One object of the present invention is to provide a plasma welding method capable of performing plasma welding while restraining initial investment in a welding device, and the present invention provide a plasma welding method includes a pilot arc generation step in which a pilot arc is generated between the electrode and the insert chip by supplying a first pilot gas which is easily converted into a plasma state between the electrode and the insert chip while supplying a shield gas between the insert chip and the shield cap; and a first welding step in which, after the pilot arc generation step, a main arc is generated between the electrode and the workpiece by electrically disconnecting the plus terminal and the insert chip by the first selector switch while supplying the first pilot gas and the shield gas.

A swirl ring for a plasma arc torch includes a body configured to at least partially surround and slidingly engage an electrode of the plasma arc torch. The body includes a first end and a second end opposite the first end, the first and second ends defining a longitudinal axis, and at least one protuberance extending from the second end in a direction of the longitudinal axis. The at least one protuberance is configured to engage a switch of the plasma arc torch for sensing a presence of a swirl ring in the plasma arc torch.

A consumable cartridge for a plasma arc torch includes a cartridge frame having a first end and a second end opposite the first end, the first and second ends defining a longitudinal axis, the second end including a plurality of discrete retaining features. The consumable cartridge includes an electrically conductive contact element secured to the cartridge frame by the plurality of discrete retaining features and translatable up to a predetermined distance within the cartridge frame along the longitudinal axis at the second end, the contact element having a core, a proximal surface, and a distal surface. The proximal surface is shaped to contact a torch plunger of the plasma arc torch upon installation into the plasma arc torch and the distal surface is shaped to contact an electrode of the plasma arc torch during an operation of the plasma arc torch.

A nozzle for a gas-cooled plasma arc torch is provided. The nozzle includes a nozzle body formed from a first metal. The nozzle body comprises a proximal portion and a distal portion extending along a longitudinal axis. The distal portion of the nozzle body comprises a first bore. The nozzle also includes an arc transition component formed from a second metal. The arc transition component is coupled to the distal portion of the nozzle body and comprises a second bore configured to substantially align with the first bore when the arc transition component is coupled to the nozzle body. The second metal of the arc transition component comprises a noble metal and the second metal is different from the first metal.

In some aspects, methods for controlling a plasma arc in a plasma torch of a plasma cutting system in a low operating current mode can include: receiving, by a computing device within the plasma power supply, a command to begin a plasma processing operation; generating a pilot arc command to generate a pilot arc within the plasma torch, the generating of the pilot arc command including directing an electrical signal and a gas flow to the plasma torch, the electrical signal being configured to generate the pilot arc at a current having a first arc amperage magnitude; and generating an operational arc command to facilitate a transition from the pilot arc to an operational plasma arc, the generating of the operational arc command including adjusting the current directed to the plasma torch to be a second arc amperage magnitude that is lower than the first arc amperage magnitude.

In some aspects, methods for controlling a pneumatic system in a plasma arc processing system can include: receiving, by a computing device, a command to begin a plasma processing operation; generating a valve command signal for a valve that includes an operational drive voltage of at least about 125% of a continuous duty cycle coil voltage rating of the valve to open the valve; and once open, adjusting the valve command signal to facilitate a steady state operation to: monitor a steady state operational duty cycle of the valve, the steady state operational duty cycle being determined by comparing the continuous duty cycle coil voltage rating of the valve to an actual operational drive voltage supplied to the valve, and control the operational drive voltage supplied to the valve to maintain a steady state operational duty cycle of the valve at less than about 60% during steady state operation.

Disclosed is a plasma torch with a structure capable of performing reversed polarity/straight polarity operation, wherein the plasma torch is coupled to a melter and melts a waste material such as radioactive waste or industrial waste by generating and sustaining a plasma arc between electrodes, the plasma torch including: a rear electrode provided inside a torch pipe and electrically connected to become one of an anode and a cathode; and a front electrode provided at a front end of the torch pipe at a position adjacent to a front end of the rear electrode and electrically connected to become a remaining one of the anode and the cathode, wherein electrical connections of the rear and front electrodes are switchable with each other so that the plasma torch operates as a reversed polarity plasma torch or a straight polarity plasma torch.

A two step process for the destruction of a precursor material using a steam plasma in a three zone reactor wherein the precursor material is hydrolyzed as a first step in the high temperature zone of the reactor, followed by a second step of medium temperature oxidation of the reactant stream in the combustion zone of the reactor where combustion oxygen or air is injected and immediate quenching of the resulting gas stream to avoid the formation of unwanted by-products. A related apparatus includes a non transferred direct current steam plasma torch, an externally cooled three zone steam plasma reactor means for introducing the precursor material into the plasma plume of the plasma torch, means for introducing the combustion air or oxygen into the combustion zone, means for exiting the reactant mixture from the reactor and means for quenching the reactant mixture located at the exit end of the reactor.

A swirl ring component of a contact start plasma arc torch is provided. The swirl ring component includes a hollow body formed of a front portion and a rear portion along a longitudinal axis and defining an exterior surface and an interior surface. The swirl ring component also includes one or more gas passageways extending from the exterior surface to the interior surface in the front portion of the hollow body and a resilient element disposed relative to the interior surface in the rear portion of the hollow body and configured to pass at least a pilot arc current to an electrode body. The swirl ring component further includes a shoulder portion configured to retain the resilient element in the hollow body.

A transferred-arc plasma torch comprising a sheath cooled using a cooling fluid and an electrode inserted in said sheath. The electrode is made of a consumable material and the torch comprises means to supply the electrode with this material so as to offset its erosion.