Blast Distribution Over the Air Tuyeres of a Blast Furnace

Resumo

The nonuniform distribution of hot blast over the tuyeres results in different lengths of the raceways of tuyeres, which is responsible for the different descent of the burden in various sectors of a blast-furnace (BF). This leads to the formation of a deformed gas flow over the cross section. In this connection, the accumulation information about the hot blast distribution over the air tuyeres is an extremely important component of the technological procedure. We propose a new technique for the determination of the blast flow rates in tuyeres based on the use of the thermal power of the flow passing through the tuyere and the intensity of the heat removal from this tuyere. It is shown that the distribution of hot blast over the tuyeres of the blast furnace is nonuniform and determined both by the technology of blast-furnace smelting and the design of air feeders. It is shown that, in the presence of a nonuniform distribution of hot blast over the tuyeres, the procedure of stabilization of the thermal state in the tuyere raceways requires the correction of flow rates of the natural gas in each tuyere with an aim to maintain the theoretical combustion temperatures on the required level.