Iron hot-blast stove of blast furnace is heated to the required temperature of blast, to improve the effectiveness and efficiency of the blast furnace; it is a "thermal" principle. In the combustion chamber the combustion gas, hot gas through the lattice and heat the brick, when Checker full heating, stove could be replaced by air, about burning the valve closed, the air valve is opened, the cold wind Checker brick is heated and sent out. Blast furnace 3-4 furnace/' furnace air ", two or three heating an air; in turn replaced/' parallel air", the two heats.