2005 China Iron and Steel Annual Conference Proceedings of Meigang 1501 Converter Body Compressed Air Jet Cooling Device Shi Weizhong 1 Chen Deliang 1 Huang Chao 21. Baosteel Group Shanghai Meishan Iron and Steel Co., Ltd. 210039; 2. Beijing Metallurgical Equipment Research and Design Institute 100029 In this paper, the reformation of No.1 converter shell of Meishan Iron and Steel Co., Ltd. was carried out, and the cause of high temperature creep of the converter shaft was analyzed. A new type of compressed air jet cooling device was proposed. The feasibility of the device was proved to be 9,1 or above. The converter body cooling provides a reliable reference. 1 Overview Shanghai Meishan Iron and Steel Co., Ltd. steelmaking plant two converters known as Rong Tong 150, the shell is sold in Japan to the Mexican Fang Dilado steel mill hand shell, the material composition is similar to the domestic 16 pressure capacity steel composition. Because of the replacement of the magnesium carbon brick lining in our factory, the temperature of the furnace body during blowing is more than 390 by thermal imaging; the cooling gap between the outer wall of the original design body and the inner wall of the support ring is 150. The measured value is about 120. After 3 years of production and use, the cold detection gap of the furnace is about 1520. The hot state of the furnace is estimated to have no gap during the blowing; the shell material works for a long time at 390 or higher temperature, and is subjected to furnace lining expansion pressure thermal stress mechanical stress. The thermal creep deformation occurs under the combined effect. When the new furnace shell is replaced, it is planned to use compressed air jet cooling technology to reduce or avoid high temperature creep deformation and prolong the service life of the furnace shell when the furnace body temperature is controlled below 300. At home and abroad, there is no practical example of the successful application of compressed air jet cooling technology in the practical technology of cooling and cooling of converter shafts above 15 and 1 capacity. This technology uses the factory's ordinary compressed air 0.83 as the ejector medium. It has low energy consumption, low price and easy to obtain. It does not need new special gas supply systems and equipment. The structure of the conveying pipe is simple, the construction cost is low, the maintenance is convenient, and the workload is small. Even if the pipeline breaks and the compressed air leaks during production and use, the treatment is simple and quick, and it does not cause safety accidents to threaten life and property. It is safer and more reliable than using water as a cooling medium. 2Technical content 2.1 General idea The furnace section of the converter shell at home and abroad is subjected to different degrees of elliptical deformation and temperature creep during use. The direction of the ellipse long axis is commonly called the peach-shaped drum belly on the tapping side. This is already The difficulty of the world metallurgical industry. The main causes of the temperature creep deformation are mainly due to the following aspects: due to the steel smelting of large children, the temperature of the tapping steel rises, and the furnace lining uses magnesia-carbon bricks with a large thermal conductivity, especially in the later stage of the furnace, severely burnt and thinned, etc. This will result in a significant increase in the amount of heat transferred per unit time. The thickness of the furnace shell is thin and the stress is large; the material of the furnace shell 16MnR belongs to CMn low-alloy high-strength steel, and its tensile strength and thermal creep resistance are poor. When the tapping or temperature measurement sampling is performed without the sub-gun or sub-gun failure operation, the total weight of the molten steel in the furnace is concentrated on the tapping side of the furnace, commonly known as the front and rear large faces. When the slag is discharged from the steel, the radiant heat reflected by the steel water tank or the slag tank and the additional heat generated by the warm smoke velocity scouring. The radial thermal expansion of the hot lining above 1000 is much larger than the radial thermal expansion of the steel shell and the expansion pressure. The combined effect of the steel slag and the gravity of the furnace lining and the mechanical stress of the furnace operation greatly exceeds the high temperature yield of the steel plate. strength. The airflow between the ring and the outer casing of the furnace body is not smooth, and the radiation and convection heat transfer are less than the heat, so that the furnace shell works for a long time under the temperature of 350,4701; the furnace shell working temperature is 350 470, which is much higher. The difference in thermal expansion between the operating temperature of the water-cooled support ring and the temperature of the furnace shell and the elliptical deformation of the furnace shell, etc., make the cooling gap between the furnace shell and the support ring smaller than the design theoretical value under actual working conditions, which is even more The heat dissipation condition of the shell plate of the furnace body is deteriorated, and the thermal stress of the working temperature of the furnace shell plate is increased. At the same time, since the cooling gap between the furnace body section and the support ring is reduced, the natural convection strength is weakened, so the hot gas film attached to the surface of the furnace shell surface is difficult to be broken, and the hot gas film blocks the subsequent heat exchange of the outer layer cold air. The function of the natural convection heat transfer of the shell plate and the air is greatly weakened. In addition, the hot gas film also reflects the heat radiation energy of the partial shell plate, and the returning shell plate also reduces the radiation heat transfer effect of the shell sheet. In view of the above-mentioned main causes, in addition to the development of new materials for furnace shells and the increase of shell thickness, another chapter is written; in order to enhance the heat transfer effect between the cooling gap between the support ring and the shell, it is proposed to develop a compressed air jet cooling device, that is, in the shell of the furnace body. The annular cooling gap between the body and the support ring is the compressed air nozzle as the jet source. The compressed air source pressure is 0.8; the distance between the nozzle and the furnace shell is optimized. The spacing between the nozzles is the number of nozzles. The nozzle jet flow rate is the pressure. Series of technical parameters such as spray angle. Finally, the impact of a plurality of compressed air jets flowing out of the nozzle breaks the hot gas film covering the outside of the shell plate, and the entrainment of the jet stream guides and drives the forced convection of the air around the annular cooling gap to improve heat transfer. Conditions, strengthen the heat transfer effect, to achieve the purpose of reducing the operating temperature of the furnace shell plate. 2.2 Technical scheme The connecting road is connected from the common compressed air main pipe of the converter workshop, and the compressed air pressure for jet cooling is about 0.8, and the flow rate is about 25353 pipe. The connecting pipe is provided with a flow pressure detector and a regulating valve, and then divided. The road is sent to the annular collecting manifold disposed at the bottom of the bracket through a gas channel of the newly modified free-end gas-water two-phase rotary joint of the converter; and then flows through several dozens of nozzles to hundreds of nozzles and sprayed to the outside of the shell Above, it acts as a jet cooling. Each branch pipe is equipped with a detector and a control valve to adjust the pressure and flow state parameters of the compressed air, and the temperature field distribution and size of the shell plate of the furnace body are observed by means of thermal imaging, and the distribution of the compressed air jet field is adjusted by means of the aforementioned adjusting device. Direction and size; finally achieve the purpose of controlling the temperature field distribution and size of the shell section by adjusting the compressed air jet field. The air jet blowing cooling simulation test was carried out in advance, and the influence of various parameters including the physical condition of the fluid flow type and the geometrical condition of the nozzle position on the heat transfer strength of the furnace shell was determined, and their quantitative relationship was determined. Nusselt number, =, meaning; Reynolds number, do = 10; Prandtl number of air; convective heat transfer coefficient, thermal conductivity of air, WrnK; v air blowing speed, air moving viscosity, 2 orifice Diameter, nozzle spacing, claws; nozzle to hot surface distance, calculation factor. The main method of the scheme is to use compressed air; 2 to appropriately increase the diameter of the air duct outside the furnace to reduce the pressure loss in the pipeline; 3 the diameter of the vent hole in the center of the trunnion is constant to reduce equipment changes; The upper air duct of the furnace is arranged on the lower side of the supporting ring, and the 5 blowing blowing pipe is changed into a tubular type, and a plurality of cooling pipes with blowing holes are arranged on the circumference of the furnace shell, and inserted into the gap between the supporting ring and the furnace shell, so that The cold air is directly sprayed onto the hot side of the shell to increase the cooling effect. 2.3 Embodiment The jet cooling device includes a compressed air delivery pipe to provide a jet air source to the system 2005 China Steel Annual Conference Proceedings, and the external gas inlet pipe 7 and the gas water rotary joint 2 are connected with the annular collecting manifold 3 at the bottom of the support ring. The collecting manifold is fixed on the bottom surface of the bracket 4 by the supporting clamping device; the plurality of branch pipes 5 are disposed in the annular cooling gap between the shell 6 and the bracket 4, and are connected to the collecting manifold 3, on which There are also different numbers of nozzles distributed according to the adjustment of the temperature field size and distribution of each part of the shell section of the furnace body. The jetting speed and pressure of each branch are poor, and the working temperature is too high. Innovation. By providing a compressed air jet device, the hot gas film attached to the outside of the shell plate is broken, and the entrainment action of the jet gas beam is used to drive the forced convection of the surrounding air; the heat dissipation effect of the shell plate is greatly enhanced, and the work of the shell plate is reduced. temperature. 4 The secret point state parameters can be satisfied by adjusting the valve separately. 2.4 Implementation effect Through the annual online application, the thermal imaging observation results show that the structure principle paper of the gas-water two-phase rotary joint; the model specification of the jet system of the compressed air jet device; and the shell surface temperature of the furnace section 250 It has the following thermal imaging 2, which achieves the target value expected to be controlled below 3001, and the temperature distribution of the annular zone is evenly poor 50; the annular gap between the ring and the shell of the furnace is still 142, not found. The furnace shell plate appears to be warm and creep. The distance between the nozzle and the shell plate of the jet cooling device since the production is started. The angle between the nozzles and the number of nozzles. The number of nozzles, the jet flow velocity, the jet velocity, the spray angle, etc. The technical parameters are 5 without any fault, safe and stable, comprehensive. Beyond the expected effect, 2. 3 found that the invention and innovation point 1 found that the annular space between the furnace body and the support ring natural convection, the double shielding of the support ring and the furnace hat heat shield, can not be successfully developed from the compressed air jet device, using Meigang 1 The renovation of the furnace was completed and the installation of the device was completed. On April 16, 2004, the investment was successful and it has been put into use for the year. The detection of the shutdown by thermal imaging has completely exceeded the expected effect. The device is intended to form a forced convection heat transfer state during the upcoming overhaul of Meigang No. 2 furnace; on the other hand, it is due to the convection. The device has a large and weak capacity above the 9,1 level, and the hot gas film attached to the outside of the furnace plate is difficult to be broken, and the type of converter has a wide application prospect. The device belongs to Meisteel to block the subsequent cooling of the surrounding air; this is the development of the furnace shell plate and has independent intellectual property rights. Thai, Shi Xiaolu and so on. Research on deformation test of Baosteel's 3,1 converter shell. Metallurgical equipment, Tan Mutian. Oxygen converter steelmaking equipment. Beijing Mechanical Industry Press, 1983 3 Tan Lihua translation. Magnesium-carbon conversion performance and its effect on 8 furnace lining and furnace shell stress gas. Foreign refractory materials 2, 1993 4 big hand Zhang and so on. Cooling furnace shell and single layer lining off the life of the converter. Refractory 7, 5 Yan Chunji, Jie Maozhao. Aerodynamics splitting and atomization characteristics of hollow cylindrical liquid jet Pet Chips Hotfilling Grade,Heat Filling Level Of Pet Chip,Juice Milk Bottles,Pet Resin For Drinking Oil Bottle Jiangyin jietong international trade company , https://www.jietongpetresin.com