Plasma arch torch cutting component with optimized water cooling

• US 8,772,667 B2
• Filed: 02/08/2008
• Issued: 07/08/2014
• Est. Priority Date: 02/09/2007
• Status: Active Grant

• Current Assignee: Hypertherm Incorporated
• Original Assignee: Hypertherm Incorporated
• Inventors: Yang, Yong, Cook, David Jonathan, Shipulski, E. Michael
• Primary Examiner(s): JENNISON, BRIAN W
• Application Number:
  US12/028,768
• Publication Number:
  US 20080210669A1
• Time in Patent Office: 2,342 Days
• Field of Search: 219/121.39, 21912148-12154, 219/121.57
• US Class Current: 219/121.48
• CPC Class Codes: B23K 10/00 Welding or cutting by means of a plasma
• CPC Class Codes: H05H 1/28 Cooling arrangements
• CPC Class Codes: H05H 1/34 Details, e.g. electrodes, nozzles
• CPC Class Codes: H05H 1/3436 Hollow cathodes with internal coolant flow
• CPC Class Codes: H05H 1/3442 Cathodes with inserted tip
• CPC Class Codes: H05H 1/3457 Nozzle protection devices

Abstract

A nozzle or retaining cap for a plasma arc torch that includes a surface defining a conductive contact portion for exchanging heat with an adjacent torch component. The adjacent torch component can be a retaining cap, electrode or nozzle. The surface of the nozzle or retaining cap can also at least partially define a cooling channel having a curvilinear surface. A sealant portion can be positioned between the conductive contact portion and the cooling channel. The sealant portion can form or create a fluid barrier between the cooling channel and the conductive portion.

Claims

1. A nozzle for a plasma arc torch comprising:

an exterior surface defining a conductive contact portion for exchanging heat with an adjacent torch component;

a curvilinear surface having a concave curvilinear portion defining a fluid flow path to reduce stagnation of a flow fluid, the curvilinear surface facing outward relative to a longitudinal axis of the nozzle; and

a sealant portion positioned between the conductive contact portion and the fluid flow path, the sealant portion prevents the flow fluid from leaking out of the plasma arc torch,

wherein the fluid flow path includes at least a portion of a fluid chamber having a convex curvilinear portion, the convex curvilinear portion promoting fluid flow into the concave curvilinear portion.

2. The nozzle of claim 1, wherein the nozzle includes an elastomeric seal disposed within the sealant portion.

3. The nozzle of claim 1 further comprising a face seal on a surface of a rear portion of the nozzle.

4. The nozzle of claim 1, wherein the fluid flow path forms at least a portion of a toroidal chamber.

5. The nozzle of claim 1, wherein the conductive contact portion defines a curved or angled contact surface.

6. The nozzle of claim 5, wherein the contact surface provides axial and radial alignment of the nozzle to the adjacent torch component.

7. The nozzle of claim 1, wherein the conductive contact portion includes a layer of a conductive metal or metal oxide disposed thereon.

8. A convective cooling structure for a plasma arc torch disposed in at least one of a nozzle and a retaining cap of the plasma arc torch, the convective cooling structure comprising:

a concave curvilinear portion defining at least a portion of a channel;

a convex curvilinear portion for promoting fluid flow into the concave curvilinear portion; and

a tangential connection portion disposed between the convex and concave curvilinear portions, wherein the convex curvilinear portion defines at least a portion of a fluid flow path.

9. The convective cooling structure of claim 8, wherein the cooling structure is at least partially disposed within the nozzle.

10. The convective cooling structure of claim 9, wherein the cooling structure is at least partially disposed within the retaining cap.

11. The convective cooling structure of claim 8, wherein the channel is disposed within the nozzle of the plasma arc torch.

12. The convective cooling structure of claim 11, wherein the channel intrudes into a wall thickness of the nozzle.

13. The convective cooling structure of claim 8, wherein the channel is configured to reduce fluid flow stagnation.

14. A nozzle for use in a fluid-cooled plasma torch, the nozzle comprising:

a body having an outer perimeter that partially defines a fluid channel that has a curvilinear surface having a concave curvilinear portion defining a fluid flow path to reduce stagnation of a flow fluid, the curvilinear surface facing outward relative to a longitudinal axis of the nozzle, the body including an end face, the end face is perpendicular to the longitudinal axis of a component;

a groove extending at least partially through the end face;

an elastomeric seal disposed within the groove to provide a barrier between a plasma gas flow and the fluid channel, the elastomeric seal prevents the flow fluid from leaking out of the plasma arc torch,

wherein the fluid flow path includes at least a portion of a fluid chamber that includes a convex curvilinear portion, the convex curvilinear portion promoting fluid flow into the concave curvilinear portion.

15. The nozzle of claim 14, wherein the elastomeric sealing element comprises an o-ring.

16. The nozzle of claim 14 further comprising a forward portion and a rear portion, the forward portion including a front face defining an exit orifice, a shoulder portion sized to provide conductive heat transfer with an adjacent component, and an elastomeric seal disposed between the shoulder portion and the rear portion, wherein the elastomeric seal deforms to provide a fluid seal with the adjacent component.

17. A fluid cooled plasma arc torch nozzle comprising:

a forward portion and a rear portion, the forward portion including a front face defining an exit orifice;

a conductive shoulder portion sized to axially align with an adjacent component;

a fluid-cooled portion disposed between the shoulder portion and the rear portion, wherein the fluid-cooled portion includes a curvilinear surface having a concave curvilinear portion defining a fluid flow path to reduce stagnation of a flow fluid, the curvilinear surface facing outward relative to a longitudinal axis of the nozzle; and

a sealing member disposed between the liquid cooling portion and the conductive shoulder portion, the sealing member prevents the flow fluid from leaking out of the plasma arc torch,

wherein the fluid flow path includes at least a portion of a fluid chamber that includes a convex curvilinear portion, the convex curvilinear portion promoting fluid flow into the concave curvilinear portion.

18. The nozzle of claim 17 wherein the fluid-cooled portion comprises a toroidal shape.

19. A plasma arc torch system comprising:

a power supply;

a torch body connected to the power supply;

an electrode disposed within the torch body;

a torch component with a surface defining a conductive contact portion for exchanging heat with an adjacent torch component and a convective cooling structure comprising a concave curvilinear portion that defines at least a portion of a cooling channel and a convex curvilinear portion, the convex curvilinear portion promoting fluid flow into the concave curvilinear portion.

20. The plasma arc torch system of claim 19 further comprising a sealing component dimensioned and configured to provide a fluid seal between the conductive contact portion and the convective cooling structure.

21. The plasma arc torch system of claim 19 wherein the sealing component is located on at least one of the torch component or the adjacent torch component.

22. The plasma arc torch system of claim 19 further comprising a controller and gas console.

23. A method of cooling a plasma torch component comprising:

exchanging heat from a nozzle with an adjacent torch component through a conductive contact portion;

flowing a cooling fluid through a cooling channel having a curvilinear surface, the curvilinear surface configured to reduce stagnation of the cooling fluid, the curvilinear surface facing outward relative to a longitudinal axis of the nozzle; and

providing a barrier comprising a sealing component between the conductive contact portion and the cooling channel, the barrier prevents the cooling fluid from leaking out of the plasma arc torch,

wherein a fluid flow path includes at least a portion of a fluid chamber that includes a convex curvilinear portion, the convex curvilinear portion promoting fluid flow into the concave curvilinear portion.