A double-parameter oxygen lance used in a 300 t converter was designed to improve the metallurgical performance. A small-scale measurement of the jet behavior was done using a computer controlled scanning system. The ...A double-parameter oxygen lance used in a 300 t converter was designed to improve the metallurgical performance. A small-scale measurement of the jet behavior was done using a computer controlled scanning system. The experimental data on the velocity distribution at the jet centerline, the contour map of the jet velocity, the deviation of the jet centerline, and the velocity distribution of the axial section were compiled. According to the results of the small-scale measurement, the double-parameter lance was also employed for a BOF experiment. The metallurgy inde- xes show that the metallurgical performance was highly promoted by use of the double-parameter lance.展开更多
A three-dimensional computational fluid dynamics (CFD) model was developed to simulate a 150-t top-blown converter. The ef-fect of different lance heights on the cavity shape was investigated using the volume of flu...A three-dimensional computational fluid dynamics (CFD) model was developed to simulate a 150-t top-blown converter. The ef-fect of different lance heights on the cavity shape was investigated using the volume of fluid (VOF) method. Numerical simulation results can reflect the actual molten bath surface waves impinged by the supersonic oxygen jets. With increasing lance height, the cavity depth de-creases, and the cavity area, varying like a parabola, increases and then decreases. The cavity area maximizes at the lance height of 1.3 m. Under the three different lance heights simulated in this study, all of the largest impact velocities at the molten bath surface are between 50 m/s and 100 m/s.展开更多
Three lance designs for argon bubbling in molten steel are presented. Bottom</span><span style="font-family:Verdana;"> bubbling is considered too. Geometries considered are straight-shaped, ...Three lance designs for argon bubbling in molten steel are presented. Bottom</span><span style="font-family:Verdana;"> bubbling is considered too. Geometries considered are straight-shaped, T-shaped, and disk-shaped. The bubbling behavior of these lances is analyzed using Computational Fluid Dynamics, so transient three dimensional, isothermal, two-phase, numerical simulations were carried out. Using the numerical results, the bubble distribution and the open eye area are analyzed for the considered lance geometries. The plume volume is calculated from the open eye </span><span style="font-family:Verdana;">area </span><span style="font-family:Verdana;">and the lance immersion depth using geometrical considerations. Among the three lance designs considered, disk-shaped lance has the bigger plume volume and the smaller mixing time. As the injection lance is deeper immersed</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the power stirring is increased and the mixing time is de</span><span style="font-family:Verdana;">creased.展开更多
当耳边响起“Star Wars Main Title”的交响乐章时,心底的激情就像被按住管口的水管内的水瞬间得以释放。这种感觉,犹如与翼神初见时从双眼直抵内心的触动,抽象得难以用字符去描述与形容这台翼神所带来的力量。但可以明显感受到,车主对...当耳边响起“Star Wars Main Title”的交响乐章时,心底的激情就像被按住管口的水管内的水瞬间得以释放。这种感觉,犹如与翼神初见时从双眼直抵内心的触动,抽象得难以用字符去描述与形容这台翼神所带来的力量。但可以明显感受到,车主对它倾注的大量心思与无比的喜爱。这种力量莫不成是原力的另一种形式?如果你有幸能在广州的街道上遇上它,或许你就会有属于你自己的答案了。展开更多
Based on the operating conditions of oxygen lance utilized for a 50 t converter in Tangsteel,gas jet flow fields of three types of oxygen lances were simulated by FLUENT software.The influence of lance configuration a...Based on the operating conditions of oxygen lance utilized for a 50 t converter in Tangsteel,gas jet flow fields of three types of oxygen lances were simulated by FLUENT software.The influence of lance configuration and lance level on penetrating area was studied through cold model experiment.The results showed that the gas flow velocities of four-hole,variable angle four-hole and five-hole oxygen lances declined rapidly with an increase in gas jet length within 1 m,1 m and 0.8 m,respectively.Besides,the multi gas streams sprayed from these three lances should be syncretized at 1.6 m,1.7 m and 1.4 m,respectively.At the highest lance level,the effective penetrating area of these three lances could be 0.255 m2,0.385 m2 and 0.0907 m2,respectively.It was suggested that the effective penetrating area of variable angle four-hole oxygen lance was the biggest,while that of five-hole oxygen lance was the least.The validity of numerical simulation results was proved through cold model experiment.The lance level was suggested to be controlled in the range of 1-1.6 m,1-1.7 m and 0.8-1.4 m for the four-hole,variable angle four-hole and five-hole oxygen lances,respectively.展开更多
Pulverized coal injection(PCI) is a key technology in modern ironmaking by blast furnace(BF) and the life of injection lance has a great influence on PCI operation and on normal running of blast furnace.It is foun...Pulverized coal injection(PCI) is a key technology in modern ironmaking by blast furnace(BF) and the life of injection lance has a great influence on PCI operation and on normal running of blast furnace.It is found that the main reasons for the failure of the lances are their outer surface oxidation and the inner surface erosion through monitoring some lances used in BF.The outer surface oxidation of the lances made of lCr18Ni9Ti is inevitable under high hot blast temperature condition through thermodynamics analysis.A mathematical model for calculating the temperature of common monocular coal lance had been developed according to the principles of mass and energy balance.Increasing temperature and flow velocity of the hot blast would cause a rise in the lance temperature.The influence of hot blast temperature is more obvious.The lance temperature would decline when compressed air flux increases.Conveying technology of dense phase pulverized coal is beneficial to extending lance’s life because decreasing solid-gas ratio would intensify erosion and burning loss.The anti-oxidation temperature of lance materials needs to be over 1000 ℃ for BF intensified smelting.In order to increase the resistance to oxidation of the coal lance’s outer surface,oxidation-resistant steel or Al coating stainless steel is the appropriate material for BF use.Employing the metal surface treatment technology to enhance the hardness of the coal lance’s internal surface could prolong the service life of coal lance展开更多
Pulverized coal utilization in the blast furnace is decided by the particle flow and combustion behaviors in the raceway.Under a specific operating condition,these behaviors are directly related to the lance configura...Pulverized coal utilization in the blast furnace is decided by the particle flow and combustion behaviors in the raceway.Under a specific operating condition,these behaviors are directly related to the lance configuration in the upstream tuyere zone.Focusing on single straight lance,six types of single lance configurations were designed by assembling four parameters in different ways.These four parameters are the lance diameter,lance insertion angle,and the horizontal and vertical distances from the lance tip to the tuyere tip.With different lance configuration schemes applied,the pulverized coal combustion process in the lance-blowpipe-tuyere zone was simulated.The simulation results regarding particle diffusion and combustion behaviors were characterized by three indicators from the viewpoint of a coal plume.They are the plume diffusion angle,diffusion uniformity,and the average plume temperature at the tuyere outlet.To promote coal utilization,the values of these indicators under different configurations were analyzed,yielding two optimal configurations.The first one is to reduce the lance length immersed in the blowpipe-tuyere by 100 mm.The other is to increase the horizontal distance from the lance tip to the tuyere outlet by 50 mm,and the insertion angle to 11° with the lance tip located at the tuyere centerline.The findings can enhance the understanding of the influence mechanism of lance con-figuration on the coal utilization and provide guidelines for the design of new lance configurations.展开更多
To improve the efficiency of the steelmaking process,a system of self-rotating lance was designed,and corresponding cold simulation mechanism was developed.The influence of the self-rotating lance on the mass transfer...To improve the efficiency of the steelmaking process,a system of self-rotating lance was designed,and corresponding cold simulation mechanism was developed.The influence of the self-rotating lance on the mass transfer rate between slag and molten steel was investigated by comparing this novel system with the traditional oxygen lance.The results show that the self-rotating lance can stably rotate with a gas jet as the power source.The mass transfer rate increases with an increase in the top and bottom blow flow rates and with a decline in the lance position.Approximately 13.7% of the top blow flow rate is converted to stirring energy,which is approximately twice that of the traditional oxygen lance,and the mass transfer rate can increase by over 30%.Furthermore,the impact energy can be concentrated at different depths of the molten bath by adjusting the rotational speed.With the same energy density,the mass transfer rate produced by the self-rotating lance is higher;however,the influence of the energy density on the mass transfer rate is low when the rotational speed is 30-50 r/min.展开更多
An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the b...An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the bath-oxygen impact area, such as the cavity depth, the lance height, the number of nozzles and the nozzles diameter. In the thermal issue, the model includes the targeted carbon content and temperature. The model is numerically solved, and is validated using reported data plant. The oxygen flow rate and the lance height are varied in the numerical simulations to study their effect on the carbon content and decarburization rate.展开更多
IN August this year,the HubeiProvincial Song and Dance Troupeput on 21 performances for 30,000people In 10 states during its one-month tour of Malaysia,entertain-ing audiences all across the coun-try.Many senior Malay...IN August this year,the HubeiProvincial Song and Dance Troupeput on 21 performances for 30,000people In 10 states during its one-month tour of Malaysia,entertain-ing audiences all across the coun-try.Many senior Malaysian gov-ernment leaders and importantpublic figures were among the au-diences,and the local newspapersreported it as the most展开更多
The water-air and Wood’s metal-air systems are modeled by means of Computational Fluid Dynamics to study the interaction between a liquid surface and an impinging air jet under the near field blowing conditions. The ...The water-air and Wood’s metal-air systems are modeled by means of Computational Fluid Dynamics to study the interaction between a liquid surface and an impinging air jet under the near field blowing conditions. The effect of the air jet velocity, the height of the injection lance, and the density of the liquid on the depth of the formed cavity is numerically studied. The CFD results of the cavity depth are compared with results previously reported by other authors. The emergence of the splashing phenomenon is predicted in terms of the critical velocity for each liquid-air system. Besides, the blowing number indicates that the drop generation rate is not significant for jet velocities below the critical velocity, and therefore neither the splashing is significant.展开更多
文摘A double-parameter oxygen lance used in a 300 t converter was designed to improve the metallurgical performance. A small-scale measurement of the jet behavior was done using a computer controlled scanning system. The experimental data on the velocity distribution at the jet centerline, the contour map of the jet velocity, the deviation of the jet centerline, and the velocity distribution of the axial section were compiled. According to the results of the small-scale measurement, the double-parameter lance was also employed for a BOF experiment. The metallurgy inde- xes show that the metallurgical performance was highly promoted by use of the double-parameter lance.
文摘A three-dimensional computational fluid dynamics (CFD) model was developed to simulate a 150-t top-blown converter. The ef-fect of different lance heights on the cavity shape was investigated using the volume of fluid (VOF) method. Numerical simulation results can reflect the actual molten bath surface waves impinged by the supersonic oxygen jets. With increasing lance height, the cavity depth de-creases, and the cavity area, varying like a parabola, increases and then decreases. The cavity area maximizes at the lance height of 1.3 m. Under the three different lance heights simulated in this study, all of the largest impact velocities at the molten bath surface are between 50 m/s and 100 m/s.
文摘Three lance designs for argon bubbling in molten steel are presented. Bottom</span><span style="font-family:Verdana;"> bubbling is considered too. Geometries considered are straight-shaped, T-shaped, and disk-shaped. The bubbling behavior of these lances is analyzed using Computational Fluid Dynamics, so transient three dimensional, isothermal, two-phase, numerical simulations were carried out. Using the numerical results, the bubble distribution and the open eye area are analyzed for the considered lance geometries. The plume volume is calculated from the open eye </span><span style="font-family:Verdana;">area </span><span style="font-family:Verdana;">and the lance immersion depth using geometrical considerations. Among the three lance designs considered, disk-shaped lance has the bigger plume volume and the smaller mixing time. As the injection lance is deeper immersed</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the power stirring is increased and the mixing time is de</span><span style="font-family:Verdana;">creased.
文摘当耳边响起“Star Wars Main Title”的交响乐章时,心底的激情就像被按住管口的水管内的水瞬间得以释放。这种感觉,犹如与翼神初见时从双眼直抵内心的触动,抽象得难以用字符去描述与形容这台翼神所带来的力量。但可以明显感受到,车主对它倾注的大量心思与无比的喜爱。这种力量莫不成是原力的另一种形式?如果你有幸能在广州的街道上遇上它,或许你就会有属于你自己的答案了。
文摘Based on the operating conditions of oxygen lance utilized for a 50 t converter in Tangsteel,gas jet flow fields of three types of oxygen lances were simulated by FLUENT software.The influence of lance configuration and lance level on penetrating area was studied through cold model experiment.The results showed that the gas flow velocities of four-hole,variable angle four-hole and five-hole oxygen lances declined rapidly with an increase in gas jet length within 1 m,1 m and 0.8 m,respectively.Besides,the multi gas streams sprayed from these three lances should be syncretized at 1.6 m,1.7 m and 1.4 m,respectively.At the highest lance level,the effective penetrating area of these three lances could be 0.255 m2,0.385 m2 and 0.0907 m2,respectively.It was suggested that the effective penetrating area of variable angle four-hole oxygen lance was the biggest,while that of five-hole oxygen lance was the least.The validity of numerical simulation results was proved through cold model experiment.The lance level was suggested to be controlled in the range of 1-1.6 m,1-1.7 m and 0.8-1.4 m for the four-hole,variable angle four-hole and five-hole oxygen lances,respectively.
基金Sponsored by National Natural Science Foundation of China(50901054)Hubei Provincial Natural Science Foundation of China(2009CDB401)
文摘Pulverized coal injection(PCI) is a key technology in modern ironmaking by blast furnace(BF) and the life of injection lance has a great influence on PCI operation and on normal running of blast furnace.It is found that the main reasons for the failure of the lances are their outer surface oxidation and the inner surface erosion through monitoring some lances used in BF.The outer surface oxidation of the lances made of lCr18Ni9Ti is inevitable under high hot blast temperature condition through thermodynamics analysis.A mathematical model for calculating the temperature of common monocular coal lance had been developed according to the principles of mass and energy balance.Increasing temperature and flow velocity of the hot blast would cause a rise in the lance temperature.The influence of hot blast temperature is more obvious.The lance temperature would decline when compressed air flux increases.Conveying technology of dense phase pulverized coal is beneficial to extending lance’s life because decreasing solid-gas ratio would intensify erosion and burning loss.The anti-oxidation temperature of lance materials needs to be over 1000 ℃ for BF intensified smelting.In order to increase the resistance to oxidation of the coal lance’s outer surface,oxidation-resistant steel or Al coating stainless steel is the appropriate material for BF use.Employing the metal surface treatment technology to enhance the hardness of the coal lance’s internal surface could prolong the service life of coal lance
基金the National Natural Science Foundation of China(Grant No.61573383).
文摘Pulverized coal utilization in the blast furnace is decided by the particle flow and combustion behaviors in the raceway.Under a specific operating condition,these behaviors are directly related to the lance configuration in the upstream tuyere zone.Focusing on single straight lance,six types of single lance configurations were designed by assembling four parameters in different ways.These four parameters are the lance diameter,lance insertion angle,and the horizontal and vertical distances from the lance tip to the tuyere tip.With different lance configuration schemes applied,the pulverized coal combustion process in the lance-blowpipe-tuyere zone was simulated.The simulation results regarding particle diffusion and combustion behaviors were characterized by three indicators from the viewpoint of a coal plume.They are the plume diffusion angle,diffusion uniformity,and the average plume temperature at the tuyere outlet.To promote coal utilization,the values of these indicators under different configurations were analyzed,yielding two optimal configurations.The first one is to reduce the lance length immersed in the blowpipe-tuyere by 100 mm.The other is to increase the horizontal distance from the lance tip to the tuyere outlet by 50 mm,and the insertion angle to 11° with the lance tip located at the tuyere centerline.The findings can enhance the understanding of the influence mechanism of lance con-figuration on the coal utilization and provide guidelines for the design of new lance configurations.
基金the National Key Research and Development Program with Project Number 2017YFB0304000the Beijing Natural Science Foundation with Project Number 2172057 in China.
文摘To improve the efficiency of the steelmaking process,a system of self-rotating lance was designed,and corresponding cold simulation mechanism was developed.The influence of the self-rotating lance on the mass transfer rate between slag and molten steel was investigated by comparing this novel system with the traditional oxygen lance.The results show that the self-rotating lance can stably rotate with a gas jet as the power source.The mass transfer rate increases with an increase in the top and bottom blow flow rates and with a decline in the lance position.Approximately 13.7% of the top blow flow rate is converted to stirring energy,which is approximately twice that of the traditional oxygen lance,and the mass transfer rate can increase by over 30%.Furthermore,the impact energy can be concentrated at different depths of the molten bath by adjusting the rotational speed.With the same energy density,the mass transfer rate produced by the self-rotating lance is higher;however,the influence of the energy density on the mass transfer rate is low when the rotational speed is 30-50 r/min.
文摘An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the bath-oxygen impact area, such as the cavity depth, the lance height, the number of nozzles and the nozzles diameter. In the thermal issue, the model includes the targeted carbon content and temperature. The model is numerically solved, and is validated using reported data plant. The oxygen flow rate and the lance height are varied in the numerical simulations to study their effect on the carbon content and decarburization rate.
文摘IN August this year,the HubeiProvincial Song and Dance Troupeput on 21 performances for 30,000people In 10 states during its one-month tour of Malaysia,entertain-ing audiences all across the coun-try.Many senior Malaysian gov-ernment leaders and importantpublic figures were among the au-diences,and the local newspapersreported it as the most
文摘The water-air and Wood’s metal-air systems are modeled by means of Computational Fluid Dynamics to study the interaction between a liquid surface and an impinging air jet under the near field blowing conditions. The effect of the air jet velocity, the height of the injection lance, and the density of the liquid on the depth of the formed cavity is numerically studied. The CFD results of the cavity depth are compared with results previously reported by other authors. The emergence of the splashing phenomenon is predicted in terms of the critical velocity for each liquid-air system. Besides, the blowing number indicates that the drop generation rate is not significant for jet velocities below the critical velocity, and therefore neither the splashing is significant.