水力旋流器分离粒度的计算

本文论述了水力旋流器中流体呈组合涡运动的基本规律,分析了组合涡中半自由涡与强制涡分界面的力学特性,提出了用最大切线速度轨迹面作为自然分级面的假说,根据平衡轨道原理导出水力旋流器分离粒度和分级粒度汁算公式,并用生产实践资料进行了验证。     

双涡自回流水力旋流器分级性能研究

通过对圆柱型、圆锥型水力旋流器的结构性能对比,设计了一种新型的两段组合式双涡自回流水力旋流器,并对三种类型的旋流器进行了清水和含砂试验研究。试验结果表明,双涡自回流水力旋流器相比其他两种,在分级效率上有了很大提高,消除了溢流中跑粗、控制了底流中细粒夹带,并通过理论分析,证明了双涡自回流水力旋流器的性能优势。     

双涡自回流水力旋流器分级性能研究

通过对圆柱型、圆锥型水力旋流器的结构性能对比,设计了一种新型的两段组合式双涡自回流水力旋流器,并对三种类型的旋流器进行了清水和含砂试验研究。试验结果表明,双涡自回流水力旋流器相比其他两种,在分级效率上有了很大提高,消除了溢流中跑粗、控制了底流中细粒夹带,并通过理论分析,证明了双涡自回流水力旋流器的性能优势。     

螺旋涡的基本性质及其在旋流器中的应用

本文简要地论述了水力旋流器中工作流体呈螺旋涡运动的基本规律和性质以及在分离过程中自然形成最大速度轨迹面的事实,并按照其轨迹面特性导出旋流器主要工艺指标计算式及其在实践中的应用效果。     

水力旋流器选型计算新程序

根据作者提出的水力旋流器分离过程中工作流体呈组合螺线涡或由其简化的组合涡中的最大切线速度轨迹特征,导出生产能力、分离粒度和基本直径3个基本公式,编制出水力旋流器选型计算新程序,并用生产实例印证了该程序的适应性和可靠性,供读者在实际工作中参考或应用。     

改进水力旋流器预分离区的研究

水力旋流器预分离区(溢流管所在区域)分离作用甚微,从而可增加溢流管外径以减小预分离区厚度。这样做的作用有四:(1)显著减少旋流器的盖下短路流;(2)增加旋流器能量在主分离区(溢流管以下区域)的分配;(3)降低旋流器内部损失;(4)改善流场条件,变原来的轴向零速面为轴向零速区,可提高分级精确性。通过对实际物料的分级考察,证明这种减薄预分离区的旋流器确可明显提高分级效率。     

科技文苑窗

水力旋流器组合涡分析及节能原理研究——李晓钟等 .《过滤与分离》2 0 0 0 (3)作者根据旋流涡运动基本理论以及水力旋流器场具有类组合涡结构的特点 ,推导出了关于压力降和能耗系数等的理论公式 ,分析了水力旋流器内各种能耗的产生机理 ,提出了若干节能措施和设想。值得重视的几个矿物加工技术发展趋势——卢寿慈.《黑龙江矿业学院学报》2 0 0 0 (3)针对我国矿产资源的特点 ,文章列举了几个具有重要发展潜势的矿物加工新技术——“多破少磨”新技术、矿石的超细磨、矿石辐射预选、超导磁选技术、地下选矿厂、新型压滤技术、矿石的微生物浸…     

用旋流器处理汞炱的技术分析

本文分析了处理汞炱的水力旋流器与金属矿选矿用旋流器在结构上及其作用原理上的差异。提出了处理汞炱的水力旋流器的圆柱体和锥角的尺寸,以及溢流管和进浆口的适宜位置等。根据旋流器处理汞炱的要求及对活汞形成的动力学分析,文中提出了处理汞炱旋流器的合理结构参数。     

选矿厂中使用的水力旋流器

作者。莫斯科1978年出版,全书232页共分六章。第一章:水力旋流器工作的理论基础;第二章:分级过程中使用水力旋流器工作的主要指标;第三章:各种参数对水力旋流器工作的影响;第四章;选矿厂水力旋流器工作的理论和实践;第五章;在分级流程中水力旋流器的工艺计算和选择;第六章:水力旋流器结构的评论,此外有五个附表,附表1:国外使用水力旋流器的选矿厂,例举了苏联以外其他国家的73个     

多锥体水力旋流器流体速度分布研究

本文采用雷诺应力模式(RSM)模拟多锥体水力旋流器流场,分析多锥体水力旋流器切向速度、轴向速度及径向速度的分布,发现多锥体水力旋流器的第二锥段具有稳定其流场的作用,因此与单锥体水力旋流器相比,多锥体水力旋流器的流场具有更好的稳定性,更有利于分离过程的进行.     

Performance of a deoiling hydrocyclone during variable flow rates

Hydrocyclones are state of the art technology for treating produced water offshore. In the acceleration field inside the hydrocyclone oil migrates to the cyclone centre as water is forced to the wall. Separation is depending on the characteristic two-fold vortex flow structure featuring hydrocyclones. Deoiling hydrocyclones do not always meet water quality requirements, however. This paper, describes experimental investigations and hydrocyclone efficiency during transient flow rates. A laboratory test rig exposed a hydrocyclone to severe transient flow rates. Efficiency disturbances may be detected by increased oil-in-underflow, which again is associated with vortex disturbances and plausible vortex breakdown. Experiments led to no such dramatic disturbances. However, separation effects traceable to a limited influence on the flow split were realized. This investigation emphasizes the importance of adequate hydrocyclone operational control. Based on experimental results it is concluded that hydrocyclone efficiency is unaffected by transient flow rates provided the hydrocyclone performance criteria are fulfilled.     

Study of flow behaviour in a three-product cyclone using computational fluid dynamics

Simplicity in design and minimal floor space requirements render the hydrocyclone the preferred classifier in mineral processing plants. Empirical models have been developed for design and process optimisation but due to the complexity of the flow behaviour in the hydrocyclone these do not provide information on the internal separation mechanisms. To study the interaction of design variables, the flow behaviour needs to be considered, especially when modelling the new three-product cyclone.Computational fluid dynamics (CFD) was used to model the three-product cyclone, in particular the influence of the dual vortex finder arrangement on flow behaviour. From experimental work performed on the UG2 platinum ore, significant differences in the classification performance of the three-product cyclone were noticed with variations in the inner vortex finder length. Because of this simulations were performed for a range of inner vortex finder lengths. Simulations were also conducted on a conventional hydrocyclone of the same size to enable a direct comparison of the flow behaviour between the two cyclone designs. Significantly, high velocities were observed for the three-product cyclone with an inner vortex finder extended deep into the conical section of the cyclone. CFD studies revealed that in the three-product cyclone, a cylindrical shaped air-core is observed similar to conventional hydrocyclones. A constant diameter air-core was observed throughout the inner vortex finder length, while no air-core was present in the annulus.     

低阻高效双出风口旋风筒的研究

旋风筒作为气固分离设备，因其结构简单、耐高温等优势，在化工、冶金、建材等行业得到了广泛的应用。自旋风筒问世以来，人们对其已做了大量研究工作，但是，它的一些主要缺点尚未得到圆满的解决，如：阻力损失大、捕集微细粉尘的效率低等。因此，有必要深入研究、开发新型高效的旋风筒。我们从降低旋风筒阻力着手，研究开发了低阻高效导流口可调式双出口旋风筒，经试验这种旋风筒具有压力损失小、分离效率高的优点，是一种很有应用前景的旋风筒。     

平底结构对水力旋流器流场特性及分离性能影响

基于数值模拟对比了渐缩平底旋流器与复合锥角旋流器流场特性,探究平底结构对水力旋流器流场的影响。结果表明,两种水力旋流器压强分布和切向速度分布基本一致,而空气柱附近压强梯度存在差异;渐缩平底旋流器溢流管下方湍流强度较低而底流口附近则相反;渐缩平底旋流器柱-锥交界面的空气柱附近轴向速度较高,导致其分流比较低。实验室旋流分离试验结果表明,平底结构能有效抑制溢流跑粗和底流夹细现象,显著提高分级效率,改善水力旋流器分离性能。     

结构参数对双溢流旋流器内空气柱性能的影响

传统旋流器一次分级只能得到溢流和底流两种产品,造成产品粒级范围太过宽泛,达不到精细分级的要求。本文提出了一种具有双溢流管结构的多产品旋流器,建立了流场模型,利用流体力学多相流理论,对旋流器内部流场进行了数值模拟,得到了内外双溢流流场分布特点,获取了流场和空气柱的形成、发展演化过程。对底流口、溢流口结构参数对旋流器内空气柱性能的影响进行了仿真分析,结果表明:旋流器内空气柱直径随着底流口和溢流口直径的增大而增大,当内溢流管直径小于底流口直径时,空气柱较为紊乱。研究结果对分析空气柱影响涡旋运动及优化旋流器结构参数奠定了理论基础。     

单、双溢流管旋流器流场特征及分离性能研究

普通旋流器完成一次分级只能得到细颗粒的溢流和粗颗粒的底流,无法实现窄粒级精细分级要求。为了使一次分级可以获得多个细粒径、窄粒级产品,提出了一种双溢流管旋流器,为探明旋流器内流场特 征及分离性能,采用数值模拟和试验研究对比研究了双溢流管旋流器和普通单溢流管旋流器内速度场、压力场、粒度场及分离性能。数值模拟结果表明：具有双溢流管结构的旋流器经过一次分离可以获取内溢流、外 溢流和底流3种粒级产品。相比于单溢流管旋流器,双溢流管旋流器的切向速度和内部静压力更大;径向速度、轴向速度和湍动能更小,说明双溢流管旋流器可以强化分离过程,有利于分离性能的提高。试验验证结果 表明：相较于单溢流管旋流器,双溢流管旋流器底流浓度降低了8.3个百分点,底流产率增大了3.25个百分点,内外溢流产品中-45 μm的颗粒累积含量增加了1.15个百分点,综合分级效率提高了1.26个百分点。研究 结果可为多产品窄粒级旋流分离装备及工艺的研发提供一定的参考。     

分级旋流器分选作用与分选旋流器分级作用试验研究

为考查颗粒粒度与密度对旋流器分级、分选的影响,采用20°锥角的分级旋流器与130°锥角的分选旋流器对＜3 mm粒级的煤泥进行了分离试验,对其产品进行筛分及分粒级浮沉,得到了不同粒度、密度颗粒在旋流器产品中的分配规律。结果表明：20°锥角旋流器以分级为主,但对各粒级均存在一定的分选作用,其中对＜0.125 mm粒级分选作用最强,这是导致溢流低灰精煤跑粗及底流细泥夹带的根源;130°锥角旋流器以分选为主,对较低密度颗粒不存在分级作用,随密度的增大,分级作用开始显现,对高密度颗粒存在明显的分级作用,这是导致溢流高灰细泥污染的根源。     

CFD validation for flyash particle classification in hydrocyclones

The investigation pertains to establishing a simulation methodology for understanding the flyash classification characteristics of a 76 and 50 mm diameter hydrocyclone where the work was carried out using commercially available CFD software. Comparative results on the simulated and experimental water throughput, split values are presented. Results indicted that there is a good match in water split between the experimental and simulated values with error values below 10% at different hydrocyclone designs. Further a discussion is made on the flow features at comparable ratio of cyclone diameter to spigot opening in the 76 and 50 mm designs. The vertical core region around the cyclone axis having static pressure equal to or below the atmospheric pressure is examined to be increasing in diameter from bottom of the spigot opening till the interface where vortex finder joins the main cylindrical cyclone body and remains more or less similar at the vortex finder outlet. The diameter of this zone at the spigot outlet is 0.6 and 5.4 mm at 3.2 and 9.4 mm spigot openings in case of 50 mm diameter hydrocyclone. The diameter of the core at spigot outlet is found to be around 9.2 and 11 mm at 15 and 20 mm for spigot openings in case of 76 mm diameter hydrocyclone.Classification of flyash particulates is simulated through discrete phase modeling using particles injection technique and the simulated results are further validated with suitably performed experiments. With 50 mm diameter hydrocyclone, reasonable predictions are observed at 9.4 mm spigot opening. Considerable deviation in particle distribution points with this hydrocyclone is observed at narrowest spigot diameter of 3.2 mm. The simulated values of d₅₀ in case of 50 mm diameter hydrocyclone are 8 and 10 μm at 9.4 and 3.2 mm diameter spigot openings. Better predictions are obtained with 76 mm diameter hydrocyclone at both 10 and 15 mm diameter spigot openings. Similarly, the simulated d₅₀ values are 14 and 20 μm at 15 and 10 mm diameter hydrocyclones. Possible reasons for deviations in the results relating the spigot opening, solids concentration at the underflow and in turn role of slurry viscosity on the air core diameter are proposed.     

溢流管直径对旋流器流场和分离影响研究

利用RSM雷诺应力模型和VOF多相流模型,系统考察了溢流管直径对Φ50 mm水力旋流器流场稳定性的影响。通过对空气柱、零速包络面、短路流及湍流强度等流场特性的分析,确定了使流场稳定的最佳溢流管直径范围,并通过旋流分离物理试验进一步验证了该溢流管直径条件下获得的稳定流场能有效提高分离效率。研究结果表明,当溢流管直径过小时,空气柱会发生中断甚至不能完整形成,分选空间内部湍流强度较高,底流分流比较大,短路流量较小。随着溢流管直径的增加,逐渐形成上下贯通的空气柱,分选空间内部湍流强度降低,零速包络面的对称性增强,底流分流比逐渐降低,流场稳定性增强,从而分离性能增强。随着溢流管直径进一步增加,空气柱直径增大,短路流量增加,流场稳定性降低,从而分离效率下降。因此,针对所考察的Φ50 mm水力旋流器最佳的溢流管直径在0.30 D左右。