Furnace temperature control
AssigneeGeneral Electric Company
InventorJohn C. Price
Life of this patent
Estimating the term…
Abstract
In controlling a slab reheat furnace, the average temperature of each slab in a zone, is predicted as a function of the radiation heat source temperature in the zone, and the thermal properties, dimensions, location, velocity, and past thermal history of the slabs. The predicted slab temperatures are compared with a range of desired slab temperatures and the slab requiring the greatest time to be heated to its desired temperature is identified. The furnace is controlled in such a manner that the identified slab will be heated to the desired temperature. Slabs likely to be overheated are identified and, if a predetermined temperature limit is to be exceeded, the furnace is controlled to prevent further heating of the slabs. Gas temperatures throughout the zone are predicted based upon only one sensed temperature in the zone.
Claims16
In a slab reheat furnace having at least one zone with a controllable heating means through which metal slabs are moved, a method of controlling the heating means, comprising the steps of:
- (a) predicting the average temperature of each slab in the zone;
- (b) establishing a deviation between the predicted average temperature of each slab and a desired average temperature of each slab for the particular location of each slab in the zone;
- (c) identifying the slab whose temperature deviation is such that the slab will require the greatest amount of time to be heated to the desired average temperature;
- and,
- (d) adjusting the output of the heating means to such an extent that the identified slab will be heated to the desired average temperature.
In a slab reheat furnace having at least one zone with a controllable heating means through which metal slabs are moved, a method of controlling the heating means, comprising the steps of:
- (a) predicting the average temperature of each slab in the zone;
- (b) establishing a deviation between the predicted average temperature of each slab and a desired average temperature of each slab for the particular location of each slab in the zone;
- (c) identifying the slab whose temperature deviation is such that the slab will require the greatest amount of time to be heated to the desired average temperature;
- (d) establishing a signal proportional to the magnitude of the temperature deviation of the identified slab;
- and,
- (e) adjusting the output of the heating means as a function of the established signal.
In a slab reheat furnace having at least one zone with a conrollable heating means through which metal slabs are moved, a method of controlling the heating means, comprising the steps of:
- (a) predicting the average temperature of each slab in the zone;
- (b) establishing a deviation between the predicted average temperature of each slab and a desired average temperature of each slab for the particular location of each slab in the zone;
- (c) identifying the slab having the greatest temperature deviation below desired average temperature;
- and,
- (d) adjusting the output of the heating means to such an extent that the identified slab will be heated to the desired average temperature.
In a slab reheat furnace having at least one zone with a controllable heating means through which metal slabs are moved, a method of controlling the heating means, comprising the steps of:
- (a) predicting the average temperature of each slab in the zone;
- (b) establishing an average temperature deviation between the predicted average temperature of each slab and a desired average temperature of each slab for the particular location of each slab in the zone.
- (c) predicting the surface temperature of each slab in the zone;
- (d) establishing a surface temperature deviation between the predicted surface temperature of each slab and a predetermined maximum surface temperature of each slab for the particular location of each slab in the zone;
- (e) identifying the slab whose average temperature deviation below the desired average temperature is such that the slab will require the greatest period of time to be heated to the desired average temperature;
- (f) establishing a first signal proportional to the magnitude of the average temperature deviation of the identified slab;
- (g) establishing a second signal if the predicted surface temperature of any slab in the zone is within a predetermined proximity of its predetermined maximum allowable surface temperature;
- (h) preventing the establishment of a first signal if a second signal is established;
- and
- (i) increasing, in the absence of a second signal, the output of the heating means as a function of the magnitude of the first signal.
Dependencies are inferred from the claim text.