关于高炉炉缸侵蚀问题的探讨

Discussion on blast furnace hearth erosion problems

为定量分析炉缸侵蚀影响因素,计算了膨胀缝、炭砖导热系数、炭砖尺寸对炭砖热应力的影响程度。当炭砖完全约束时,炭砖的热应力是未约束的3倍多;当断面尺寸由1 500mm×400mm×400mm变到300mm×220mm×114mm时,热应力从11.8 MPa降至3.9 MPa,导热系数由5 W/(m·℃)增大到30W/(m·℃),热应力从13.3MPa降至10.2MPa;计算出死料堆漂浮与沉坐炉底这2种工况下炉缸大部分区域铁水的流速在2.5×10-3 m/s以下,并分析铁流在炉缸内的变化规律,且计算出铁水对炭砖的机械冲刷力在1Pa以下,分析了铁水温度和流速对炭砖溶解的影响。在此基础上,提出建立炉缸良好传热体系是解决炉缸炭砖侵蚀的重要技术方向。

In order to analyze the hearth erosion influencing factors quantitatively, the influence degrees of expansion joints, heat conductivity coefficient and size of carbon brick on its thermal stress were calculated. When carbon brick was in fully constrained condition, the thermal stress of carbon brick was over three times compared with that in unconstrained condition. When the section size was changed from 1 500 mm x400 mm x 400 mm to 300 mm x220 mm x114 mm , the thermal stress was decreased from 11.8 MPa to 3.9 MPa. When the heat conductivity coefficient changed from 5 W /（ m？℃） to 30 W / （m？ ℃）, the thermal stress decreased from 13.3 MPa to 10.2 MPa. The flow velocity of hot metal in most areas of hearth was calculated in both deadman floating and sitting conditions and the value was below 2.5×10-3m/s.The variation rules of hot metal in the hearth were analyzed. The mechanical erosion force of hot metal affecting carbon brick was below 1 Pa. In addition, the effects of hot metal temperature and flow velocity on carbon brick dissolution were also discussed. It showed that the establishment of a fine heat transfer system for the hearth should be an important technical direction to solve the erosion problem of carbon brick hearth.