Current Distribution, Forces, and Circulation in the Coreless Furnace

Bath circulation is an important and desirable feature of the coreless induction furnace. Existing theoretical models based on an infinite geometry provide little insight into the stirring problem. This paper describes practical experimental techniques used to measure current density distributions in solid conducting cylinders. Experimental results are presented for a wide range of induction melting situations and are used to explain the dependence of circulation and meniscus formation on power density, frequency, and force distribution in the metal. Changes in current density and force distribution due to the relative position of the charge with respect to the furnace coil axe examined. The results are extended to large furnaces by means of simple mathematical formulas.