Study On The Machining Mechanism Of Blast Furnace Taphole Clay And Tapping Equipment

Steel and iron industry of China has made great progress in the past few years. Higher requests to the blast furnace ironmaking technology and equipment were proposed to fit the rapid development in steel and iron industry and the optimization of product structures. The crude steel annual production of China is 630 million tons, which is about 45% of the world's production. The board rate increases rapidly and the quality of steel is improved continuously. The self-sufficient rate of steel and ironin in China is more than 96% at the present time. The capability of independent innovation has been enhanced continuously. The technique and equipment level has been improved obviously. Major progress has been made in the integrated innovation of ten million ton iron and steel complex. Therefore, it is necessary to improve the technique and equipment level.Tapping machine and its drilling tool are the keys to blast furnace ironmaking, their operation effect has direct impact to the production efficiency and safety of blast furnace. Short service life, high cost and low efficiency of the drilling tool have always been the technical problems which puzzle the steel and iron industry in China. At present, domestic steel manufacturers are faced with the important task of rebuilding and upgrading tapping machine from electrical or pneumatic to entire hydraulic. This research complies with the requirements of development in the steel and iron industry, and specifically address the technical problems of drilling tool and tapping machine existing in the practical production of the Jinan Steel and Iron Group, aims to breakthrough the technical bottleneck in drilling tool and tapping machine of the blast furnace, to enhance the production efficiency, reduce production cost, and promote the development of iron and steel industry.This research combines theoretical analysis, virtual prototype technology and finite element method to complete the analysis of the blast furnace taphole clay temperature field. The structure characteristic of taphole clay and the strength theory about brittle material were studied in terms of its physical and chemical properties, high temperature phase and theoretical strength, which made a foundation for stress analysis of drilling tool in the next stage. The kinematical and dynamical analysis of the working process is taken by using ADAMS software for its structure design. Practical results have proved that the taphole drilling machine meet low energy consumption, environmental protection and efficient performance.The finite element method analysis model of the blast furnace taphole clay is established and its temperature field is analyzed. Temperature contour of taphole clay was carried out, which made a foundation for stress analysis of drilling tool in the next stage. In addition, basic characteristics of blast furnace taphole clay, such as the function requirements, raw materials allocated proportion, the physical and chemical properties etc. were analyzed. The structure characteristic of taphole clay and the strength theory about brittle material were studied. The destruction criterion of brittle material which is similar to concrete and suitable for taphole clay has been determined.According to the theoretical strength and failure criterion, experimental study of taphole clay's cutting property has been finished. Cemented carbide tool was used for the experiment. The cutting scrap and tool wear mechanism of different roasted clay were investigated.Virtual prototype model of the tapping machine and drilling tool system was built, dynamic simulation analysis with ADAMS was carried out, and the dynamic characteristics of the system were obtained. The stress distribution in drill was analyzed in theory and was simulated. Different failure modes of the drill under normal temperature and high temperature were analyzed, the main reason for its failure in the process of opening taphole is that the drill edges falling off from the tank of drill body. A new tapping drill was developed according to the design criterion of rock drill on the basis of full consideration the failure reasons of dill, and the preliminary scene examination was carried. Practical results indicated that the defect which the blade fell off under high temperature would be overcome through the adoption of this new drill. Its working efficiency was distinct enhanced and its cost was obvious reduced compared with original one.Based on the principle of two-flow atomization, a new atomized water cooling system has been developed. It can effectively reduce drill pipe deformation and drill failure, and also conducive to the high-temperature taphole clay occurs micro-cracking and crushing, result in reducing drilling resistance, improving the efficiency of opening furnace taphole, reducing emissions of soot and dust pollution.Virtual prototype model of the entire hydraulic tapping machine was built, and its dynamic simulation analysis was carried out. Force status of the tapping machine and the maximum force in each constraint in the whole work process were obtained. The finite element analysis and the strength check of each key element of the tapping machine were finished.Research and developed a new kind of short body hydraulic tapping machine, which is especially suitable for the limited space of blast furnace production environment. A rotary structure was designed to replace the traditional folding structure to improve the whole system rigid. An anchor structure was developed to improve the stability and work reliability of dirlling system.