EP0196264A2
Expired / Lapsed
EP
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Inductor configuraton for eddy current heating in the papermaking process
Assignee: Beloit Technologies Inc
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Filing: 1986-03-06
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Granted: —
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Expires: 2006-03-06
Abstract
Abstract Inductors for heating rolls especially of the type used in rolling mills for sheet materials such as paper, textiles, plastics and the like, are configured to enhance and concentrate eddy currents in areas along the length of the roll to selectively heat the roll as desired and control moisture and caliper properties of the sheet. The inductors have cores with a center leg around which the exciting coil is wound and an outer leg surrounding the coil and connected at one.end to the inner leg. These inductors or electromagnet are mounted immediately adjacent a roll of magnetic flux conducting material, such as iron or steel, to heatthe roll surface as desired across the length of the roll as it is rotated through the concentrated electromagnetic field generated by the inductor. The magnetic field or flux is concentrated in an annular zone and passes between the nested inner and outer legs of the core through the roll without travelling through a wide air gap and the desired roll temperatures are achieved with minimum current input to the coil. The air gap may be varied in the cross machine direction and the excitation of the inductors may be varied to induce or compensate for temperature variations across the roll.
Inventors
- 👤 Jeffrey Henry Pulkowski
- 👤 Steven James Siler
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:41
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/36; H05B6/365; H05B6/10; H05B6/14; H05B6/145
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
89 words
An induction heater for rolls and the like which comprises a core having a center leg and a surrounding outer leg spaced therefrom with a connecting leg at one end of the center and outer legs, and exciting coil wrapped around the center leg filling the space between the inner and outer legs having ends adapted to be connected to a power source, and said center and outer legs having free inboard end faces for confronting the roll contoured to provide a desired heat input pattern to the roll.
Claim 2
Dependent Claim
89 words
An induction heater for rolls and the like which comprises a core having a center leg and a surrounding outer leg spaced therefrom with a connecting leg at one end of the center and outer legs, and exciting coil wrapped around the center leg filling the space between the inner and outer legs having ends adapted to be connected to a power source, and said center and outer legs having free inboard end faces for confronting the roll contoured to provide a desired heat input pattern to the roll.
Claim 3
Dependent Claim
128 words
A roll assembly for papermaking machines which comprises, a roll of magnetic flux conducting material, a row of induction heaters mounted along the length of the roll, each heater having a core composed of an inner leg, an outer leg completely surrounding the inner leg in spaced relation therefrom and an end leg connecting the ends of the inner and outer legs, an exciting coil wound around the inner leg and snugly fitting in the outer leg, said core having an inboard end closely adjacent the roll surface remote from the connecting leg, means for electrically exciting the coil of each heater to create a magnetic flux through the roll surface confined to a zone immediately adjacent each core, and means for rotating the roll through said zones.
Claim 4
Dependent Claim
128 words
A roll assembly for papermaking machines which comprises, a roll of magnetic flux conducting material, a row of induction heaters mounted along the length of the roll, each heater having a core composed of an inner leg, an outer leg completely surrounding the inner leg in spaced relation therefrom and an end leg connecting the ends of the inner and outer legs, an exciting coil wound around the inner leg and snugly fitting in the outer leg, said core having an inboard end closely adjacent the roll surface remote from the connecting leg, means for electrically exciting the coil of each heater to create a magnetic flux through the roll surface confined to a zone immediately adjacent each core, and means for rotating the roll through said zones.
Claim 5
Dependent Claim
65 words
An inductor for heating rolls and the like which comprises an electromagnet having a ferrous metal core with upstanding spaced concentric legs connected at one end by a leg closing the space therebetween , an exciting coil filling the space between the inner and outer legs, and said inner and outer legs having end faces adapted to closely overlie the roll to be heated .
Claim 6
Dependent Claim
65 words
An inductor for heating rolls and the like which comprises an electromagnet having a ferrous metal core with upstanding spaced concentric legs connected at one end by a leg closing the space therebetween , an exciting coil filling the space between the inner and outer legs, and said inner and outer legs having end faces adapted to closely overlie the roll to be heated .
Claim 7
Dependent Claim
18 words
The heater of claim 1 wherein the connecting leg closes the space between the center and outer legs.
Claim 8
Dependent Claim
13 words
The heater of claim 1 wherein the center and outer legs are concentric.
Claim 9
Dependent Claim
14 words
The roll assembly of claim 2 including means for independently electrically exciting each coil.
Claim 10
Dependent Claim
15 words
The roll assembly of claim 2 wherein the flux zone of each heater is annular.
Claim 11
Dependent Claim
17 words
The roll assembly of claim 2 wherein the heaters are mounted in side-by-side relation in said row.
Claim 12
Dependent Claim
24 words
The roll assembly of claim 2 wherein the outer legs of adjacent heaters in the row are flat and adapted to be abutted together.
Claim 13
Dependent Claim
20 words
The inductor.of claim 3 wherein the end faces are concave following the contour of the adjacent roll to be heated.
Claim 14
Dependent Claim
26 words
The inductor of claim 3 wherein the end faces are concave and struck from a radius centered on the axis of the roll to be heated.
Claim 15
Dependent Claim
41 words
The induction heater of claim 1 wherein said free inboard end faces are concave in the machine direction of the roll and convex in the cross machine direction of the roll to provide the desired heat input pattern to the roll.
Claim 16
Dependent Claim
17 words
The roll assembly of claim 2 wherein the magnetic flux zone of each induction heater is annular.
Claim 17
Dependent Claim
15 words
The roll assembly of claim 13 wherein the heaters in the row are abutted together.
References Cited (Backward Citations)
No citation records indexed.
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