Cartridge for a plasma torch and plasma torch fitted therewith

• US 6,525,292 B1
• Filed: 10/02/2001
• Issued: 02/25/2003
• Est. Priority Date: 04/14/1999
• Status: Expired due to Term

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Girold, Christophe
• Primary Examiner(s): PASCHALL, MARK H
• Application Number:
  US09/958,029
• Time in Patent Office: 511 Days
• Field of Search: 219/212.48, 219/121.49, 219/121.5, 219/121.52, 219/121.59, 219/74, 219/75, 313/231.31, 313/231.41
• US Class Current: 219/121.49
• CPC Class Codes: H05H 1/34 Details, e.g. electrodes, nozzles
• CPC Class Codes: H05H 1/3478 Geometrical details

Abstract

A plasma torch includes an interchangeable cartridge (100) consisting of just six parts:

an anode nozzle made of electrolytic copper 1

a cathode support made of el S32-0684-AMctrolytic copper 2

a doped tungsten cathode 3

a cathode centring diffuser device made of plastic material 4

an assembler made of plastic material 5

a ceramic insert 6.

These parts are assembled by means of a press and the assembly of these parts constitutes volumes 71, 72, 73 constituting the cooling circuit of the anode 1 and other components of the torch, and plasmagene gas inflow conduits and connectors.

Fluid inflows and outflows are ensured through a connecting and holding structure provided for easy cartridge (100) assembly.

Claims

1. A cartridge (100) generating plasma for a plasma torch, having, centered on an axis AA′

, an annular anode (1) comprising a central cavity (10) formed inside a central ring (123) of the anode (1), this central cavity (10) receiving a cathode (3) centred on AA′

, means (2, 23, 4) for positioning the cathode (3), the anode (1) and the cathode (3) providing between them an annular space for producing an arc, plasmagene gas distribution means, the distributed gas circulating in the annular space between the cathode (3) and the anode (1), anode (1) cooling means, comprising particularly conduits for an anode (1) cooling fluid, these conduits having an inlet and an outlet, assembly means, comprising particularly a cathode (3) support (2), a cartridge characterised in that the cathode support (2) has a conductive part to bring the electrical currents necessary for the operation of the torch from a current input to the cathode (3), and in that the assembly means additionally comprise an assembler (5) the cathode (3) support (2), the assembler (5) and the annular anode (1) comprising hollow parts (24, 122) and projecting parts (51, 56) all centred parallel to the axis AA′

, the projecting parts (51, 56) being fitted tightly into the hollow arts (24, 122).

2. A cartridge according to claim 1 characterised in that one or more hollow part(s) (24, 122) are constituted by annular grooves (24, 122) and in that one or more projecting parts (51, 56) are constituted by annular rings (51, 56), the outer diameter of the rings (51, 56) being greater than the outer diameter of the grooves (24, 122) in such a way that one or more annular rings (51, 56) are fitted tightly into one or more annular grooves (24, 122).

3. A cartridge according to claim 2 characterised in that a projecting part (51) of the assembler (5) is constituted by a lower annular ring (51) of axis AA′

, having an outer diameter, an inner diameter and a lower surface, in that a hollow part (24) of the cathode (3) support (2) is constituted by an annular groove (24) centred on the axis AA′

, the groove (24) having an outer diameter, an inner diameter and a groove (24) bottom surface (27), and in that the outer diameter of the lower annular ring (51) of the assembler (5) is slightly greater than the outer diameter of the annular groove (24) of the cathode (3) support (2) in such a way that the lower annular ring (51) of the assembler (5) is fitted tightly into the annular groove (24) of the cathode (3) support (2).

4. A cartridge (100) according to claim 3 characterised in that a projecting part (56) of the assembler (5) is constituted by an upper annular ring (56) of axis AA′

, having an outer diameter, an inner diameter and an upper surface, in that a hollow part (122) of the annular anode (1) is constituted by an annular groove (122) centred on the axis AA′

, the groove (122) having an outer diameter, an inner diameter and a groove bottom surface (124), and in that the outer diameter of the upper annular ring (56) of the assembler (5) is slightly greater than the outer diameter of the annular groove (122) of the anode (1) in such a way that the upper annular ring (56) of the assembler (5) is fitted tightly into the annular groove (122) of the anode (1).

5. A cartridge (100) according to claim 2 characterised in that a first projecting part (51) of the assembler (5) is constituted by a lower annular ring (51) of axis AA′

, having an outer diameter, an inner diameter and a lower surface (59), in that a hollow part (24) of the cathode (3) support (2) is constituted by an annular groove (24) centred on the axis AA′

, the groove (24) having an outer diameter, an inner diameter and a groove bottom surface (27), and in that the outer diameter of the first annular ring (51) of the assembler (5) is slightly greater than the outer diameter of the annular groove (24) of the cathode (3) support (2) in such a way that the lower annular ring (51) of the assembler (5) is fitted tightly into the annular groove (24) of the cathode (3) support (2), and in that a second projecting part (56) of the assembler (5) is constituted by an upper annular ring (56) of axis AA′

, having an outer diameter, an inner diameter and an upper surface (60), in that a hollow part (122) of the annular anode (1) is constituted by an annular groove (122) centred on the axis AA′

, the groove having an outer diameter, an inner diameter and a groove bottom surface (124), and in that the outer diameter of the second annular ring (56) of the assembler (5) is slightly greater than the outer diameter of the annular groove (122) of the anode (1) in such a way that the upper annular ring (56) of the assembler (5) is fitted tightly into the annular groove (122) of the anode (1).

6. A cartridge (100) according to claim 5 characterised in that the assembler (5) comprises a central hollow part (69) joining the lower and upper rings (51, 56), this central part (69) having an inner diameter, in that the groove (122) of the anode (1) receiving the upper ring (56) of the assembler (5) is peripheral of the central ring (123) of the anode (1), forming the central cavity (10) of the anode (1), the inner diameter of a part at least of the assembler (5) being greater than the outer diameter of the central ring (123) of the anode (1) in such a way that a first annular volume (72) is provided between the assembler (5) and the central ring (123) of the anode (1), this volume (72) being in communication with the outside of the cartridge (100) through at least two conduits (130, 28), a cooling fluid inflow conduit (13) and a cooling fluid outflow conduit (28).

7. A cartridge (100) according to claim 6 characterised in that, in the assembled position, the upper surface (60) of the upper ring of the assembler (5) does not abut the groove bottom (124) of the anode (1), in such a way that a second annular volume (71) is provided between this upper surface (60) and the groove bottom (124), one (130) of the conduits communicating with the outside emerging in this volume (71).

8. A cartridge (100) according to claim 6 characterised in that, in the assembled position, the lower surface (59) of the lower ring (51) of the assembler (5) does not abut the bottom (27) of the groove (24) of the support (2), in such a way that a third annular volume (73) is provided between this lower surface (59) and the bottom (27) of the groove (24), one of the conduits (28) communicating with the outside emerging in this volume (73),

9. A cartridge (100) according to claim 1 characterised in that it comprises a centring device (4) having an axial cavity centred on the cathode (3), a lower surface (46), a lateral outer surface (38, 50), a lateral inner surface (39), an upper surface (48, 49) at least one upper part (42) of the centring device (4) being fitted inside the central cavity (10) of the anode (1), one or more passages (44, 144, 95, 45, 64, 68, 74) bringing into communication the lateral outer or lower surface (50, 46) with the upper surface (48, 49) of the upper part (42) of the centring device (4).

10. A cartridge (100) according to claim 9 characterised in that passages (44, 144) are constituted by conduits (44, 144) joining the lateral outer surface (50) of the centring device (4) either in an axial annular groove (45) of the centring device (4) formed between the centring device (4) and the cathode (3) by a detachment from the lateral inner surface (39) of the centring device (4), or in apertures 95 formed on the upper surface (49) of the centring device (4).

11. A cartridge (100) according to claim 10 characterised in that conduits (44, 144) have an axial line not contained in an axial plane of the centring device (4).

12. A cartridge (100) according to claim 10 characterised in that conduits (44, 144) have an end emerging in a radial groove (148) formed on the lateral outer surface (50) of the centring device (4).

13. A cartridge (100) according to claim 10 characterised in that conduits (44, 144) have an end emerging in a radial inner groove (135) of the inner cavity (10) of the anode (1).

14. A cartridge (100) according to claim 9 characterised in that the anode (1) is fitted with one or more conduits (127) passing axially through a central ring (123) of the anode (1) surrounding the central cavity (10) of the anode (1) and emerging opposite one end of the passages (44, 144) of the centring device (4).

15. A cartridge (100) according to claim 9 characterised in that the support (2) is fitted with one or more conduits (75) passing through the support (2) and communicating with passages (64, 68, 74) of the centring device (4).

16. A cartridge (100) according to claim 9 characterised in that the support (2) is fitted with a central bore (23), this bore (23) housing a lower part of the cathode (3).

17. A cartridge (100) according to claim 16 characterised in that the support (2) is fitted with a central ring (29) formed around the bore (23) housing the lower part of the cathode (3), an upper surface (30) of this ring (29) being in contact with the lower surface (46) of the centring device (4).

18. A cartridge (100) according to claim 17 characterised in that the centring device (4) is fitted with a lower shoulder (41) having a lower surface (46) and an upper surface (47), the lower surface of this shoulder constituting the lower surface (46) of the centring device (4), and the upper surface (47) of this shoulder (41) being in contact with a lower surface (134) of the central ring (123) of the anode (1).

19. A plasma torch characterised in that it comprises a structure for connecting and holding in place a cartridge (100) for a plasma torch according to claim 1, this structure having an upper part (82) comprising a bore (83) for receiving the anode (1) of the cartridge (100), a central axial hole (91) the diameter of which is at least equal to or greater than the diameter of the upper part (13) of the central cavity (10) of the anode (1), and a lower part (81) comprising a bore (83) for receiving the support (2) of the cartridge, the structure having means (89, 90, 92, 96, 97) of fixing to the cartridge (100) and carrying inlets (86, 87) for a cooling fluid, plasmagene gas, and means (84) of draining the cooling fluid these means positioning themselves, when the cartridge (100) is assembled in the structure (80), opposite the corresponding conduits (127, 130, 75) of the cartridge (100).

20. A plasma torch according to claim 19 characterised in that the means of fixing to the cartridge (100) the fixing and holding structure (80) comprises a stirrup piece (92) fixed rotationally to the upper part (82) of the structure (80) comprising the bore (85) for receiving the anode (1) of the cartridge, a screw (94) mounted in the stirrup piece (92) acting as support on the lower part (81) of the structure (80) comprising the bore (83) for receiving the support (2) of the cartridge (100).

21. A cartridge (100) according to claim 7 characterised in that, in the assembled position, the lower surface (59) of the lower ring (51) of the assembler (5) does not abut the bottom (27) of the groove (24) of the support (2), in such a way that a third annular volume (73) is provided between this lower surface (59) and the bottom (27) of the groove (24), one of the conduits (28) communicating with the outside emerging in this volume (73).

22. A cartridge (100) according to claim 8 characterised in that it comprises a centring device (4) having an axial cavity centred on the cathode (3), a lower surface (46), a lateral outer surface (38, 50), a lateral inner surface (39), an upper surface (48, 49) at least one upper part (42) of the centring device (4) being fitted inside the central cavity (10) of the anode (1), one or more passages (44, 144, 95, 45, 64, 68, 74) bringing into communication the lateral outer or lower surface (50, 46) with the upper surface (48, 49) of the upper part (42) of the centring device (4).

23. A cartridge (100) according to claim 11 characterised in that conduits (44, 144) have an end emerging in a radial groove (148) formed on the lateral outer surface (50) of the centring device (4).

24. A cartridge (100) according to claim 11 characterised in that conduits (44, 144) have an end emerging in a radial inner groove (135) of the inner cavity (10) of the anode (1).

25. A cartridge (100) according to claim 13 characterised in that the anode (1) is fitted with one or more conduits (127) passing axially through a central ring (123) of the anode (1) surrounding the central cavity (10) of the anode (1) and emerging opposite one end of the passages (44, 144) of the centring device (4).

26. A cartridge (100) according to claim 13 characterised in that the support (2) is fitted with one or more conduits (75) passing through the support (2) and communicating with passages (64, 68, 74) of the centring device (4).

27. A cartridge (100) according to claim 13 characterised in that the support (2) is fitted with a central bore (23), this bore (23) housing a lower part of the cathode (3).

28. A plasma torch characterised in that it comprises a structure for connecting and holding in place a cartridge (100) for a plasma torch according to claim 18, this structure having an upper part (82) comprising a bore (83) for receiving the anode (1) of the cartridge (100), a central axial hole (91) the diameter of which is at least equal to or greater than the diameter of the upper part (13) of the central cavity (10) of the anode (1), and a lower part (81) comprising a bore (83) for receiving the support (2) of the cartridge, the structure having means (89, 90, 92, 96, 97) of fixing to the cartridge (100) and carrying inlets (86, 87) for a cooling fluid, plasmagene gas, and means (84) of draining the cooling fluid these means positioning themselves, when the cartridge (100) is assembled in the structure (80), opposite the corresponding conduits (127, 130, 75) of the cartridge (100).