Calculation And Research On Blast Furnace Hearth Repairing Furnace With Ceramic Material

The blast furnace is an important production equipment in steel production,but also the core of its production process equipment.The hearth is an important part of the blast furnace,and it is also the reactor for the smelting process and the container for high temperature hot metal.Hearth structure is composed of lining refractory brick masonry,cooling stave and steel shell composition.Blast furnace hearth poor working conditions,high temperature hot metal and direct contact with the hearth,hearth erosion is difficult to avoid.The working conditions of the hearth and the service time are different,and the erosion morphology and degree formed after the erosion are also different.In order to prolong the service life of the blast furnace,the hearth after the erosion needs to be repaired in time.The overall hearth brick method is the traditional process,construction efficiency is low,ranging from 40 to 50 days,as many months or even six months.Spraying repair method is a new technique of repairing hearth lining in recent years.However,from the repair effect of use,some use 3 to 5 years,while others are only 1 to 3 years or less.There are many factors that lead to the different lifetimes of spray casting repair hearth,among which there is a great relationship between the properties of spray casting material and the erosion morphology of lining before repair,that is,there is a suitable condition for spray casting repair method.In this paper,the heat transfer,temperature distribution,stress and distribution of the lining of the hearth and the strength of the lining and the shell of the hearth are studied by studying the different eroded topography,the remaining thickness and the physical properties of the injected material.From the aspect of longevity,Casting repair applicable conditions,the establishment of spray ceramic material repair hearth assessment method to provide a technical basis for the rational application of this hearth rapid repair technology.Aiming at the three typical erosion topography of hearth,such as foot-shaped erosion,pan-shaped erosion and mushroom erosion,the finite element analysis technology of ANSYS was used to establish the spray-painted ceramics with different erosion topography and different residual thickness The heat transfer and stress calculation model of the hearth after repaired by the material method was used to calculate the inner liner and shell stress and evaluate the liner and shell strength so as to extract the minimum value of the liner strength and shell strength corresponding to the eroded topography The remaining thickness,forming strength based on the conditions of ceramic materials to repair hearth assessment method.In order to compare the erosive characteristics of the inner lining like the foot so as to make a reasonable comparison,the definition of the erosion angle is used to describe the sharpness of the depression and use it as the characteristic parameter of the erosive topography of the foot,which is combined with the remaining thickness of the inner lining to construct the erosional topography.In this paper,we get the number table of erosion morphology,residual thickness,material properties,stress magnitude and strength by variable parameters.It is of theoretical and practical significance to design a scheme for repairing the new technology of blast furnace hearth based on the strength conditions and the evaluation method of the hearth for different shapes of the sprayed ceramic materials to repair the hearth based on the strength conditions.