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在连铸程序中,设计中间包和结晶器之间的浸入式水口(中间包长水口或套管)的目的是为了防止从中间包流入结晶器的钢水再氧化。该水口提供了一个均匀钢流,防止钢水流散。 相似文献
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连铸结晶器中钢水流动的控制会直接影响板坯和产品的表面和内部质量。虽然结晶器中的钢水来源于浸入式水口,但着眼于浸入式水口中液流方面的研究却很少。本研究借助于液态合金模型与钢流模型,通过透明的浸入式水口现场观察了浸入式水口中的钢水流动情况。随后又在工业连铸机上测量了结晶器弯月面处排出的氩气。在液态合金模型试验中,势流和活塞流的形成取决于氩气流量、金属流量以及水口直径。减少氩气流量、增加金属流量以及缩小水口直径都会导致水口中弯月面高度的升高。通过透明的石英玻璃水口观察钢流。势流与活塞流的出现也都取决于氩气流量。根据从结晶器弯月面处测量的氩气净流量,发现从上滑板中吹入的氩气有20%左右被带入水口中。根据这些试验结果可以得出以下结论:在平常操作过程中,传统板坯连铸机的浸入式水口内充满钢水,钢流类似活塞流。 相似文献
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采用测速棒偏转法对工业生产连铸结晶器表面流速进行了高温实际测量,并依据测量结果对数学模型的计算结果进行了对比分析与验证。并进一步利用数学模型对比分析了侧孔出口为方形、矩形和跑道形的浸入式水口(Submerged Entry Nozzle,SEN)在不同拉速和水口浸入深度情况下结晶器内流场的变化规律。结果表明,采用三种不同类型水口的表面流速随着拉速的增大而增加,随着SEN浸入深度的增大而减小。在相同的连铸工艺条件下,采用方形水口的结晶器表面流速大于采用矩形水口和跑道形水口的表面流速。采用矩形水口的结晶器表面流速与采用跑道形水口的表面流速大小相当。采用三种不同类型水口的液面湍动能随着拉速的增大而增加,随着水口浸入深度的增大而减小。在相同的连铸工艺条件下,采用跑道形水口的液面湍动能最小。 相似文献
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通过对150 mm×150 mm方坯结晶器钢水流场的模拟和卷渣机理的分析,改进了连铸的有关工艺参 数:浸人式水口浸人深度由70~80 mm提高到120~135 mm;浸入式水口下口直径由25 mm增大至32 mm;保护渣 粘度由0.38 Pa ·8提高到0.40 Pa ·8;结晶器钢液面波动由±5.0mm降低到±3.0 mm。结果使C72DA钢的夹杂 物合格率由92.10%提高到99.51%。 相似文献
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ZHU Miao-yong WANG Jun ZHANG Ying 《钢铁研究学报(英文版)》2005,12(6):14-19
SymbolList Ab,An———Surfaceareaofbroadfaceandnarrowfaceof moldrespectively,m2;Cp———Effectiveheatcapacity,J·kg-1·K-1;Cp,s———Heatcapacityofsolidphase,J·kg-1·K-1;Cp,l———Heatcapacityofliquidphase,J·kg-1·K-1;Cw———Waterheatcapacity,J·kg-1· 相似文献
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Lu-Sha Zhang Xiao-Feng Zhang Bao Wang Qing Liu Zhi-Gang Hu 《Metallurgical and Materials Transactions B》2014,45(1):295-306
A three-dimensional mathematical model of the magnetic field, flow field, and temperature field in a 1500 mm × 90 mm CSP funnel-type mold is used to numerically study the effect of an electromagnetic brake (EMBr) on flow and heat transfer behavior of molten steel. A number of effects of EMBr on the flow pattern and temperature distribution of molten steel are simulated. The jet flow discharge from the submerged entry nozzle (SEN) is significantly suppressed. In addition, heat transfer in the upper part of the mold increases under the influence of EMBr, which can improve the mobility of liquid steel at the meniscus and achieve low superheat casting. The relations between casting speed and magnetic flux density, and between SEN submergence depth and the installation position of the EMBr device, are taken into account to study the effects of braking on molten steel. The results show that the braking effect is weakened with an increase in either the casting speed or the SEN submergence depth. In order to insure the efficient and stable operation of a continuous casting production, the magnetic flux density should be increased by approximately 0.1 T when the casting speed increases by 1 m/min. In addition, an optimal braking effect for molten steel can be obtained when the distance between the bottom of the nozzle and the upper surface of the EMBr device is 100 mm. 相似文献
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内冷却器-U形管对板坯连铸结晶器内钢水流动的影响 总被引:4,自引:2,他引:2
针对1 240 mm×200 mm板坯连铸提出了一种钢水内外复合冷却技术,即在“结晶器内设置内冷却器-U形管”,起到提高传热效率和改善钢液流动之目的。运用流体力学分析软件,就内外复合冷却结晶器内钢水的流动状态进行了数值模拟,发现内冷却器可以使结晶器内钢水的流动状态均匀,部分起到电磁制动之功效,有利于钢液中的夹杂物上浮。 相似文献
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Interfacial Fluctuation Behavior of Steel/Slag in Medium-Thin Slab Continuous Casting Mold With Argon Gas Injection 总被引:1,自引:0,他引:1
The flow field of molten steel and the interfacial behaviour between molten steel and liquid slag layer in medium-thin slab continuous casting mold with argon gas injection was studied by numerical simulation, in which the effects of nozzle submergence depth and port angle, casting speed, and argon gas flow rate on the flow and the level fluctuation of molten steel were considered. The results show that the molten steel jet from the submerged entry nozzle (SEN) with three ports into the mold and form three re-circulation zones including one upper re-circulation zone and two lower re-circulation zones. Argon gas injection results in a secondary vortex flow in the upper zone near the nozzle. For a given casting speed and argon gas flow rate, increasing the side port angle and submergence depth of nozzle can effectively restrain the steel/slag interfacial fluctuation. Increasing the casting speed would prick up the level fluctuation. For a fixed casting speed, argon gas flow rate has a critical value, the interfacial fluctuation with argon gas injection are stronger than the case without argon gas injection when the argon gas flow rate is less than the critical value, but when the argon gas flow rate exceeds the critical value, the level fluctuation is calmer than that without argon gas injection. 相似文献
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为研究水口结构形状对连铸中低碳钢结晶器内流场和温度场分布的影响,采用有限容积法建立连铸圆坯三维数学模型,模拟了不同水口形状下圆铸坯的流场和温度场。结果表明,在水口浸入深度为80 mm、其他参数不变时,与直水口相比,旋流水口使钢水冲击深度降低,结晶器内涡流增强,弯月面温度和二冷区凝固率提高,且随着水口数量的增加,弯月面波高和结晶器出口温度降低;采用旋流水口并施加结晶器电磁搅拌(M EMS)时,结晶器中钢液温度升高,弯月面有卷渣行为,结晶器出口未形成凝固坯壳。在实际应用中,应避免同时使用M EMS和旋流水口,或使用旋流水口时采用低强度的M EMS。 相似文献