Progress in Plasma Processing of Materials, 2003

ISBN Print: 978-1-56700-192-1

ISBN Online: 978-1-56700-447-2

NEW DEVELOPMENTS IN DC-PLASMA TORCHES

DOI: 10.1615/ITPPC-2002.200
pages 165-174

Abstrakt

In a short survey of Direct Current (DC) Plasma torches used in industry mainly for plasma spraying applications, different principles of torch construction and operation are described. Some restrictions of these conventional torches have led to the development of two innovative torches: With the TRIPLEX-torch characterized by three cathodes, a cascaded nozzle and a single ringshaped anode a substantial reduction of plasma jet fluctuations as well as an increased plasma spraying efficiency has been achieved. In the LARGE-torch, which can be operated with oxidizing and corrosive gases, the plasma gas is fed perpendicularly to and through a long straight arc. The generated broad flat plasma flow can be used for many plasma based modifications particularly of extended or band shaped surfaces.