Investigation of the Arc-Anode Attachment Area by Utilizing a High-Speed Camera

Abstract

The arc-anode attachment in the DC plasma arc influences power distribution in the plasma, a lifespan of anode and flow structure of plasma jet. A movement of the attachment and the surrounding plasma was directly observed by using a high-speed camera (max. 1,080,000 fps). The observations were compared with cathode-anode voltage measurements (sample rate 80 MHz). We have directly measured the average velocity of the attachments and hydrodynamic waves above them, as well as the characteristic dwell times and dwell frequencies of the attachments.

Experimental investigation of anode arc attachment area in DC arc plasma torch at low pressures

“…The mentioned turbulent flow was also studied in [34] and the Kelvin-Helmholtz instability in the plasma jet was directly observed e.g. in [35]. It is easier to detect the plasma vortices further from the plasma jet (figure 3(e)) than close to (figure 3(d)) or even inside it (figure 2(b)).…”

Numerical simulation of DC air plasma torch modes and plasma jet instability for thermal spraying technology

“…The efficiency of plasma spraying technology and the quality of the applied coating mainly depend on the properties of powder materials and the characteristics of the plasma flow. That is why the main task in the technological development of new plasma torches for spraying is to obtain optimal flow parameters and operation modes of the plasma torch, providing high service life of the plasma torch's constructive elements [2][3][4][5].…”