| China is a country with a large demand for steel.The development of the national economy and the improvement of national defense forces cannot be separated from the steel industry.In the steel industry,blast furnace smelting is a very important production method.In the production process,blast furnace equipment plays a key role.Blast furnaces that are put into production all year round are prone to damage.One of the more common situations is excessive erosion of the lining of the blast furnace hearth.If it is not found in time,it will cause a major impact on the company's safety in production and economic benefits.At present,most of the commonly used methods for detecting erosion of blast furnace linings are to use the thermocouple parameters in the furnace and the heat transfer model to empirically estimate the erosion of the blast furnace lining.However,due to the continuous erosion of the blast furnace lining,the life of the thermocouple near the hot end is continuously reduced until failure,which will affect the detection accuracy.Therefore,it is necessary to develop an efficient and reliable detection method to improve the detection accuracy of the lining thickness of the blast furnace hearth.As researchers' research on stress waves deepens,a new nondestructive testing technology is gradually popularized and applied,that is,the impactecho technology that this article will study.In this paper,the related theories of the technology in the lining erosion detection of blast furnace hearth are studied from the following aspects:(1)The impact-echo technique is simulated dynamically by ABAQUS,the stress distribution caused by impact is analyzed,and the propagation law of stress wave in objects is studied;(2)The acceleration response generated by the impact load in the concrete slab is studied by ABAQUS,meanwhile the influence of the distance between the impact point and the signal receiving point,the distance between the detection point and the boundary,and the impact hammer diameter on the thickness of the detection object is analyzed;(3)Through the field experiment,the thickness of the concrete slab is tested by the impact-echo technique,and the experimental data is analyzed and processed by Lab VIEW software.The analysis results are compared with the actual thickness,and verify accuracy the impact-echo technique is used to detect the thickness of the object;(4)A blast furnace hearth model is established to perform the simulation and analysis of impact-echo(not considering the influence of temperature field)by ABAQUS.Then,the thickness of the blast furnace is detected,the simulated thickness with the actual model thickness are compared,and verify the reliability of the impactecho technology in testing blast furnace hearth thickness at normal temperature;(5)Temperature field analysis on the blast furnace model is performed to calculate the temperature factor of each layer,and perform impact-echo simulation analysis on the basis of this.In the calculation process,two calculation methods are used,one is to consider the temperature factor,and the other is not to consider the temperature factor.Then,the two calculation results are compared to study the influence of the temperature factor on the detection result,and finally the thinnest part of the blast furnace hearth is detected.This subject has important reference significance for improving the thickness accuracy of blast furnace hearth lining by improving the impact-echo technology,realizing the erosion status of blast furnace hearth lining in real time,prolonging the service life of blast furnace and reducing safety accidents in blast furnace production process. |
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