Editing Plasma torch (section)

=== Transferred vs. non-transferred ===
There are two types of DC torches: non-transferred and transferred. In non-transferred DC torches, the electrodes are inside the body/housing of the torch itself (creating the arc there). Whereas in a transferred torch one electrode is outside (and is usually the conductive material to be treated), allowing the arc to form outside of the torch over a larger distance.

A benefit of transferred DC torches is that the plasma arc is formed outside the water-cooled body, preventing heat loss—as is the case with non-transferred torches, where their electrical-to-[[thermal efficiency]] can be as low as 50%, but the hot water can itself be utilized.<ref name="Hrabovsky" /> Furthermore, transferred DC torches can be used in a twin-torch setup, where one torch is [[Cathodic#Chemistry cathode|cathodic and the other anodic]], which has the earlier benefit of a regular transferred single-torch system, but allows their use with [[Insulator (electricity)|non-conductive]] materials, as there is no need for it to form the other electrode.<ref name="Gomez" /> However, these types of setups are rare as most common non-conductive materials do not require the precise cutting ability of a plasma torch. In addition, the discharge generated by this particular plasma source configuration is characterized by a complex shape and fluid dynamics that  requires a 3D description in order to be predicted, making performance unsteady. The electrodes of non-transferred torches are larger, because they suffer more wear by the plasma arc.

The quality of plasma produced is a function of density (pressure), temperature and torch power (the greater the better). With regards to the efficiency of the torch itself—this can vary among manufacturers and torch technology; though for example, Leal-Quirós reports that for Westinghouse Plasma Corp. torches “a thermal efficiency of 90% is easily possible; the efficiency represents the percentage of arc power that exits the torch and enters the process”.<ref name="Leal-Quiros">{{cite journal |author=Leal-Quirós, Edbertho |date=2004 |title=Plasma Processing of Municipal Solid Waste |journal= Brazilian Journal of Physics |volume=34 |issue=4B |page=1587 |bibcode = 2004BrJPh..34.1587L |doi=10.1590/S0103-97332004000800015|doi-access=free }}</ref>