Induction heating coil assembly for prevent of circulating current in induction heating lines for continuous-cast products

A roller induction heating line, comprising conveyor rolls for conveying a workpiece to be inductively heated along a linear path and an induction heating coil assembly surrounding the path, the induction heating coil assembly having a central axis substantially collinear with said path and a preselected axial length and comprising an induction coil having a plurality of turns and being shaped to define a preselected perimeter for permitting the workpiece to be received within the perimeter and conveyed therethrough along said path, first and second pluralities of transverse yokes at opposite ends of the coil, and a plurality of intermediate yokes spaced apart from each other, and disposed between said first and second pluralities of transverse yokes and extending parallel to the central axis of the coil assembly, said first and second pluralities of transverse yokes and said plurality of intermediate yokes surrounding the coil, said intermediate yokes extending around a major portion of the perimeter defined by said induction coil, said first and second yokes being axially separated from each other and electromagnetically coupled together by said plurality of intermediate yokes.