宝钢4BF无衬套风口小套内壁结壳现象分析

宝钢4BF在无衬套风口使用过程中,发现一个定修周期中无衬套风口小套内表面出现最大厚度为5 mm的沉积结壳层,分析结果表明,该沉积物中氧化锌含量大于50%,钾钠含量为5%~30%。分析认为,因有害元素在高炉内富集,生产中风口区存在一个有害金属元素与氧化物达到平衡的边界层,在冷却强度大的无衬套风口小套内表面沉积而形成结壳层,临时休风的煤气倒流则会加剧这一现象发生。提出几种应对措施,以减小无衬套风口结壳现象对送风制度的影响。通过采取相应措施,宝钢4BF无衬套风口内壁结壳现象得到明显改善。

Analysis on the deposition of the inner wall of bushless tuyere sleeve of Baosteel No.4 BF

During the operation of bushless tuyere in Baosteel No.4BF,a deposited layer with the maximum thickness of 5 mm was found on the inner surface of bushless tuyere sleeve during a maintenance cycle.The analysis results show that the content of zinc oxide in the deposition is more than 50%,the total content of potassium oxide and sodium oxide is between 5%to 30%.This paper considers that due to the enrichment of harmful elements in blast furnaces,there exists a boundary layer between harmful elements and oxides in the tuyere area of production,which deposits on the inner surface of the small tuyere sleeve without bushing and forms a crust layer.The phenomenon will be aggravated by the discharge gas of temporary blowing down.Several measures are put forward to reduce the crust phenomenon of the bushless tuyere.By adopting corresponding measures,the phenomenon of inner wall crust of bushless tuyere of Baosteel No.4 BF has been obviously improved.