| 摘要 |
Apparatus for inductively heating metal can lids (50) includes high permeability, low-conductivity cores (10, 12, 14) having at least two magnetically opposite polar portions (20, 22, 24) both directed toward a conveyance path (16) for the can lids (50). High-frequency AC currents (68) are applied to the windings (352) of the cores (10, 12, 14), thereby inducing AC heating currents in the can lids (50) and heating them sufficiently to drive off moisture. The cores (10, 12, 14) may be E-shaped (Fig. 1), and may be disposed in modules (Fig. 12) at various longitudinal positions (Fig. 5) along the conveyance path (16) and/or radial positions (Fig.6) around the conveyance path (16). Closed-loop temperature control apparatus (80) may also be included to prevent overheating of the can closures (50) in the event of unintended stoppage of the production line. |
