Displacement of Torch Plasma Arc on Anode by External Magnetic Field

Summary form only given. The plasma arc has numerous applications in materials processing, metallurgy, welding and so on. Types of arc can be categorized by ambient pressure, arc current, and electrode geometry. The interaction of various arcs with applied dc magnetic fields has been researched extensively with regard to applications such as driven arcs, and magnetically balanced arcs. In these applications, the arc is normally moving in the surrounding atmosphere. The plasma arc is a kind of high current magneto-dynamics, and it is known that the arc mode is greatly changed by Lorentz force due to external magnetic field. However, there are few reports about this relation. To understand the quantification of a basic characteristic, the transformation of the plasma arc mode was obtained when an external magnetic field is applied. As the evaluating method of the plasma arc mode transformation, a momentum model was adopted. The momentum model can be calculated by the balance of plasma jet momentum and electromagnetic force. As a result, the displacement of a torch plasma arc on the anode is theoretically estimated to be proportional to magnetic flux density 2nd power of electrode gap and power of plasma current, which is very near to the measured result to be proportional to magnetic flux density, power of electrode gap and power of plasma current.