en) Rod-feed torch apparatus and method
US3179784A (en) Method and apparatus for spraying plastics
US2960594A (en) Plasma flame generator
US3149222A (en) Electrical plasma-jet apparatus and method incorporating multiple electrodes
US3313908A (en) Electrical plasma-torch apparatus and method for applying coatings onto substrates
US3179782A (en) Plasma flame jet spray gun with a controlled arc region
US3071678A (en) Arc welding process and apparatus
US5420391A (en) Plasma torch with axial injection of feedstock
US4841114A (en) High-velocity controlled-temperature plasma spray method and apparatus
US3387110A (en) Apparatus for uniform feeding of powder into a plasma spray gun
KR930005953B1 (ko) 개량 플라즈마 아아크 토오치 시동방법
US3264508A (en) Plasma torch
US3075065A (en) Hyperthermal tunnel apparatus and electrical plasma-jet torch incorporated therein
US3914573A (en) Coating heat softened particles by projection in a plasma stream of Mach 1 to Mach 3 velocity
US6706993B1 (en) Small bore PTWA thermal spraygun
US3077108A (en) Supersonic hot gas stream generating apparatus and method
US4916273A (en) High-velocity controlled-temperature plasma spray method
US3823302A (en) Apparatus and method for plasma spraying
US3064114A (en) Apparatus and process for spraying molten metal
US2806124A (en) Arc torch and process
US3246114A (en) Process for plasma flame formation
US3707615A (en) Nozzle for a plasma generator
US20100200549A1 (en) Microplasma Spray Apparatus and Method for Coating Articles Using Same
US3304402A (en) Plasma flame powder spray gun