Determining the air excess in the heating of coke furnaces. 3. Calculation of the air excess

Resumo

The chemical mechanism by which coke-oven gas burns in the heating ducts of coke ovens is considered. A formula is obtained for the air excess. In contrast to the existing formula, the proposed version takes account of not only the content of oxygen, carbon monoxide, and carbon dioxide in the combustion products but also the content of sulfur dioxide, hydrogen, methane, nitrogen oxides. Analysis of the combustion products in the heating ducts of a coke battery with 30.9-m³ ovens shows that the content of incombustible components in the coke-oven gas may reach 3%. Calculation of the air excess by means of the proposed formula permits improvement in the uniformity of the temperature distribution in the heating system, the prevention of specific lining defects, and decrease in atmospheric emissions when the coke battery is heated by means of coke-oven gas. The proposed method of determining the air excess may be used not only in equipment for coke production but also in other metallurgical systems where coke-oven gas is burned.