Dual cascade control system for a long rolling mill
AssigneePrimetals Technologies USA LLC
InventorPaul Barry Riches
Life of this patent
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Abstract
A system for maintaining a continuous speed in a long rolling mill is provided that includes a plurality of guide rollers that feed a billet product from a caster to an entry roll stand along a mill pass line to an exit roll stand. Also, the system includes a plurality of gauges positioned at a plurality of locations along the mill pass line, the gauges perform speed measurement of the billet product passing along the guide rollers. Furthermore, the system includes a logic controller that receives the speed measurement and maintains a speed relationship where the speed between the caster and the entry roll stand is constant as well as the exit speed of the end roll stand is also constant.
Claims16
A speed control system for a long rolling mill having a pass line defined by a plurality of roll stands beginning with an entry roll stand and terminating at an exit roll stand, said entry roll stand being positioned to receive a billet product produced by a caster, said control system comprising:
- a plurality of gauges for performing speed measurements of the billet product at a plurality of locations along the pass line;
- a logic controller that operates in response to the speed measurements received from the gauges to maintain a speed relationship where the speed of the entry roll stand is adjusted to match the variable output speed of the caster as well as to maintain a constant delivery speed of the exit roll stand constant, the logic controller communicates with one or more other roll stands positioned between the entry roll stand and exit roll stand to adjust their respective delivery speeds in order to maintain the constant delivery speed at the exit roll stand, the adjusted delivery speeds are cascaded upstream from the exit roll stand to the one or other roll stands so as to maintain the constant delivery speed at the exit roll stand;
- and
- a loop storage that minimizes a plurality of effects of cascading in two directions to compensate for equipment wear and temperature changes.
A method for maintaining a speed of a billet product moving along a rolling mill, comprising the steps of:
- providing a pass line defined by a plurality of roll stands beginning with an entry roll stand and terminating at an exit roll stand, said entry roll stand being positioned to receive a billet product produced by a caster;
- positioning a plurality of gauges at a plurality of locations along the mill pass line, the gauges perform speed measurements of the billet product passing along the pass line;
- and
- providing a logic controller that receives the speed measurements from the gauges to maintain a speed relationship where the speed of the entry roll stand is adjusted to match the variable output speed of the caster as well as to maintain a constant delivery speed of the exit roll stand constant, the logic controller communicates with one or more other roll stands positioned between the entry roll stand and exit roll stand to adjust their respective delivery speeds in order to maintain the constant delivery speed at the exit roll stand, the adjusted delivery speeds are cascaded upstream from the exit roll stand to the one or other roll stands so as to maintain the constant delivery speed at the exit roll stand;
- and
- providing a loop storage that minimizes a plurality of effects of cascading in two directions to compensate for equipment wear and temperature changes.
Dependencies are inferred from the claim text.