KR铁水脱硫顶吹扒渣工艺试验研究

为了提高脱硫扒渣效率及消除底吹扒渣存在的漏铁风险,武钢炼钢总厂二分厂开发了KR顶吹扒渣设备,并用于铁水脱硫。起初生产中存在喷枪寿命低及喷吹效果差的问题,有针对性地对喷枪顶吹系统进行了改造,并对喷吹工艺进行了优化,喷枪寿命由最初30次提高到了62次,扒渣时间缩短了2min。     

铁水包吹气辅助扒渣工艺的物理模拟研究

通过水模试验模拟研究了铁水包吹气辅助扒渣工艺，并系统研究吹气元件类型、安装位置以及吹气流量等因素对吹气辅助扒渣效果的影响。结果表明：采用双吹法吹气辅助扒渣效果好于单吹法；双胞胎透气砖吹气元件的辅助扒渣效果好于其它类型的传统单砖心透气砖；吹气元件安装位置越低，吹开液面面积越大，辅助扒渣效果越好。试验结果成功应用于生产现场以后，扒渣时间由原来的12min缩短到6min左右，铁水渣扒净率有很大提高，转炉回硫质量分数控制在0．005％以内。     

铁水罐吹气辅助驱渣水模型实验

以钢厂90～105 t铁水罐为原型,在实验室建立几何相似比1:4水模型,用物理模拟方法研究铁水罐侧吹辅助扒渣对驱渣面积的影响。结果表明,在吹气流量为0.25～2.0 m~3/h时,随着吹气流量的增大驱渣面积增大。同时随着透气砖安装角度从0°到70°、安装高度从174 mm到294 mm时,驱渣面积均会增大。当用单透气砖侧吹驱渣,安装角度为70°,安装高度294 mm,流量为0.8～1.2 m~3/h时,驱渣效果最好。     

铁水罐侧吹辅助扒渣水模实验研究

针对颗粒镁脱硫工艺存在的渣稀量少、不易扒尽,导致转炉回硫率高等问题,对铁水罐侧吹辅助扒渣进行水模实验研究,确定透气砖合理的安装位置和侧吹气体流量,以提高和改善颗粒镁脱硫后的扒渣效率.     

铁水复合喷吹脱硫生产低硫钢的实践

结合复合喷吹脱硫的工艺特点,分析确定转炉出钢回硫的原因主要受铁水及脱硫渣、原材料带入硫的影响。通过控制原材料硫含量,提高品位,选择合适的喷吹速度、合理控制脱硫剂配比,合理控制喷吹罐压力及助吹气体压力,调整喷枪插入铁水液面的深度,对脱硫扒渣工艺进行优化;调整扒渣板的角度和透气砖的安装高度,对扒渣设备进行攻关。对脱硫工艺条件和转炉冶炼进行规范,通过全工序控制的方法,有效控制转炉钢液回硫的现象,实现了低硫出钢的目标,转炉钢液回硫质量分数控制在25×10-6以内,出钢w(S)稳定在40×10-6以内。     

提高镁粒铁水脱硫利用率的技术手段

介绍了莱钢喷镁脱硫的工艺流程、生产现状及镁粒脱硫机理。系统分析了制约镁粒利用率提高的影响因素。采取优化扒渣器结构以提高扒渣洁净度、改造喷枪气化室等措施,并通过正交试验确定喷枪插入深度、喷吹速度、喷吹压力等重要工艺参数组合,实现了镁粒利用率的大幅度提高,为转炉的快节奏生产及产品质量的提高创造了条件。     

喷吹颗粒镁铁水脱硫影响因素的数值模拟

在CFD软件平台上进行了青钢新区喷吹颗粒镁铁水脱硫影响因素的数值模拟,研究了载气流量、喷枪插入深度、喷嘴直径、喷嘴夹角对脱硫过程铁水罐内流场以及混匀死区的影响。结果表明,在原有工艺参数下,随载气流量适当减小、喷枪插入深度最大、喷嘴直径稍微增大和喷嘴夹角适当增大,均可改善铁水罐内速度场和湍动能的分布,减小混匀死区,增加停留时间。推荐的工艺参数为载气流量90 Nm~3/h、喷枪插入深度200 mm、喷嘴直径8 mm、喷嘴夹角60°~90°。     

转炉型反应器内熔池传热的研究

通过水力学模型，对转炉反应中各流量参数、熔池深度、喷枪高度及底吹喷嘴位置等因素对熔池传热规律的影响进行了研究。结果表明，在一定范围内，增加顶吹喷枪主孔气体流量及底吹气体流量，都将使熔池表现传热系数提高，从而有利于熔池传热，提高转炉热利用率；顶吹喷枪副孔气体流量在本试验中对熔池表现传热系数无影响；熔池深度、喷枪高度以及底吹喷嘴的布置等因素对熔池传热有一定的影响。文中还从熔池搅拌角度对各因素的影响进行了分析，并通过试验得到了用准数方程表示的描述转炉型反应器内传热规律的经验关系式，为今后工业生产提供了试验依据。     

全量铁水预处理技术

对莱钢股份炼钢厂铁水预处理系统存在的问题进行了分析.通过脱硫与扒渣工位的复合设置改造、优化喷枪各项工艺参数和插入深度、应用高效扒渣机以及自主开发CaO-Al2O3-SiO2系聚渣剂等措施,脱硫处理率达到了90%以上,提高了脱硫效率及工艺稳定性,减少了扒渣铁损和回硫,使回硫量控制在0.002%以内,减轻了喷吹脱硫作业负担,满足了全量铁水预处理与转炉快节奏生产并吹氩直上工艺的匹配.     

马钢KR脱硫吹气聚渣辅助扒渣工艺的开发与应用

马钢股份公司(以下简称马钢)第四钢轧总厂于2007年引进了KR脱硫工艺,处理率超过98%。由于其脱硫采用CaO基脱硫剂,造渣量大,扒渣时铁损高。为了解决这一问题,开发了KR脱硫吹气聚渣辅助扒渣工艺,应用结果表明:吹气扒渣炉次较常规工艺的平均用时缩短了0.92min,吹气扒渣处理后的硫含量较常规工艺低0.002 1%,平均温降较正常生产炉次增加了0.21℃,平均扒净率达到93%,吨铁扒损降低了1.52kg。大幅缩短扒渣时间、显著降低扒渣铁损,使脱硫技术经济指标得到较大提升,能够满足转炉炼钢大规模低成本制造的需求。     

复吹转炉钢-渣间容量传质系数的水-油模型

在熔池直径880mm、深258mm的冷态模型中，利用水模拟钢水、机油模拟渣、苯甲酸模拟钢-渣间传输物质来研究熔池直径5285mm、深1545mm的复吹转炉吹炼工艺参数对钢-渣间容量传质系数的影响。结果表明，枪位350mm，顶吹流量117m^3/h，底吹流量1．68m^3/h至2．36m^3/h时，传输物质苯甲酸的容量传质系数变化最显著，在采用枪位350mm，顶吹流量140m^3/h，底吹流量1．68m^3/h，底枪布置方式为8孔对称布置在0．66直径的圆上时，传输物质的容量传质系数最大。     

铁浴炉内部气-液流场模拟研究

使用Fluent模拟了铁浴炉内部气-液的流场,通过改变顶枪气体的入射角度来考察气体对液体流场的影响。结果表明：气体的入射角度对射流深度和旋涡大小有直接的影响;铁水基本保持稳定,熔渣会随气体的流动而运动,甚至被带出铁浴炉。分析认为当顶枪射流角度为15度时对工艺的顺行较为有利。     

Cold Simulation of Oxygen Transfer Rate in BOF

 By measuring the mass transfer coefficient of between water and oil, the oxygen transfer rate of bath in the BOF smelting process is researched, and the influence of top and bottom blowing gas flow rate on the mechanism of mass transfer between metal and slag is discussed. The results show that when the bottom blowing gas flow rate increases on the conditions of top blowing, the mass transfer rate evidently increases, and the influence ratio of top blowing on the mass transfer is 10 percent of bottom blowing; The relation among top gas flow rate, bottom gas flow rate and lance height are established by the stirring power density. The equation between the mass transfer coefficient between metal and slag is formed, which furnishes reference for optimizing process parameters of BOF. The relation between the emulsification ratio between water and oil and the bottom blowing gas flow rate on the condition of top and bottom blowing is obtained. The result shows that with the increase of the bottom blowing gas flow rate the emulsification ratio increases in linearity, which increases the mass transfer rate of benzoic acid between water and oil.     

180 t转炉底吹和顶-底复吹射流与熔池作用的水模型研究

根据180 t转炉的实际生产情况,以修正的Froude准数为相似准数,建立几何相似比10 ： 1水模型,进 行了四孔对称单纯底吹试验,并在最佳的底吹工艺参数下(底吹最佳位置为喷嘴所在同心圆直径:转炉熔池直径= 0. 3处;最佳流量为0. 7 m³/h,均混时间18. 2 s),通过改变顶吹氧枪的气体流量和吹炼枪位进行了顶底复吹转炉射 流与熔池作用的试验。结果表明,在底吹条件下,增加顶吹工艺(最佳枪位150 mm,最佳流量39 m³/h),熔池平均 的均混时间减少了 5.6 s, 180 t转炉顶底复吹可显著提高经济效益。     

130 t单嘴精炼炉真空室内覆盖脱硫渣的钢液流场数值模拟

用Fluent软件和VOF模型模拟了130 t单嘴精炼炉内覆盖脱硫渣时钢包底吹氩流量(150～450L/min)和吹氩位置(中心至3/4浸渍管半径)对钢渣界面平均速度的影响。结果表明,吹气位置为1/2浸渍管半径(R)处最合理,钢渣界面平均速度随吹气流量的增加而增加,当流量一定时吹气位置为1/2R时界面平均速度最大;吹气位置﹥1/2R时才会对界面上渣相体积分数变化有显著影响。     

铁水包扒渣过程的数值模拟

 对炼钢来说,入炉的铁水渣量大,使得冶炼周期长、消耗高。因此,在铁水进入转炉前,将铁水包内的高硫渣除去显得十分重要。实验中采用一种新型喷枪,置于铁水包后部,向铁水包喷吹氮气,使渣聚集,从而提高扒渣效率,减少铁水损失。并采用数值模拟的方法研究各项生产因素对吹渣效果和温度的影响。结果表明：枪浸入深度的增加会改善吹渣效果,吹气量的增大也有助于气体排渣。     

Physical and mathematical models of gas‐liquid fluid dynamics in LD converters

Fluid dynamics of gas‐liquid interactions in a LD converter to refine steel was physically and mathematically simulated. Using a water model three cases of gas supply were considered, top blowing, bottom injection and combined process top blowing‐bottom injection. Mixing time in top blowing increases with bath height and the distance between the lance of the gaseous jet and the bath surface. The jet penetration was found to be dependent on the modified Froude number. The unstable and unsteady behaviour of the bath topography, as affected by the gaseous jet, was well simulated through a multiphase momentum transfer model. In top blowing, three zones of liquid splashing were found, penetration with low splash, heavy splash and dimpling with low splash intensity. These zones depend on the gas flow rate and the distance from the lance to the bath surface. During bottom injection mixing times decrease with the number of tuyères, increases of bath height and gas flow rate. In a combined process mixing time decreases considerably due to the recirculating flow formed by the action of the top jet and the submerged jets. When a submerged jet is located just below the top jet the mixing time does not decrease as compared with the separated processes either top blowing or bottom stirring.     

单嘴精炼炉合金料加入方式及混匀特性水模型研究

根据相似理论,以80 t单嘴精炼炉1:4的水模型模拟,研究了单嘴精炼炉加合金料位置、吹气流量(2～10 L/min)、单嘴内液面高度(18.5～67.0 cm)、浸入深度(75～150 mm)、吹气位置等对混匀时间的影响。结果表明,在单嘴气体上升区对面加料混匀时间较短;吹气流量为6 L/min、浸入深度100～125 mm、单嘴内液面高度≥52 cm、在钢包底r/R=0.5位置吹气有利于混匀时间的缩短。     

RH喷吹参数对循环流量和均混时间影响的物理模拟

以某厂300tRH真空精炼装置为研究原型,建立1∶6.5的水力模型对RH喷吹精炼工艺进行物理模拟。研究了喷吹位置、喷吹气量及驱动气体流量对循环流量和均混时间的影响。结果表明:不同喷吹气量、驱动气体流量条件下,获得大循环流量和短均混时间的最优喷吹位置不同。较小的喷吹气量(2.98~3.53m3/h)或者较小的驱动气体流量(0.93~1.02m3/h)时,宜采用低顶枪枪位(153.8mm)喷吹;喷吹气量大于3.91m3/h或者驱动气体流量大于1.12m3/h时,宜采用真空槽底部喷吹角度120°的侧喷嘴喷吹。顶枪与侧喷嘴复合喷吹有利于提高RH喷吹工艺的适应性及循环效率。     

Cold Modelling of Slag Splashing in LD Furnace by Oxygen Lance with Twisted Nozzle Tip

The effects of a conventional lance tip with 4 normal nozzles and a lance tip with 4 twisted nozzles on slag splashing were investigated. A cold model for LD converters, Jiuquan Iron & Steel Co., was established and the amount of slag splashed onto the model walls was measured in the cold modelling experiments. The results from the experiments show that at low top gas flow rate the amount of slag splashing for the tip with twisted nozzles is less than that for the conventional tip, whereas at high top gas flow rate the amount of slag splashing for the nozzle twisted lance is greater than that for the conventional lance. For the nozzle twisted lance tip, slag splashing rates increase with increase in slag amount, lance height and top gas flow rate and the maximum amount of slag splashing for the tip with twisted nozzles can be obtained under the process parameters of 47.6 Nm³/h gas flow rate, 12% slag amount and 247 mm lance height. More slag droplets can be directed onto the cone with a nozzle twisted lance tip than with a normal lance tip at high top gas flow rate.