Cooled induction heating coil

• US 20040069774A1
• Filed: 10/31/2003
• Published: 04/15/2004
• Est. Priority Date: 12/27/2000
• Status: Active Grant

• Current Assignee: EFD Induction Incorporated, Metso Automation OY (Vanowen Group Acquisition Co., Inc.)
• Original Assignee: EFD Induction Incorporated, Metso Automation OY (Vanowen Group Acquisition Co., Inc.)
• Inventors: Andersson, Lars, Hoyssa, Pekka, Saynavajarvi, Risto, Markegård, Leif
• Granted Patent: US 6,900,420 B2
• Time in Patent Office: Days
• US Class Current: 219/677
• CPC Class Codes: H05B 6/74 Mode transformers or mode stirrers

Abstract

The present invention relates to an induction heating coil comprising a litz cable which is wound into a spiral to form a bobbin, and means for cooling said cable indirectly. The litz cable is arranged to be cooled by means of an indirect cooling system that comprises a tube which is wound in an intermeshed fashion with the windings of the litz cable. The present invention relates also to a method on a paper or board machine or on a paper finishing machine, in which method at least one induction heating coil comprising a wound litz cable is used for heating a component, and said coil is cooled indirectly by a cooling medium.

Claims

1. An induction heating coil comprising a litz cable which is wound into a spiral to form a bobbin, and means for cooling said cable indirectly, characterised in that the litz cable is arranged to be cooled by means of an indirect cooling system that comprises a tube which is wound in an intermeshed fashion with the windings of the litz cable.

2. The coil according to the claim 1, characterised in that a cooling medium is arranged to flow in the tube.

3. The coil according to the claim 1 or 2, characterised in that the tube is made of a flexible, heat conducting and electrically insulated material.

4. The coil according to any of the preceding claims 1 to 3, characterised in that the tube includes plastic material.

5. The coil according to the claim 2, characterised in that the cooling medium is water, oil or liquid nitrogen.

6. The coil according to the claim 1, characterised in that the coil is arranged to heat a component of a paper or board machine or a paper finishing machine.

7. The method according to the claim 6, characterised in that the component is a rotating roll in contact with a paper or board web.

8. The method according to the claim 7, characterised in that the rotating roll is a calender roll.

9. A method on a paper or board machine or on a paper finishing machine, in which method at least one induction heating coil comprising a wound litz cable is used for heating a component, and said coil is cooled indirectly by a cooling medium, characterised in that the induction heating coil is cooled by a cooling medium which is circulated in a tube which is wound in an intermeshed fashion with the windings of the litz cable.

10. The method according to the claim 9, characterised in that the tube is made of a flexible, heat conducting and electrically insulated material.

11. The method according to the claim 9 or 10, characterised in that the cooling medium is water, oil or liquid nitrogen.

12. The method according to the claim 9, characterised in that the coil heats the component of a paper or board machine or a paper finishing machine.

13. The method according to the claim 12, characterised in that the component is a rotating roll in contact with a paper or board web.

14. The method according to the claim 13, characterised in that the rotating roll is a calender roll.