Water injection and venting of a plasma arc torch

Patent metadata

Field	Value
Publication number	US-10149376-B2
Application number	US-201414567387-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 11, 2014
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A plasma arc torch system comprising a plasma arc torch is provided. The torch includes an electrode, a nozzle, a vent passage and a shield. The nozzle is spaced from the electrode to define a plasma chamber therebetween. The plasma chamber is configured to receive a plasma gas. The vent passage, disposed in the nozzle body, is configured to divert a portion of the plasma gas exiting the plasma chamber from a nozzle exit orifice. The shield is spaced from the nozzle to define a flow region therebetween. The flow region is configured to (i) receive a liquid and (ii) expel the liquid along with a plasma arc substantially surrounded by the liquid via a shield exit orifice.

First claim

What is claimed is:

1. A plasma arc torch system having a supply system including a liquid source for supplying a liquid, and a liquid supply conduit in fluid communication with a liquid passageway between a nozzle and a shield of a plasma arc torch to introduce the liquid from the liquid source to a flow region of a plasma arc torch, thereby surrounding the plasma arc with the liquid, the plasma arc torch including:
an electrode;
the nozzle spaced from the electrode to define a plasma chamber therebetween, the nozzle comprising a nozzle body, a nozzle exit orifice, and a vent outlet, wherein the plasma chamber is configured to receive a plasma gas;
a vent passage disposed in the nozzle body configured to divert a portion of the plasma gas exiting the plasma chamber to the vent outlet, thereby constricting the plasma arc; and
a shield spaced from the nozzle to define the liquid passageway and the flow region therebetween, the shield comprising a shield exit orifice in fluid communication with the nozzle exit orifice, wherein the liquid passageway is configured to receive the liquid and introduce the liquid having a liquid swirl strength to the flow region such that the liquid surrounds and constricts the plasma arc, and the flow region is configured to expel the liquid along with the plasma arc surrounded by the liquid at the shield exit orifice,
wherein diverting the portion of the plasma gas by the vent passage in the nozzle and expelling the liquid at the shield exit orifice both provide constriction of the plasma arc.

2. The plasma arc torch system of claim 1 , wherein the supply system further includes:
an activation valve disposed between the liquid source and the torch along the liquid supply conduit, the activation valve configured to enable or disable a flow of the liquid to the flow region.

3. The plasma arc torch system of claim 2 , wherein the supply system further comprises a pressure regulator coupled to the liquid supply conduit for regulating a liquid pressure value associated with the flow of the liquid in the liquid supply conduit.

4. The plasma arc torch system of claim 2 , wherein the supply system further comprises a flow valve disposed between the liquid source and the torch along the liquid supply conduit, the flow valve configured to regulate a flow rate of the flow of the liquid in the liquid supply conduit.

5. The plasma arc torch system of claim 2 , wherein the supply system further comprises a flow meter disposed between the liquid source and the torch along the liquid supply conduit, the flow meter configured to measure a flow rate of the flow of the liquid in the liquid supply conduit.

6. The plasma arc torch system of claim 2 , further comprising:
a gas supply conduit configured to supply a shield gas from a gas source to the flow region; and
a shield fluid conduit formed by joining the gas supply conduit and the liquid supply conduit downstream from the activation valve, wherein the shield fluid conduit is configured to convey one of the shield gas from the gas supply conduit or the liquid from the liquid supply conduit to the flow region depending on an operator selection.

7. The plasma arc torch system of claim 1 , wherein the supply system further includes:
a pressure regulator coupled to the liquid supply conduit for regulating a liquid pressure value associated with a flow of the liquid in the liquid supply conduit;
a flow valve disposed between the liquid source and the torch along the liquid supply conduit for regulating a flow rate of the flow of the liquid in the liquid supply conduit;
an activation valve disposed between the liquid source and the torch along the liquid supply conduit for enabling or disabling a flow of the liquid to the flow region; and
an optional flow meter configured to measure the flow rate of the flow of the liquid in the liquid supply conduit.

8. The plasma arc torch system of claim 1 , wherein the supply system further includes:
the liquid supply conduit for conducting the liquid from the liquid source to the torch;
a pressure regulator coupled to the liquid supply conduit for regulating a liquid pressure value associated with a flow of the liquid in the liquid supply conduit;
an activation valve disposed between the liquid source and the torch along the liquid supply conduit for enabling or disabling the flow of the liquid to the flow region; and
an optional flow meter configured to measure a flow rate of the flow of the liquid in the liquid supply conduit.

9. The plasma arc torch system of claim 1 , wherein the supply system further includes:
a flow valve disposed between the liquid source and the torch along the liquid supply conduit for regulating a flow rate of a flow of the liquid in the liquid supply conduit;
an activation valve disposed between the liquid source and the torch along the liquid supply conduit for enabling or disabling the flow of the liquid to the flow region; and
a flow meter disposed between the liquid source and the torch along the liquid supply conduit for measuring the flow rate of the flow of the liquid in the liquid supply conduit.

10. The plasma arc torch system of claim 1 , wherein the vent passage has an inlet located upstream from the nozzle exit orifice.

11. The plasma arc torch system of claim 1 , wherein the shield exit orifice is aligned with the nozzle exit orifice to define a conduit for expelling the liquid, the plasma arc and an unionized portion of the plasma gas.

12. The plasma arc torch system of claim 1 , wherein the liquid introduced to the shield has low or no swirl.

13. The plasma arc torch system of claim 1 , wherein the nozzle exit orifice is configured to constrict the plasma arc exiting the plasma chamber to the flow region via the nozzle exit orifice.

14. The plasma arc torch system of claim 1 , wherein the plasma gas is at least one of nitrogen, F5 or air.

15. The plasma arc torch system of claim 1 , wherein the liquid is water.

16. The plasma arc torch system of claim 1 , wherein a combination of the plasma gas and the liquid produces hydrogen.

Assignees

• Hypertherm Inc

Inventors

• Mitra Madhura
• Mitra Soumya
• Liebold Stephen

Classifications

• H05H1/34

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

• H05H1/42 Primary

  with provisions for introducing materials into the plasma, e.g. powder or liquid {(arc stabilising or constricting arrangements H05H1/3405; coaxial protecting fluids H05H1/341)} · CPC title

• B23K10/00

  Welding or cutting by means of a plasma · CPC title

• H05H1/341

  Arrangements for providing coaxial protecting fluids · CPC title

• H05H1/28 Primary

  Cooling arrangements · CPC title