100t电炉集束氧枪技术转化

通过对设备方案的重新设计和工艺制度的调整,电炉厂实现了集束射流技术的转化,发挥了集束氧枪的功效,技经指标得到大幅优化。     

电弧炉炼钢集束射流氧枪的射流特征

对电弧炉炼钢用集束射流氧枪的射流特性进行了冷态和热态试验。50tUHP EAF的工业试验表明，使用集束射流氧枪可降低电耗20kWh/t，降低氧耗15％,提高生产作业率5％，降低吨钢成本10元。     

100t电炉水冷炉壁的改造

针对电炉装有集束氧枪的水冷炉壁在冶炼过程中经常被氧枪氧流反射烧漏水的问题,提出了相应的改进措施。通过去除水冷炉壁氧枪铜盘下方水冷管的方案,彻底解决了氧枪氧流反射烧漏水冷炉壁的问题,提高了电炉水冷炉壁的使用寿命。     

集束射流氧枪技术及应用

集束射流氧枪具有射流长度长、穿透深度大、对钢液熔池搅拌能力强等特点。介绍了集束射流氧枪技术的原理、特点以及在国内外电炉和转炉上的应用情况,并对该技术在国内的应用前景进行了分析。     

炼钢氧枪的集束射流数值模拟研究

利用Fluent软件对炼钢氧枪射流流场的速度进行了模拟,发现集束氧枪较超音速氧枪气流沿中心轴线的速度衰减显著下降。对集束氧枪流场的温度和密度进行模拟,采用燃气燃烧产生的高温的、低密度保护区域是集束氧枪核心段延长的主要原因;而采用纯氧作为保护气不能增加主射流核心段长度,因此纯氧方案作为保护气是不可行的。研究为炼钢用氧的集束射流设计提供了理论依据。     

70 t 电弧炉炼钢集束射流氧枪流场的数值模拟及应用

用CFX5.7.1 软件对电弧炉炼钢用集束射流氧枪和普通氧枪的射流特征进行了数值模拟和冷态试验。结果表明,集束射流氧枪比普通超音速氧枪射流长,射流集中、衰减慢。在鄂钢70 t Consteel电弧炉 上应用表明,使用集束氧枪后平均电耗由338 kWh/t降低到219 kWh/t,电极消耗未变,为1.86 kg/t,氧耗由 51.6 m³/t提高到60.3 m³/t。     

PTI Jetbox系统在杭钢电炉上的应用

简要阐述了Jetbox多功能集束氧抢的技术原理，介绍了杭钢80t电炉安装Jetbox系统的情况及使用效果。     

集束化护理对严重脓毒症患者早期脱机的影响

目的 探讨集束化护理对严重脓毒症患者早期脱机的影响.方法 将2010年收住ICU18岁以上的严重脓毒症患者设为实验组,其采用集束化护理的方法,把2009年收住ICU18岁以上的严重脓毒症患者设为对照组,其采用常规护理方法.观察2组患者28d内机械通气时间及脱机再次应用呼吸机的情况,2组比较采用χ2检验.结果 实验组28d内机械通气时间较对照组缩短,实验组脱机后再次应用呼吸机的人数比对照组少,差异具有统计学意义(P＜0.05).结论 集束化护理能明显缩短脓毒症患者的机械通气时间,减少再次使用呼吸机,提高护理质量,缩短住ICU时间.     

集束氧枪技术在韶钢的应用

介绍了韶钢90tConsteel电炉进行集束氧枪技术改造的工艺流程及降成本的生产实践情况,可供同类型企业参考。     

淮钢70 t电弧炉PTI JetBOx系统的应用

淮钢70t电弧炉安装3套阿JetBOx集束射流氧枪系统后，冶炼周期降低3—5min，电耗降低25—40kWh／t，电极消耗降低0．4kg/t。     

聚合射流氧枪射流特性的实验研究

利用带有中心主孔的Laval喷管和16个副孔的聚合射流氧枪喷头的氧枪射流检测系统研究氧枪射流中心速度的衰减规律,测试常温氦气代替高温燃烧的保护气体作为伴流而产生的聚合射流,以及高温以主孔通空气,两副孔分别通入氧气和丙烷来产生保护气体模拟的聚合射流。结果表明,聚合射流特性优于传统射流特性,常温下随氦气入口压力增加,中心射流的轴向衰减变缓,获得比传统超音速射流更长的超声速区域;高温下通过调节燃气和氧气流量可改变环状火焰长度,同时可以根据生产实际情况变化主射流长度,满足冶炼工艺要求。     

传统与聚合射流氧枪冲击炼钢熔池效果的数值模拟

通过90 t转炉的传统氧枪喷孔周围增加环氧孔,通人辅助氧气保护主氧射流形成聚合状态,建立二维两相数值模型,分析传统氧枪和聚合射流氧枪射流轴线上氧气射流速度分布及不同枪位下熔池中钢液的流动特性和冲击深度。结果表明,与传统氧枪相比,枪位相同时,聚合射流氧枪射流衰减慢,冲击力大,冲击凹坑深度深;在30De(De-氧枪出口直径)枪位下的最大冲击深度与20De枪位下的传统氧枪相同,当聚合射流氧枪在40De枪位下喷吹得平均冲击深度与传统氧枪20De枪位喷吹时相当。     

Modelling on the penetration depth of the coherent supersonic jet in EAF steelmaking

The coherent supersonic oxygen supplying technology is now widely adopted in EAF steelmaking process. However, there has been limited research on the impact characteristics of the coherent supersonic jet. In this work, integrating theoretical modelling and numerical simulations, a hybrid computing model was developed to predict the penetration depth of the coherent and conventional supersonic jet. The results show that the lance height has much significant influence on the jet penetration depth, and the penetration depth of the coherent supersonic jet is much larger than that of the conventional supersonic jet at the same lance height. The k value reflects the velocity attenuation of the main supersonic jet, which is a key parameter of the hybrid computing model. Finally, the hybrid computing model and its modified models can well predict the penetration depth of the coherent and conventional supersonic jet with the error being no more than 3.92?pct.     

Effect of methane-hydrogen mixtures on flow and combustion of coherent jets

Coherent jets are widely used in electric arc furnace(EAF)steelmaking to increase the oxygen utilization and chemical reaction rates.However,the influence of fuel gas combustion on jet behavior is not fully understood yet.The flow and combustion characteristics of a coherent jet were thus investigated at steelmaking temperature using Fluent software,and a detailed chemical kinetic reaction mechanism was used in the combustion reaction model.The axial velocity and total temperature of the supersonic jet were measured via hot state experiments.The simulation results were compared with the experimental data and the empirical jet model proposed by Ito and Muchi and good consistency was obtained.The research results indicated that the potential core length of the coherent jet can be prolonged by optimizing the combustion effect of the fuel gas.Besides,the behavior of the supersonic jet in the subsonic section was also investigated,as it is an important factor for controlling the position of the oxygen lance.The investigation indicated that the attenuation of the coherent jet is more notable than that of the conventional jet in the subsonic section.     

Computational Fluid Dynamics Modeling of Supersonic Coherent Jets for Electric Arc Furnace Steelmaking Process

Supersonic coherent gas jets are now used widely in electric arc furnace steelmaking and many other industrial applications to increase the gas–liquid mixing, reaction rates, and energy efficiency of the process. However, there has been limited research on the basic physics of supersonic coherent jets. In the present study, computational fluid dynamics (CFD) simulation of the supersonic jet with and without a shrouding flame at room ambient temperature was carried out and validated against experimental data. The numerical results show that the potential core length of the supersonic oxygen and nitrogen jet with shrouding flame is more than four times and three times longer, respectively, than that without flame shrouding, which is in good agreement with the experimental data. The spreading rate of the supersonic jet decreased dramatically with the use of the shrouding flame compared with a conventional supersonic jet. The present CFD model was used to investigate the characteristics of the supersonic coherent oxygen jet at steelmaking conditions of around 1700 K (1427 °C). The potential core length of the supersonic coherent oxygen jet at steelmaking conditions was 1.4 times longer than that at room ambient temperature.     

180 t转炉超音速射流和聚合射流与炼钢熔池作用的水模型实验研究

以鞍钢180 t顶底复吹转炉为原型,设计超音速氧枪喷头进行了复吹转炉传统射流与聚合射流对熔池相互作用的水力学模型实验。超音速射流水模实验确定最佳的均混时间为12.6 s;在保持最佳顶吹气体流量的条件下,以降低枪位模拟聚合射流对熔池的相互作用。结果表明:当氧枪枪位下降到40 mm时,均混时间为11.8 s,这说明聚合射流完全可以达到传统射流对熔池的搅拌效果,可取消底吹系统,简化转炉设备和提高转炉炉龄。     

环氧温度对超音速主射流特性的影响

超音速氧气射流喷吹工艺是炼钢过程的重要技术,通过在主氧周围增加环状高温伴随流是改善主氧射流特性、提高冶炼效率的重要途径。通过数值模拟的方法研究集束射流条件下环氧温度对超音速氧气射流特性的影响。研究结果表明,高温环氧可抑制超音速主射流速度的衰减,环氧温度越高,速度衰减越慢,射流核心区长度明显延长;不同环氧温度下,主射流温度均呈现先增大后减小的趋势,环氧温度的升高使得主射流温度的快速增长受到抑制;环氧在主射流周围形成高温低密度区域,将主射流与环境介质隔离,延缓主射流与周围介质的掺混,对主射流起到封套作用。     

180 t转炉聚合射流流场的水力学模型的实验研究

采用几何相似比1∶10水模型对180 t顶底复吹转炉内射流与熔池相互作用进行模拟试验,研究了在最佳枪位(150 mm)时氧气流量(38~42 m³/h)对均混时间的影响以及最佳顶枪流量(39 m³/h)下聚合射流氧枪枪位(40~150 mm)对均混时间的影响。结果表明,聚合射流氧枪对熔池的搅拌效果完全能达到顶底复吹的搅拌效果,如能在转炉冶炼工艺中应用,可取消底吹系统,简化转炉设备,提高转炉炉龄。