Study On No.2 BF Longevity Of Baosteel Stainless Steel Co.,Ltd.

No.2 blast furnace of Baosteel Stainless Steel Co.,Ltd whose designed furnace volume of 2500m3 and designed one-generation life of 12 years without medium-sized maintenance was put into operation in October 8th,1999.Until shut down in October 17th,2012,its total production is 25.814 MtHM;iron production per furnace volume is 10325.6t/m3,so the longevity of it steps into advanced level in China.In this paper,it mainly focuses on how to prolong its life at the late period of blast furnace.Survey was conducted to know its existing damage and analysis about the causes and its coping strategies of furnace shell settling was done in order to ensure its longevity,so that it came the protection measure and operation of later period of the furnace services.Firstly,investigation into the damaged cooling plate and wall found that it left a stress risks due to the corner of the cooling plate pore directly adopted the gas cutting reaming method because the construction schedule before the blast furnace was put into use.For the reasons mentioned above,from the mid to late period of the blast furnace,gas leaked from the flange and the furnace shell seams,even furnace shell cracked,the loading jetted.Sometimes the furnace was forced to drastically reduce wind blast,and even stopped to weld.Some impact like the cooling device massive burning,furnace skin redding,cracking and spitting fire,the furnace shell exacerbating deformation resulting from the deterioration of working conditions,obvious local regional settlement appeared due to blast furnace operation disorder during the period 2005-2008.Secondly,for the first phase of the furnace shell settlement status,a certain effect was made by conducting welding treatment toward furnace shell,grouting the weak parts and increasing the intensity of the cooling water by using planned maintenance opportunity.Furnace shell redness,disclosure,settlement had been controlled from November 2006 to June 2009.But later,blast furnace entered the second phase of the settlement,the settling velocity sped up,the corrugated pipe of cooling plate flange cracked down,up and down cooling plate flange overplayed,cooling plate seriously burned.Measures like limiting production,watering outside the furnace shell,supporting,reducing load,furnace frame reinforcement and other measures were taken toFinally,measures like taking a complete inspection,strengthening hearth cooling,strengthening taphole maintenance,controlling clay content ceiling,newly devising galvanic in tap hole area,adjusting the operation to reasonable smelting strength,feeding wire around the tuber,calming hearth in long blast break and other measures to make some parameters including galvanic temperature of hearth charcoal brick,the heat flow intensity of cooling wall and other parameters stay in a relatively safe range.Therefore it came to the effective mitigation of charcoal brick erosion of hearth to maintain safe production in mid to late life of blast furnace.