CIPASS — An ignition method for the innovative plasma torch “LARGE”

Department of Electrical Engineering, UniBw-Munich, Germany

Corresponding author: ralf.hartmann@unibw-muenchen.de

Received: 10 June 1999
Revised: 23 September 1999
Accepted: 24 September 1999
Published online: 15 December 1999

Abstract

Most plasma torches applied in modern thermal plasma processes can be ignited by a high voltage sparkover or by a pilot arc because of the small distance between cathode and anode. The innovative plasma torch LARGE however is characterized by an arrangement of the electrodes opposite to each other on a common axis with a variable distance up to some hundred millimeters. The central part of the torch between the electrodes is divided into electrically insulated cascade plates. For industrial application of the torch LARGE a complete electronic ignition for high currents is substantial. A new semiconductor based method of Combined Ignition by Pilot Arcing and Successive Switching (CIPASS) was developed. This ignition technique was investigated by electrical and optical diagnostics.