The present invention relates to a method and device for CO.sub.2 plasma cutting of a work piece, using a plasma cutting torch, wherein an arc is generated between the cutting head and the work piece, and a shielding gas is provided around the arc, characterized in that the shielding gas comprises CO.sub.2-snow or a mixture containing CO.sub.2-snow.

The present invention relates to a device for plasma cutting, comprising a cutting torch (100) provided with an electrode (120), which is coaxially surrounded by a nozzle (110), thereby defining a passage (112) for passing of a plasma gas between electrode and nozzle, wherein the nozzle is coaxially surrounded by a shielding cap (122), thereby defining a passage (114) for passing of a shielding flow between nozzle and shielding cap, the device further comprising an annular member (200) coaxially surrounding the cutting torch (100) configured and adapted to provide a further curtain flow coaxially surrounding the shielding flow through passage (250a and 250b) wherein annular member (200) is configured and adapted for use of CO.sub.2-snow or a mixture containing CO.sub.2-snow as shielding flow.

A plasma cutting method providing a plasma torch having an electrode disposed within a first nozzle with a first exit section facing an end of the electrode. The first gas source supplies a gas to the first nozzle. A second nozzle is arranged concentrically around the first nozzle and has a second exit section substantially facing the first exit section. A second gas source supplies the gas between the first nozzle and the second nozzle. The electrode is supplied with a current, and the first and second nozzles are supplied with the gas to form a plasma with the gas introduced into the first nozzle. The surrounding pressure around the plasma jet in the second nozzle at the exit of the first nozzle is controlled to be at least superior to the atmospheric pressure and inferior to the pressure in the first exit section.

Embodiments of the present invention are directed to an air cooled cutting torch having improved performance. The torch comprises an improved electrode, where the electrode has at least one gas flow port to allow air flow to pass through the electrode to improve cooling and performance.

This specification describes systems, methods, and architectures related to generating a plasma shield for laser operations. An example system for generating a plasma shield includes a laser head for directing a laser beam towards a target area on a workpiece. The path of the laser beam from the laser head to the target area on the workpiece is substantially surrounded by a plasma shield, which may form a gas-impermeable barrier. The plasma shield is configured to prevent the ingress of atmospheric or environmental gases, for example oxygen, into an area which would allow the gas to be in contact with the area of the workpiece being interacted with by a laser beam. The shape or location of the plasma shield may be controlled or altered using a magnetic field.

The present invention relates to a plasma-generating device, comprising an anode, a cathode and at least one intermediate electrode, said intermediate electrode being arranged at least partly between said anode and said cathode, and said intermediate electrode and said anode forming at least a part of a plasma channel which has an opening in said anode. Further, the plasma-generating device comprises at least one coolant channel which is arranged with at least one outlet opening which is positioned beyond, in the direction from the cathode to the anode, said at least one intermediate electrode, and the channel direction of said coolant channel at said outlet opening has a directional component which is the same as that of the channel direction of the plasma channel at the opening thereof. The invention also concerns a plasma surgical device and use of such a plasma surgical device.

This specification describes systems, methods, and architectures related to generating a plasma shield for laser operations. An example system for generating a plasma shield includes a laser head for directing a laser beam towards a target area on a workpiece. The path of the laser beam from the laser head to the target area on the workpiece is substantially surrounded by a plasma shield, which may form a gas-impermeable barrier. The plasma shield is configured to prevent the ingress of atmospheric or environmental gases, for example oxygen, into an area which would allow the gas to be in contact with the area of the workpiece being interacted with by a laser beam. The shape or location of the plasma shield may be controlled or altered using a magnetic field.

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.

The present invention relates to a plasma-generating device, comprising an anode, a cathode and at least one intermediate electrode, said intermediate electrode being arranged at least partly between said anode and said cathode, and said intermediate electrode and said anode forming at least a part of a plasma channel which has an opening in said anode. Further, the plasma-generating device comprises at least one coolant channel which is arranged with at least one outlet opening which is positioned beyond, in the direction from the cathode to the anode, said at least one intermediate electrode, and the channel direction of said coolant channel at said outlet opening has a directional component which is the same as that of the channel direction of the plasma channel at the opening thereof. The invention also concerns a plasma surgical device and use of such a plasma surgical device.

Embodiments of the present invention are directed to an air cooled cutting torch having improved performance. The torch comprises an improved electrode, where the electrode has at least one gas flow port to allow air flow to pass through the electrode to improve cooling and performance.