Study on the influences of the anode structures on the jet characteristics of a laminar plasma torch

Abstract

There are two types of direct current thermal plasma jet based on flow status: turbulent plasma jet and laminar plasma jet. Laminar plasma jet has more advantages for high-precision applications than turbulent jet. Previous researches have been done to study factors that influence the jet characteristics for particular applications. However, more researches should be done to understand the influences of the anode structures on the jet characteristics. Therefore, this paper aims to study the jet characteristics of the laminar plasma torch with different anode structures experimentally. The experimental setup and methods are explained in detail in section 2. Then, results with different anode structures are examined and discussed. The experimental results show that different anode structure results in different jet characteristics, which is beneficial for the design of the laminar plasma torch. To conclude, a bigger diameter of the anode is beneficial for obtaining a higher arc voltage and thermal efficiency, nevertheless, a medium jet length and an anode with a smaller diameter is not recommended because of the low jet length. Furthermore, an anode with semicircular grooves on the inner surface can generate a more stable and long laminar plasma jet with a lower arc voltage but more intense erosion.