日本京浜厂板坯连铸防止水口堵塞的措施

1 前言 在连铸中浸入式水口的堵塞,特别由Al_2O_3在内壁的附着引起的堵塞问题不仅给生产率带来非常不利的影响,而且由于生长的Al_2O_3被裹入方坯中,所以也成了产生质量恶化的原因。本文报道京浜厂板坯连铸用中间包上水口及滑板的种种改进过程及其对由Al_2O_3附着引起堵塞导致的降低效果。     

浇铸不锈钢时β—Al2O3在浸入式水口上的应用

1 前言 不锈钢浇铸用浸入式水口,因钢水中氧浓度和Cr、Mn含量高,所以Al_2O_3-C-SiO_2这种材质水口中的SiO_2与钢水中生成的FeO、MnO、Cr_2O_3反应产生低熔物,水口熔损有增大的趋势。因此许多用户通常把无SiO_2型的Al_2O_3-C材质配置在水口的主体部位。但是一部分用户发现随着多炉连铸化的进行,水口内孔出现了变质层,这成了限制浸入式水口寿命的原因之一。针对这一问题,通过把材质中的主要成分Al_2O_3由。α-Al_2O_3(刚玉)部分改换     

吹气式浸入式水口的透气性

1 前言 连铸工艺中使用的吹气式浸入式水口,其Al_2O_3附着及夹杂物成了阻碍全连铸和造成钢坯质量缺陷的原因。为了防止Al_2O_3附着及促使夹杂物上浮,浸入式水口具有通过其内壁吹人惰性气体的功能,由于这种类型水口的透气性对钢质量的影响很大,所以对这种特性进行控制是极其重要的。 以前关于透气性已有很多报道,但这次研究的是透气质碳材料对该种浸入式水口狭缝内孔材质透气性的效果,其内容报道如下。     

ZrO2—CaO—C耐火材料对Al2O3附着性能的改善

1 前言 在低碳铝镇静钢连铸中,由于Al_2O_3附着于浸入式水口内壁,限定了浸渍水口的寿命,给多炉连铸作业带来困难。 针对该问题,使用了在水口内壁设置了ZrO_2-CaO-C(以下简称ZCG)材质的浸入式水     

锆钙碳质浸入式水口上的Al2O3结瘤

1 前言 ZCG(ZrO_2-CaO-C)质浸入式水口,作为防止连铸时因Al_2O_3附着而引起水口内孔狭窄、堵塞的技术之一已实用化。其防止机理可理解为:水口内壁附着的Al_2O_3粒子与水口中ZrO_2-CaO骨料分解生成的CaO反应,生成低熔点化合物,继而被钢水除去。但是,目前实际上还存在着必须与吹Ar沸腾并用,以及防止附着效果不明显等不清楚之处。尤其是防止附着机理虽然有许多研究例子,但关于ZCG质     

ZrO2／CaO比不同对ZrO2.CaO材料组织结构的影响

连铸浸入式水口中Al_2O_3的堵塞,阻碍了连铸优质钢的发展,新型锆钙碳质水口的应用取得了良好效果,这种水口的主要成份即ZrO_2、CaO,由于CaO的水化问题,使得钙质材料应用受到了限制。本试验采用不同ZrO_2/CaO比的成分设计,观察了其组织结构的变化,找出了防止CaO水化的CaO添加范围。     

各种添加物对铝碳质耐火材材的氧化铝附着性的影响

1.前言 浸入式水口由于Al_2O_3附着而造成的堵塞是妨碍多连铸化的重要因素之一,这是重要的课题。为抑制氧化铝的附着,采取使耐火材料工作面光滑,以抑制其牢固附着的方法。本文采用了添加各种化合物,使在铝碳质耐火材料(以下间称AG质)的工作面上生成低熔点化     

浸入式水口Al2O3附着堵塞机理及防止办法

综述了国内外浸入式水口Al2O3附着堵塞机理的研究现状,分析了水口堵塞的影响因素,提出了防止Al2O3附着堵塞的基本原则和研究方向,并对几类具有防止Al2O3附着作用的材料和防范措施进行了重点介绍,探讨了浸入式水口用碱性材料的研究方向和重点.     

通过对连铸水口沉积物的研究探索静态水口的堵塞

利用盛装多种钢水的铝碳质耐火材料坩埚研究影响水口堵塞的热化学反应。从这些静态实验中,进行了许多观察。与铝镇静钢相接触形成堵塞的主要氧化物是Al_2O_3,然而在堵塞物与耐火材料内表面之间也观察到有尖晶石(MgO·Al_2O_3)和CA_6(CaO·6Al_2O_3)形成。     

连铸用无碳和SiO_2质水口的开发

1 前言 近年来,由于对多炉连铸和高清洁钢的要求越来越高,因此有必要确立防止氧化铝堵塞水口的技术,并采用耐腐蚀性高的水口材质。 为防止氧化铝粘附水口,进行了无碳和SiO_2质水口的开发,本文就此介绍如下。2 无SiO_2AG材质在实机上的应用 为抑制氧化铝粘附在浸入式水口上,一般认为有效的办法是去除水口材质中SiO_2成分,囚为SiO_2与钢中的Al反应后会生成氧化铝。因此,把在浇铸高氧钢和不锈钢用水口上已取得实绩的无硅Al_2O_3-C-SiC     

双层喷嘴提升管进料区内气固流动特性的数值模拟

为了改善催化裂化工艺的产品分布,提出了一种双层喷嘴提升管进料方案,即在原有喷嘴层下方加设2个对称的“副喷嘴”,目前尚缺少此类双层喷嘴结构提升管内气固流动特性的研究。采用能量最小化方法考虑介尺度非均匀结构的影响,气固相间曳力采用EMMS曳力模型,采用了适用于模拟提升管内油剂混合和流动规律的数学模型。为保证模拟的准确性,确定了适宜的颗粒与壁面间镜面反射系数。主副喷嘴间距为0.5 m,同时改变主副喷嘴进料方向,形成了4种组合结构,即down?down结构、down?up结构、up?down结构和up?up结构。通过比较双层喷嘴与单层喷嘴提升管进料段内油剂混合和流动特性发现,双层喷嘴结构对提升管进料区气固流动的影响较大,尤其对于主喷嘴向上的传统进料结构,副喷嘴射流能加快气固两相达到均匀稳定。副喷嘴射流会加剧进料区副喷嘴以上高度处固含率分布的不均匀程度。当主喷嘴向下时,单层喷嘴down结构具有较小的平均停留时间和停留时间分布的离散程度,当主喷嘴向上时,双层喷嘴up?up结构的平均停留时间和离散程度最小,表明两种结构能使油剂在较短的接触时间内实现强混合,同时抑制目标产品继续裂解,降低生焦量。     

An Electrospray Method Using a Multi‐Capillary Nozzle Emitter

A multi‐capillary nozzle emitter consisting of one metal plate with capillary nozzles and a ring type counter electrode was used as a multi‐electrospray atomizer. The number of capillary nozzles, flow rate of the liquid and the interval between the capillary nozzles were changed, and the droplet diameter and the voltage required for a steady cone‐jet mode were measured. For the multi‐capillary nozzle emitter, the interaction between the capillary nozzles is the important factor for obtaining fine droplets of uniform size. These fine droplets are obtained when there is only a small interaction between the capillary nozzles, and the equations obtained from the single capillary nozzle case are also applicable for the multi‐capillary nozzle emitter. When the number of capillary nozzles decreases (a situation which is not good for obtaining a large amount of droplets) or the interval between the capillary nozzles increases, the interaction between the capillary nozzles can be reduced. As the number of capillary nozzles increase, a higher voltage is required to obtain a fine droplet of uniform size.     

喷嘴形状对喷射能力的影响

以喷射钻井为例,对不同入口形状的喷嘴的射流水力参数进行对比,在同一喷砂介质和同一气流压力下进行喷射实验,对比4种喷嘴的使用寿命,得出碳化硼喷嘴是最理想的井下喷射材料,同一种材料的喷嘴入口形状为流线性和等变速的喷射效果最佳。     

Steelcasting nozzles of calcined dunite

Conclusions Dunite steelcasting nozzles were subjected to testing with melts of the entire range of steel grades produced by the Nizhne-Tagil Metallurgical Combine.The nozzles gave normal casting and no difference was noted in the behavior and wear of unfired dunite and magnesite nozzles with channel diameters of 30 and 70 mm. The quality of rail steel in terms of surface flaws was the same for both nozzle types.In casting wheel and tire steels the experimental nozzles proved to be superior. Dunite nozzles are less susceptible to channel constriction but more susceptible to burn-through by oxygen.Channel encrustation was more prevalent in fired than in unfired dunite nozzles but less prevalent than in unfired magnesite nozzles, in addition to which wear was more rapid in the case of the latter.Translated from Ogneupory, No. 4, pp. 3–7, April, 1975.     

球形容器接管环带区球壳侧应变场在线性条件下的工程估算研究

本文用电测法对３台带接管的球形容器（两台带正交接管，一台带切向接管）接管环带区的应变进行了测试，对应变分布进行了分析。认为球形容器接管环带区的峰伍应变位于离焊缝较近的球壳侧，且峰值应变和压力具有线性关系。在线性条件下，对球壳侧应变的工程估算进行了探讨，得出的经验式可供压力容器安全评定时参考。     

假塑性流体的雾化研究Ⅲ.具有螺旋导流槽的二流式喷嘴

用于高粘度物料的二流式喷嘴，在气体通道内放置螺旋槽后，使进入喷嘴的气流在螺旋槽的引导下成为有一定旋转角度的高速气流。考察了该气流对物料雾化的效果，并比较了喷嘴的不同结构形式对雾化特性的影响     

Vibromolded and cast zircon nozzles for the pony ladles in continuous steelcasting

Conclusions It was shown that vibromolding and slip-easting techniques can be used to produce nozzles with a more homogeneous structure and higher thermal strength and density than those of industrial nozzles. The durability in service of the experimental nozzles was better than that of the industrial nozzles.Translated from Ogneupory, No. 3, pp. 20–24, March, 1977.     

Submersible Ladle Nozzles for Continuous Casting Machines: State of the Art and Prospects of Development

The state of the art in the technology, properties, and uses of submersible quartz and corundum-graphite nozzles for continuum steel casting is considered. Corundum-graphite nozzles display a low heat resistance, increased air permeability and, moreover, are environmentally hazardous. The existing methods for updating corundum-graphite nozzles fail to settle the question of channel clogging in casting rimmed steel and other types of steel. Quartz nozzles fabricated by conventional technologies are devoid of these shortcomings; however, they have a shorter life because of the chemical interaction of alloying steel components and their oxides with SiO₂. Comparative tests on submersible quartz nozzles differing in structure and chemical and phase composition showed the emerging potential for new technologies and approaches in the production and uses of updated quartz glass-based nozzles for casting common and low-alloy steels. For casting common steels, updated submersible quartz nozzles are developed with a warranty endurance, under slab CCM operating conditions, of 720 tons (in terms of steel cast) against the rated life of 1200 tons. For low-alloy steels, modified submersible quartz nozzles are recommended with a warranty endurance of 360 tons (in terms of steel cast) against the rated life of 540 tons.     

大型化肥厂尿素造粒测定报告

调查与测定了６个大化肥厂造粒和储运包装的运行情况。结果表明：锥形与斜孔喷头所造粒的合格率均在９８％以上，横向喷洒密度分布均呈突出的驼峰状，斜孔喷头更为突出，两种喷头颗粒分布均呈现喷洒带外区为大颗粒，斜孔喷头所造颗粒在储运包装过程易粉化，锥形喷头塔顶排尘较大。针对所存在的问题提出改进建议     

陶瓷喷砂嘴的冲蚀磨损机理研究

以B4C和Al203／(W，Ti)C陶瓷材料制备喷砂嘴，以SiC和Al2O3作为冲蚀磨料进行了喷砂冲蚀试验。研究了陶瓷喷嘴材料的冲蚀磨损机理以及不同冲蚀磨科对陶瓷喷嘴冲蚀磨损的影响。结果表明：喷嘴材料的硬度对陶瓷喷嘴的冲蚀磨损起重要作用。在相同条件下，具有高硬度的B4C陶瓷喷砂嘴的磨损率较小，相对硬度较低的Al2O3/（W,Ti）C陶瓷喷嘴磨损率较大。B4C陶瓷喷嘴的主要磨损机理为脆性断裂，而Al2O3/（W,Ti）C陶瓷喷嘴的主要磨损机理为微观切削。冲蚀用磨科的硬度和粒度对陶瓷喷嘴的磨损也有一定的影响，磨料的硬度和粒度越大，陶瓷喷嘴的磨损速度加快。