Method and system for controlling multi-zone reheating furnaces
AssigneeNorth American Mfg. Co.
InventorsJames D. Wilde, Rolland L. Hoffman
Life of this patent
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Abstract
A method and system is provided for controlling a reheating furnace having entrance and discharge ends, a preheating zone at the entrance end, and heating and soaking zones sequentially adjacent the preheating zone in the direction toward the discharge end, and an exhaust gas flue at the entrance end. The method and control system provides for obtaining an optimum temperature profile through the preheating and heating zones with minimum fuel consumption in connection with operation of the preheating zone by controlling the fuel supply to the preheating zone in accordance with the rate or quantity of fuel flow to the heating zone and the temperature of the exhaust gas from the furnace.
Claims10
A method of controlling a fuel fired reheat furnace having input and discharge ends, a preheat zone near said input end, a heat zone between said preheat zone and said discharge end, fuel burner means in each said preheat and heat zones and exhaust gas fuel means between said input end and said preheat zone, said method comprising measuring the fuel flow rate for heating said heat zone as a function of a given throughput rate for said furnace, establishing an exhaust gas temperature corresponding to said flow rate as a further function for said given throughput rate, and controlling heating of said preheat zone to obtain said established exhaust gas temperature.
A heating control system for a reheat furnace having input and discharge ends, a preheat zone near said input end, a heat zone between said preheat zone and said discharge end, fuel burner means in each said preheat and heat zones, means for supplying fuel to each said burner means, and exhaust gas flue means between said input end and said preheat zone, said control system including means for producing a first control signal representing fuel flow to said fuel burner means in said heat zone, means for producing a second control signal representing the temperature of exhaust gas, means for comparing said first and second control signals and providing an output signal, and means responsive to said output signal for controlling fuel flow to said burner means in said preheat zone.
Dependencies are inferred from the claim text.