超重力水力聚结分离器流场分析与性能评估

采用离散相模型以脱油型水力旋流器为研究对象,分析了不同粒径油滴粒子在旋流场内的运移轨迹,得出随着粒径的增大旋流器的粒级效率逐渐升高。基于油滴运移轨迹设计了一种水力聚结旋流分离装置,可在旋流分离前端通过水力聚结使小颗粒油滴聚并成大颗粒油滴,进而增强旋流分离性能。开展室内试验对水力聚结分离器的分离性能和适用性进行验证。结果表明:粒径在100～900μm范围内随着油滴粒径的逐渐增大,旋流分离效率逐渐升高;水力聚结器可在油滴进入旋流分离器前使油滴碰撞聚结致使离散相油滴粒径分布增大,从而提高旋流器分离效率,其最佳入口进液量在4. 12m~3/h左右,最佳分流比为20%。     

高含硫天然气三相分离器分离性能实验研究

通过应用旋流三相分离方法,以缩尺工艺样机为实验模型进行实验,通过实验测定发现,高含硫天然气液相分离效率在90％左右,固相分离效率在86％左右,并且随着入口流量的增大,分离效率呈增大趋势,气相出口检测到的颗粒数较少,说明流体经过三相分离器,可以脱除绝大部分粒径10μm以上的液固相颗粒,分离效果显著.     

含聚结构件油水分离器性能研究

由沉降和聚结机理可知选取适当的聚结构件可增加油水乳状液的粒径,加快沉降速度,从而提高分离器性能.今设计了一种含聚结构件的分离器,在长为1800 mm,内径为384 mm的重力式分离器内安装入口构件和聚结板,通过测量不同流速和工况条件下四种聚结板对油水乳状液的粒径质量分离效率,研究分离器性能.结果表明,倒T型入口构件可有效减少分离器流场中的回流和二次涡流,还引入了重力消能和水洗作用.聚结板可显著提高油水分离效率,在流量较大的时候,聚结板分离效果下降,出现对粒径选择性的单一分离作用.聚结板的结构和材质对液滴的聚结沉降影响很大,应根据工况和处理条件进行合理选择.     

重力分离器聚结构件数值模拟及优化研究

使用Fluent数值模拟软件,采用标准k-ε湍流模型和多项混合算法对不同入口分散相粒径和不同构造聚结板的分离器内部流场进行了三维数值模拟,对比通过聚结板前后油水浓度分布以确定分离器有效处理分散相颗粒的粒径范围;同时在尺寸为384mm×20mm×1800mm的分离器上更换4种不同材料与流道形状的聚结板进行了分离特性研究,得出了影响聚结板分离特性的因素和处理分散相粒径的范围,选出适于本分离器的聚结板;通过对比实验数据评价不同聚结板下分离器的聚结分离效率,提出了不同工况下选取聚结构件的依据。     

EII型多管旋风分离器分离性能的试验研究

为了系统评价EII型旋风分离器的分离性能,探究了入口气速为6～20.5m/s,入口颗粒质量浓度为8.6～17.5g/m~3时,多管旋风分离器的分离效率和压降。结果表明:多管旋风分离器的分离效率随入口气速和入口颗粒质量浓度的增大而出现先升高后下降的趋势,多管旋风分离器的压降随入口气速的增大而增大。在相同实验条件下,与单个旋风子相比,多管旋风分离器的压降升高幅度为20%～25%,分离效率下降不大于2%,具有很好的细粉尘捕集能力。     

天然气聚结过滤器气液分离性能的实验研究

为了系统地评价天然气聚结过滤器的气液分离性能,采用两种加入液滴方式,获得较大范围的液滴粒径分布,液滴中位粒径分别为8.7、40.0μm,在流量为94~220m3/h范围内进行实验研究,并通过Winner318B激光粒度仪对出口粒径进行在线测量。实验结果表明:压降会随加液时间发生变化,液滴粒径对分离效率的影响显著;当流量为94~182m3/h、入口液体浓度为30~75g/m3时,气液分离效率随着气体流量和入口液体浓度的增加而增大,当流量超过220m3/h时,分离效率迅速降低;分离器出口处粒径大于8μm的液滴基本除尽。     

含油污水旋流分离器性能研究

对油水分离用水力旋流分离器的分离性能和压力降进行了实验研究,分别考察了进料流量,进料含油量,油滴聚结器对分离效率的影响.同时,考察了进料流量,溢流比,溢流管直径对旋流分离器的压力降的影响.     

天然气净化用多管旋风分离器的分离性能

为了系统评价天然气净化用多管旋风分离器的分离性能,在线测量了入口气速6~24 m/s、入口颗粒浓度30~2000 mg/m3范围内多管旋风分离器的分离效率和分级效率. 结果表明,多管旋风分离器的分离效率和分级效率都随入口气速和入口颗粒浓度增大而提高. 与单管旋风分离器相比,在相同实验条件下,多管旋风分离器的分离效率下降2%~15%;单管旋风分离器基本能除净粒径大于10 mm的颗粒,而多管旋风分离器只能去除15 mm以上的颗粒. 多管旋风分离器的压降主要是内部单管旋风分离器的压降,占整个压降的80%~90%.     

呼图壁储气库低温分离器的应用

新疆油田呼图壁储气库工程对低温分离器结构进行了优化改造,该分离器与卧式的低温分离器相比具有占地面积小、储液段的液位控制平稳等优点。其主要构成元件为:气体旋流器;降液旋流器;丝网捕雾器。通过对旋流元件实验发现:随着流量的增加,旋流子分离效率增大;当流量为8913m3/d时,出口颗粒中径粒在3μm左右。该低温分离器具有分离效率高、体积小、成本低、压降小、噪音小等特点,具有很强的推广应用价值。     

旋风分离器分离性能的数值模拟与分析

以XLPB-5.0和XCX-5.0两种旋风分离器为原型,采用CFD软件对这两种旋风分离器进行了流场与分离效率的数值模拟,初步探讨了入口蜗壳形式与芯管结构对分离效率的影响。模拟结果显示:旋风分离器内流场呈各向异性分布特点,切向速度是影响分离效率的首要因素,径向速度的存在会造成"流场短路"现象,使轴向速度呈不对称分布,导致分离效率的降低。轴向速度与径向速度的共同作用促使颗粒在旋风分离器内做螺旋运动;XLPB-5.0和XCX-5.0的分离效率分别为92.55%和94.96%,与实验结果基本吻合,且不同芯管参数下XCX型的分离效率比XLPB型高;螺旋式入口蜗壳(XCX-5.0型)对旋风分离器上部流场的影响相比直流式入口蜗壳(XLPB-5.0型)复杂;对于两种旋风分离器,随着芯管直径的增大,分离效率逐渐变小;随着芯管深度的增大,分离效率先增大后减小。     

Analytical Approach for Calculating the Separation Efficiency of Uniflow Cyclones

An approach for calculating the separation efficiency of uniflow cyclones for the separation of solid particles from gases is proposed. The analytical model is based on an equilibrium orbit concept, similar to that used in the Barth‐Muschelknautz model for conventional reverse‐flow cyclones, which has been proven to be successful for designing and calculating cyclones in a wide range of industrial applications. The proposed model takes into account the special flow pattern of uniflow cyclones, which differs substantially from that in reverse‐flow cyclones. The model provides correct dependencies of the separation efficiency on the main geometry and operation data of low‐loaded uniflow cyclones. Applying the calculation method to uniflow cyclones operated in test facilities indicates good agreement with experimental data.     

Comparing Efficiency per Volume of Uniflow Cyclones and Standard Cyclones

A competitive alternative to the standard reverse flow cyclone for gas-solids separation is the uniflow cyclone. Gas and particles passing through it in only one direction, allowing a cost-effective usage in space limited applications. Comprehensive studies of uniflow cyclones have strongly improved their understanding and led to approved design criteria and calculation methods. Here it is shown that uniflow cyclones can achieve higher efficiencies per volume with a low pressure drop than standard cyclones.     

Development of a new high‐efficiency simple structure cyclone

A novel uniflow cyclone design was evaluated using three prototype cyclones. For the first two, the efficiency and Euler number were determined using airborne solid particles with a number mean diameter of 12.5 µm. Then a larger scale prototype based on the optimized geometry was compared with an existing conventional high efficiency cyclone and a vane‐induced uniflow cyclone, using mineral oil droplets with a number mean diameter of 8.9 µm. Both sets of experiments showed that the newly designed cyclone had a higher efficiency at a higher pressure requirement, in addition to the feature of a small footprint.     

Study of the gas circulation patterns in a uniflow cyclone

A uniflow cyclone is being studied to achieve the separation of hot solids from the gaseous products of ultra-rapid fluidized (URF) processes. An experimental method with hot wire probes was developed to study the gas flow around the gas outlet, where the solids exit. The vortex penetration in the solids exit could be determined. The presence of solids greatly reduced the vortex penetration in the uniflow cyclone. Restricting gas circulation around the gas outlet dramatically impaired the cyclone collection efficiency. Therefore, good cyclone performance requires a proper design below the gas outlet.     

一种新型旁路式直流旋风分离器的性能研究

针对传统的直流旋风分离器分离效率低的问题,提出了一种新型旁路式直流旋风分离器。通过模型试验,对比分析了传统的、旁路式和带稳流器的旁路式等三种直流旋风分离器的性能。结果表明,采用旁路和稳流器可显著提高直流旋风分离器的分离效率。进而又通过数值模拟的方法,研究了其内部流场,分析了旁路和稳流器提高直流旋风分离器效率的流体力学机理。     

PSC100型旋风单管多相分离性能的实验研究

为研究流动参数对多相分离性能的影响,选用PSC100型旋风单管在常温常压下进行性能实验研究。结果表明:在气固液三相分离实验中,液相和固相分离效率比单独的气液、气固两相实验中液相和固相的分离效率分别增加1%、5%;液相分离效率受固相进料浓度的影响不大,固相分离效率受固相进料浓度的影响较大;在气液分离实验中,分离效率随入口流量的增大出现一个极大值,为99.6%。     

Analysis of particle trajectories in a quick-contact cyclone reactor using a discrete phase model

The Eulerian–Lagrangian approach with a discrete phase model (DPM) is used to investigate the motion trajectories of the particles at the range of 1–50 μm in the quick-contact cyclone reactor, in which the cracking reactions and the separations of catalysts and products can occur respectively and simultaneously. The results show that the typical motion trajectories of the particles in the quick-contact cyclone reactor can be described as three types: trapping, escaping and dust ring. The first typical motion of particles corresponds to the particles successfully separated from the gas flow, while the other two types can lead to more coking and erosion in the reactor. Moreover, a pre-vortex flow is observed in the mixing-reaction chamber. Additionally, the grade separation efficiency of each particle size is also obtained by counting the numbers of escaping and capturing particles. The particles with diameter larger than 10 μm are separated completely from the gas. The reactor also has a strong capability to trap the particles of small diameters (5 μm <d_p<10 μm). Both results indicate that the separation efficiency of the reactor has met the requirement as a primary separator. Compared with the experimental results, the separation efficiency in the simulated method is higher than 98% with errors of no more than 1.31%. It is illustrated that separation efficiency of the reactor can be predicted by CFD simulation.     

Numerical and Experimental Study on a New Separation Device for Gas-Solid Two-Phase Flows

A novel separation device is designed to separate solid particles from the high-temperature, high-pressure dusty gas based on oblique shock wave theory. Two-dimensional numerical simulations and a series of experiments of the separation of the supersonic gas-solid two-phase flow are carried out. The aim is to validate the conditions for realizing the gas dedusting and to study the performance of the separation device. It is found that the gas dedusting can be realized only when the physical interface which basically overlaps the geometrical interface are stable and the design flow velocities at the dust-carrying and dust-absorbing nozzles are close to each other. Besides, the experimental results show that 57.83%～67.28% particles with a sauter average diameter of 9.84 µm can be separated by the experimental device. 75.73%～80.15% particles with diameters above 8.31 µm and 96%～100% particles with diameters above 15 µm can also be separated. Larger particles correspond to higher separation efficiency. The same conclusions are also drawn from the numerical simulation results. The study indicates that the present method for the separation of gas-solid two-phase flow is feasible and highly efficient.     

Separation performance of an 8 mm mini-hydrocyclone and its application to the treatment of rice starch wastewater

ABSTRACT

The rice starch particles are difficult to separate from starch suspensions for its fine diameter. In this work, an 8 mm mini-hydrocyclone is designed, and its separation performance and potential for the treatment of rice starch wastewater is investigated. The capacities, total separation efficiencies of an 8 mm mini-hydrocyclone and a 10 mm mini-hydrocyclone are compared. The experimental results reveal that the total separation efficiency of the 8 mm mini-hydrocyclone is approximately 13% higher than that of the 10 mm mini-hydrocyclone. A total separation efficiency of 92.1% was obtained using a two-stage hydrocyclone separation process comprising two 8 mm mini-hydrocyclones connected in series. The research findings can be utilized to efficiently treat the rice starch wastewater.