Heating device for the inductive heating of a flat steel strip in a hot rolling mill

Patent metadata

Field	Value
Publication number	US-12090535-B2
Application number	US-202017599088-A
Country	US
Kind code	B2
Filing date	Mar 4, 2020
Priority date	Mar 29, 2019
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

A heating device and a method for the inductive heating of a flat steel strip in a hot rolling mill. The heating device is between two rolling trains of the hot rolling mill and the flat steel strip runs at a speed through the heating device in a transporting direction. The heating device includes: transverse-field modules arranged one after the other along the transporting direction of the flat steel strip; longitudinal-field modules arranged one after the other along the transporting direction of the flat steel strip and arranged before or after the transverse-field modules along the transporting direction; a first power supply supplying at least one transverse-field module with a first alternating voltage; and a second power supply supplying at least one longitudinal-field module with a second alternating voltage. The power supplies have a converter and an electrically connected capacitor bank with multiple capacitors connected in parallel.

First claim

The invention claimed is:

1. A method for the inductive heating of a flat steel strip in a hot rolling mill by a heating device, wherein the heating device is arranged between two rolling trains of the hot rolling mill and the flat steel strip runs at a speed through the heating device in a transporting direction, comprising the method steps of:
heating the flat steel strip by a first module group with a plurality of transverse-field modules, which are arranged one after the other along the transporting direction; and heating the flat steel strip by a second module group with a plurality of longitudinal-field modules, the second module group being arranged one after the other along the transporting direction and being arranged before or after the first module group along the transporting direction, and adjusting with a lift actuator a height position of at least one coil of at least one of the transverse-field modules;
wherein a power supply for supplying at least one transverse-field module or at least one longitudinal-field module has a converter, which is operated as a load-commutated converter; and
wherein the frequency f of the generated alternating voltage is

f
=

1

2
⁢
π
⁢

L
Ges

⁢

C
Ges

,

 where L Ges indicates the total inductive load and C Ges indicates the total capacitive load in the circuit.

2. The method as claimed in claim 1 , wherein the heating device is arranged between two rolling trains of the hot rolling mill and the flat steel strip runs at a speed through the heating device in a transporting direction, comprising the method steps of:
heating the flat steel strip by a plurality of transverse-field modules, which are arranged one after the other along the transporting direction; and
heating the flat steel strip by a plurality of longitudinal-field modules, which are arranged one after the other along the transporting direction and are arranged before or after the transverse-field modules along the transporting direction;
wherein a power supply for supplying at least one transverse-field module or at least one longitudinal-field module has a converter, which is operated as an externally commutated converter; and
wherein the frequency f of the generated alternating voltage is

f
≠

1

2
⁢

⁢

L
Ges

⁢

C
Ges

,

 where L Ges indicates the total inductive load and C Ges indicates the total capacitive load in the circuit.

3. The method as claimed in claim 1 , wherein a transverse-field module is operated with an alternating voltage with a frequency and the frequency is changed during a rolling campaign or between two rolling campaigns.

4. The method as claimed in claim 3 , wherein the frequency is set in dependence on the thickness of the flat steel strip.

5. The method as claimed in claim 1 , wherein a transverse-field module is operated with a current intensity and the current intensity is set in dependence on at least one parameter of the flat steel strip from the group comprising the thickness, the speed, the temperature before entering the heating device, and the temperature after leaving the heating device.

6. A heating device for the inductive heating of a flat steel strip in a hot rolling mill, the heating device being arranged between two rolling trains of the hot rolling mill and the flat steel strip runs at a speed through the heating device in a transporting direction, the heating device comprising:
a first module group with a plurality of transverse-field modules arranged one after the other along the transporting direction of the flat steel strip;
a second module group with a plurality of longitudinal-field modules arranged one after the other along the transporting direction of the flat steel strip, the second module group being arranged before or after the first module group along the transporting direction;
a first power supply adapted to supply at least one transverse-field module with a first alternating voltage; a second power supply adapted to supply at least one longitudinal-field module with a second alternating voltage; and a lift actuator for changing the height position of at least one coil of a transverse-field module;
wherein the power supplies have in each case a converter and an electrically connected capacitor bank with multiple capacitors connected in parallel.

7. The heating device as claimed in claim 6 , wherein at least one of the first and the second power supply comprises a frequency input for determining a setpoint frequency and the frequency of the generated alternating voltage follows the setpoint frequency.

8. The heating device as claimed in claim 6 , wherein at least one of the first and the second power supply comprises a current input for determining a setpoint current intensity and the current intensity follows the generated alternating voltage of the setpoint current intensity.

9. The heating device as claimed in claim 6 , wherein at least one of the first and the second power supply comprises a voltage input for determining a setpoint voltage and the voltage amplitude (U) of the generated alternating voltage follows the setpoint voltage.

10. The heating device as claimed in claim 6 , wherein at least one of the first and the second power supply comprises a power input for determining a setpoint power and the heating power of the generated alternating voltage follows the setpoint power.

11. The heating device as claimed in claim 6 , further comprising a thrust actuator for changing the width position of at least one coil of a transverse-field module.

12. The heating device as claimed in claim 11 , wherein the transverse-field module comprises a width input for determining a setpoint width position and the width position of a coil of the transverse-field module in the direction of the width follows the setpoint width position.

13. The heating device as claimed in claim 6 , wherein a transverse-field module comprises a height input for determining a setpoint height position and the height position of a coil of a transverse-field module in the direction of the thickness follows the setpoint height position.

14. The heating device as claimed in claim 6 , further comprising an open-loop or closed-loop control device, wherein the open-loop or closed-loop control device comprises at least one output from the group compr

Assignees

• Primetals Technologies Austria GmbH

Inventors

• Lengauer Thomas
• Linzer Bernd
• Zahedi Michael

Classifications

• C21D9/60

  with induction heating · CPC title

• C21D1/42

  Induction heating · CPC title

• B21B1/04

  in a continuous process · CPC title

• B21B1/026

  Rolling · CPC title

• Y02P10/25

  Process efficiency · CPC title