EP0178288B1 - Plasma burner - Google Patents
Plasma burner Download PDFInfo
- Publication number
- EP0178288B1 EP0178288B1 EP85890220A EP85890220A EP0178288B1 EP 0178288 B1 EP0178288 B1 EP 0178288B1 EP 85890220 A EP85890220 A EP 85890220A EP 85890220 A EP85890220 A EP 85890220A EP 0178288 B1 EP0178288 B1 EP 0178288B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- electrode
- nozzle
- diffuser
- outlet
- plasma
- 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
Links
- 238000001816 cooling Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000155 melt Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 239000002893 slag Substances 0.000 description 2
- 230000001154 acute effect Effects 0.000 description 1
- 239000000110 cooling liquid Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Images
Classifications
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- 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
- H05H1/34—Details, e.g. electrodes, nozzles
-
- 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
- H05H1/34—Details, e.g. electrodes, nozzles
- H05H1/3436—Hollow cathodes with internal coolant flow
-
- 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
- H05H1/34—Details, e.g. electrodes, nozzles
- H05H1/3478—Geometrical details
-
- 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
- H05H1/34—Details, e.g. electrodes, nozzles
- H05H1/3484—Convergent-divergent nozzles
Definitions
- the invention relates to a plasma torch with an electrode inserted in a nozzle body for supplying gas along the outer jacket of the electrode, the electrode having a flow channel with a central outlet for an ionizable gas and being attached to a liquid-cooled electrode holder.
- the outlet nozzle of the arc combustion chamber of the plasma jet generator is designed as a double nozzle, the inner nozzle outlet opening on the one hand and the outer, annular nozzle outlet opening on the other hand forming a Laval nozzle.
- a disadvantage of this known plasma jet generator is that an increase in the burner output due to the design of the outlet nozzle is no longer possible because the plasma jet already formed in the arc combustion chamber is present in the area of the outlet nozzle.
- the invention is therefore based on the object of avoiding these deficiencies and of improving a plasma torch of the type described at the outset such that the burner output can be increased and the service life of the electrode can be increased using comparatively simple means.
- the invention achieves the object in that the central outlet of the flow channel is designed as a diffuser and that the outlet opening of the diffuser projects from the nozzle body at an axial distance.
- the diffuser By designing not the outlet nozzle of an arc combustion chamber, in which two electrodes are provided for generating a plasma jet, but rather the central flow channel outlet of an electrode as a diffuser, expansion of the supplied plasma gas and, in connection with an enlarged surface compared to a cylindrical bore, additional cooling the electrode is reached.
- the diffuser also ensures an advantageous flow formation of the plasma gas, which stabilizes the plasma jet generated immediately after the nozzle.
- the higher arc stability also requires a bath movement in the area of the arc, so that due to the movement-related breaking of the slag layer floating on the melt, an immediate heat transfer to the melt is made possible.
- the larger electrode surface achieved by the diffuser results in a larger emission area, which results in a lower surface load on the electrode and thus a higher burner output.
- the outlet opening of the diffuser protrudes from the nozzle body at an axial distance. Since the plasma jet can be largely stabilized by the diffuser, there is hardly any risk that the nozzle body, which is set back relative to the electrode and is cooled in the usual way, is exposed to a destructive heat load. The nozzle geometry is therefore retained even over longer service lives, in particular if the radial distance between the electrode and the nozzle body increases towards the outlet opening of the diffuser. This increase in distance not only has an advantageous effect on the thermal load on the nozzle body, but also on the flow of the gas supplied through the nozzle, because the formation of a laminar flow is supported by a diffuser effect.
- the diffuser can be part of a Laval nozzle.
- the diffuser or the Laval nozzle is connected to the flow channel via at least two passage openings.
- the surfaces of two or more passage openings are correspondingly larger than the surface of a single passage opening, so that the emission area of the electrode is significantly increased by this measure and the specific areas load on the electrode is reduced, which allows a corresponding increase in the burner output for a predetermined, maximum permissible surface load.
- the plasma torch shown essentially consists of an electrode 1 which is attached to a water-cooled electrode holder 2 in a conventional manner.
- This electrode 1 is inserted with the electrode holder 2 in a water-cooled nozzle body 3, which forms an annular gap 4 with the electrode 1 for the passage of a flushing gas or a plasma gas.
- a partition wall 5 consisting of a tube is provided both in the nozzle body 3 and in the electrode holder 2.
- a conduit 6, which penetrates tightly through the electrode holder 2 and is inserted in a corresponding receiving recess of the electrode 1, is used for the central supply of an ionizable plasma gas.
- This conduit 6 forms a flow channel 7, the central outlet of which is designed as a Laval nozzle 8.
- This Laval nozzle 8 is connected via at least two through openings 9 to the flow channel 7, so that the ionizable gas from the flow channel 7 first passes through the through openings 9 into the tapering part 10 of the Laval nozzle 8, and then via the part designed as a diffuser 11 Laval nozzle to flow out of the electrode 1.
- the outlet opening 12 of the diffuser 11 lies at an axial distance a in front of the nozzle body 3. If the distance a corresponds to at least one fifth of the electrode diameter, particularly advantageous nozzle conditions result.
- the electrode 1 Since the electrode 1 has a hemispherical outer jacket in the region of its projecting end, while the inner jacket of the nozzle body 3 is conical, the radial distance b between the electrode 1 and the nozzle body 3 increases towards the outlet end 12 of the diffuser 11.
- the gas passed through the annular gap 4 can therefore be passed on due to the diffuser effect which can thereby be achieved while avoiding disturbing eddy formation.
- the distance b, which increases towards the exit of the annular gap 4 also effectively prevents a secondary arc from spreading over the nozzle body 3, especially since the arc is stabilized well with the diffuser 11 of the projecting electrode 1.
- the design of the flow channel outlet in the form of a Laval nozzle not only ensures particularly favorable flow conditions for the centrally supplied plasma gas, but also results in an enlargement of the emission area of the electrode 1, which results in a reduction in the specific area load on the electrode.
- the surface enlarged by the passage openings 9 supports this effect, so that the current load can be increased significantly compared to conventional electrodes.
- the thermal load remains due to the electrode cooling by the supplied plasma gas within permissible limits, because the comparatively large emission surface and the expansion of the gas in the diffuser 11 improve the cooling of the electrode.
- the extensive avoidance of turbulence also entails a plasma flow which permits bath movement at the other end of the arc, so that the slag layer floating on the melt is torn open and an immediate heat transfer to the melt can be achieved.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Geometry (AREA)
- Plasma Technology (AREA)
Description
Die Erfindung bezieht sich auf einen Plasmabrenner mit einer in einem Düsenkörper eingesetzten Elektrode zum Zuführen von Gas entlang des Außenmantels der Elektrode, wobei die Elektrode einen Strömungskanal mit einem zentralen Austritt für ein ionisierbares Gas aufweist und an einem flüssigkeitsgekühlten Elektrodenhalter befestigt ist.The invention relates to a plasma torch with an electrode inserted in a nozzle body for supplying gas along the outer jacket of the electrode, the electrode having a flow channel with a central outlet for an ionizable gas and being attached to a liquid-cooled electrode holder.
Bei Plasmabrennern ist es bekannt (US-A-3 130 292), die in einem Düsenkörper eingesetzte Elektrode sowohl mit als auch ohne Strömungskanal für ein ionisierbares Gas auszubilden. Nicht durchbohrte Vollelektroden, die gegenüber dem Düsenkörper zurückversetzt angeordnet sein sollen, um einen entsprechenden Elektrodenschutz zu erhalten und einen unwirtschaftlichen Einsatz an Schutzgas zu vermeiden, werden allerdings nur für geringere Stromstärken eingesetzt, weil die einen zentralen Strömungskanal bildenden Hohlelektroden eine zusätzliche Kühlung über das zentral zugeführte Plasmagas erlauben. Um bei Elektroden mit einem zentralen Strömungskanal stabile Lichtbögen sicherzustellen, ist es bekannt (DE-A-32 41 476), zwischen der kegelstumpfförmigen Elektrode und einem die Elektrode aufnehmenden, koaxialen Düsenkörper eine Ringdüse zu schaffen, durch die das Plasmagas unter einem spitzen Winkel in den Lichtbogen geleitet wird. Die durch diese Düsenform erzwungene Gasströmung soll die Bogenstabilität entscheidend verbessern. Nachteilig ist allerdings, daß wegen der besonderen Düsenform, bei der die Elektrode gegenüber dem Düsenkörper in üblicher Weise axial zurückversetzt ist, der Düsenkörper einer großen thermischen Belastung unterworfen wird, die zu einem raschen Abbrand der Düse und damit zu einer Veränderung der Düsengeometrie führt, was die Einhaltung der gewünschten Strömungswinkel über einen längeren Zeitraum in Frage stellt. Außerdem bleibt die Strombelastbarkeit der Elektroden begrenzt.In plasma torches it is known (US Pat. No. 3,130,292) to design the electrode used in a nozzle body both with and without a flow channel for an ionizable gas. Solid electrodes which are not pierced and which are to be set back in relation to the nozzle body in order to obtain appropriate electrode protection and to avoid uneconomical use of protective gas are, however, only used for lower current intensities because the hollow electrodes forming a central flow channel provide additional cooling via the centrally supplied one Allow plasma gas. In order to ensure stable arcing in electrodes with a central flow channel, it is known (DE-A-32 41 476) to create an annular nozzle between the truncated cone-shaped electrode and a coaxial nozzle body receiving the electrode, through which the plasma gas enters at an acute angle the arc is conducted. The gas flow forced by this nozzle shape is said to decisively improve the bow stability. A disadvantage, however, is that because of the special nozzle shape, in which the electrode is axially set back in relation to the nozzle body in the usual way, the nozzle body is subjected to a large thermal load, which leads to a rapid erosion of the nozzle and thus to a change in the nozzle geometry, which the compliance with the desired flow angle over a longer period in question. In addition, the current carrying capacity of the electrodes remains limited.
Um die elektrische Leistung und den Wirkungsgrad eines Plasmastrahlgenerators zu erhöhen, ist es schließlich bekannt (DE-B-1 954 851), die Geschwindigkeit des aus der Düse austretenden Plasmasfrahles zu erhöhen. Zu diesem Zweck ist die Austrittsdüse der Lichtbogenbrennkammer des Plasmastrahlgenerators als Doppeldüse ausgebildet, wobei die innere Düsenaustrittsöffnung einerseits und die äußere, ringförmige Düsenaustrittsöffnung anderseits eine Lavaldüse bilden. Nachteilig bei diesem bekannten Plasmastrahlgenerator ist, daß eine Erhöhung der Brennerleistung durch die Ausgestaltung der Austrittsdüse nicht mehr möglich ist, weil im Bereich der Austrittsdüse der bereits in der Lichtbogenbrennkammer entstehende Plasmastrahl vorliegt.Finally, in order to increase the electrical power and the efficiency of a plasma jet generator, it is known (DE-B-1 954 851) to increase the speed of the plasma jet emerging from the nozzle. For this purpose, the outlet nozzle of the arc combustion chamber of the plasma jet generator is designed as a double nozzle, the inner nozzle outlet opening on the one hand and the outer, annular nozzle outlet opening on the other hand forming a Laval nozzle. A disadvantage of this known plasma jet generator is that an increase in the burner output due to the design of the outlet nozzle is no longer possible because the plasma jet already formed in the arc combustion chamber is present in the area of the outlet nozzle.
Der Erfindung liegt somit die Aufgabe zugrunde, diese Mängel zu vermeiden und einen Plasmabrenner der eingangs geschilderten Art so zu verbessern, daß mit vergleichsweise einfachen Mitteln die Brennerleistung erhöht und die Standzeit der Elektrode vergrößert werden kann.The invention is therefore based on the object of avoiding these deficiencies and of improving a plasma torch of the type described at the outset such that the burner output can be increased and the service life of the electrode can be increased using comparatively simple means.
Die Erfindung löst die gestellte Aufgabe dadurch, daß der zentrale Austritt des Strömungskanales als Diffusor ausgebildet ist, und daß die Austrittsöffnung des Diffusors mit axialem Abstand aus dem Düsenkörper vorragt.The invention achieves the object in that the central outlet of the flow channel is designed as a diffuser and that the outlet opening of the diffuser projects from the nozzle body at an axial distance.
Durch die Ausbildung nicht der Austrittsdüse einer Lichtbogenbrennkammer, in der zwei Elektroden für die Erzeugung eines Plasmastrahles vorgesehen sind, sondern des zentralen Strömungskanalaustrittes einer Elektrode als Diffusor wird eine Expansion des zugeführten Plasmagases und damit im Zusammenhang mit einer gegenüber einer zylindrischen Bohrung vergrößerten Oberfläche eine zusätzliche Kühlung der Elektrode erreicht. Der Diffusor gewährleistet aber auch eine vorteilhafte Strömungsausbildung des Plasmagases, was eine Stabilisierung des unmittelbar nach der Düse entstehenden Plasmastrahles bewirkt. Die höhere Lichtbogenstabilität bedingt darüber hinaus eine Badbewegung im Bereich des Lichtbogens, so daß aufgrund des bewegungsbedingten Aufbrechens der auf der Schmelze schwimmenden Schlackenschicht ein unmittelbarer Wärmeübergang auf die Schmelze ermöglicht wird. Die durch den Diffusor erreichte größere Elektrodenoberfläche ergibt eine größere Emissionsfläche, was eine geringere Flächenbelastung der Elektrode und damit eine höhere Brennerleistung mit sich bringt.By designing not the outlet nozzle of an arc combustion chamber, in which two electrodes are provided for generating a plasma jet, but rather the central flow channel outlet of an electrode as a diffuser, expansion of the supplied plasma gas and, in connection with an enlarged surface compared to a cylindrical bore, additional cooling the electrode is reached. However, the diffuser also ensures an advantageous flow formation of the plasma gas, which stabilizes the plasma jet generated immediately after the nozzle. The higher arc stability also requires a bath movement in the area of the arc, so that due to the movement-related breaking of the slag layer floating on the melt, an immediate heat transfer to the melt is made possible. The larger electrode surface achieved by the diffuser results in a larger emission area, which results in a lower surface load on the electrode and thus a higher burner output.
Damit trotz der Vergrößerung der Brenrerleistung eine ausreichende Standzeit sichergestellt werden kann, ragt die Austrittsöffnung des Diffusors mit axialem Abstand aus dem Düsenkörper vor. Da durch den Diffusor der Plasmastrahl weitgehend stabilisiert werden kann, besteht kaum eine Gefahr, daß der gegenüber der Elektrode zurückgesetzte Düsenkörper, der in üblicher Weise gekühlt wird, einer zerstörenden Wärmebelastung ausgesetzt ist. Die Düsengeometrie bleibt daher auch über längere Standzeiten erhalten, insbesondere wenn sich der radiale Abstand zwischen der Elektrode und dem Düsenkörper gegen die Austrittsöffnung des Diffusors hin vergrößert. Diese Abstandsvergrößerung wirkt sich nicht nur auf die thermische Belastung des Düsenkörpers vorteilhaft aus, sondern auch auf die Strömung des durch die Düse zugeleiteten Gases, weil mit einer Diffusorwirkung die Ausbildung einer laminaren Strömung unterstützt wird.So that a sufficient service life can be ensured despite the increase in the burner output, the outlet opening of the diffuser protrudes from the nozzle body at an axial distance. Since the plasma jet can be largely stabilized by the diffuser, there is hardly any risk that the nozzle body, which is set back relative to the electrode and is cooled in the usual way, is exposed to a destructive heat load. The nozzle geometry is therefore retained even over longer service lives, in particular if the radial distance between the electrode and the nozzle body increases towards the outlet opening of the diffuser. This increase in distance not only has an advantageous effect on the thermal load on the nozzle body, but also on the flow of the gas supplied through the nozzle, because the formation of a laminar flow is supported by a diffuser effect.
Um besonders vorteilhafte Strömungsbedingungen für das dem Lichtbogen zugeleitete Plasmagas zu erhalten, kann der Diffusor Teil einer Lavaldüse sein.In order to obtain particularly advantageous flow conditions for the plasma gas supplied to the arc, the diffuser can be part of a Laval nozzle.
Da sich die Emissionszone der Elektrode über den Diffusor bzw. die Lavaldüse hinaus gegen den Strömungskanal hin erstrecken kann, ist es vorteilhaft, wenn der Diffusor bzw. die Lavaldüse über wenigstens zwei Durchtrittsöffnungen an den Strömungskanal angeschlossen ist. Bei gleichem Strömungsquerschnitt sind die Oberflächen von zwei oder mehreren Durchtrittsöffnungen entsprechend größer als die Oberfläche einer einzigen Durchtrittsöffnung, so daß die Emissionsfläche der Elektrode durch diese Maßnahme merklich vergrößert und die spezifische Flächenbelastung der Elektrode herabgesetzt wird, was bei einer vorgegebenen, maximal zulässigen Flächenbelastung eine entsprechende Erhöhung der Brennerleistung erlaubt.Since the emission zone of the electrode can extend beyond the diffuser or the Laval nozzle towards the flow channel, it is advantageous if the diffuser or the Laval nozzle is connected to the flow channel via at least two passage openings. With the same flow cross-section, the surfaces of two or more passage openings are correspondingly larger than the surface of a single passage opening, so that the emission area of the electrode is significantly increased by this measure and the specific areas load on the electrode is reduced, which allows a corresponding increase in the burner output for a predetermined, maximum permissible surface load.
In der Zeichnung ist der Erfindungsgegenstand beispielsweise dargestellt, und zwar wird ein erfindungsgemäßer Plasmabrenner in einem vereinfachten Axialschnitt gezeigt.The subject matter of the invention is shown in the drawing, for example, namely a plasma torch according to the invention is shown in a simplified axial section.
Der dargestellte Plasmabrenner besteht im wesentlichen aus einer Elektrode 1, die an einem wassergekühlten Elektrodenhalter 2 in herkömmlicher Weise befestigt ist. Diese Elektrode 1 ist mit dem Elektrodenhalter 2 in einem wassergekühlten Düsenkörper 3 eingesetzt, der mit der Elektrode 1 einen Ringspalt 4 für den Durchtritt eines Spülgases oder eines Plasmagases bildet. Um einen Kühlflüssigkeitsumlauf sicherzustellen, ist sowohl im Düsenkörper 3 als auch im Elektrodenhalter 2 eine aus einem Rohr bestehende Trennwand 5 vorgesehen. Zum zentralen Zuleiten eines ionisierbaren Plasmagases dient ein Leitungsrohr 6, das den Elektrodenhalter 2 dicht durchsetzt und in einer entsprechenden Aufnahmeausnehmung der Elektrode 1 eingesetzt ist. Dieses Leitungsrohr 6 bildet einen Strömungskanal 7, dessen zentraler Austritt als Lavaldüse 8 ausgebildet ist. Diese Lavaldüse 8 ist über wenigstens zwei Durchtrittsöffnungen 9 an den Strömungskanal 7 angeschlossen, so daß das ionisierbare Gas aus dem Strömungskanal 7 durch die Durchtrittsöffnungen 9 zunächst in den sich verjüngenden Teil 10 der Lavaldüse 8 gelangt, um dann über den als Diffusor 11 ausgebildeten Teil der Lavaldüse aus der Elektrode 1 auszuströmen. Wie der Zeichnung deutlich entnommen werden kann, liegt die Austrittsöffnung 12 des Diffusors 11 in einem axialen Abstand a vor dem Düsenkörper 3. Entspricht der Abstand a wenigstens einem Fünftel des Elektrodendurchmessers, so ergeben sich besonders vorteilhafte Düsenverhältnisse. Da die Elektrode 1 im Bereich ihres vorragenden Endes einen halbkugelförmigen Außenmantel aufweist, während der Innenmantel des Düsenkörpers 3 kegelförmig ausgebildet ist, vergrößert sich der radiale Abstand b zwischen der Elektrode 1 und dem Düsenkörper 3 gegen das Austrittsende 12 des Diffusors 11 hin. Das durch den Ringspalt 4 geführte Gas kann daher auf Grund der dadurch erzielbaren Diffusorwirkung unter Vermeidung störender Wirbelbildungen weitergeleitet werden. Der sich gegen den Ausgang des Ringspaltes 4 vergrößernde Abstand b verhindert auch wirksam ein Übergreifen eines Nebenlichtbogens auf den Düsenkörper 3, zumal mit dem Diffusor 11 der vorragenden Elektrode 1 eine gute Stabilisierung des Lichtbogens erreicht wird.The plasma torch shown essentially consists of an
Die Ausbildung des Strömungskanalaustrittes in Form einer Lavaldüse gewährleistet nicht nur besonders günstige Strömungsverhältnisse für das zentral zugeführte Plasmagas, sondern ergibt auch eine Vergrößerung der Emissionsfläche der Elektrode 1, was eine Herabsetzung der spezifischen Flächenbelastung der Elektrode mit sich bringt. Die durch die Durchtrittsöffnungen 9 vergrößerte Oberfläche unterstützt diese Wirkung, so daß die Strombelastung gegenüber herkömmlichen Elektroden entscheidend vergrößert werden kann. Die thermische Belastung bleibt dabei auf Grund der Elektrodenkühlung durch das zugeführte Plasmagas in zulässigen Grenzen, weil die vergleichsweise große Emissionsoberfläche und die Expansion des Gases im Diffusor 11 die Kühlung der Elektrode verbessert. Die weitgehende Vermeidung von Turbulenzen bringt außerdem eine Plasmaströmung mit sich, die eine Badbewegung am anderen Ende des Lichtbogens erlaubt, so daß die auf der Schmelze schwimmende Schlackenschicht aufgerissen wird und ein unmittelbarer Wärmeübergang auf die Schmelze erreicht werden kann.The design of the flow channel outlet in the form of a Laval nozzle not only ensures particularly favorable flow conditions for the centrally supplied plasma gas, but also results in an enlargement of the emission area of the
Claims (4)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT3232/84 | 1984-10-11 | ||
| AT0323284A AT381826B (en) | 1984-10-11 | 1984-10-11 | PLASMA TORCH |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0178288A2 EP0178288A2 (en) | 1986-04-16 |
| EP0178288A3 EP0178288A3 (en) | 1988-08-03 |
| EP0178288B1 true EP0178288B1 (en) | 1990-10-24 |
Family
ID=3547431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP85890220A Expired - Lifetime EP0178288B1 (en) | 1984-10-11 | 1985-09-12 | Plasma burner |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4650953A (en) |
| EP (1) | EP0178288B1 (en) |
| JP (1) | JPS61179100A (en) |
| AT (1) | AT381826B (en) |
| CA (1) | CA1241999A (en) |
| DD (1) | DD239707A5 (en) |
| DE (1) | DE3580233D1 (en) |
| ZA (1) | ZA857486B (en) |
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| JPH0658840B2 (en) * | 1988-04-26 | 1994-08-03 | 新日本製鐵株式会社 | Transfer type plasma torch |
| US4954683A (en) * | 1989-05-26 | 1990-09-04 | Thermal Dynamics Corporation | Plasma arc gouger |
| US4990739A (en) * | 1989-07-07 | 1991-02-05 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Plasma gun with coaxial powder feed and adjustable cathode |
| IN180745B (en) * | 1990-01-17 | 1998-03-14 | Univ Sydney | |
| US5079403A (en) * | 1990-10-22 | 1992-01-07 | W. A. Whitney Corp. | Nozzle for plasma arc torch |
| GB9108891D0 (en) * | 1991-04-25 | 1991-06-12 | Tetronics Research & Dev Co Li | Silica production |
| US5208448A (en) * | 1992-04-03 | 1993-05-04 | Esab Welding Products, Inc. | Plasma torch nozzle with improved cooling gas flow |
| US5257500A (en) * | 1992-07-27 | 1993-11-02 | General Electric Company | Aircraft engine ignition system |
| US5640841A (en) * | 1995-05-08 | 1997-06-24 | Crosby; Rulon | Plasma torch ignition for low NOx combustion turbine combustor with monitoring means and plasma generation control means |
| US5771818A (en) * | 1996-05-20 | 1998-06-30 | Prometron Technics Co., Ltd. | Cooling system for waste disposal device |
| DE19626941A1 (en) * | 1996-07-04 | 1998-01-08 | Castolin Sa | Processes for coating or welding easily oxidizable materials and plasma torches therefor |
| US6207923B1 (en) | 1998-11-05 | 2001-03-27 | Hypertherm, Inc. | Plasma arc torch tip providing a substantially columnar shield flow |
| US6362450B1 (en) | 2001-01-30 | 2002-03-26 | The Esab Group, Inc. | Gas flow for plasma arc torch |
| KR101131531B1 (en) * | 2003-02-06 | 2012-04-04 | 가부시키가이샤 한도오따이 에네루기 켄큐쇼 | Method for manufacturing display |
| US6969819B1 (en) * | 2004-05-18 | 2005-11-29 | The Esab Group, Inc. | Plasma arc torch |
| US20070045241A1 (en) * | 2005-08-29 | 2007-03-01 | Schneider Joseph C | Contact start plasma torch and method of operation |
| CN101998750B (en) * | 2009-08-14 | 2012-09-26 | 中国科学院金属研究所 | Plasma cathode and protecting method thereof |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2967926A (en) * | 1958-03-10 | 1961-01-10 | Union Carbide Corp | Testing process and apparatus |
| US3130292A (en) * | 1960-12-27 | 1964-04-21 | Union Carbide Corp | Arc torch apparatus for use in metal melting furnaces |
| US3304719A (en) * | 1964-07-28 | 1967-02-21 | Giannini Scient Corp | Apparatus and method for heating and accelerating gas |
| SU437320A3 (en) * | 1969-10-31 | 1974-07-25 | Сименс Аг (Фирма) | Device for high-speed gas jet |
| FR2156978A5 (en) * | 1971-10-13 | 1973-06-01 | Anvar | |
| BE795891A (en) * | 1972-02-23 | 1973-06-18 | Electricity Council | PLASMA TORCH IMPROVEMENTS |
| DE2603413A1 (en) * | 1976-01-29 | 1977-08-04 | Ustav Pro Vyzkum Vyrobu A Vyuz | Plasmatron with stabilisation plate - between electrodes and oblique sample feed passage to plasma stream nozzle through anode |
| DE2900330A1 (en) * | 1978-01-09 | 1979-07-12 | Inst Elektroswarki Patona | PROCESS FOR PLASMA GENERATION IN A PLASMA ARC GENERATOR AND DEVICE FOR CARRYING OUT THE PROCESS |
| DE3241476A1 (en) * | 1982-11-10 | 1984-05-10 | Fried. Krupp Gmbh, 4300 Essen | METHOD FOR INTRODUCING IONIZABLE GAS INTO A PLASMA OF AN ARC BURNER, AND PLASMA TORCHER FOR CARRYING OUT THE METHOD |
| US4521666A (en) * | 1982-12-23 | 1985-06-04 | Union Carbide Corporation | Plasma arc torch |
| US4558201A (en) * | 1984-12-10 | 1985-12-10 | Thermal Dynamics Corporation | Plasma-arc torch with gas cooled blow-out electrode |
-
1984
- 1984-10-11 AT AT0323284A patent/AT381826B/en not_active IP Right Cessation
-
1985
- 1985-09-12 EP EP85890220A patent/EP0178288B1/en not_active Expired - Lifetime
- 1985-09-12 DE DE8585890220T patent/DE3580233D1/en not_active Expired - Lifetime
- 1985-09-27 ZA ZA857486A patent/ZA857486B/en unknown
- 1985-09-30 CA CA000491846A patent/CA1241999A/en not_active Expired
- 1985-10-07 US US06/785,285 patent/US4650953A/en not_active Expired - Fee Related
- 1985-10-09 JP JP60223905A patent/JPS61179100A/en active Granted
- 1985-10-10 DD DD85281613A patent/DD239707A5/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0514399B2 (en) | 1993-02-24 |
| ZA857486B (en) | 1986-06-25 |
| AT381826B (en) | 1986-12-10 |
| US4650953A (en) | 1987-03-17 |
| DE3580233D1 (en) | 1990-11-29 |
| DD239707A5 (en) | 1986-10-01 |
| ATA323284A (en) | 1986-04-15 |
| EP0178288A2 (en) | 1986-04-16 |
| JPS61179100A (en) | 1986-08-11 |
| EP0178288A3 (en) | 1988-08-03 |
| CA1241999A (en) | 1988-09-13 |
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