Control of workpiece heating

In apparatus for controlling the operation of a furnace for heating workpieces traveling through said furnace and including a heating zone having an effective temperature and having a predetermined control area in which at least one workpiece is positioned, with said furnace being operative in relation to an associated rolling mill, the combination of

• first means for providing a signal indicative of the effective temperature of said heating zone,
• second means for determining the remaining time period said one workpiece will be positioned in said heating zone and during which said one workpiece will travel from said control area to the end of said heating zone, for determining the remaining heat content to be supplied to said one workpiece during said time period in response to the provided signal indicative of said effective temperature of said heating zone, and for determining a temperature control setpoint for said heating zone in accordance with a predetermined relationship between said determined remaining time period and said determined remaining heat content,
• third means for modifying said determined temperature control setpoint in accordance with the operation of the associated rolling mill, and
• fourth means for controlling the operation of said heating zone to provide an effective temperature of said heating zone in accordance with said modified determined temperature control setpoint.

A control system for a workpiece furnace having at least one heating zone through which individual workpieces travel in succession for providing a predetermined heat content into each of said workpieces when the latter workpiece leaves said heating zone, with said heating zone including a predetermined control area, said control system comprising,

• first means for providing a control signal representative of the actual effective temperature of said control area,
• second means for determining the time period remaining for a representative workpiece in said control area to travel to the end of said heating zone, for determining in response to said control signal the remaining heat content to be provided into said representative workpiece during said time period, and for determining an output signal to provide a desired temperature setpoint for said control area in accordance with said time period and said remaining heat content,
• third means for modifying said output signal by a predetermined gap time increment, and
• fourth means responsive to said modified output signal for controlling said effective temperature of said control area in relation to said temperature setpoint.

An automated method of controlling the total heat content supplied to at least one workpiece passing through a heating furnace operative with an associated workpiece processing device and having a first heating zone and a second heating zone, with said first heat zone having a predetermined control area, said method being operative after predicting the travel time of said one workpiece through said second heating zone, said method including the steps of

• measuring a first effective temperature of said first heating zone and a second effective temperature of said second heating zone,
• determining a first heat content to be supplied to said one workpiece by said first heating zone in relation to said measured first effective temperature and a second heat content to be supplied to said one workpiece by said second heating zone in relation to said measured second effective temperature and said predicted travel time,
• determining the needed heat content to be supplied by said first heating zone to said one workpiece in relation to said first heat content and said second heat content when said one workpiece is positioned in said predetermined control area,
• determining a modified remaining time period for said one workpiece to be positioned in said first heating zone in accordance with the operation of the associated workpiece processing device, and
• controlling the operation of said first heating zone to provide an effective temperature of said first heating zone in relation to said determined needed heat content and said determined modified remaining time period.

A control system for determining the heat content of at least one slab passing through a slab heating furnace operative with an associated rolling mill and having a first heating zone and a second heating zone, with each of said heating zones including a control location in which said slab is successively positioned, said control system comprising

• first means for providing a first control signal representative of the effective temperature of said first heating zone,
• second means for providing a second control signal representative of the effective temperature of said second heating zone,
• third means for establishing a modified first time period remaining for said slab to leave said first heating zone when said slab is positioned in said control location of said first heating zone and for establishing a modified second time period remaining for said slab to leave said second heating zone when said slab is positioned in said control location of said second heating zone, with said third means being responsive to a gap time increment in accordance with the operation of the associated workpiece processing device to modify said first and second time periods,
• means responsive to said first control signal for controlling the first heat content supplied to said slab by said first heating zone in relation to said modified first time period remaining, and
• means responsive to said second control signal for controlling the second heat content supplied to said slab by said second heating zone in relation to said modified second time period remaining.

An automated method of determining the heat content of workpieces traveling through a heating furnace operative with a workpiece processing device and being operative after predicting the remaining travel time of said representative workpiece through said one heating zone in relation to the location of said control area in said heating zone, with said furnace having at least one heating zone in which a representative workpiece is positioned within a predetermined control area located in said heating zone, said method including the steps:

• generating a signal representative of the effective temperature of at least said one heating zone,
• establishing the remaining heat content to be supplied to said representative workpiece by at least said one heating zone in accordance with a predetermined relationship with said generated signal representative of said effective temperature,
• modifying the predicted remaining travel time of said representative workpiece through the one heating zone in accordance with the actual operation of the workpiece processing device, and
• controlling the operation of said furnace to provide an effective temperature in accordance with a predetermined relationship between said modified predicted remaining travel time and said established remaining heat content to be supplied to said representative workpiece.

In apparatus for controlling the operation of a furnace for heating a representative workpiece traveling through said furnace and including at least one workpiece heating zone having a predetermined control area in which said representative workpiece is positioned and after a determination has been made of the remaining time period said representative workpiece will be positioned in said heating zone in relation to the travel of said representative workpiece from said control area to the end of said heating zone, with said furnace being operative in relation to an associated rolling mill, the combination of

• means for providing a signal indicative of the actual effective temperature of said heating zone in relation to said representative workpiece positioned in said control area,
• means for modifying the determined remaining time period in relation to the actual operation of the rolling mill,
• means for determining the heat content to be supplied to said representative workpiece during said modified determined remaining time period, and for determining an output signal representative of a desired temperature control setpoint for said heating zone in accordance with a predetermined relationship between said modified remaining time period and said determined heat content, and
• means operative with said furnace in response to said output signal for controlling said effective temperature in accordance with said desired temperature control setpoint.