The pinch force which is one of the most common electromagnetic forces in the metallurgical field can be generated by imposing an electrical current on a liquid metal. In this force field, electrically nonconductive particles suspended in a liquid metal experience a force in the opposite direction to the pinch force, and are squeezed out from the liquid metal.
In this study, the above principle was applied to the separation of nonmetallic inclusion particles from liquid steel. Firstly, the separation efficiency, η, of nonmetallic inclusion particles from the liquid steel flowing in a circular pipe was calculated by the trajectory method under laminar flow conditions. The value of η was found to be a function of V_R, (C_ID_R²/Re)Z and r₁/δ, where r₁ is the radius of the pipe, δ is the skin depth and V_R, C_I, D_R, Re and Z are nondimensional parameters. The estimated value of η is a continuous casting tundish equipped with a channel-induction furnace was greater than 95% for particles with a diameter over 60 μm. Secondly, the value of η for a square pipe was computed by the concentration method. In this case, the value of η was found to be a function of V'_R and (C_ID_R²/Re)Z at x₁/δ=0, where x₁ is the half width of the square pipe. However, with increasing x₁/δ, secondary flows appeared in a cross section of the pipe because of the skin effect. These flows were found to increase the value of η by transporting the particles in the inner region toward the wall.