偏心搅拌混合特性水模试验研究

基于国内外KR搅拌脱硫混合特性的理论成果,提出一种偏心搅拌脱硫新工艺,完成了常规四叶搅拌器与相同叶片结构的WG-3Y搅拌器的偏心搅拌水模试验。试验结果表明,在合理的偏心距和搅拌器潜入深度条件下,偏心搅拌具有明显地改善搅拌混合性能的效果,与常规四叶搅拌器相比,WG-3Y搅拌器的搅拌混合性能更优,偏心距影响程度更大。     

Development and application of long life technology of WG-3Y stirrer in KR desulphurization

根据KR搅拌脱硫的水模试验与理论研究结果,针对国内外改善KR搅拌混合特性存在的问题不足,研试了一种WG-3Y搅拌器新结构。在水模试验研究的基础上,完成了100、200t铁水罐搅拌脱硫用WG-3Y搅拌器的研制,并在工业性试验与推广应用中,取得了改善脱硫动力学条件、提高脱硫技术经济指标的优良效果。     

国际领先的武钢铁水脱硫搅拌器

由研究院和武钢炼钢总厂共同完成的“WG-37铁水脱硫搅拌器的研制与应用”顺利通过公司科技创新部组织的成果鉴定，达到国际领先水平。课题组针对常规铁水脱硫搅拌器脱硫动力学条件差、叶片间粘渣严重等实际问题，在系统分析KR搅拌脱硫常规四叶搅拌器结构优缺点的基础上，创造性地提出了三叶星形结构的WG-37脱硫搅拌器，并完成了搅拌器用新型浇注料、搅拌器制备工艺、热修维护用修补料、水基防粘渣涂料以及搅拌器在线维护工艺的研究，取得了良好效果。鉴定委员会一致认为，该项目立意新颖，综合经济技术指标达到国际领先水平，WG-37铁水脱硫搅拌器研制成苏式对武钢进一步引领铁水脱硫领域技术进步意义重大。     

改善KR搅拌脱硫混合特性的理论分析与实践

通过KR搅拌脱硫流动状态分析,探明了其局域卷吸混合分散特性;根据固体回转部半径rc与搅拌器叶轮半径r1间的经验公式与搅拌功率影响因素,探讨了改善KR搅拌脱硫混合特性（动力学条件）的具体措施;通过对国内外不同结构搅拌器的工业性试验与应用研究结果的分析,证实了改善措施的理论研究结果对实际生产良好的指导价值。     

加压釜搅拌槽气液两相流动的数值模拟

利用计算流体力学(CFD)软件Fluent,对某冶炼厂现有搅拌器和优化后搅拌器搅拌槽内的气液两相流动和混合进行了数值模拟,对比了两种搅拌器搅拌槽内的速度分布、局部气含率和搅拌功率。计算结果表明,优化后的搅拌器搅拌混合效果和气体分散优于现有搅拌器,且搅拌功率基本不变。     

搅拌器磨损对搅拌喷吹法脱硫流场影响的数值分析

为探究搅拌器被铁水腐蚀后对搅拌流场的影响,以四叶搅拌喷吹复合脱硫搅拌器为研究对象,应用Fluent软件,采用Eulerian模型,对流场速度和湍动能分布两方面进行了数值分析.结果 表明:相同搅拌喷吹工艺参数条件下,随着搅拌器磨损程度的增加,铁水罐内铁水整体的流场速度和湍动能会减小,液面漩涡深度也随之下降.其中,磨损程度...     

KR脱硫搅拌器结构参数的水模优化实验

通过常规搅拌器与异形叶片搅拌器在不同直径搅拌罐上的水力学模拟实验,探讨了搅拌器旋转直径与搅拌罐直径比对脱硫剂卷吸深度的影响,获得了两种叶片结构搅拌器的最佳搅拌旋转直径。实验结果表明,适当扩大常规搅拌器旋转直径可提高KR脱硫效率。     

KR法中桨叶结构对搅拌效率影响的数值模拟研究

KR法是铁水预处理中主流的脱硫方法。采用数值模拟方法研究了正四叶桨、螺旋三叶桨和双层正四叶桨三种桨叶的搅拌效率,结果表明：双层正四叶桨的混匀时间比正四叶桨短7.3%,比螺旋三叶桨短37.9%;通过对铁水中轴向速度、湍动能分布的分析发现,双层正四叶桨搅拌器中铁水轴向速度更大,并且铁水中湍动能广泛扩散,双层正四叶桨的平均湍动能比正四叶桨大28%,比螺旋三叶桨大1.8%。     

方形液—液萃取搅拌槽搅拌功率准数的测定

实验测定了不同类型的多种搅拌器在方形搅拌槽内的两液相混合过程中的搅拌功率准数,为液-液萃取过程的搅拌输入功率的计算提供了依据。实验表明,搅拌功率准数的大小不仅与搅拌器的类型有关,而且与搅拌槽的结构有关,在方形槽内装置挡板,搅拌功率准数显著加大,从而可改善萃取过程的传质效果。     

新型叶片结构搅拌器的水模试验研究

通过水力学模拟试验,探讨了搅拌器叶片结构、搅拌速度、搅拌器潜入深度对液面旋涡面积、卷吸循环量、卷吸深度的影响规律,获得了改善KR,脱硫动力学条件的新型叶片结构搅拌器。     

Solidification processing of Al-Al2O3 composite using turbine stirrer

Solidification processing of Al-Al₂O₃ composites involves mixing of nonwetting alumina particles in molten aluminum alloy resulting in a slurry where the particles are often attached to bubbles sucked at the center of vortex below the stirrer. The internal surface of bubbles is eventually oxidized by oxygen from air entrapped in it. These bubble-particle combines may float or settle during casting depending on the overall density influencing the particle and porosity distribution in a cast composite ingot where the performance of a stirrer may be evaluated under a given condition of processing. Particle incorporation is more for turbine stirrers instead of flat blade stirrers, but the porosity also increases. Flotation of bubble-particle combines during casting of ingot results in higher particle content at the top. Microstructure shows clusters of particles along circular boundaries of thin oxides at the top of the ingot and sometimes at the bottom. This may be a consequence of filling of bubbles to different extents by surrounding liquid puncturing the oxide layer, if necessary, during solidification. When the manner of stirring is changed to 2 minutes of stirring of particles into molten alloy with an intermediate 2-minute period of no stirring before stirring the slurry again for 2 minutes, relatively uniform particle incorporation results along the height of cast ingot compared to that obtained by continuous stirring. This difference in particle distribution may be attributed to flotation of bubble-particle combines to release the particles on the top of the slurry when stirring ceases and its remixing into the slurry when it is stirred again. However, an increase in the intermediate period of no stirring and a higher processing temperature result in enhanced porosity and a more inhomogeneous particle distribution along the height of the ingot.     

电磁/永磁搅拌器在熔铝炉上的应用及比较

本文着重阐述磁搅拌器应用于熔铝炉的优越性,并对永磁搅拌器与电磁搅拌器的优缺点进行了比较.     

搅拌器的结构参数对钢液内电磁场和流场分布的影响

利用ANSYS5．6软件对单侧线性电磁搅拌作用下钢液内的电磁场分布和流场分布进行了数值模拟，分析了搅拌器的结构参数对钢液流动状况的影响，结果表明，在搅拌器长度，线圈匝数及电流强度均相同的条件下，采用集中绕组的搅拌器所产生的电磁场最弱，而重叠绕组搅拌器和克兰姆绕组搅拌器的电磁利用率较高，所产生的磁场强度越大，钢液的流动速度和紊流动能均较大；此外，尽管磁轭不影响电磁场的分布趋势，但却显影响磁场强度的大小，所以，在数值模拟中应当考虑磁轭的存在，当搅拌器极距和其它参数一定时，增加搅拌器长度有利于扩大搅拌的作用范围，但对提高搅拌无明显效果，在搅拌器长度和其它参数一定的情况下，增大搅拌器的极距却不影响搅拌的作用范围，但却使搅拌强度明显提高。     

强力搅拌机的改造和应用效果

为了解决强力搅拌机简体内壁粘料严重、耙杆齿断裂、混料效果不明显等问题。对强力搅拌机进行了改造，采用超高分子量聚乙烯衬板，耙齿改用65Mn钢板、表面喷焊耐磨粉末合金，耙杆齿改为铆焊件并调整耙齿安装角度，改造后强力搅拌机的混合效率由75％提高到90％，耙齿的寿命延长至150天，提高了生球的质量和均匀性，年增加球团矿产量3万t，创效200余万元。     

An Experimental Prototype of an Innovative Fluid-driven Electromagnetic Stirring Technique

A new electromagnetic stirring technique that is driven by hydrodynamic forces was presented. This technique offers the following advantages. First,the stirrer can be immersed in the liquid metal,thereby significantly increasing the penetration depth of the electromagnetic forces and significantly improving the stirring efficiency; thus,this technique is particularly suitable for large-scale liquid metal. Second,under certain conditions,this technique can overcome difficulties that are encountered with traditional stirrers,such as accessing regions that are difficult to reach in working spaces with complex or narrow shapes. This stirrer also has a simpler structure than a traditional stirrer; thus,the design can be easily modified,and no external power supply is required. An experimental prototype was also presented for controlling the fluid flow rate,thereby controlling the electromagnetic force and velocity field of the driven liquid metal. The velocity distribution in a liquid Ga In Sn alloy under fluid-driven electromagnetic stirring was quantitatively measured using ultrasonic Doppler velocimetry( UDV). The primary results show that a remarkable velocity field has been achieved and that fluid-driven electromagnetic stirring is an effective means of stirring liquid metal. Finally,the potential applications of this technique in industry,along with key challenges,were discussed.     

Numerical Simulation of Electromagnetic Field and Flow Pattern in a Continuous Slab Caster with In-roll Type Strand Electromagnetic Stirring

The electromagnetic field and flow analysis model were developed to simulate the electromagnetic field and the flow pattern in a vertical curved continuous slab caster with the in-roll type strand electromagnetic stirring.The transient electromagnetic field distribution and the induced electromagnetic force were numerically described.The effects of stirring current,stirring frequency,and different stirrer configurations on the electromagnetically driven flow field in the strand were investigated and the optimization of the stirring parameters was discussed by performing a relative comparison of numerical results.Results show that the in-roller type strand electromagnetic stirrer(SEMS)pair generates the fluctuating magnetic fields,penetrating through the cast slab and periodically parallel shifting along the slab wide face with time evolution.The transient induced electromagnetic forces travels toward the magnetic flux shifting direction.Different stirring parameters(i.e.current and frequency)and stirrer configurations affect the stirring strength and the flow recirculation pattern in the strand,which are closely related to metallurgical performances of the stirrers.There is an optimum frequency to obtain the maximum stirring.The present model provides a relatively theoretical insight into the in-roll type strand electromagnetic stirring system for best operating.     

Physical Simulation of New Desulphurization Technology Using Pulsed and Rotary Stirring-Injection

The contrast experiment of different stirring modes,which includes a new type of stirring-injection with the method of pulse and rotation,and the initial one-way stirring method,is done through physical simulation in the laboratory.The stirring methods of pulse and rotation are of two kinds.One is pulsed and rotary stirrer with positive and opposite directions.The other is pulsed and rotary stirrer with rotation-stop-rotation.The results show that the stirring mode of pulse and rotation has better effects than the one-way stirring method.The specific effects are that the mixing time of the melting bath is apparently shortened,the number of grains involved in the liquid surface is increased,and the residence time of air bubble in water is doubled.     

萃取混合澄清槽混合过程的数值模拟

应用Fluent软件对混合澄清槽的搅拌混合过程进行模拟分析,以水相和有机相(P507)两种液体为模拟对象,搅拌器采用上两层为平直叶桨和下层为涡轮桨的三层组合桨。结果表明,搅拌轴中心即前室口上方产生低压区,从而使前室液体抽吸至混合室,并在混合室内形成了周期性的上下循环流动;各层叶轮转矩由上而下逐渐递增。