Temperature control system for mill runout table

Claim 2

For use in a rolling mill including a finishing train, a runout table with controllable cooling sprays, and a coiler, the method of cooling a strip as the strip traverses the runout table at varying velocities comprising the steps of: a. calculating the time at which each of contiguous fixed length sections of the strip are situated at predetermined locations along the runout table; said calculation being accomplished by: I. predictively establishing a velocity profile for the strip traversal along the runout table; II. integrating the velocity profile with respect to time to ascertain the elapsed distance traveled by each fixed length section of the strip as a function of time; and III) determining from the integral the time required for each section of strip to travel the elapsed distance between entry to the runout table and predetermined locations along the runout table, b. determining the number of sprays required to cool each of the contiguous sections from a finishing train temperature to a desired coiling temperature as a function of the residence times of said sections on said runout table; and c. altering the initiation and number of sprays applied to the strip in a sequence coinciding with the movement of the sections across the runout table whereby each of the contiguous sections is subjected to the number of sprays determined to be required for each section, each of said sprays being initiated at a time when said sections are determined to have traveled the required distance from entry to said table to be in registration with each of said number of sprays.

Claim 3

For use in a rolling mill including a finishing train, a runout table with controllable cooling sprays, and a coiler, the method of cooling a strip as the strip traverses the runout table at varying velocities comprising the steps of: a. determining the amount of time during which each of contiguous sections of the strip will reside on the runout table; b. determining the number of sprays required to cool each of the contiguous sections from a finishing train temperature to a desired coiling temperature as a function of the residence times, said required number of sprays being determined by: I. calculating the number of sprays required to cool a strip section traversing the runout table at a lower base speed requiring a predetermined lower residence time from one of a family of stored curves wherein each curve in the family expresses the number of required sprays at the lower base speed for ranges of finishing train temperatures and coiling temperatures for a strip section having a gage falling within a particular gage range; II. calculating the number of sprays required to cool the same strip section when that section traverses the runout table at an upper base speed requiring a predetermined upper residence time from one of a second family of stored curves where each curve in the second family expresses the number of required sprays at the upper base speed for ranges of finishing train temperatures and coiling temperatures for a strip section having a gage falling within a particular gage range; and III. calculating the number of sprays required for each section having another residence time as a function of the relative magnitude of the other residence time and the upper and lower residence times, and c. altering the number of sprays applied to the strip in a sequence coinciding with the movement of the sections across the runout table, whereby each of the contiguous sections is subjected to the number of sprays determined to be required for that particular section.

Claim 4

For use in a rolling mill including a finishing train, a runout table with controllable cooling sprays, and a coiler, the method of cooling a strip as the strip traverses the runout table at varying velocities comprising the steps of: a. determining the amount of time during which each of contiguous sections of the strip will reside on the runout table; b. determining the number of sprays required to cool each of the contiguous sections from a finishing train temperature to a desired coiling temperature as a function of the residence times, said required number of sprays being determined by: I. calculating the number of sprays required to cool a strip section traversing the runout table at a lower base speed requiring a predetermined lower residence time from one of a family of stored curves wherein each curve in the family expresses the number of required sprays at the lower base speed for ranges of finishing train temperatures and coiling temperatures for a strip section having a gage falling within a particular gage range; II. calculating the number of sprays required to cool the same strip section when that section traverses the runout table at an upper base speed requiring a predetermined upper residence time from one of a second family of stored curves where each curve in the second family expresses the number of required sprays at the upper base speed for ranges of finishing train temperatures and coiling temperatures for a strip section having a gage falling within a particular gage range; and III. calculating the number of sprays required for each section having another residence time as a function of the relative magnitude of the other residence time and the upper and lower residence times, and c. altering the number of sprays applied to the strip in a sequence coinciding with the movement of the sections across the runout table, whereby each of the contiguous sections is subjected to the number of sprays determined to be required for that particular section.

Claim 5

The method recited in claim 2 including the further steps of: a. measuring the temperature of each section of the strip near the exit from the finishing train; b. comparing the measured finishing train temperature with an expected finishing train temperature to determine the magnitude and type of temperature deviation exhibited by each section; c. determining the number of sprays required to cool each section at the measured finishing train temperature utilizing said ones of said families of stored curves expressing the number of required sprays at the lower and upper base speeds; and d. modifying the number of sprays applied to each section as the section traverses the runout table as a function of the difference between the number of sprayS required for the expected finishing train temperature and the number of sprays required for the measured finishing training temperature.

Claim 6

The method recited in claim 2 including the additional steps of: a. measuring the coiling temperatures obtained by use of the cooling sprays at strip sections requiring predetermined residence times to traverse the runout table; b. comparing the measured coiling temperatures with the desired coiling temperatures to establish a temperature error; c. displacing said ones of said families of stored curves by an amount proportional to the established temperature error; and d. calculating the number of sprays required to cool a subsequently processed strip utilizing said displaced ones of said families of curves.

Claim 7

The method recited in claim 1 wherein the time at which a particular spray is to be added or removed to control the cooling of a particular section is established by establishing the time at which a spray-controlling signal should be generated both as a function of the determined travel time and the known response time of the spray.

Claim 8

A method as recited in claim 5 wherein the required number of sprays for each section is determined by: a. calculating the number of sprays required to cool a strip section traversing the runout table at a lower base speed requiring a predetermined lower residence time from one of a family of stored curves where each curve in the family expresses the number of required sprays at the lower base speed for ranges of finishing mill temperatures and coiling temperatures for a strip section having a gage falling within a particular gage range; b. calculating the number of sprays required to cool the same strip section when that section traverses the runout table at an upper base speed requiring a predetermined upper residence time from one of a second family of stored curves where each curve in the second family expresses the number of required sprays at the upper base speed for ranges of finishing mill temperatures and coiling temperatures for a strip section having a gage falling within a particular gage range; and c. calculating the number of sprays required for each section having another residence time as a function of the relative magnitude of the other residence time and the upper and lower residence times.

Claim 9

The method recited in claim 2 including the further steps of: a. measuring the temperature of each section of the strip near the exit from the finishing train; b. comparing the measured finishing train temperature with an expected finishing train temperature to determine the magnitude and type of temperature deviation exhibited by each section; c. modifying the number of sprays applied to the particular section as it traverses the runout table as a function of the temperature deviation exhibited by that section.

Claim 10

The method recited in claim 2 including the additional steps of: a. measuring the coiling temperatures obtained by use of the cooling sprays on strip sections requiring predetermined residence times to traverse the runout table; b. comparing the measured coiling temperatures with the desired coiling temperatures to establish a temperature error; and c. modifying the relationship between the number of sprays and the finishing train and coiling temperatures as a function of the magnitude and type of temperature error to reduce the error during the cooling of subsequently processed strips.

Claim 11

The method recited in claim 6 including the additional steps of: a. measuring the temperature of each section of the strip near the exit from the finishing train; b. comparing the measured finishing train temperature with an expected finishing train temperature to determine the magnitude and type of temperature deviation exhibited by each section; c. modifying the number of sprays applied to each particular section as it traverses the runout table as a function of the temperature deviation eXhibited by that section.

Claim 12

The method recited in claim 6 including the additional steps of: a. measuring the coiling temperatures obtained by the use of cooling sprays on strip sections traversing the runout table at the upper and lower base speeds; b. comparing the measured coiling temperatures with the desired coiling temperatures to establish temperature errors at the upper and lower base speeds; and c. modifying the number of sprays to be applied to sections of subsequently processed strips traversing the runout table at the upper and lower base speeds as a function of the magnitude and types of temperature errors measured at those speeds.

Claim 13

The method recited in claim 7 including the additional steps of: a. measuring the coiling temperatures obtained by the use of cooling sprays on strip sections requiring predetermined residence times to traverse the runout table; b. comparing the measured coiling temperatures with the desired coiling temperatures with the desired coiling temperatures to establish a temperature error; and c. modifying the number of sprays required to cool contiguous sections of the strip from the finishing train temperature to the desired coiling temperature as a function of the magnitude and type of temperature error.