Plasma Torch

plasma torch [′plaz·mə ‚tȯrch]

(engineering)

A torch in which temperatures as high as 50,000°C are achieved by injecting a plasma gas tangentially into an electric arc formed between electrodes in a chamber; the resulting vortex of hot gases emerges at very high speed through a hole in the negative electrode, to form a jet for welding, spraying of molten metal, and cutting of hard rock or hard metals.

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Plasma Torch 

a hand-operated arc plasmatron used in applying coatings, cutting, welding, hard facing, and other processes. Two types exist; they differ in their principle of operation, using either plasma arcs or plasma jets. For mechanized work plasma torches are attached to special mounts. When used in applying coatings and in hard facing, they are usually equipped with devices for feeding the material to be sprayed or hard faced, which is in the form of a powder or wire. Such plasma torches are called plasma heads. The power output of plasma torches may be as high as 100 kilowatts. Ar, He, N₂, NH₃, air, and mixtures thereof can be used as plasma-forming gases. Various methods of initiating the arc discharge are possible; for example, the gap between the torch’s cathode and anode—for a plasma jet —or between the cathode and the metal being processed—for a plasma arc—may be closed.