Nucor Corporation

Siemens Aktiengesellschaft

Harold Bradley Rees

Tino Domanti

Richard Britanik

Glen Wallace

Terry L Gerber

Neera Jain Sundaram

George T C Chiu

Florian Maurice Browne, Iii

Jason A Mueller

Robert Nooning, Jr

Jeffery Edward Keffer

Walter N Blejde

Rama Ballav Mahapatra

Mark Schlichting

Nikolco S Nikolovski

James W Watson

Alan J Deno

Volus McKenna

James M Thomas

Philippe Maurice Fettig

Ansgar Gruess

Nick Corea

James D Edwards

Michael Ponder

Robert G Nooning

A twin roll casting system includes a pair of counter-rotating casting rolls having an adjustable nip therebetween, a casting roll controller configured to adjust the nip between the casting rolls in response to control signals; a cast strip sensor measuring a parameter of the cast strip and generating strip measurement signals; and an iterative learning control (ILC) controller receiving the strip measurement signals and providing control signals to the casting roll controller. The ILC controller includes a fault detection algorithm receiving the control signals and the strip measurement signals and generating a fault detection signal indicating when a fault condition is detected and an iterative learning control algorithm to generate the control signals. The fault detection algorithm indicates a fault condition when it detects the control signal exceeding an upper control saturation threshold or the ILC controller operating a state that is not guaranteed as stable.

Fault detection for iterative learning control of time-varying systems

Systems and apparatus for continuously casting thin strip where one or more expansion rings are positioned within at least one of a pair of casting rolls, and automatically measuring a thickness of the cast strip close to the first side edge of the strip using at least one sensor. If the thickness measured is too thin, automatically decreasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to contract and increase the thickness of the cast strip during casting. If the thickness measured indicates that the thickness of the cast strip is too thick, automatically increasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to expand and reduce the thickness of the cast strip during casting.

Method for casting metal strip with edge control

A twin roll casting system where the casting rolls have a nip between the casting rolls, each roller having a circumference and a rotational period. The casting roll controller adjusts the nip between the casting rolls in response to control signals. The sensor measures at least one parameter of the cast strip. The ILC controller receives strip measurement signals from the sensor and provides control signals to the casting roll controller. The ILC controller includes an ILC control algorithm to generate the control signals based on the strip measurement signals and a time delay estimate based on circumference, rotational period, and a length of cast strip between the nip and the sensor to compensate for an elapsed time from the cast strip exiting the nip to being measured by the cast strip sensor.

Iterative learning control for periodic disturbances in twin-roll strip casting with measurement delay

An apparatus for continuous casting a metal strip and reducing snake eggs in the metal strip. A pair of counter rotating casting rolls through which a thin strip can be cast are provided. A metal delivery system is disposed above the nip for discharging molten metal into a casting pool supported on the rolls. A pair of side dam holders and a pair of side dams are assembled adjacent each end portion of the rolls. Each side dam holder is tapered and dovetails with an adjacent side dam to confine the casting pool of molten metal supported on casting surfaces of the rolls. An oscillation mechanism provides lateral oscillation to each side dam and side dam holder at a frequency 2-50 hertz and with an amplitude 100-2000 &#x3bc;m during casting.

Method of thin strip casting

Methods and apparatus for continuously casting thin strip where one or more expansion rings are positioned within at least one of a pair of casting rolls, and automatically measuring a thickness of the cast strip close to the first side edge of the strip using at least one sensor, and if the thickness measured is too thin, automatically decreasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to contract and increase the thickness of the cast strip during casting, and if the thickness measured indicates that the thickness of the cast strip is too thick, automatically increasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to expand and reduce the thickness of the cast strip during casting.

Apparatus and method of controlling strip geometry in casting strip having a rolling mill. A target thickness profile is calculated as a function of the measured entry thickness profile of the strip while satisfying profile and flatness parameters. A differential strain feedback from longitudinal strain in the strip is calculated by a control system by comparing the exit thickness profile with the target thickness profile, and a control signal is generated to control a device capable of affecting the geometry of the strip processed by the hot rolling mill. A feed-forward control reference and/or sensitivity vector may also be calculated as a function of the target thickness profile, and used in generating the control signal sent to the control device. The control device may be selected from one or more of the group consisting of a bending controller, gap controller and coolant controller.

Method and plant for integrated monitoring and control of strip flatness and strip profile

Apparatus for continuously casting metal strip includes a pair of counter-rotatable casting rolls laterally positioned to form a nip therebetween through which thin strip can be cast, a pair of confining side dams adjacent the ends of the casting rolls capable of confining a casting pool of molten metal supported on the casting rolls and formed on the casting surfaces above the nip, a metal delivery system disposed above the nip and capable of discharging molten metal to form the casting pool supported on the casting rolls, side dam actuators each capable of applying cyclical axial force to the side dams without leakage, and a control system capable of actuating at least one side dam actuator to cyclically vary the apply force of the side dam against the ends of the casting rolls during a casting campaign.

Strip casting apparatus with improved side dam force control

An apparatus and method for continuously casting thin steel strip includes a pair of counter-rotatable casting rolls laterally positioned to form a nip there between through which thin cast strip can be cast, an actuator capable of moving each casting roll independently toward and away from a given reference location as desired, location sensors capable of sensing the location of the casting rolls relative to the given reference location and producing electrical signals indicative of each casting roll position and a control system capable of receiving the electrical signals and causing the actuator to move the casting rolls into desired position. Force sensors may be provided capable of sensing the forces exerted on the strip and producing electrical signals indicative of the sensed forces, and the control system may be capable of receiving the electrical signals indicative of the sensed forces and causing actuators to vary the position of the casting rolls responsive to the electrical signals as desired.

Strip casting apparatus with casting roll positioning

A method of continuously casting metal strip for a twin roll caster may include steps of sensing images of a casting pool in the casting area indicative of the casting pool depth, displaying the sensed images to an operator, and controlling a flow of molten metal from a metal supply system into the casting pool responsive to the sensed images indicative of the casting pool depth. The method may include producing separate electrical signals corresponding to the sensed images and controlling the flow of molten metal from the metal supply system into the casting pool responsive to one or more of the electrical signals. The electrical signals may be processed to determine the casting pool depth in each of the plurality of locations and the casting pool depth displayed to the operator. One or a combination of the electrical signals may be selected for providing a determined casting pool depth, and the flow of molten metal may be controlled responsive to the determined casting pool depth. The determined casting pool depth may be an average of casting pool depths from the selected electrical signals.

Production of thin steel strip

Apparatus and method of controlling strip geometry in casting strip having a rolling mill. A target thickness profile is calculated as a function of the measured entry thickness profile of the strip while satisfying profile and flatness operating requirements. A differential strain feedback from longitudinal strain in the strip is calculated by a control system by comparing the exit thickness profile with the target thickness profile, and a control signal is generated to control a device capable of affecting the geometry of the strip processed by the hot rolling mill. A feed-forward control reference and/or sensitivity vector may also be calculated as a function of the target thickness profile, and used in generating the control signal sent to the control device. The control device may be selected from one or more of the group consisting of a bending controller, gap controller and coolant controller.

Growing community of inventors

Ladoga, IN, United States of America

Harold Bradley Rees