Patent ID: 7540992

Claim:
A reheat furnace process for reducing a hot point of the flames of a burner and continuously moving iron and steel products through the furnace resulting in control of the temperature homogeneity of the products in the furnace which is equipped with lateral burners, the process comprising the steps: providing at least two spread flame lateral burners on each lateral wall of the furnace; operating the lateral burners in bang bang mode, the operating and stoppage time of each burner adjusted to obtain a desired temperature; operating the burners at a regime close to or at maximum state, choosing the order of ignition of the burners to— a) promote swirling and circulation of the flue gases so as to reduce a hot point of the flame and to obtain a better temperature homogeneity of walls of the furnace and of the products; and b) reduce the pressure variations in the furnace and in circuits for feeding the burners with fuel and oxidizer wherein burners are started and stopped for modifying the circulations of the flue gases in an enclosure of the furnace by a computer using mathematical control algorithms based on a thermal objective defined for the product; and wherein the computer controls thermal distribution selectively in accordance with longitudinal and/or transverse curves of temperature of the furnace, as a function of the position of a charge, of its characteristics and of its progress along the length of the furnace and of the temperature and exit temperature distribution objective sought for the product.