铁水脱硫粉剂喷吹罐的工作原理和性能分析

铁水脱硫喷吹系统对喷吹罐有较高的要求,本文研究了目前铁水脱硫工艺中采用的不同喷吹罐的工作原理和性能。研究表明,向上出料的喷吹罐对喷吹速率的调节能力强,但是操作更复杂;向下出料的喷吹罐对喷吹速率的调节能力弱,但是结构更简单,易于操作,可以利用粉末控制调节阀控制脱硫粉剂的喷吹速率。喷吹罐的流化装置有多种不同的材料和形式,应该根据脱硫粉剂的具体性能参数和喷吹罐的具体结构形式选择不同的流化装置。     

采用CaO基复合脱硫剂脱硫喷吹罐设计改进研究

喷吹罐是脱硫工艺中的主要设备,通过比对向上出料和向下出料两种喷吹罐的结构及工作方式,根据喷吹罐的工作原理,结合Ca O基复合脱硫剂脱硫的特点对已有的喷吹罐罐体锥体部分、转动机构、喉口等装置进行了一定的改进设计。改进后减少了喷吹罐操作步骤,且方便控制喷吹速率。     

单喷颗粒镁脱硫与镁基复合喷吹脱硫喷吹系统的区别

单喷颗粒镁脱硫和镁基铁水脱硫是最常见的铁水脱硫技术,对单喷颗粒镁脱硫与镁基复合喷吹脱硫喷吹系统进行了比较,主要区别在于:单喷镁脱硫系统要求的镁颗粒较大,球形度好,采用机械给料的方式精确给料,料罐容积小,利于实现设备的小型化,但是喷枪需要设置气化室,结构复杂;复合喷吹铁水脱硫通过调节动力学参数来调节镁粉喷吹速率。     

天津钢管公司喷粉脱硫系统功能概述

天津钢管公司配备了一套脱硫粉剂输送及喷吹设备。该系统设有2个不同容积的贮料仓,可以装载不同配比的粉料,粉料经溜管到气力发送罐,再由其在气体带动下压送到喷吹罐系统,并通过喷吹罐将粉料压送到多功能顶枪而喷入RH真空槽内,从而达到喷吹脱硫的作用。通过反复生产运行,在喷吹粉剂总量为1000 kg时,喷吹速度达到222.2 kg/min,经脱硫后钢水中硫质量分数在20×10-6左右,脱硫率在50%以上,满足了喷粉脱硫工艺的要求。     

铁水喷粉脱硫的数学模型

铁水喷粉脱硫 ,特别是用镁粒脱硫 ,已为越来越多的钢铁厂所采用。预测喷吹操作和粉剂特性对脱硫效率影响的动力学模型将有助于改善喷吹操作 ,并使喷吹操作达到最佳化。对于铁水喷粉脱硫 ,热力学和化学动力学条件 (脱硫剂和温度 )通常是固定的。脱硫效率主要由传质动力学 (喷吹参数和在罐内的混合程度 )决定。因经 ,有必要对传质动力学进行详细的系统的模拟研究 ,以提高粉剂的利用率和铁水的脱硫率。通过动力学分析 ,能得到一些重要的可决定脱硫率和粉剂利用率的参数。这些重要参数是粉剂进入铁水的穿透比 (ＰＲ) ,粉剂在熔池内的停留时间分…     

铁水包喷吹镁-碳化钙复合粉剂脱硫的数学模拟

鉴于金属镁粒和碳化钙粉这两种脱硫粉剂的物理和化学性质有着本质的区别 ,作者重点分析研究了镁粒在脱硫过程中的热力学、反应机理和动力学。在具体分析熔池均混时间、粉剂穿透比及粉剂停留时间这 3个基本参数对脱硫过程影响的基础上 ,建立了能体现这 3个参数影响的模拟铁水喷吹镁粒和碳化钙复合粉剂脱硫处理的数学模型 ,并讨论了两种粉剂在脱硫过程中的耦合效果。结合水模实验、流场计算和宝山钢铁集团公司的铁水包喷粉深脱硫生产数据确定了该模型的参数 ,并对其进行了验证。模型计算结果表明 ,复合粉剂脱硫的总速率与喷粉速率、载气流量、镁蒸汽与溶解态镁的比率等有关 ;镁脱硫是以溶解态镁脱硫为主 ;在脱硫处理的不同阶段 ,镁和碳化钙的相对脱硫速率不同。并依此对喷吹工艺给出了合理的建议     

天铁6~#高炉三罐并列混合喷煤控制技术的开发

叙述了天铁集团6#高炉三罐并列混合喷煤控制系统的开发及运行工艺特性。阐述了该喷煤系统中单罐的自动循环控制,喷吹过程中三罐的循环倒换控制、喷吹罐手/自动切换控制与基本保护措施、喷吹控制及速率调节、报警与紧急停喷控制等控制系统开发和应用效果。该技术使三罐之间的自动循环和倒换控制更加安全可靠,喷吹速率均匀平稳,降低了喷吹罐压力和输送气的使用量,使喷煤系统的控制水平大幅提升,防止了恶性事故的发生。     

喷吹Mg+CaO粉剂脱硫技术在本钢的应用

本文主要介绍了本钢炼钢厂喷吹Mg+Ca O粉剂脱硫工艺的原理,分析了喷粉速率、铁水温度和铁水重量对脱硫剂消耗的影响,喷吹Mg+Ca O粉剂脱硫深度可实现10×10-6。     

铁水包喷吹Mg+CaO粉剂脱硫技术

分析了宝山钢铁股份有限公司采用TDS(Torpedo Car Desulphurization)、PTC(Hot Metal Pre-treatment Center)和铁水包单枪、双枪喷Mg+CaO脱硫模式的生产情况.结果表明,采用铁水包喷吹Mg+CaO脱硫在喷吹时间、脱硫效果、粉剂消耗、生产组织及经济效益等方面明显优于混铁车喷吹脱硫.脱硫时间可缩短50%以上,终点硫质量分数可达到0.001%～0.003%,粉剂总耗量仅为CaC2基粉剂耗量的50%、CaO基粉剂耗量的20%,综合成本比TDS或PTC混铁车脱硫低18%～30%.铁水罐双枪喷Mg+CaO脱硫模式的效果最好.     

我国喷射冶金技术的发展

1980年4月在北京召开了喷粉冶金技术表演会,重点介绍了国内喷粉设备类型——局部流态化下口出料、局部流动化上口出料和局部松动下口出料三种结构,和喷粉工艺等取得的初步结果。并结合国内情况就今后有关喷粉罐、喷吹工艺的选择;喷射冶金工程;新型粉剂和耐火材质;喷射冶金机制等方面研究,提出看法。     

Water modelling study of the jet characteristics in a continuous casting mould

The jet characteristics and the fluid flow pattern in a continuous slab caster have been studied using a water model. The fluid jet is studied under free fall and submerged discharge conditions. In the latter case, the jet was followed by dye-injection technique and image analyser was used to find out the effect of nozzle parameters on jet-spread angle, jet-discharge angle and the volume entrainment by the jet. All free-fall jets with nozzle port angle zero and upward are found to be spinning. Some of the free-fall jets with downward nozzle-port angle are found to be spinning and rest are smooth. The spinning direction of the jets are found to change with time. The well depth, port diameter and the inner diameter of the nozzle have a clear effect on the free-fall jets with downward port angle. The jet-spread angle is found to be about 17° for smooth jets. The spread angle for spinning jet increases as the nozzle-port angle is increased from downward 25 to upward 15°. The jet-discharge angle is always downward even when the nozzle-discharge ports are angled upward. The extent of volume entrainment by the spinning jet is higher and it increases as the nozzle-port angle is increased from 25 downward to 15° upward.     

Effects of several casting parameters on slag entrapment in mould( part A: water modeling)

The mechanism of slag entrapment in the mould was analyzed and the water modeling experiment was done according to the industrial manufacturing. The results show that the flow of the liquid steel becomes more active and the level fluctuation in the mould becomes bigger when the casting speed increases from 1. 0 m / min to 1. 2 m / min. So the control of slag entrapment in the mould becomes more difficult. When the depth of the nozzle increases from 30mm to 42. 5mm and the angle increases from 15° downward to 30° downward,the level fluctuation in the mould becomes smaller and the slag entrapment in the mould also decreases. But the impact depth increases and the circumfluence vortex center moves downward,which is unfavorable for the flotation of gas bubbles and inclusions. Furthermore,the impact depth with side holes a ( 16. 3 × 20 mm 2 ) and b ( 10 ×10 mm 2 ) is almost equal,but a smaller level fluctuation can be obtained with side hole a.     

The Effects of Electromagnetic Brake on Liquid Steel Flow in Thin Slab Caster

Computational fluid dynamics (CFD) model with magneto hydro dynamics (MHD) is developed for a thin slab caster to investigate the effects of electromagnetic brake (EMBr) on liquid steel flow in continuous casting mold and to determine the EMBr practices which lead to optimal flow structure. Particle Image Velocimetry (PIV) tests in water model and meniscus flow measurements in real caster are performed to validate the predictions obtained with CFD models. The performance of different submerged entry nozzle designs, SEN 1 and SEN 2, are evaluated. The effects of nozzle submergence in relation to the applied magnetic field on mold flow structure are quantified. There are significant differences between flow structures obtained with SEN 1 and SEN 2, even though both designs have fundamental similarities and contain four ports. EMBr mainly reduces the meniscus velocities for SEN 2 as opposed to the foremost influence of EMBr for SEN 1 that is to significantly slow down the downward jet coming from the bottom ports. In addition, reducing the EMBr strength for shallow nozzle submergence and increasing the EMBr strength for deep nozzle submergence help to maintain similar meniscus activity for all conditions.     

CSP结晶器内钢液流动的水模型研究

采用1:1水力学模型对厚度60 mm薄板坯连铸水口浸入深度220～310 mm、出口角度-30°～-60°、拉速4.2～6.0 m/min条件下CSP结晶器内钢液流动行为进行模拟研究。在拉速4.2～5.0 m/min时双侧孔水口下CSP结晶器流场股流冲击深度达850～1010 mm;流场内存在三个滞区,液面波动不稳定;水口角度对结晶器窄面和水口附近波动影响很显著,拉速对结晶器和窄面中心处波动影响较大,浸入深度对水口附近波动影响较大。     

Sprinkler Head Maintenance Effects on Water Application Uniformity

The effects of wear on the ability of hand-move and side-roll sprinkler irrigation systems to maintain the designed water application rate and uniformity are of concern with regards to crop performance, water use efficiency, and environmental impact. Six hand-move and six side-roll sprinkler irrigation systems used under commercial crop production in Lane County, Oreg., were evaluated for equipment wear and performance. Individual sprinkler nozzle size and discharge rates were measured for each system and used in a computer model to estimate field application rate and uniformity. New nozzles were installed on six systems to compare potential application rate and uniformity with existing performance. Despite reducing the coefficient of variation in discharge between sprinklers from 10 to 2%, little increase in water application uniformity was attained. A 13% decrease in mean water application rate was documented after nozzle replacement. Ignored overapplication due to worn or mismatched nozzles results in overirrigation in both rate and total amount, which gives rise to the potential for increased surface redistribution and deep percolation, resulting in water and nutrient losses.     

电液伺服系统的动压反馈网络校正方法研究

为提高板带轧机电液伺服系统的动态品质,设计了蓄能器加可调阻尼器组成的动压反馈网络。在四辊板带轧机液压弯辊系统中,对其进行了计算机仿真和频率响应实验研究。证明了采用动压反馈网络校正配合调整系统增益的方法,不仅能够有效地抑制供油压力波动干扰,提高系统的控制精度,而且可以提高系统的稳定性和快速性     

不同粉末粒径粉芯丝材双丝电弧喷涂声发射技术分析

阻碍热喷涂技术广泛应用的最大障碍之一就是在喷涂过程中缺乏在线控制方法。热喷涂涂层的优化方法是通过对喷涂参数和喷涂参数一涂层性能相关性的经验性调整。而对于一些固有参数是无法调整的,如双丝电弧喷涂过程中的焰流波动和雾化喷嘴磨损,尽管这些参数对涂层的质量有巨大影响,但出于简化目的通常系统地忽略不计。本文中采用声发射分析法,基于所获得的声信号对不可调节参数的影响进行分析。将声发射感应器同时安装在基体和喷嘴上,使得对喷涂过程中的声信号变化进行简单测定成为可能。当增加电流时,一个降低的声信号被记录下来,从而可对不可控参数、声信号和涂层质量之间的相关性进行分析研究。这项研究将有助于探索喷涂过程中的在线控制方法。     

全水口自旋流连铸水口钢水流动行为

摘要： 全水口自旋流连铸是从源头上优化结晶器流场的重要技术,利用数值模拟手段,研究了拉坯速度和旋流发生装置入口尺寸对自旋流连铸钢水流动行为的影响。研究表明,拉坯速度和入口尺寸对水口内钢水旋流具有重要影响,旋流强度随拉速增大而增大,随入口面积增大而减小,且随钢水向下流动近似呈线性减小;当旋流装置入口流速为1.1m/s时,水口内钢水旋转速度达4.10m/s,受旋流影响水口中心钢水反重力向上流动;水口流场沿径向可分为湍流各向同性区、各向异性区和近壁区,随入口速度增加湍流各向异性区范围增大。研究明确了全水口自旋流连铸过程钢水旋流行为的关键控制因素,为旋流连铸的参数优化提供了支撑。     

Flow behavior of molten steel in SEN during full nozzle self swirling flow continuous casting

Full nozzle self swirling flow continuous casting is an important technology to optimize the mold flow field from the source. Numerical simulations were carried out to investigate the influence of casting speed and inlet area of the swirling flow generator on steel flow behavior in SEN (submerged entry nozzle). The results show that the casting speed and the inlet area have important effects on the swirling steel flow in SEN. The swirl intensity increases with the increase of casting speed, decreases with the increase of inlet area, and decreases approximately linearly with the downward flow of molten steel in SEN. The swirling flow velocity can reach 410m/s with the generator inlet velocity of 11m/s. Due to the effect of swirling flow, molten steel at the nozzle center moves upwards. The flow field in SEN along the radial direction can be divided into three regions, namely, the isotropic turbulent fluctuation region, the anisotropic turbulent fluctuation region, and the near wall region. With the increase of inlet velocity, the anisotropic turbulent fluctuation region increases. This study reveals the key control factors on steel flow behavior in a full nozzle self swirling flow continuous casting process, which provides a good support for the parameter optimization of the swirling flow continuous casting process.     

非对称控流结构中间包流场一致性的物理模拟

国内某钢厂使用的两流板坯连铸中间包因受固定位置排渣口的限制,包内控流装置采用左右不对称布置。生产实践发现,排渣口侧的水口对应铸坯大型夹杂物含量高、热轧卷探伤合格率低,疑与中间包流场的一致性有关。为此,采用1∶3.5的水模型对中间包流场进行了模拟研究,并基于流体动力学原理对其控流效果进行了优化。结果表明,原型中间包两个水口的滞止时间差高达36 s,钢液在排渣口侧的1号水口形成短路流,因而导致两流铸坯洁净度的差异。经水模优化后,方案F1下两流平均停留时间标准差和滞止时间标准差分别可降到0.12和0.35 s,明显改善了中间包内两流浇铸流动特性的一致性,且死区比例较原型降低8.87%、平均停留时间延长了30 s。