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随着经济发展对矿产资源需求的不断增长,大型浮选机以其高效率和低能耗优势已成为国际潮流;作为辅助设计和效能评估的重要工具,CFD技术已成为进行大型浮选机研究、设计的关键技术手段之一。本文利用CFD技术针对320 m3充气机械搅拌式浮选机槽内气液两相流进行仿真计算,在确定合适模型的情况下,将得到的气、液流场、液面气液流速、叶轮功耗等在浮选机工业清水试验中较为重要的参数与工业试验所得的数据进行对比。结果表明,所选用的数学模型可以较准确地描述浮选机槽内气液流场,可以为浮选机的设计、改进提供依据。 相似文献
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A full-scale, three-dimensional, transient CFD modelling approach capable of predicting the three-phase fluid-flow characteristics and desulphurisation behaviour in an argon-stirred ladle was developed. The model can accurately predict the molten steel flow and slag eye behaviour. The predicted sulphur content in ladle as a function of time agrees well with the experimental data. The effects of the initial sulphur content, the gas flow rate and the slag layer thickness on the desulphurisation efficiency were also investigated. The predicted results show that the desulphurisation efficiency improves with the increase of the initial sulphur content, the gas flow rate and the slag layer thickness. Higher gas flow rate can improve the slag–steel interaction, which, in turn, helps improving the desulphurisation rate. The thinner the slag layer, the larger the slag eyes and the smaller the interfacial area between the slag and steel phases. The consequence is the decrease in the desulphurisation rate. 相似文献
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建立了环缝式电磁搅拌法制备半固态金属浆料系统电磁场的计算模型,采用商用ANSYS软件对制浆系统内电磁场分布进行了数值模拟,分析了电流、频率、坩埚材质、冷却器材质和环缝宽度对磁感应强度的影响规律,并进行了相应的实验验证.研究结果表明:电磁场模拟结果与实验结果具有较好地一致性,验证了计算模型与软件算法的可行性;系统电磁力主要分布于环缝内,提高了对合金熔体的搅拌强度;在相同的环缝宽度下,磁感应强度随频率的增大而依次减小,随电流的增大而依次增大;同时选用不锈钢坩埚与石墨冷却器可以使环缝内铝合金熔体的磁感应强度获得最大;相同电流和频率条件下,磁感应强度随着环缝宽度减小而逐渐增大;相同搅拌功率条件下,环缝式电磁搅拌法可以获得更加细小均匀的半固态组织,平均晶粒尺寸较普通电磁搅拌法减小31%. 相似文献
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《钢铁冶炼》2013,40(5):390-400
AbstractThe erosion of hearth refractories is widely recognised as the main limitation for a long campaign blast furnace life. Distributions of liquid iron flow and refractory temperatures have a significant influence on hearth wear. In this investigation, a comprehensive computational fluid dynamics model is described which predicts the fluid flow and heat transfer in the hearth; specifically, the flow and temperature distributions in the liquid iron melt, and temperature distributions in the refractories. The accuracy and representativeness of the model was evaluated using plant data from BHP Steel's Port Kembla no. 5 blast furnace and OneSteel's Whyalla no. 2 blast furnace. Generally, there is good agreement between measured and calculated refractory temperature profiles. A series of sensitivity tests provided cause-effect relationships between operational and fluid flow parameters (floating deadman, different extent of refractory erosion, presence of embrittled layer). 相似文献
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为获取浮选气泡在矿浆中的运动规律及三相流中浮选气泡的最佳尺寸,运用欧拉模型模拟不同初始直径的气泡在不同密度矿浆中的运动过程.结果表明:在给定的初始条件下,同一浓度的矿浆中,单个浮选气泡所能捕获的矿物量以直径4mm的气泡最多,气泡尺寸增大或减小后,其矿物捕获量都有所减少.当矿浆中固相质量分数在20%~40%之间变化时,矿物捕获量最多的气泡尺寸变化不大,并且随着矿浆中固相质量分数的增大,单个气泡的捕获量增大,矿物粒子回收率增加.在实际生产中,直径为3.5~4 mm的中等大小气泡在运动过程中变形程度小,气泡水平偏移及浮升速度适中,对矿物粒子的捕获率及运载能力和浮升能力较强,有利于提高浮选产量和质量. 相似文献
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A full-scale, three-dimensional, transient CFD modelling approach capable of predicting the three-phase fluid flow characteristics and the inclusion removal in a gas-stirred ladle was developed. The comparison with experimental data indicates that this model can accurately predict the multiphase fluid flow and slag eye behaviour. The transport and removal of the inclusions in the gas-stirred ladle were predicted by tracing the movement of individual inclusions through computing their particle trajectories and considering a fluctuant top slag layer. The effects of inclusion size, gas flow rates, and injected bubble diameters as well as various removal mechanisms including slag capture, bubble attachment, and ladle wall adhesion on the removal of inclusions were investigated. It is shown that the slag capture is the prevailing mechanism for inclusion removal and the gas flow rate is the most important parameter for enhancing the inclusion removal efficiency. 相似文献
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以钢包精炼底吹氩气过程中氩气泡为研究对象,运用VOF模型追踪氩气与钢液的界面,在层流条件下三维数值模拟了氩气泡的生成和运动过程。采用Tecplot进行模拟结果的后处理,研究了不同气体流量条件对气泡脱离直径的影响以及气泡的运动特性。模拟结果显示,氩气泡的形成历经膨胀、脱离两个阶段,气泡脱离直径随着气体流量的增加而增加,针对2 mm直径的孔口,其鼓泡流量上限为1.325 L/min。气泡从孔口脱离后历经近似球形、扁平的椭球形、规则的椭球形和不规则的球帽形的形状变化;气体流量越大,气泡的变形程度越剧烈,气泡位于钢包高度中上部位置时,全部呈现近似规则的球形,不随流量的改变而改变。 相似文献
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建立了折流式移动流化床内粉铁矿预还原的二维气固反应流CFD模型.模型的数值求解采用PHOENICS和FLUENT的联合求解.与之前的实验结果相比,在冷态条件下单床层平均压降和气固相流动行为的数值模拟结果与其基本一致,得出所提出的数学模型是可靠的.在此模型基础上,对采用COREX输出煤气对铁矿粉预还原的工艺过程进行热态模拟.在模拟的工况条件下,还原气温度的整体降幅700 K,气相CO和H_2还原势的利用率分别达到38%和26%,矿粉的还原分数达到75%,即反应器内有良好的气固换热而且对COREX煤气还原势的利用率较高,实现了对还原气热能和还原势的梯度利用. 相似文献
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为了掌握皮带运输巷道粉尘质量浓度的分布规律,获取通风除尘设计的合理参数,以西石门铁矿提升车间系统40#皮带运输平巷为研究背景,依据气固两相流理论,运用计算流体力学的离散相模型对皮带运输巷道粉尘质量浓度进行数值模拟,并与现场实测的粉尘质量浓度分布情况进行对比分析,模拟结果与实测数据基本吻合.研究表明,运用欧拉-拉格朗日法对皮带运输巷道粉尘质量浓度分布规律进行模拟是可行的.在通风除尘设计中,当巷道风速为3 m·s-1时,排尘效果最好,粉尘质量浓度整体保持在3 mg·m-3以下;皮带运输速度为2.5 m·s-1时粉尘质量浓度较低;定期进行壁面洒水也能在一定程度上实现降尘目标. 相似文献
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摘要:准确预测连铸结晶器内多尺寸泡状流的流动特性对洁净钢水和提高铸坯质量至关重要。为了考虑气泡聚并、破碎等微观现象对气泡尺寸、数密度、含气率等宏观参量的影响,分别采用2种基于群体平衡方程的数学模型—多气泡组质量传递模型(MUSIG)与平均气泡数密度模型(ABND),对连铸结晶器内的多尺寸泡状流进行了数值模拟,并与水模型实验结果进行了对比研究。结果发现:2种群体平衡模型均可以较准确地捕捉到结晶器多尺寸泡状流中的液相流型、气泡尺寸以及含气率分布特征,尤其是较好地预测了浸入式水口内部含气率的“中间峰”和“出口峰”分布特征;相比于MUSIG模型,ABND模型对靠近水口处气泡尺寸分布的预测结果更加准确。2种群体平衡模型扩展了传统单一粒径双流体模型的适用范围,为结晶器内多尺寸泡状流研究提供了理论基础和数学框架。 相似文献
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Accurately predicting the flow characteristics of multi scale bubble flow in continuous casting mold is of great significance for cleaning molten steel and improving slab quality. To consider the influence of bubble coalescence, breakage, and other microscopic phenomena on the macroscopic characteristics such as bubble size, number density, and gas void fraction, two mathematical models based on population balance equation, MUltiple SIze Group (MUSIG) model and Average Bubble Number Density (ABND) model, were employed to simulate the multi size bubbly flow in the mold. The predicted results have been compared with the water model experiments. Results show that the two population balance models can accurately capture the liquid flow pattern, bubble size and void fraction distribution characteristics of the multi size bubble flow in the mold, especially the " intermediate peak" and "outlet peak" distribution characteristics of void fraction in the submerged entry nozzle(SEN). Compared with the MUSIG model, the ABND model is more accurate in predicting the bubble size distribution near the SEN. The two population balance models contribute to expanding the applicable scope of the two fluid model with a single size bubble and provide the theoretical fundament and mathematical framework for studying the multi size bubbly flow. 相似文献
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