Cooled plasma torch and method for cooling the torch

• US 20060289406A1
• Filed: 09/17/2004
• Published: 12/28/2006
• Est. Priority Date: 09/17/2003
• Status: Active Grant

• Current Assignee: Tomion OY
• Original Assignee: Tomion OY
• Inventors: Ahola, Kari, Helenius, Pekka
• Granted Patent: US 7,544,913 B2
• Time in Patent Office: Days
• US Class Current: 219/121.480
• CPC Class Codes: H05H 1/28 Cooling arrangements
• CPC Class Codes: H05H 1/34 Details, e.g. electrodes, nozzles
• CPC Class Codes: H05H 1/3478 Geometrical details

Abstract

The invention relates to a cooled plasma torch comprising an electrode, a plasma chamber surrounding the electrode, and a coolant space surrounding the plasma chamber with at least one common wall with the plasma chamber. The plasma torch further comprises means for feeding a coolant medium into the coolant space. The coolant medium pressure is reduced in a fashion that causes a phase change in the coolant medium as it is passed from the coolant feed means to the coolant space, whereby the plasma torch is cooled.

Claims

1-13. -13. (canceled)

14. A cooled plasma torch comprising:

an electrode,

a plasma chamber surrounding the electrode,

a coolant space surrounding the plasma chamber with at least one common wall with the plasma chamber,

means for feeding a coolant medium into the coolant space, and

means for reducing the pressure of the coolant medium in a fashion that causes a phase change in the coolant medium as it is passed from said means to said coolant space.

15. The plasma torch of claim 14, wherein said means for reducing the pressure of the coolant medium is an evaporation nozzle exiting into said coolant space.

16. The plasma torch of claim 14, wherein said means for reducing the pressure of the coolant medium is a channel formed into said coolant space.

17. The plasma torch of claim 14, wherein said means for reducing the pressure of the coolant medium is a porous material adapted into said coolant space.

18. The plasma torch of claim 14, wherein the coolant medium is a liquefied gas that regains its gasous form in a phase change.

19. The plasma torch of claim 18, wherein the coolant medium is carbon dioxide.

20. The plasma torch of claim 14, further comprising a plasma torch handle, wherein said plasma torch handle incorporates at least at least one check valve capable of controlling coolant medium flow to means adapted to feed said coolant medium into said coolant space.

21. The plasma torch of claim 14, further comprising an electrode holder with a bore for accommodating an electrode bushing, wherein said electrode bushing is provided with a groove serving to form in cooperation with said bore a flow channel suited for passing therethrough a plasma gas into said plasma chamber.

22. The plasma torch of claim 14, comprising means for reliquefication of said coolant medium.

23. A method for cooling a plasma torch, in which method a coolant medium passed into a coolant space surrounding the plasma chamber of the plasma torch, the method including the steps of:

using a coolant medium having at least a liquid phase and a gaseous phase,

feeding the coolant medium in liquid phase into the plasma torch, and

reducing the pressure of the coolant medium at the instant it enters the coolant space so much as to convert the coolant medium into gaseous form.

24. The method of claim 23, whereby there is used a coolant medium pressurized into liquid form from its natural gaseous form at room temperature.

25. The method of claim 24, wherein the coolant medium is carbon dioxide.

26. The method of claim 23, wherein the coolant medium discharged in gaseous form is recovered and reliquefied back into liquid form by compression.