Induction dryer and magnetic separator

Apparatus for heating an electrically conductive workpiece, comprising:

• a path of travel along which said workpiece is being moved longitudinally, said path of travel having a longitudinal segment;
• a non-liquid cooled induction coil at least partly enclosing said longitudinal segment of said path of travel;
• and
• a source of medium frequency oscillating electrical current, said source being coupled to pass said current through said induction coil,
• wherein said induction coil comprises at least one wire wrapped entirely around said longitudinal segment of said path of travel.

Apparatus for heating an electrically conductive workpiece, comprising:

• a path of travel along which said workpiece is being moved longitudinally, said path of travel having a longitudinal segment;
• a non-liquid cooled induction coil at least partly enclosing said longitudinal segment of said path of travel;
• and
• a source of medium frequency oscillating electrical current, said source being coupled to pass said current through said induction coil,
• wherein said apparatus lacks cores which focus the magnetic field generated by said induction coil into said workpiece.

Apparatus for heating an electrically conductive workpiece, comprising:

• a path of travel along which said workpiece is being move longitudinally, said path of travel having a longitudinal segment;
• a tube enclosing said longitudinal segment of said path of travel circumferentially;
• a pancake coil subtending substantially completely around said tube, said pancake coil including at least one pancake sub-coil;
• and
• a source of varying electrical current, said source being coupled to pass said current through said at least one pancake sub-coil.

Apparatus for heating an electrically conductive workpiece, comprising:

• a path of travel along which said workpiece is being moved longitudinally, said path of travel having a longitudinal segment;
• a tube having a tube wall enclosing said longitudinal segment of said path of travel circumferentially;
• a magnet occupying a portion of arc of said tube wall;
• a pancake coil subtending substantially completely around said tube wall circumferentially, except for said portion of arc occupied by said magnet, said pancake coil including at least one pancake sub-coil;
• and
• a source of varying electrical current, said source being coupled to pass said current through said at least one pancake sub-coil.

A method of treating electrically conductive can ends, comprising the steps of:

• applying a water-based sealant compound to the can ends;
• providing the can ends to an inlet of a dryer, the can ends already having the water-based sealant compound applied thereto;
• transporting the can ends through the dryer in face-to-face relationship along an electrically nonconductive support structure;
• and
• during the transporting step, passing the can ends through an alternating magnetic field to induce current flow in the can ends to induction heat the can ends and thereby heat the compound applied to the can ends to remove water from the compound,
• wherein the electrically nonconductive support structure comprises an electrically nonconductive tube.

A method of treating electrically conductive can ends, comprising the steps of:

• applying a water-based sealant compound to the can ends;
• providing the can ends to an inlet of a dryer, the can ends already having the water-based sealant compound applied thereto;
• transporting the can ends through the dryer in face-to-face relationship along an electrically nonconductive support structure;
• and
• during the transporting step, passing the can ends through an alternating magnetic field to induce current flow in the can ends to induction heat the can ends and thereby heat the compound applied to the can ends to remove water from the compound,
• wherein the step of transporting the can ends through the dryer in face-to-face relationship comprises the step of transporting the can ends through the dryer in face-to-face contact.

A method of drying water-based sealant compound applied to electrically conductive can ends, comprising the steps of:

• providing can ends to an inlet of a dryer, the can ends already having the water-based sealant compound applied thereto;
• transporting the can ends through the dryer in face-to-face relationship along an electrically nonconductive support structure;
• during the transporting step, passing the can ends through an alternating magnetic field to induce current flow in the can ends to induction heat the can ends and thereby heat the compound applied to the can ends to remove water from the compound;and
• during the transporting step, spacing the can ends apart magnetically.

Induction heating apparatus, comprising:

• a plurality of can ends in face-to-face relationship with each other, said can ends having compound material applied thereto;
• an electrically nonconductive support structured to support the can ends while being transported in face-to-face relationship along the support;
• an alternating current source;
• an electrical conductor connected to the alternating current source and disposed insufficient proximity to the support to produce an alternating magnetic field within the support;
• and
• a transporting device which transports the can ends in face-to-face relationship along the support and through the alternating magnetic field to induce current flow in the can ends to induction heat the can ends and thereby heat the compound material applied to the can ends,
• wherein the electrically nonconductive support comprises an electrically nonconductive tube.

Induction heating apparatus, comprising:

• a plurality of can ends in face-to-face relationship with each other, said can ends having compound material applied thereto;
• an electrically nonconductive support structured to support the can ends while being transported in face-to-face relationship along the support;
• an alternating current source;
• an electrical conductor connected to the alternating current source and disposed in sufficient proximity to the support to produce an alternating magnetic field within the support;
• and
• a transporting device which transports the can ends in face-to-face relationship along the support and through the alternating magnetic field to induce current flow in the can ends to induction heat the can ends and thereby heat the compound material applied to the can ends,
• wherein said transporting device transports the can ends in face-to-face contact along the support.

Induction heating apparatus, comprising:

• a plurality of can ends in face-to-face relationship with each other, said can ends having compound material applied thereto;
• an electrically nonconductive support structured to support the can ends while being transported in face-to-face relationship along the support;
• an alternating current source;
• an electrical conductor connected to the alternating current source and disposed in sufficient proximity to the support to produce an alternating magnetic field within the support;
• a transporting device which transports the can ends face-to-face relationship along the support and through the alternating magnetic field to induce current flow in the can ends to induction heat the can ends and thereby heat the compound material applied to the can ends;
• and
• a magnet disposed to produce a magnetic field within the support which is effective to cause the can ends to space apart to share the magnetic field.