US3818174A - Long arc column forming plasma generator - Google Patents
Long arc column forming plasma generator Download PDFInfo
- Publication number
- US3818174A US3818174A US00305092A US30509272A US3818174A US 3818174 A US3818174 A US 3818174A US 00305092 A US00305092 A US 00305092A US 30509272 A US30509272 A US 30509272A US 3818174 A US3818174 A US 3818174A
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- United States
- Prior art keywords
- nozzle
- housing
- electrode
- arc
- section
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-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K10/00—Welding or cutting by means of a plasma
-
- 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
- Such long arc column forming plasma generators as described in the above cited reference and elsewhere in the prior art, have characteristically included a cylindrical internal electrode forming a gas vortex chamber within itself, a gas directing nozzle located forwardly of and insulated from the cylindrical electrode, and a cylindrical outer housing secured to the nozzle and enclosing the electrode. That portion of the cylindrical outer housing residing in proximity to the nozzle has in the past been electrically connected to the nozzle and susceptible to damage from so-called double arcing of the plasma column.
- Double arcing occurs in one case when one arc is formed inside the generator between the internal electrode and the nozzle, and another are is formed outside the generator between the nozzle and a workpiece also in the electrical circuit.
- double arcing may occur, for example, during scrap steel melting when a transferred plasma arc is formed between the internal electrode and a metal scrap and another return are is formed between another portion of the scrap and the generator housing. In either case, substantial damage to the nozzle, housing or both nearly always results.
- the method and apparatus of the present invention are directed to an improved long arc column forming plasma generator based on the long are column forming plasma generator taught in the above cited U.S. Pat. No. 3,673,375.
- An improved long are column forming plasma generator according to the invention is primarily directed at the abatement of double arcing of the plasma column and comprises a two part cylindrical insulated and water cooled housing and an improved nozzle face configuration.
- One member of the two part housing is adapted to overlay the rearward or mounting end of the generator, while a second housing member is adapted to overlay the forward or nozzle end of the generator.
- the respective housing members are adapted to be electrically insulated from each other as well as from the generator nozzle and internal generator parts.
- the plasma column is in no way attracted to the housing member overlaying the nozzle because of its isolation from the electrical circuit. Double arcing to the housing is thus effectively prevented.
- the arc column in order for the arc column to double arc to the rear housing member or that housing in closest proximity to the mounting end of the generator, it must traverse the forward housing member by forming two external arcs simultaneously. The likelihood of this occurrence is very small.
- water cooling of the housing members further limits the possibility of a double arcing situation since an arc column will be attracted to hotter rather than cooler surfaces as is well-known.
- this invention contemplates the use of an aerodynamic nozzle face configuration which is adapted to cause a non-laminar flow of air across the nozzle face during operation of the arc column. The result is a greatly stabilized arc column and substantial reduction in double arcing and resulting damage to the nozzle.
- FIG. 1 is a partial cross sectional view of a long arc column forming plasma generator based on those of the prior art, which has been modified in accordance with the invention.
- FIGS. 2 and 3 show cases of the prior art in which destructive double arcing has been known to occur.
- FIG. 4 shows a prior art plasma generator in a typical insulated mounting in which the accumulation of kish has caused short circuiting across a prior art insulated mounting collar resulting in damage to the insulator as well as the generator.
- FIG. 5 is a detailed broken view of a plasma generator of the preferred embodiment.
- FIG. 6 is a somewhat enlarged cross sectional view showing an insulated joint employing Fibrefrax insulation according to the preferred embodiment.
- FIG. 1 an improved long arc column forming plasma generator constructed according to one embodiment of the present invention is generally designated 10.
- Such improved plasma generator is herein shown in simplified form to eliminate unnecessary and well-known internal construction details.
- the particular embodiment shown in FIG. 1 represents a plasma generator of the prior art which has been adapted to receive a two-part cylindrical housing 12 according to this invention.
- a plasma generator of the prior art has included a cylindrical internal electrode 13 and a gas directing nozzle 14 forwardly spaced and insulated from said electrode 13.
- Other conventional parts are included such as gas, water and electrical supplies.
- Known long are column forming plasma generators of the prior art have also included a one-piece cylindrical housing (not shown) secured to the nozzle 14.
- FIG. 1 of that patent which shows the described unitary housing.
- Such prior art housings have been in physical as well as electrical attachment with the nozzle and as previously mentioned any current above ground which the nozzle received by way of adouble arcing condition, later described in detail, was also passed through the entire housing.
- this invention provides a housing comprised of at least two separated and insulated members l8, 19 instead of the prior art unitary housing in order to prevent such double are induced current from being connected with such housing.
- a first cylindrical housing member 18 is adapted to be secured via an appropriate electrical insulator 24, to said nozzle 14.
- a second cylindrical housing member 19 is adapted to be located rearwardly of and slightly spaced from said first housing member 18. Additional electrical insulating material is adapted to line the space 26 formed at the joint 27 between housing members l8 and 19. Housing members 18 and 19 are preferably formed from stainless steel. Insulators 24 and 25 are preferably formed from Synthane insulating material and may assist in supporting housing members 18 and 19 in addition to providing electrical insulation therebetween. Additional internal support of insulator 25 and housing members 18 and 19 may be provided by radial support members 29. Finally, insulated separation of housing members'l8 and 19 from each other and from nozzle 14 enable the rearward housing member 19 to be grounded directly to furnace mountings or r the like.
- FIG. 2 a long are column forming plasma generator of the prior art, generally designated 38 is shown in a sidewall mounted operating position inside a conventional fumace 39 adapted for melting scrap metals 35.
- a plasma generator as previously stated normally includes a one-piece cylindrical steel housing 37 pysically and electrically connected to the nozzle 14 (shown in cutaway).
- the transferred plasma arc will follow an axis generally indicated by dashed line X. Quite often, however, the distance along axis X to a metal scrap may exceed the outer range of the transferred column due to a pocket in the scrap or sudden melting or shifting, for example.
- a double arc in this instance comprises an internal are 40 extending between internal electrode and nozzle 14, and an external are 41 extending between nozzle 14 and/or housing 38 and proximate scrap metal 35.
- an external are 41 often creeps rearward to encounter additional proximate metallic scrap as indicated by dashed line 42. Extensive damage to the housing 37 and the nozzle 14 nearly always results.
- FIG. 3 which shows a second typical case of double arcing
- a plasma column being generated along a nonnal axis is indicated at Z. Due to electrical connection throughout the scrap 35, current may return back to the generator housing 37 or nozzle 14 by forming an external arc 43 between the housing 37 and a proximate portion of the scrap indicated at 36. Are 43 being of shorter length than the are shown at Z may cause the are at Z to be extinguished and simultaneously therewith may cause an internal arc to form identical with 40 in FIG. 2. Again, substantial damage nearly always results.
- FIG. 4 a long are column forming plasma generator of the prior art is generally designated by numeral 41.
- Mounting of such generator in a furnace 39 has in the past required the use of insulated collars 43, linings and the like in order to prevent grounding of the generator housing 37 against the furnace walls 39'. Such grounding precludes normal operation of the arc circuit, in addition to creating a safety hazard to persons near the mountings.
- a stainless steel shell 45 has normally housed such insulated collar and retained it within an appropriate mounting aperture 46.
- a usual problem of such collars 43 when in use for prolonged periods of time is the gradual accumulation of kish generally represented by 48.
- Kish is widely known as a particulate substance resembling graphite, comprising carbon, iron and manganese and which often becomes airborne during iron smelting operations.
- a particulate substance resembling graphite comprising carbon, iron and manganese and which often becomes airborne during iron smelting operations.
- a long are column forming plasma generator utilizing a two part housing constructed and insulated in accordance with the first described embodiment is capable of being mounted directly to a furnace aperture without the usual insulated linings, because the rear housing portion of said generator is insulated at considerable distance (the length of forward housing member 18) away from nozzle 14.
- housing member 18 being in effect electrically floating prevents current originating in nozzle 14 from being conducted rearward to the generator mountings. Double arcing of the plasma column to the housing, damage and electrical shock hazard caused therefrom are thus effectively eliminated.
- a two-part housing comprises members 51 and 52.
- Each housing member 51, 52 is adapted for cooling by internal manifold structures 60, 61 which form passages 63 for the reception of coolant, e.g., water.
- internal electrode 55 has been adapted by manifold structure 64 for the reception of coolant as indicated at 65. Since the arc originates internally along a distance of internal electrode 55 indicated by D it is desirable to forceably cool this region especially whenthe generator is being operated in extremely high power applications.
- Manifold 64 has therefore been adapted to form a narrower passageway nearest the region designated D of internal electrode 55 than rearward of said region in order to accelerate the flow of coolant, e.g., water over the said critical region. Coolant is adapted to flow through manifold 64 in the directions indicated by arrows .68.
- Water cooling of the housing members 51, 52 has the effect of minimizing the possibility of double arcing to the housing due to the reduced surface temperature.
- Water cooling of the housing members as well as the internal electrode have the added advantage of prolonging the life of the parts in high temperature and power applications. While water cooling of the housing members 51, 52 as well as the internal electrode 55 is regarded as novel in the instant invention, the importance of water cooling of the nozzle 56 has been known in the art for sometime. It satisfies the needs of this invention to state that nozzle 56 is adapted by internal passages, indicated by dashed lines 71, to
- the face configuration of nozzle 56 has been adapted to include a somewhat annular shaped depression 66 formed near the center bore 69. Said depression has been adapted in the instant invention to prevent the laminar flow of air across the heretofore relatively flat nozzle face during operation of the arc column.
- Such laminar flow of air is diagramatically indicated by arrows 73, '74 in FIG. 1 wherein nozzle 14 exhibits a face configuration typical of the prior art long arc column forming plasma generators.
- air has been found to flow inward across the flat nozzle face and follow the curvature into the bore 69. Such flow of air has been found to contribute to internal arcing to the nozzle itself.
- This invention effectively breaks the laminar air flow by providing the undulations in the nozzle face 76 of the preferred em bodiment created by annular depression 66. Air now tends to circulate within the depression 66 as indicated by arrows 78. The drastic reduction of the flow of air into the bore 69 appears to enhance vortex stability of the plasma column since internal arcing is noticeably reduced.
- a further unique aspect of the invention relates to effectively insulating the various cooperating parts of this invention, i.e., housing members 51, 52 improved nozzle 56 and internal electrode 55 in such a manner as to permit greatly prolonged use of the plasma generator in extremely high temperature andpower applications and in the virtual absence of destructive double arcing.
- cylindrical insulator 81 is adapted to extend partially the length of the plasma generator and is adapted to supportively line housing members 51 and 52.
- a second cylindrical insulator 82 is adapted to extend partially the length of the plasma generator to supportively line the outside of the combined internal electrode 55 and water manifold structure 641.
- Insulator 82 is also adapted to line the spaces between nozzle 56 and internal electrode 55 which has in the past been lined with an annular insulator (See 21 FIG. 1) to prevent electrical short circuiting therebetween.
- Arc gas flow is adapted to bypass insulator82 of the preferred embodiment and is appropriately ducted through tubes 85 and channels 86, indicated by dashed lines, provided in nozzle 56.
- Insulators 81 and 82 are preferably formed from Synthane material and may be provided with threads 88, 89 for purposesof securement to nozzle 56. Instead of Synthane material which is available from Synthane Corporation, 1 River Road, Oaks, Pa.
- this invention contemplates employing Synthane or like forms of insulation in an enclosed manner by sealing exposed portions of insulator 81 with a so-called Fibrefrax refractory insulation 96, FIG. 6.
- a so-called Fibrefrax refractory insulation 96 FIG. 6.
- Such an insulating refractory is available from the Carborundum Company, Niagara Falls, NY, in a mortar-like refractory compound which solidifies when heat treated, becomes highly reflective, and extremely high temperatures.
- So-called Ram-90 insulating refractory material made by Har- 7 binson-walker Company of Pittsburgh, Pa. may also be employed.
- Curved recesses 91 are formed between the forward end of housing member 51 and nozzle 56, best shown in FIG. 6. Curved recesses 92 are also formed between the opposite end of housing member 51 and the forward end of housing member 52.
- housing member 52 preferably includes an integral end plate at the rearward end which consequently does not require insulated sealing by the Fibrefrax insulation. It is apparent that insulators 81 and 82 may be formed from many interlocking cylindrical pieces, that nozzle face 76 may employ various alternate configurations and that the invention housing may comprise two or more housing members and still be consistent with the intended breadth and scope of this invention.
- the concave recess 91 formed in nozzle 56 resides opposite a convex tip portion 91' of forward housing section 51 and that the annular void between recess 91 and tip portion 91 is filled with the insulating refractory material 90.
- Such a disposition of mated and spaced curved surfaces between the nozzle and housing eliminates any sharp points of electrical field concentrations on either nozzle or housing, makes the electrical field essentially uniform through the insulating refractory material 90 and thus avoids electrical breakdown between housing 51 and nozzle 56.
- the insulating refractory in this configuration is essentially locked into place once it has been heated.
- the curved recesses 92 act similarly.
- an external tubular thin wall housing fonned of a plurality of aligned tubular sections of electrically conducting material including a forward section extending from the discharge end of the apparatus rearwardly, each section including said forward section being electrically insulated from the next rearward section and to the extent that any section provides a point of double arc attachment each such section being further insulated from electrical 8 ground;
- a fluid cooled cylindrical shaped electrode centrally positioned and supported within said housing and having its forward end proximate the discharge end of the apparatus and its rearward end positioned to receive the usual plasma gas supply therein;
- a fluid cooled gas directing nozzle axially aligned with, forwardly spaced and insulated from both said electrode and housing forward section, said nozzle with said electrode providing a vortex forming chamber, said nozzle having an internal diameter designated C and a length designated B and with said electrode providing said vortex forming gas chamber of a width designated A, said dimension A being selected as the minimum width at which a vortex strength of 0.25 Mach is obtained when B is of minimum arc sustaining width and C is equal to the internal diameter of said electrode, and B a d C hav t e elat n-s iny? 2.0- fe the transferred mode and B/C 2 4 for the nontransferred mode;
- gas supply means for introducing an arc gas through said electrode into said chamber to produce a vortical flow in said chamber and nozzle;
- cooling fluid supply means for introducing a cooling fluid into said electrode and nozzle to cool the same.
- said nozzle having an annular depression formed in the forward end of said nozzle and in a form effective to prevent laminar flow in the space immediately adjacent the forward end of said nozzle and surrounding the plasma generated by said apparatus.
- said fluid cooled electrode includes fluid cooling passages proximate the forward internal are generating surface of said electrode formed in a manner adapted to provide a higher rateof heat removal from such surface than from the more rearward internal non-arc generating surface of said electrode.
Abstract
Description
Claims (7)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US00305092A US3818174A (en) | 1972-11-09 | 1972-11-09 | Long arc column forming plasma generator |
Applications Claiming Priority (1)
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US00305092A US3818174A (en) | 1972-11-09 | 1972-11-09 | Long arc column forming plasma generator |
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US3818174A true US3818174A (en) | 1974-06-18 |
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US00305092A Expired - Lifetime US3818174A (en) | 1972-11-09 | 1972-11-09 | Long arc column forming plasma generator |
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Cited By (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4067390A (en) * | 1976-07-06 | 1978-01-10 | Technology Application Services Corporation | Apparatus and method for the recovery of fuel products from subterranean deposits of carbonaceous matter using a plasma arc |
FR2539942A1 (en) * | 1983-01-21 | 1984-07-27 | Plasma Energy Corp | PLASMA GENERATOR AND METHOD OF OPERATION |
FR2556168A1 (en) * | 1983-12-02 | 1985-06-07 | Plasma Energy Corp | CONVERTIBLE PLASMA ARC TORCH, OF THE TYPE THAT CAN BE TRANSFORMED AT ITS PLACE OF USE |
FR2574165A1 (en) * | 1984-11-30 | 1986-06-06 | Plasma Energy Corp | ARC-PLASMA HEATING APPARATUS FOR HEATING LARGE QUANTITIES OF AIR, PARTICULARLY FOR DRYING RAW MATERIALS |
FR2581396A1 (en) * | 1985-05-03 | 1986-11-07 | Huron Valley Steel Corp | METHOD AND APPARATUS FOR SIMULTANEOUSLY SEPARATING VOLATILE METALS AND NON-VOLATILE METALS |
US4718477A (en) * | 1986-07-30 | 1988-01-12 | Plasma Energy Corporation | Apparatus and method for processing reactive metals |
US4891490A (en) * | 1987-04-29 | 1990-01-02 | Aerospatiale Societe Nationale Industrielle | Tubular electrode for plasma torch and plasma torch provided with such electrodes |
WO1992010325A1 (en) * | 1990-12-05 | 1992-06-25 | Hydro Quebec | Opening a taphole with a plasma torch |
US5233155A (en) * | 1988-11-07 | 1993-08-03 | General Electric Company | Elimination of strike-over in rf plasma guns |
US5362939A (en) * | 1993-12-01 | 1994-11-08 | Fluidyne Engineering Corporation | Convertible plasma arc torch and method of use |
US5756959A (en) * | 1996-10-28 | 1998-05-26 | Hypertherm, Inc. | Coolant tube for use in a liquid-cooled electrode disposed in a plasma arc torch |
US5880426A (en) * | 1996-08-28 | 1999-03-09 | Doryokuro Kakunenryo Kaihatsu Jigyodan | Indirectly-cooled plasma jet torch |
US6121571A (en) * | 1999-12-16 | 2000-09-19 | Trusi Technologies Llc | Plasma generator ignition circuit |
US6203661B1 (en) | 1999-12-07 | 2001-03-20 | Trusi Technologies, Llc | Brim and gas escape for non-contact wafer holder |
US6398823B1 (en) | 1999-12-07 | 2002-06-04 | Tru-Si Technologies, Inc. | Dynamic break for non-contact wafer holder |
US6402843B1 (en) | 1999-12-07 | 2002-06-11 | Trusi Technologies, Llc | Non-contact workpiece holder |
US20040200810A1 (en) * | 2003-04-11 | 2004-10-14 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US20070175870A1 (en) * | 2004-10-07 | 2007-08-02 | Phoenix Solutions Co. | Plasma arc collimator design and construction |
US20080116179A1 (en) * | 2003-04-11 | 2008-05-22 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US20110031224A1 (en) * | 2009-08-10 | 2011-02-10 | The Esab Group, Inc. | Retract start plasma torch with reversible coolant flow |
US8581496B2 (en) | 2011-07-29 | 2013-11-12 | Oaks Plasma, LLC. | Self-igniting long arc plasma torch |
JP2017516006A (en) * | 2014-05-15 | 2017-06-15 | ティッセンクルップ アクチェンゲゼルシャフト | How to make a borehole |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3097292A (en) * | 1959-11-14 | 1963-07-09 | Kralovopolska Slrojirna Zd Y C | Method and apparatus for the maintenance of the arc column in the core of a liquid vortex |
US3130292A (en) * | 1960-12-27 | 1964-04-21 | Union Carbide Corp | Arc torch apparatus for use in metal melting furnaces |
US3194941A (en) * | 1962-09-13 | 1965-07-13 | Union Carbide Corp | High voltage arc plasma generator |
US3221212A (en) * | 1961-10-27 | 1965-11-30 | Gen Electric | Plasma accelerator |
US3242305A (en) * | 1963-07-03 | 1966-03-22 | Union Carbide Corp | Pressure retract arc torch |
US3294953A (en) * | 1963-12-19 | 1966-12-27 | Air Reduction | Plasma torch electrode and assembly |
US3375392A (en) * | 1964-03-07 | 1968-03-26 | Brzozowski Wojciech | Plasma generator utilizing a ribbonshaped stream of gas |
US3588594A (en) * | 1968-01-19 | 1971-06-28 | Hitachi Ltd | Device for bending a plasma flame |
US3674978A (en) * | 1970-04-24 | 1972-07-04 | Messer Griesheim Gmbh | Torch, especially for plasma cutting |
-
1972
- 1972-11-09 US US00305092A patent/US3818174A/en not_active Expired - Lifetime
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3097292A (en) * | 1959-11-14 | 1963-07-09 | Kralovopolska Slrojirna Zd Y C | Method and apparatus for the maintenance of the arc column in the core of a liquid vortex |
US3130292A (en) * | 1960-12-27 | 1964-04-21 | Union Carbide Corp | Arc torch apparatus for use in metal melting furnaces |
US3221212A (en) * | 1961-10-27 | 1965-11-30 | Gen Electric | Plasma accelerator |
US3194941A (en) * | 1962-09-13 | 1965-07-13 | Union Carbide Corp | High voltage arc plasma generator |
US3242305A (en) * | 1963-07-03 | 1966-03-22 | Union Carbide Corp | Pressure retract arc torch |
US3294953A (en) * | 1963-12-19 | 1966-12-27 | Air Reduction | Plasma torch electrode and assembly |
US3375392A (en) * | 1964-03-07 | 1968-03-26 | Brzozowski Wojciech | Plasma generator utilizing a ribbonshaped stream of gas |
US3588594A (en) * | 1968-01-19 | 1971-06-28 | Hitachi Ltd | Device for bending a plasma flame |
US3674978A (en) * | 1970-04-24 | 1972-07-04 | Messer Griesheim Gmbh | Torch, especially for plasma cutting |
Cited By (38)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4067390A (en) * | 1976-07-06 | 1978-01-10 | Technology Application Services Corporation | Apparatus and method for the recovery of fuel products from subterranean deposits of carbonaceous matter using a plasma arc |
FR2539942A1 (en) * | 1983-01-21 | 1984-07-27 | Plasma Energy Corp | PLASMA GENERATOR AND METHOD OF OPERATION |
US4549065A (en) * | 1983-01-21 | 1985-10-22 | Technology Application Services Corporation | Plasma generator and method |
FR2556168A1 (en) * | 1983-12-02 | 1985-06-07 | Plasma Energy Corp | CONVERTIBLE PLASMA ARC TORCH, OF THE TYPE THAT CAN BE TRANSFORMED AT ITS PLACE OF USE |
FR2574165A1 (en) * | 1984-11-30 | 1986-06-06 | Plasma Energy Corp | ARC-PLASMA HEATING APPARATUS FOR HEATING LARGE QUANTITIES OF AIR, PARTICULARLY FOR DRYING RAW MATERIALS |
FR2581396A1 (en) * | 1985-05-03 | 1986-11-07 | Huron Valley Steel Corp | METHOD AND APPARATUS FOR SIMULTANEOUSLY SEPARATING VOLATILE METALS AND NON-VOLATILE METALS |
US4718477A (en) * | 1986-07-30 | 1988-01-12 | Plasma Energy Corporation | Apparatus and method for processing reactive metals |
DE3723418A1 (en) * | 1986-07-30 | 1988-02-11 | Plasma Energy Corp | MELTING DEVICE FOR REACTIVE METALS AND SIMILAR MATERIALS |
US4891490A (en) * | 1987-04-29 | 1990-01-02 | Aerospatiale Societe Nationale Industrielle | Tubular electrode for plasma torch and plasma torch provided with such electrodes |
US5233155A (en) * | 1988-11-07 | 1993-08-03 | General Electric Company | Elimination of strike-over in rf plasma guns |
WO1992010325A1 (en) * | 1990-12-05 | 1992-06-25 | Hydro Quebec | Opening a taphole with a plasma torch |
US5254829A (en) * | 1990-12-05 | 1993-10-19 | Hydro Quebec | Use of a plasma torch to open a tap hole in a metal furnace |
US5362939A (en) * | 1993-12-01 | 1994-11-08 | Fluidyne Engineering Corporation | Convertible plasma arc torch and method of use |
WO1995015238A1 (en) * | 1993-12-01 | 1995-06-08 | Fluidyne Engineering Corporation | Convertible plasma arc torch and method of use |
US5451740A (en) * | 1993-12-01 | 1995-09-19 | Fluidyne Engineering Corporation | Convertible plasma arc torch and method of use |
US5880426A (en) * | 1996-08-28 | 1999-03-09 | Doryokuro Kakunenryo Kaihatsu Jigyodan | Indirectly-cooled plasma jet torch |
US5756959A (en) * | 1996-10-28 | 1998-05-26 | Hypertherm, Inc. | Coolant tube for use in a liquid-cooled electrode disposed in a plasma arc torch |
US6203661B1 (en) | 1999-12-07 | 2001-03-20 | Trusi Technologies, Llc | Brim and gas escape for non-contact wafer holder |
US6398823B1 (en) | 1999-12-07 | 2002-06-04 | Tru-Si Technologies, Inc. | Dynamic break for non-contact wafer holder |
US6402843B1 (en) | 1999-12-07 | 2002-06-11 | Trusi Technologies, Llc | Non-contact workpiece holder |
US6448188B1 (en) | 1999-12-07 | 2002-09-10 | Tru-Si Technologies, Inc. | Method of preventing motion of article in an article holder |
US6121571A (en) * | 1999-12-16 | 2000-09-19 | Trusi Technologies Llc | Plasma generator ignition circuit |
US7193174B2 (en) | 2003-04-11 | 2007-03-20 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US7754996B2 (en) | 2003-04-11 | 2010-07-13 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US6946617B2 (en) | 2003-04-11 | 2005-09-20 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US7019255B2 (en) | 2003-04-11 | 2006-03-28 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma ARC torch |
US20060151447A1 (en) * | 2003-04-11 | 2006-07-13 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US20070045245A1 (en) * | 2003-04-11 | 2007-03-01 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US20040200810A1 (en) * | 2003-04-11 | 2004-10-14 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US20050092718A1 (en) * | 2003-04-11 | 2005-05-05 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma ARC torch |
US20080116179A1 (en) * | 2003-04-11 | 2008-05-22 | Hypertherm, Inc. | Method and apparatus for alignment of components of a plasma arc torch |
US7297893B2 (en) | 2004-10-07 | 2007-11-20 | Phoenix Solutions Co. | Plasma arc collimator design and construction |
US20070175870A1 (en) * | 2004-10-07 | 2007-08-02 | Phoenix Solutions Co. | Plasma arc collimator design and construction |
US20110031224A1 (en) * | 2009-08-10 | 2011-02-10 | The Esab Group, Inc. | Retract start plasma torch with reversible coolant flow |
US8258423B2 (en) | 2009-08-10 | 2012-09-04 | The Esab Group, Inc. | Retract start plasma torch with reversible coolant flow |
US8633414B2 (en) | 2009-08-10 | 2014-01-21 | The Esab Group, Inc. | Retract start plasma torch with reversible coolant flow |
US8581496B2 (en) | 2011-07-29 | 2013-11-12 | Oaks Plasma, LLC. | Self-igniting long arc plasma torch |
JP2017516006A (en) * | 2014-05-15 | 2017-06-15 | ティッセンクルップ アクチェンゲゼルシャフト | How to make a borehole |
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