Process and apparatus for preheating the combustion mediums used for firing blast furnace stoves
AssigneeDidier-Werke AG
InventorHelmut Palz
Life of this patent
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Abstract
Combustion air and fuel gas used for firing blast furnace stoves is preheated by utilizing the heat of waste gases resulting from such firing. The combustion air and fuel gas are passed through respective heat exchangers in heat exchange relationship with the waste gases, thereby preheating the combustion air and fuel gas. The combustion air, after passage thereof through the respective heat exchanger, is further preheated by an externally fired recuperator. The flue gases from the externally fired recuperator are fed to the waste gases before preheating of the combustion air by such waste gases. The external firing of the recuperator is controlled as a function of the final preheated temperature of the thus twice preheated combustion air.
Claims17
A process for preheating the combustion mediums of combustion air and fuel gas used for firing blast furnace stoves by utilizing the heat of waste gases resulting from such firing, said process comprising:
- passing said combustion mediums through respective heat exchangers in heat exchange relationship with said waste gases, and thereby preheating said combustion mediums;
- further preheating one said combustion mediums, after the passage thereof through the respective said heat exchanger, by an externally fired recuperator;
- feeding flue gases from said externally fired recuperator to said waste gases before preheating of said one combustion medium by said waste gases;
- and
- controlling the external firing of said recuperator as a function of the final preheated temperature of the thus twice preheated said one combustion medium.
An apparatus for preheating the combustion mediums of combustion air and fuel gas used for firing blast furnace stoves by utilizing the heat of waste gases resulting from such firing, said apparatus comprising:
- a waste gas main for conveying waste gases resulting from firing blast furnace stoves;
- first and second heat exchangers arranged serially along said waste gas main for passing combustion mediums in heat exchange relationship with said waste gases, and thereby preheating the combustion mediums;
- an externally fired recuperator;
- means for passing one said combustion medium, after the passage thereof through the respective said heat exchanger, in heat exchange relationship with flue gases of said recuperator, thereby further preheating said one combustion medium;
- means for feeding said flue gases of said recuperator, after said further preheating of said one combustion medium thereby, to said waste gas main at a position upstream of said heat exchanger for said one combustion medium;
- and
- first temperature sensor control means for detecting the final preheated temperature of the thus twice preheated said one combustion medium and controlling the external firing of said recuperator as a function of said detected temperature.
Dependencies are inferred from the claim text.