Influence of Novel Anode Structure on the Heat Flow Characteristics and Jet Stability of Pure Nitrogen Laminar Torch

For improving the jet stability of pure laminar plasma torch to ensure the consistency of the surface treatment, based on previous studies, a novel anode structure, named as internal step anode, has been proposed. Sequences, the effects of axial lengths of the internal step anode on the jet stability and heat flow characteristics have been explored by using a home-made simulation model. Finally, corresponding experiments have been conducted to verify the effectiveness of the anode optimization. Research results show that: (1) With increasing the axial lengths of the internal step anode, the temperature and velocity of the anode area increase slightly, on the contrary, the corresponding anode current density decreases slightly, which is conducive to extending the electrode life; (1) the internal step anode is beneficial for improving the jet stability of pure laminar plasma torch. With increasing the axial length of the internal step anode, the jet stability increases to certain level and then decreases smoothly. When the axial length is 5 mm, the plasma torch presents the highest jet stability.