Electromagnetic device for stabilizing and reducing the deformation of a strip made of ferromagnetic material, and related process

Patent metadata

Field	Value
Publication number	US-9968958-B2
Application number	US-201715410552-A
Country	US
Kind code	B2
Filing date	Jan 19, 2017
Priority date	Aug 7, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

An electromagnetic device ( 1 ) for stabilizing and minimizing the deformation of a strip ( 4 ) made of ferromagnetic material during its feeding in a system for coating the same strip with molten metal, by applying a distribution of force which is continuous in the direction transversal to the strip regardless of the width thereof. The device comprises first electromagnets and second electromagnets mirroring the tirst electromagnets with respect to said theoretical pass-line ( 50 ) of said strip ( 4 ). Each electromagnet includes a core comprising one pole and one feeding coil wound about the pole. The electromagnetic device comprises a connection element ( 26 ) made of ferromagnetic material which connects the cores of the first electromagnets ( 15, 15′, 15″, 15 ′″) and a connection element ( 26 ′) made of ferromagnetic material which connects the cores of the second electromagnets ( 16, 16′, 16″, 16 ′″). The connection elements ( 26, 26 ′) mirror the theoretical pass-line ( 50 ) of the strip ( 4 ).

First claim

The invention claimed is:

1. A system of coating a strip made of ferromagnetic material, with a molten metal, comprising:
a pot containing a molten metal bath;
a unit for removing an excess coating placed downstream of said pot;
a support structure for supporting said pot;
an electromagnetic device for stabilizing and reducing the deformation of the strip made of ferromagnetic material during its feeding,
wherein said electromagnetic device comprises:
first electromagnets aligned along a transversal direction parallel to a theoretical pass-plane of said strip made of ferromagnetic material and orthogonal to a transportation direction of said strip made of ferromagnetic material;
second electromagnets arranged in a position mirroring the first electromagnets with respect to said theoretical pass-plane of said strip made of ferromagnetic material,

wherein each of said first electromagnets and said second electromagnets comprises a core provided with at least one pole and at least one feeding coil wound about said at least one pole and wherein said electromagnetic device further comprises:
a first connection element made of ferromagnetic material which connects the cores of said first electromagnets, the first connection element being in an intermediate position between said cores of said first electromagnets and said theoretical pass-plane;
a second connection element made of ferromagnetic material which connects the cores of said second electromagnets, the second connection element being placed in a position mirroring the position of said first connection element with respect to said theoretical pass-plane of said strip made of ferromagnetic material.

2. The system according to claim 1 , wherein said pot is provided for containing a molten metal bath and an electromagnetic apparatus is provided for keeping said molten metal bath suspended within said pot, said pot comprising an inlet opening for introducing said strip made of ferromagnetic material and an outlet opening for said strip made of ferromagnetic material, opposite to said inlet opening, said electromagnetic device being operatively placed at said inlet opening.

3. The system according to claim 1 , wherein each of said first electromagnets and said second electromagnets of said electromagnetic device comprises:
a first pole;
a second pole in a position above said first pole;
a middle pole interposed between said first pole and said second pole;
a yoke which connects said first pole, said second pole and said middle pole;
and wherein said first connection element made of ferromagnetic material connects the middle poles of said first electromagnets and wherein said second connection element made of ferromagnetic material connects the middle poles of said second electromagnets.

4. The system according to claim 1 , wherein said electromagnetic device comprises a plurality of position sensors adapted to measure a position of said strip made of ferromagnetic material with respect to said theoretical pass-plane, each of the at least one feeding coil of each of said first electromagnets and said second electromagnets being fed according to said position of said strip made of ferromagnetic material with respect to said theoretical pass-plane.

5. The system according to claim 3 , wherein said electromagnetic device comprises a plurality of position sensors adapted to measure a position of said strip made of ferromagnetic material with respect to said theoretical pass-plane, each of the at least one feeding coil of each of said first electromagnets and said second electromagnets being fed according to said position of said strip made of ferromagnetic material with respect to said theoretical pass-plane.

6. The system according to claim 4 , wherein said plurality of position sensors are placed on opposite sides with respect to said theoretical pass-plane of said strip made of ferromagnetic material so as to be, two by two, in a mirroring position with respect to said theoretical pass-plane.

7. The system according to claim 5 , wherein said plurality of position sensors are placed on opposite sides with respect to said theoretical pass-plane of said strip made of ferromagnetic material so as to be, two by two, in a mirroring position with respect to said theoretical pass-plane.

8. The system according to claim 5 , wherein each of said at least one feeding coil of each of said first electromaanets and said second electromaanets is wound about said middle pole of a resoective one of each of said first electromaanets and said second electromagnets.

9. The system according to claim 3 , wherein each of said fir electromaanets and said second electromagnets comprises:
a middle feeding coil wound about said middle pole;
a first auxiliary feeding coil wound about said first pole;
a second auxiliary feeding coil wound about said second pole.

10. The system according to claim 1 , wherein said first connection element and said second connection element of said electromagnetic device have an extension, measured according to said transversal direction, which is greater than or equal to an extension of said strip made of ferromagnetic material, also measured along said transversal direction.

11. The system according to claim 1 , wherein said first connection element and said second connection element of said electromagnetic device consist of a bar made of ferromagnetic material which is laminated or not laminated and with a rectangular section, said bar having a section which is greater than or equal to one fifth of a square of a length of a middle pole connected by the bar itself.

12. The system according to claim 3 , wherein the distance of one of said first connection element and said second connection element of said electromagnetic device from said theoretical pass-plane is less than or equal to a distance of said first pole and of said second pole from the same theoretical pass-plane, said distances being measured according to a direction orthogonal to said theoretical pass-plane.

13. The system according to claim 1 , wherein said electromagnetic device comprises:
a first connecting body made of ferromagnetic material which connects individual yokes of the first electromagnets to one another;
a second connecting body made of ferromagnetic material which connects individual yokes of the second electromagnets to one another.

14. The system according to claim 13 , wherein each of said first connecting body and said second connecting body comprises a plate made of ferromagnetic material having a rectangular section and wherein, for each of said first connecting body and said second connecting body a height of said rectangular section measured according to a direction parallel to said theoretical pass-plane, is greater than or equal to a height of the connected individual yokes.

15. The system according to claim 3 , wherein the yokes of the first electromagnets and/or the yokes of said second electromagnets of said electromagnetic device are made in a single body.

16. A method for stabilizing and/or correcting a deformation of a strip made of ferromagnetic material during its feeding, by coating the strip made of ferromagnetic material with molten metal, comprising:
providing a first set of electromagnets aligned along a transversal direction parallel to a theoretical pass-plane of said strip made of ferromagnetic material and orthogonal to a transportation direction of said strip made of ferromagnetic material;
providing a first connection element made of ferromagnetic material which connects cores of said first set of electromagnets, the first

Assignees

• Danieli Off Mecc

Inventors

• Guastini Fabio
• Minen Michele

Classifications

• B65G43/00

  Control devices, e.g. for safety, warning or fault-correcting · CPC title

• B05C13/02 Primary

  for particular articles · CPC title

• B21B37/007

  Control for preventing or reducing vibration, chatter or chatter marks (B21B37/66 takes precedence) · CPC title

• C23C2/40 Primary

  Plates; Strips · CPC title

• B05C3/125

  the work being a web, band, strip or the like · CPC title