Effects of Operating Variables on the Yeast Separation Process in a Hydrocyclone

This work involved the use of a hydrocyclone to separate yeast from alcoholic fermentation suspensions. The performance of the hydrocyclone was quantified using empirical models that describe the capacity, total separation efficiency, flow ratio, and reduced separation efficiency as a function of the concentration of the suspension and the operating pressure drop. The results showed capacities of 0.1283 to 0.1820 m³/h, total separation efficiencies of 81.96% to 92.19%, reduced separation efficiencies of 0.63% to 58.44%, and flow ratios ranging from 81.05% to 84.85%.     

优选去除油田采出水固体的水力旋流器

设计了几种适用于油田除砂系统所用的小型水力旋流器,并进行了优选实验,得出一种最适合于油田微细颗粒分离的旋流器,这种直径为10mm的旋流器在悬浮液进口浓度为5000ppm时,溢流浓度达240ppm.,修正效率达98.5%。串联使用可广泛用于油田除砂。     

Hydrocyclone Performance with Complex Oil‐Water Emulsions in the Feed

Separation performance of an oil‐water hydrocyclone depends very much on the physical properties of the feed emulsion or dispersion. These properties can be influenced by numerous factors, particularly water cut and the type of emulsion.In this exploratory work, the effects of water cut and flowrate on de‐watering capabilities of a hydrocyclone with a complex emulsion in the feed line are investigated. Two flow rates of 25 and 35L/min were studied and the water cut was varied from about 8 to 65%. For each case separation, efficiency was measured, the emulsion characterized and its stability checked for the three hydrocyclone streams. Drop size distribution was also examined. Comparison of performance with a simple emulsion was also made.     

水力旋流器的底流口直径对其分离性能的影响

底流口直径对旋流器的性能有着非常显著的影响。本研究采用体积法测量并计算了颗粒浓度和分离效率,在流化催化裂化(FCC)催化剂-水液固体系内考察了底流口直径对水力旋流器分离性能的影响。发现在入口浓度不同时,底流口直径对旋流器性能的影响规律不同。在低浓度体系(C入≤10%)内,随着底流口直径的增加底流液浓度急剧减小,但溢流液浓度基本不变。在高浓度体系(C入≥15%)内,随底流口直径的增加底流液浓度变化不大,但溢流液浓度显著降低。在本实验范围内,随着底流口直径的增加,分流比显著增加,分离效率明显增加,压降略有降低。     

Optimization of Hydrocyclone Performance Using Multi-Objective Firefly Colony Algorithm

Hydrocyclones consist basically of a cylindrical part associated to a conical region for solid-liquid and liquid-liquid separation in centrifugal field. The geometric dimensions of each part are important in the separation process, being related to capacity and classification power of equipment. Thus, this paper aims to propose a systematic strategy to determine the geometric dimensions by formulating an optimization problem using the Firefly Colony Algorithm in the multi-objective optimization context. From the obtained results it was possible to find a hydrocyclone design capable of providing both high overall efficiency (E _T ) associated with low Euler number (Eu) and underflow-to-throughput ratio (R _L ).     

水力旋流器分离性能强化研究

设计了一种在旋流器轴心线位置具有中心固棒的新型水力旋流器,该中心固棒的引入有效地消除了旋流器内的中心空气柱。实验研究了该中心固棒替代空气柱对旋流器性能指标的系统影响。研究结果表明,采用中心固体棒取消旋流器内的空气柱后,旋流器的分离性能得到了有效的强化。与具有空气柱的旋流器相比,不管旋流器锥段结构如何变化(从普通直锥、到抛物线型锥、到双曲线型锥),具有中心固棒的旋流器均具有更高的分离总效率、更高的修正分离总效率、更小的修正分离粒度以及更高的分离精度。随着旋流器锥段内部空间的增大,中心固棒使旋流器分离性能提高的幅度也增大。     

油水分离充气旋流器的研究进展

充气旋流器是利用离心惯性力强化浮选效果的新型设备，综述了用于油水分离的充气旋流器的结构，分离机理和影响因素的研究进展，并提出展望。     

液-液旋流分离器内流场的数值模拟研究

用计算流体动力学(CFD)的数值方法,采用RSM模型对油水分离用液一液水力旋流器的流场进行了数值模拟。单相流场的模拟结果表明,旋流器内的流场结构是强旋转和非对称的三维结构,因而对旋流器的研究(无论是数值模拟还是实验测量)必须是基于三维的;旋流器上游区内流体紊流现象严重,两侧有循环流存在,这都对两相分离不利,应改进结构以改变这种流动形式;其模拟结果与他人实验结果吻合较好,说明该湍流模型和算法是可靠的。另外还对油一水两相流场进行了研究,初步揭示了液一液两相分离的现象,这都为进一步研究旋流器特性参数对分离效率的影响和旋流器的结构优化提供了参考。     

除油型水力旋流分离器压降研究

采用各向异性k ε模型,用有限差分法,以SIMPLE算法为基础对旋流器内流场进行了数值模拟,通过数值计算得到了液液水力旋流分离器溢流管直径对压力降的影响、压降与流量的关系。通过算例与实验校验,得出各向异性κ ε模型能够模拟旋流器内湍流流场。     

除油型水力旋流分离器压降研究

:采用各向异性k-ε模型,用有限差分法,以SIMPLE算法为基础对旋流器内流场进行了数值模拟。通过数值计算得到了在流量一定的情况下,随溢流比的增加,进料口与溢流口之间的压力降△Piu增大,进料口与底流出口之间的压力降△Pid几乎不变。△Piu与△Pid随进料流量的增大而增大,△Piu随溢流管孔径的减小而变大,△Pid几乎不变。通过算例与实验校验,得出各向异性k-ε模型能够模拟旋流器内湍流流场。     

液-液旋流器分流比特性系数研究

通过实验证明 :分流比特性系数的大小决定了溢流口、底流口含油浓度高低 ,影响了旋流器油水分离性能。对预分离旋流器 ,分流比特性系数的合理选择 ,尤其显得重要。     

CFD Study on the Effect of Hydrocyclone Structure on the Separation Efficiency of Fine Particles

Abstract

Effects of geometric structure parameters of 10 mm-diameter hydrocyclones on the particle separation efficiency are studied using computational fluid dynamics (CFD). The fluid velocity profiles and particle trajectories are simulated using RFLOW software with a standard isotropic k-ε turbulent model. The JIS standard CaCO₃-17 particles are adopted as a particulate sample in simulations and experiments. Comparing the simulated results with experimental data, a maximum deviation about 20% in partition curves occurs for 5–10 µm particles. However, fairly good agreements for the cut-size predictions and the fish-hook phenomenon are obtained. The simulated cut-size d ₅₀ is only 2 µm larger than that measured in experiments, while the value of d ₁₀₀ can be accurately predicted. An increase in overflow diameter or a decrease in underflow diameter leads to a lower separation efficiency but a clearer separation sharpness due to lower fluid underflow rate. A short-and-wide rectangular inlet is more efficient for particle separation than a tall-and-narrow one. An inclined inlet conduit plays an inessential role on the efficiency improvement but gains a 2 µm reduction in d ₁₀₀. Comparing the simulated results, the hydrocyclone used in the experiments of this study exhibits a higher separation sharpness than the Rietema type and a higher efficiency than the Bradley type based on the same operation capacity and hydrocyclone size.     

环流旋流器的结构与性能研究

以细沙和水的混合物作实验物系,分别对4种不同结构尺寸的旋流器进行了研究．测定了不同操作条件的压降和分离效率?实验结果表明,带分离柱的环流式旋流器压降最低,效率最高。由该旋流器的粒级效率曲线可以看出,直径小于5μm的颗粒,由于比较容易被大颗粒夹带分离,其分离效率比7．5μm左右颗粒高。     

一种新型水力旋流器的机理研究及设计

介绍了水力旋流器的工作原理,分析了水力旋流器内部流场和旋流器内颗粒的运动状态,在此基础上提出一种新型的水力旋流器-宽域水力旋流器,可同时分离重质和轻质固体颗粒物.并给出了该水力旋流器的结构设计参数标准.     

含油废水动态旋流分离技术研究

介绍了重力沉降法、浮选法、混凝法和电解法这些传统的含油废水处理方法的原理和优缺点,重点研究了动态旋流废水处理技术。设计了动态旋流器及其关键部件,并在此基础上搭建了含油废水动态旋流处理系统。研究发现,该系统在油水分离方面优势明显,在合理的转速范围内,能在非常宽的处理域内保持较高的分离效率。     

液-液水力旋流器两相湍动流数值模拟研究进展

对水力旋流器内的单相流场和液．液水力旋流器轻相浓度场两个方面的数值模拟研究进行了论述,通过分析国内外近二十年的重要研究成果,提出了今后液-液水力旋流器内两相湍流场数值研究的重点和发展方向。     

固-液-液三相水力旋流器内部固相颗粒受力分析研究

在进料浓度较低时,固相颗粒之间距离较大,相互之间的作用以及影响极微,颗粒的分离可以通过对其施加一个外力,将其往器壁方向推,这样就完成了固-液-液三相的分离。这个外即惯性离心力的大小很容易得到,但颗粒所受流体介质阻力则很难得到。文章文通过研究对对旋流器内部固相颗粒进行了受力分析并从理论上对细颗粒易受参数影响的原因进行了阐述。     

注气对油水分离水力旋流器流场影响模拟分析

采用雷诺应力湍流模型、混合模型和离散相模型对注气型油水分离水力旋流器进行数值模拟,得到其内部流场的速度分布和油滴粒子运动轨迹,分析对比了注气前后进口流量、分流比和充气量对分离效率的影响,数值计算结果与文献实验值进行了比较。结果表明,充气后流场速度增加,油滴粒子逃逸时间缩短,旋流器分离效率提高5%~10%,在一定条件下气浮对旋流分离起到强化作用。     

动态旋流分离技术研究进展

在对国内外技术文献广泛分析的基础上,结合研究实际,从动态旋流器的结构形式、结构参数等方面,较为深入地论述了动态旋流分离技术的研究进展.并对动态旋流分离技术的发展趋势作了简要分析.