Plasma arc cutting system, including nozzles and other consumables, and related operational methods

Patent metadata

Field	Value
Publication number	US-10681799-B2
Application number	US-201715484182-A
Country	US
Kind code	B2
Filing date	Apr 11, 2017
Priority date	Apr 11, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A nozzle for a liquid-cooled plasma arc torch is provided. The nozzle includes a thermally conductive body having a distal end, a proximal end, and a longitudinal axis extending therethrough. The nozzle also includes a plasma arc exit orifice at the distal end of the thermally conductive body. The nozzle additionally includes a cooling waist located circumferentially about an exterior surface of the thermally conductive body. The cooling waist includes a liquid inlet slope, a liquid outlet slope and a heat exchange region between the liquid inlet slope and the liquid outlet slope. The heat exchange region extends substantially parallel to the longitudinal axis, and the liquid inlet slope and the liquid outlet slope are oriented generally perpendicular to the longitudinal axis.

First claim

What is claimed is:

1. A nozzle for a liquid-cooled plasma arc torch, the nozzle comprising:
a thermally conductive body having a distal end, a proximal end, and a longitudinal axis extending therethrough;
a plasma arc exit orifice at the distal end of the thermally conductive body;
a cooling waist located on an external surface of the body and disposed circumferentially about the exterior surface, the cooling waist including a liquid inlet slope, a liquid outlet slope and a heat exchange region between the liquid inlet slope and the liquid outlet slope, wherein the heat exchange region extends substantially parallel to the longitudinal axis, and wherein the liquid inlet slope and the liquid outlet slope are oriented generally perpendicular to the longitudinal axis such that the liquid inlet and outlet slopes extend radially outward from the external surface of the body while being disposed circumferentially about the external surface;
a first sealing member located on the external surface between the liquid outlet slope and the distal end of the thermally conductive body; and
a second sealing member located on the external surface between the proximal end of the thermally conductive body and the liquid inlet slope.

2. The nozzle of claim 1 , wherein the liquid inlet slope and the liquid outlet slope are at different axial locations in relation to the longitudinal axis.

3. The nozzle of claim 1 , wherein the cooling waist is configured to facilitate a laminar flow of a liquid coolant therethrough, such that the liquid coolant entering the liquid inlet slope does not substantially intermingle with the liquid coolant exiting from the liquid outlet slope.

4. The nozzle of claim 1 , wherein the liquid inlet slope comprises an axial alignment flange configured to axially align the nozzle with another component of the plasma arc torch.

5. The nozzle of claim 1 , wherein the cooling waist is generally located in a center portion of the body.

6. The nozzle of claim 1 , further comprising a third sealing member located between the second sealing member and the proximal end of the body.

7. The nozzle of claim 6 , further comprising a vent hole located between the third sealing member and the second sealing member, the vent hole configured to connect an interior surface of the body to the exterior surface of the body.

8. The nozzle of claim 6 , further comprising a supply hole located between the third sealing member and the proximal end of the body, the supply hole configured to connect an exterior surface of the body to the interior surface of the body.

9. The nozzle of claim 1 , further comprising a vent hole between the first sealing member and the distal end of the body, the vent hole configured to connect an interior surface of the body to a shield gas supply channel.

10. The nozzle of claim 1 , further comprising a retaining cap coupled to the exterior surface of the body to define a chamber in cooperation with the cooling waist.

11. The nozzle of claim 10 , wherein the chamber has a volume of about 0.03 cubic inches.

12. A nozzle for a liquid cool plasma torch, the nozzle comprising:
a body having a distal end, a proximal end, and a longitudinal axis extending therethrough;
a plasma arc exit orifice disposed at the distal end of the body;
a cooling means centrally located on an exterior surface of the body between the distal end and the proximal end, the cooling means circumferentially oriented about the body, the cooling means having an inlet means for receiving a liquid coolant and an outlet means for redirecting the liquid coolant radially outward from the external surface of the body in a laminar flow pattern around a circumference of the external surface, the inlet and the outlet means are axially spaced from one another on the external surface;
a first sealing means located on the external surface of the body between the outlet means and the distal end of the body; and
a second sealing means located on the external surface of the body between the inlet means and the proximal end of the body.

13. The nozzle of claim 12 , further comprising at least one venting means disposed in the body.

14. The nozzle of claim 12 , wherein the cooling means is configured to prevent liquid coolant in the inlet means from intermingling with the liquid coolant in the outlet means.

15. A method for liquid cooling the nozzle of claim 1 in a plasma arc torch, the method comprising:
directing a liquid coolant flow along the inlet slope of the cooling waist on the external surface of the nozzle body at an angle generally perpendicular to the longitudinal axis;
conducting the liquid coolant flow along the heat exchange region of the cooling waist substantially parallel to the longitudinal axis, the heat exchange region located between the inlet slope and the outlet slope of the cooling waist on the external surface of the body; and
directing the liquid coolant flow over the outlet slope radially outward away from the external surface of the nozzle at an angle generally perpendicular to the longitudinal axis, the outlet slope distal to the inlet slope,
wherein the liquid coolant flow through the cooling waist comprises a substantially laminar flow such that the liquid coolant flow through the inlet slope does not substantially intermingle with the liquid coolant flow over the outlet slope.

16. The method of claim 15 , further comprising sealing the nozzle by one or more of the first sealing member at a first sealing location between the outlet slope and the distal end of the body, the second sealing member at a second sealing location between the proximal end of the body and the inlet slope, and a third sealing member at a third sealing location between the second sealing member and the proximal end of the body.

17. The method of claim 16 , further comprising venting at least a portion of a gas flow through at least one of a first vent hole located between the third sealing location and the second sealing location and a second vent hole between the first sealing location and the distal end of the body.

18. The method of claim 16 , further comprising supplying a gas flow into an interior region of the nozzle through a supply hole located between the third sealing location and the proximal end of the body.

19. The method of claim 15 , further comprising coupling a retaining cap to the exterior surface of the body to create a chamber in cooperation with the cooling waist.

20. The method of claim 19 , wherein the chamber has a volume of about 0.03 cubic inches.

21. The method of claim 15 , further comprising axially aligning the nozzle in relation to another component in the plasma arc torch using an axial alignment flange at the inlet slope.

22. The method of claim 15 , further comprising operating the plasma arc torch at about 170 amps or less.

Assignees

• Hypertherm Inc

Inventors

• Peters John
• Currier Brian J
• Mitra Madhura S
• Mitra Soumya

Classifications

• H05H1/34 Primary

  Details, e.g. electrodes, nozzles · CPC title

• B23K10/006

  Control circuits therefor · CPC title

• B23K37/003

  Cooling means for welding or cutting · CPC title

• H05H2001/3468

  Electricity · mapped topic

• H05H1/3405

  Arrangements for stabilising or constricting the arc, e.g. by an additional gas flow · CPC title