Uniformity and activity of blast furnace hearth by monitoring flame temperature of raceway zone

Abstract

With the effective volume of the blast furnace is upsizing in recent years, the effective volume and the hearth diameter of largest blast furnace are reached to 5 800 m3 and 15 m in China, respectively. The numbers of raceway zones are increased from one dozen to several dozens, the hearth uniformity and the activity become more important for large blast furnaces. The uniformity and activity of hearth are very crucial to produce the high quality hot metal and prolong the campaign life of blast furnace, it also could influence the stability state and operation indexes of a blast furnace. Currently, there is still no effective evaluation system for estimating whether the hearth is uniformity and activity or not. In this paper, the Uniformity Index and Activity Index in the peripheral direction and local regions were proposed to evaluate the hearth condition by measured the flame temperature of raceway zones in 2 000 m3 and 2 500 m3 blast furnaces. The established uniformity and activity evaluation system for blast furnace hearth, not only has academic value in understanding the formation of raceway zone and combustion mechanism, but also has tremendous application values to estimate work state of hearth and maintain a stable state of the blast furnace.