Can coating and curing system having focused induction heater using thin lamination cores

Can side seam heating apparatus comprising:

• a conveyor conveying a can along a path of travel, said can having a longitudinally oriented side seam;
• a magnetic flux concentrator having a plurality of pole pieces each directed toward said path of travel, said pole pieces being disposed in a row along said path of travel;
• and
• an induction coil for carrying an oscillating current, said induction coil being wound on said concentrator such that sequential ones of said pole pieces along said path of travel have alternatingly magnetically opposite polarities, and such that a plurality of said sequential pole pieces simultaneously induce a plurality of eddy current loops in said can and crossing said side seam.

A system for coating and curing a coating on a side seam of a can;

• the can being formed from a blank by a can-forming machine into a cylinder, with the abutting edges of the blank being welded to form a side seam inside the cylinder, the side seam inside the cylinder being said side seam of the can, comprising:
• an applicator for applying a coating to said side seam of the can;
• an induction heating device disposed proximate to said applicator to heat said side seam of said can, said induction heating device including a work coil that is non-liquid cooled;
• a conveyor for transporting said can from said applicator through said induction heating device;
• and
• an air-cooling system, said air-cooling system removing heat from said induction heating device.

Apparatus for inductively heating an electrically conductive region of a workpiece, comprising:

• a path of travel along which said workpiece is being moved;
• a non-liquid cooled induction coil;
• and
• a source of electrical current oscillating between approximately 800 Hz and approximately 20 kHz, said source being coupled to pass said current through said induction coil,
• said induction coil being disposed and oriented relative to said path of travel so as to induce an oscillating current in said electrically conductive region of said workpiece as said workpiece is moved along said path of travel.