GENERATION OF LARGE VOLUME ARC PLASMA, CONTROL AND ITS APPLICATION

Electric arc is a common way to generate thermal plasma, which is widely used in industrial field. However, due to the effect of its self-magnetic compression, the temperature gradient of arc plasma is large and the volume of the high temperature region is small, which restricts the wide application in various fields and the deepening of the application of this technology. To solve this problem, based on arc generation technology, large volume uniform thermal plasma is obtained by various control means, which has shown a very good application prospects in the fields of thermal spraying, micro and nano-powder preparation, coal pyrolysis to produce acetylene, and so on. Based on the application requirements of large-size arc plasma, the paper reviews the research progress of large volume arc plasma technology and application at domestic and abroad. Firstly, in terms of the generation method, various types of large volume arc plasma generators are introduced, including the multiphase AC, multi-electrode DC and magnetic driven rotating arc plasma generators. And the basic principle of these large volume thermal plasma generation and the basic characteristics of arc plasma are further described in the paper, respectively. Secondly, regarding arc characteristic control, the control methods and mechanisms of plasma are summarized from the electrode geometry, air flow driving and magnetic field driving according to the structure characteristics of these large volume arc plasma generator. Their effects are further discussed on plasma configuration, dynamic and flow characteristics. Finally, the application and research progress are introduced for the large-size arc plasma at home and abroad. In the view of pain point of arc plasma application, we need to further focus on key scientific and technological issues that urgently need to be addressed. The future development trend of arc plasma technology is prospected, which provides support for the application upgrade and the expansion of new fields of application.