Theoretical and practical research on relationship between blast air condition and hearth activity in large blast furnace

Abstract

From the results calculated by theoretical derivations, it was found that the characteristics of tuyere raceway determined by the operation condition for blast air played a critical effect on the heart activity. The speed and kinetic energy of blast air should be proportional to the volume of blast furnace (BF), and the comprehensive optimization of air volume and tuyere which should vary with the quality of raw materials was essential. The calculation methods of air volume ratio and coefficient for different BFs were put forward. Moreover, the details on hearth activity recovery of a 4747 m3 blast furnace in China were elaborated. Based on the extensive experience in blast furnace production, the various phenomena used to judge air speed and kinetic energy whether reasonable were discussed. In summary, hearth activity was closely related to the characteristics of BF raceway and reasonable air speed and kinetic energy could effectively improve the activity.