高效复合聚结板式油水分离器的开发

通过对聚结板式油水分离器传质过程机理的研究,开发出能够强化油水分离过程的新型高效复合聚结板。复合聚结板的两表面分别具有良好的亲水和亲油性能,迎合了油水分离过程要求,从而使聚结板式油水分离器的分离效率提高25%,处理能力增加40%。文中还对复合聚结板式油水分离器的主要结构参数和操作参数进行了优化,为工程设计提供可靠的理论依据。     

高效复合聚结板式油水分离器数学模型

通过对油水分离过程中油滴在聚结板间浮升和在聚结板表面聚结的过程机理的研究,建立了关于聚结板式油水分离器的油水分离过程数学模型,求得分散相液滴分离所需的时间。该模型充分考虑了油水两相的物性以及两相分层流动对分离过程的影响。     

复合聚丙烯板在油水分离中的应用

采用化学改性处理的方法，使聚丙烯表面覆盖一层氧化薄膜，从而改善聚丙烯的亲水性。基于聚丙烯本身良好的亲油性，开发出两表面分别具有良好亲油、亲水性能的复合型聚丙烯板。这种复合型聚丙烯板应用于聚结板式油水分离器，迎合了油水分离机理，强化了油水分离过程。实验结果表明，复合聚丙烯聚结板使油水分离器的分离效率提高了25％，分离器的处理能力提高了40％。     

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。     

油水重力分离原理及聚结破乳机理初探

对油水重力分离的基本原理进行了阐述,并对油水乳状液聚结破乳机理进行了探讨。分析表明,从浅池原理和聚结原理入手,可对分离器的结构和聚结板的材料进行优化,以提高其流动特性以及分离性能;若有效地分离油水两相,必须施加外力场,使得坚固的界面膜削弱并破坏,促进其聚结破乳;应根据聚结破乳发生的条件对分离器的结构进行优化,以保证其具有优良的水力特性。     

聚结技术及其乳化油水分离性能

聚结分离是一种利用油、水两相对材料浸润性的不同而实现乳化液滴聚结长大并最终通过重力沉降实现油水分离的物理方法,这种方法结构可控性好、分离效率高、运行成本低,是乳化油水分离领域的研究热点。本文首先对聚结分离方法进行详细阐述,介绍了聚结分离原理和影响因素;总结了近年来国内外学者对聚结材料表面改性和修饰等方面的研究。通过调控聚结材料的表面具有特殊浸润性,可显著提高油水分离效率;系统介绍聚结分离器的分类及其应用。最后阐述了聚结分离技术在石油化工领域的应用。本文对聚结分离技术进行展望,指出可以进一步研究实际液滴聚结过程和分离效果影响因素,应深入研究分离器在乳化油水分离过程中液滴聚结行为、机理、控制机制将是研究的重点。     

双维弦波聚结板油水分离流场数值模拟

介绍了一种用于油水分离的双维弦波聚结板分离器,给出了计算模型和数值模拟方法。运用Fluent软件对4种不同尺寸的双维弦波聚结板流场进行了数值模拟。结果表明:双维弦波聚结板的波幅为10mm、周期为100mm、板间距为25mm时,分离效果最好。     

波纹板填料油水分离器及其计算方法

研制了1种新的脱除水中分散油滴的油水分离器,采用斜通道波纹板填料作为内部分离组件.由于液流在组件内的流动形态提供了频繁的油滴之间碰撞聚结和油滴在波纹板上粘附聚结机会,因而该油水分离器具有较高的分离效率.文中提出了油水分离过程的3个简化假定条件,在此基础上建立了波纹板组件内油水分离过程的数学模型,该模型能与实验结果相吻合.     

结构参数对聚并-旋流耦合油水分离器性能影响

为了探究结构参数对聚并-旋流耦合油水分离器性能的影响,基于水力聚结机理和旋流分离理论,通过计算流体动力学分析方法,以聚并-旋流耦合油水分离器结构参数为研究对象,油水分离效率为指标,开展多场耦合油水分离装置的结构参数优化设计。针对不同螺旋流道长度和聚结管段长下的聚并-旋流耦合油水分离器结构模型,进行数值模拟研究验证,探究不同结构参数下模型的分离性能。结果表明,在聚并器螺旋流道长度L₂=100 mm、聚结管段长L₃=350 mm时分离效率达到最高。选取不同入口流量和分流比对聚并-旋流耦合油水分离器最优结构的不同工况下的分离性能进行分析,当入口流量Q=8m³/h、分流比F=40%时,油水分离效率达到最高值93.62%。     

炼厂污油静电聚结脱水研究

针对目前炼油厂污油乳化严重、高含水、高含盐、性质复杂难处理的特点,在现有的静电聚结理论研究基础之上,采用绝缘复合电极装置,开展静电聚结污油脱水研究。通过静电聚结脱水试验考察了绝缘电极杆长度、电压、停留时间、温度、注水量等因素对污油脱水效率的影响。试验结果表明,对某炼厂含水率为15.36%的污油,进行一级电脱分离,即可满足污油脱后含水率小于0.5%的回炼指标,脱水效率可达97%以上。     

Vergleich des Koaleszenzverhaltens ruhender und umströmter Wasser‐in‐Öl‐in‐Wasser‐Einzeltropfen

Phase inversion of a water‐in‐oil emulsion to a water‐in‐oil‐in‐water double emulsion is practically used for liquid/liquid separation. For successful separation in the water leg the coalescence of the internal droplets with the surrounding continuous water phase is decisive. The determination of this coalescence phenomenon is applied for the process design. Therefore, single water‐in‐oil‐in‐water drops are investigated under static and dynamic conditions by means of high speed imaging. The influence of physical and geometrical parameters on the coalescence time and partial coalescence is determined.     

疏水性油水分离膜及其过程研究进展

油水分离是治理含油废水和含水油液的重要工业过程。本文概括了疏水性油水分离膜的类型与制备方法,包括常规分离膜和高度疏水/超亲油分离膜。前者为常规微滤、超滤及纳滤过程用膜;后者由构筑高度疏水（水滴接触角≥120°）表面方法得到,形式有金属网膜、纤维膜、滤纸、复合膜及不对称膜,其为制备耐污染的疏水性油水分离膜提供了新思路。指出了疏水性膜用于油水分离的过程原理及应用现状：含油废水除油中,疏水性膜可实现O/W乳液的破乳、粗粒化油滴、滤除油滴及吸附油分子几方面的功能;含水油液除水中,膜被用来截留水滴,可直接得到净化的油品。最后,指出了其过程规模化应用前尚需解决的重要问题,特别是高度疏水/超亲油分离膜的制备、相关过程研究的深入及其规模化试验等方面需着力加强。     

聚结分离过程的机理、方法及应用

随着对环境保护的要求越来越严格,对于互不相溶流体体系中分散相的处理变得越来越重要,对它的分离变得也越来越困难,这就要求聚结技术的发展。本文对在重力场中的聚结、电场聚结、超声波聚结、旋流聚结等技术的机理、方法及其应用进行了介绍。     

Flocculation and Separation of Oil Droplets in Ultrasonic Standing Wave Field

A new method for breaking oil in water emulsion based on flocculation of droplets in high intensity ultrasonic standing wave field was developed in this study and the effect of initial droplets size, type of disperse phase as well as the time of sonication and the height of emulsion in the chamber on the extent of interdroplet interactions were investigated. The results showed that type of disperse phase affects the efficiency of separation process through controlling the initial size of droplets. For the two types of disperse phase in question the efficiency of separation was calculated to be 42.7% for canola oil/water emulsion and 37% for sunflower oil/water emulsion. The time of sonication was found to have a positive contribution to the percent of flocculation and coalescence, so that the largest aggregates were formed after 30 minutes treatment. Also, the optimum height of emulsion in the treatment chamber was determined to be λ/4 at which the strongest flocculation and highest percent of coalescence took place. Increasing the height of emulsion did not significantly influence the course of aggregation and separation.     

Gravity induced coalescence in emulsions with high volume fractions of dispersed phase in the presence of surfactants

We report studies on the effect of volume fraction and surfactant concentration on the kinetics of destabilization of emulsions under the influence of gravity. Model oil‐in‐water emulsions, designed to mimic crude oil–water emulsions, were prepared with varying volume fractions of dispersed oil but nearly identical normalized initial drop size distributions. The gravity separation process was observed by periodically withdrawing samples, and examining the droplet size distribution under the microscope. Experiments were performed for three volume fractions of dispersed phase and two surfactant concentrations (0.4 and 1.6% by weight). At higher oil fractions (20%) and a lower surfactant concentration (0.4%), it was observed that although the rate of coalescence increased, the actual oil separation was delayed. At higher surfactant concentrations (1.6%), the dominant factor in suppressing destabilization is the rate of drop to interface coalescence. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4379–4389, 2017     

Water-in-triglyceride oil emulsions. Effect of fat crystals on stability

The influence of low concentrations (0.1-5%) of fat crystals on the stability of water-in-soybean oil emulsions was examined by light scattering and sedimentation experiments. Both the initial flocculation/coalescence rate and long-term stability against water separation were determined. The initial flocculation/coalescence rate increased upon addition of small amounts of fat crystals. When the crystal concentration was increased above a critical concentration (specific to a system), a decrease in the flocculation/coalescence rate occurred. The increased flocculation/coalescence rate is likely the effect of bridging of water droplets by fat crystals. Fat crystal wetting by water is an important criterion for this phenomenon to occur. Emulsion stabilization for crystal concentrations above critical is caused by a mechanical screening of water droplets. The presence of considerable amounts of crystals in oil also lowered the density difference between droplet and medium, and enhanced viscosity. The degree of increase in viscosity depended upon the emulsifier. Both a decrease in density difference and an increase in viscosity play a role in hindering flocculation/coalescence of droplets. In long-term studies of water separation, all concentrations of fat crystals stabilized the water-in-oil emulsions. The droplet size of these emulsions increased until the critical droplet size was approached where the screening effect of crystals on the droplets no longer stabilized the emulsions. The stabilizing effect for emulsions with monoolein was continuously improved by increasing the amount of crystals up to 5%. For lecithin-stabilized emulsions, an optimal effect was achieved for fact crystal concentrations of 1–2%.     

玻璃纤维聚结器脱除油中乳化水

随着油水分离技术的进步及新材料的开发,聚结法脱除油中乳化水的技术得以实现。本文采用亲水性玻璃纤维作为聚结元件,脱除白油中的乳化水（d₉₅=10μm）。通过实验考察聚结器中进料的表观流速（5~30m/h）、油品初始含水量（500~4000μL/L）、聚结器床层厚度（100~400mm）和玻璃纤维的孔隙率（0.80~0.95）对聚结分离效率的影响,并应用响应面法对各变量之间的协同效应进行分析,确定最佳操作条件,分析该条件下的粒级分离效率。实验结果显示,当表观流速为14m/h、初始含水量为1278μL/L、床层厚度为275mm和孔隙率为0.85时,分离效率最高,为95.18%。结果与响应面预测值（95.02%）相比,相对误差仅为0.17%,表明回归模型的可靠性高和实验的重现性较好。进出口粒径的分析表明聚结器的分离效果随水滴粒径的增加而提高,有效分离粒径>5μm。本文研究结果对采用玻璃纤维为聚结元件,分离密度差较大的成品油中乳化水的聚结器选型及操作参数设计具有实际应用价值。     

Enhanced coalescence separation of oil-in-water emulsions using electrospun PVDF nanofibers

A novel and high-efficiency coalescence membrane enhanced by nano-sized polyvinylidene fluoride(PVDF) nanofibers based on polyester (PET) substrate was fabricated using electrospinning method.The properties of the electrospun nanofibers such as roughness and surface morphology greatly affected the oil droplet interception efficiency and surface wettability of the membrane.A series of coalescence units were prepared with different layers of nanofibrous membrane and the separation efficiencies at dif-ferent initial concentrations,flow rates,and oil types were tested.It is very interesting that the obtained nanofibrous membrane exhibited superoleophilicity in air but poor oleophilicity under water,which was beneficial to the coalescence process.The coalescence unit with four membrane layers had excellent per-formances under different initial concentrations and flow rates.The separation efficiency of the 4-layers unit remained above 98.2％ when the initial concentration reached up to 2000 mg·L-1.Furthermore,the unit also exhibited good performance with the increasing oil density and viscosity,which is promising for large-scale oil wastewater treatment.