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1.
为了深入探究W/O乳状液静电聚结过程中水滴间距对静电聚结特性的影响,本文在高压高频脉冲电场条件下,通过实验研究了水滴间距对水滴平均变形度及相互靠近速率的影响.结果表明:随着电场施加时间增加,水滴相互靠近,水滴的平均变形度随聚并时刻比的增大而增大;不同粒度条件下,随着水滴中心距比的增大,水滴的平均变形度呈现下降的趋势,水...  相似文献   

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3.
孟文 《化工设计》2020,30(6):9-11
某油田项目的聚结器介质中氯离子含量达135900 mg/L,设备面临严重的腐蚀危险.本文在分析氯离子腐蚀机理的基础上查阅相关文献并结合工作经验,给出了针对性的选材方案及具体防护措施.  相似文献   

4.
为优化聚结器结构,应用计算流体力学(CFD)方法,选用RNG k-ε模型,以SIMPLE算法为基础,对旋流式和蛇形管式聚结器在湍流状态下的流体流动场进行数值模拟,得出该两种结构聚结器的油相浓度分布云图。数值模拟结果表明,蛇形管式聚结器对油滴的兼并和聚结效果优于旋流式聚结器。  相似文献   

5.
介绍了氯乙烯深度脱水工艺及聚结器脱水原理,将高效聚结器应用于氯乙烯精馏工序中,实现了氯乙烯的深度脱水,满足了聚合工序的工艺要求,提高了产品的质量。  相似文献   

6.
推导了扩散相液滴运动轨迹模型和基本流模型,并优化了计算方法,同时,将分层二相流中的界面波用于聚结机理的研究。直接数值模拟结果表明:波数对液滴在界面处的平均速度、相对速度及绝对速度的影响不明显,但对液滴所受到的不平衡剪力有显著的影响;波数的变化将使液滴的旋转运动具有倾向性,较大的波数比较小的波数对液滴的运动方式影响显著;界面波的存在使得液滴的运动方式更具有复杂性,尽管流动状态为层流,界面波的存在也会使液滴所受到的不平衡剪力与液滴直径的关系曲线发生变化,其中既包含有随机因素也包含有确定性因素;波数对阿基米德数与雷诺数的关系曲线的影响也具有一定的随机因素,但这些曲线的偏移量变化不大,这将为理论计算和工程上的简化应用提供一个良好的平台。  相似文献   

7.
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。  相似文献   

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利用计算流体动力学(Computational Fluid Dynamics,CFD)软件Fluent,采用群体平衡模型(Population Balance Model,PBM),以常规双锥型液-液旋流分离器结构为基础,研究聚结器Ⅰ~Ⅵ(不同结构形式)对聚结性能的影响。分析了不同截面上油相体积分布、油相粒径分布及油相迹线分布等,对不同粒径聚结性能的影响,获取了不同结构形式聚结器出口粒径分布和变化规律。结果表明:油相在聚结器Ⅴ经聚结后出口粒径最大可以达到290μm,且含有粒径270、290μm的油相数量最多。同时在截面3,聚结器Ⅴ粒径最大,且整体看聚结器Ⅴ粒径大多集中在200μm,表明聚结器Ⅴ聚结效果最好。  相似文献   

9.
高压静电破乳中离散液滴的动力学分析   总被引:3,自引:1,他引:2  
张军  何宏舟 《化工学报》2013,64(6):2050-2057
考虑乳化液离散液滴的直径分布,对高压直流静电破乳过程中离散液滴的运动进行了理论模拟。模拟及实验结果表明,在高压静电作用下,离散滴液从一侧电极向另一侧电极运动。沿液滴运动方向,液滴浓度逐渐增大,并在电极附近达到最大。随着静电作用时间的延长,电极附近液滴浓度近似呈线性规律增大。在相同的作用时间内,高电压液滴浓度的增长幅度要更大。因此,尽可能提高施加电压要比单纯延长静电作用时间的破乳效果更好。此外,大的液滴运动速度更快,故对于离散相滴径较大的乳化液,破乳效率会更高。  相似文献   

10.
介绍了河南联创化工有限公司氯乙烯单体含水的除去方法,一期采用固碱干燥,二期采用高效聚结器,运行后,树脂粉的白度有了显著提高,热稳定性等更加稳定。  相似文献   

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Electrocoalescence has long been known for the separation of a water-in-oil emulsion. An associated challenge with electrocoalescers is the undesired noncoalescence and consequently chain formation of aqueous phase droplets. This leads to low separation efficiency and damage of electrical equipment. Recently Hasib et al. proposed an electric field modulated scheme that showed significant improvement in dehydration of water-in-oil emulsions. They investigated the range of modulation parameters when the scheme is most effective. The fundamental process in electrostatic dehydration of an emulsion is the interaction between a pair of water droplets. In the present study, two suspended aqueous drops in insulated oil experiments are compared for their behavior under unmodulated and modulated electric fields. Further, a model is developed and the experimental behavior under unmodulated and modulated electric fields is compared with numerical solutions. The model predicts the experimental observations accurately by balancing electrostatic, electrophoresis, dipolar, and resisting viscous drag forces, ignoring the end (bridge) effect during the contact. The study shows that the increase in the rate of dehydration of a water-in-oil emulsion under modulated electric fields with an increase in duty ratio and its near independence on the modulation time period can be explained by the two-drop studies. However, several other processes such as multidrop interactions as well as scavenging of fine droplets by charged droplets created as intermediates in the interaction of two droplets cannot be explained by the two-drop studies.  相似文献   

12.
静电粉末喷涂中一次上粉率浅析   总被引:1,自引:0,他引:1  
分析了静电粉末喷涂中影响一次上粉率的主要因素以及在应用中如何提高一次上粉率。  相似文献   

13.
摘要:为了使静电纺丝过程高效稳定,明确多射流喷头电场分布规律与控制策略,开展结构优化、减少电场抑制,提出了一种新的静电纺丝多射流喷头——错列喷头。从理论分析了多射流存在边缘现象的原因,开展单列、双列、错列喷头的电场仿真分析。结果表明,无论何种结构,随着喷头中的针头间距由15 mm增加到30 mm,边缘效应减弱而电场强度增加,但针头间距的增加必然导致射流密度降低;和单列喷头相比,双列喷头有增加射流密度的优势,是批量生产的最普遍方法,但其电场强度均低于单列喷头且边缘效应有所加强;错列喷头因针头间距的互补而在提高射流密度方面有一定的优势,电场强度和边缘效应均优于针头间距15 mm双列喷头而劣于针头间距30 mm喷头。总之,错列喷头在保证一定的射流密度条件下,可获得相对较高的电场强度。这为多射流静电纺丝过程的稳定和持续提供了技术保障,为后续多针头喷头规模化生产的设备制造提供了研究基础。  相似文献   

14.
海上油田电脱分离器结构设计研究   总被引:1,自引:0,他引:1  
作为原油净化处理的关键步骤,电脱分离效果的好坏直接决定原油能否达到深加工或销售的要求。对电脱分离器的机理和结构进行了详细分析,并针对海上油田的特殊工况,提出了设计海上油田电脱分离器时应考虑的因素和设计方法。  相似文献   

15.
高压脉冲电场中乳化油最佳破乳电场参数   总被引:1,自引:0,他引:1  
合理的电场参数是确保高压脉冲电场实现乳化油液高效破乳脱水的重要前提,目前关于电场参数的理论研究鲜有报道。通过建立乳化油液滴在高压脉冲电场中的振动动力学模型,研究液滴振动幅频特性,得到液滴共振频率及共振振幅。在此基础上,根据乳化油系统物性参数,结合液滴最大稳态拉伸变形条件,利用作图法可计算出乳化油最佳破乳电场频率与电场强度的值。实验结果表明,计算得到的最佳破乳电场参数能够实现乳化液滴高效结聚。因此,利用非线性振动动力学确定的乳化油最佳破乳电场参数是合理可靠的。  相似文献   

16.
静电强化乳液中油滴(纳米尺度)聚并过程(英文)   总被引:1,自引:0,他引:1       下载免费PDF全文
Oil droplets in nanometer scale which are dispersed in water cannot be separated easily.An attractive technique is carried out by electrical phenomena to demulsify oil in water emulsion.In this research,non-uniform electric field or dielectrophoresis(DEP) is applied to remove sunflower oil(which is dispersed in the water).Effects of temperature,time and voltage(using AC-electric field) were considered to get the highest DEP-force(Fdi) and the best results.The oil particles sizes with average of approximately 76 nm have been shown using a ZetaSizer Nano ZS,Model ZEN 1600(Malvern Instrument Ltd.).The maximum separation efficiency of 85% is obtained at the optimum temperature of 38 ℃ and voltage of 3000 V.  相似文献   

17.
    
Droplet dynamic response in low-viscosity fluid under a pulsed direct-current (DC) electric field and a sinusoidal electric field is investigated by experiments and numerical simulations. The coupled level set and volume of fluid method is employed to capture moving interface and the numerical method is validated by experimental results. This article focuses on the effects of waveform, frequency and initial phase on the dynamic response. The deformation period is identical with the electric period for the pulsed DC electric field but the deformation period is half of the electric period for the sinusoidal electric field. As the frequency increases, the maximum deformation degree Dmax first climbs steadily to a peak value, then decreases steeply and finally approaches an equilibrium value. The maximum Dmax appears at f = 50 Hz for the pulsed DC electric field and appears at f = 100 Hz for the sinusoidal electric field according to numerical results. These results are helpful for the optimization of electro-coalescence.  相似文献   

18.
    
The excessive electric field gives rise to droplet non-coalescence and droplet chains in the electric dehydrator, which severely deteriorates oil–water separation efficiency and even leads to short circuit. To reveal the underlying mechanism of droplet non-coalescence, dynamic behavior of two neutral droplets in silicone oil under a direct current electric field is investigated by using high-speed photography. The experimental results show that there exists a critical electric field strength above which two droplets will bounce off after the contact. The critical electric field strength of droplet non-coalescence is affected by the initial separation distance between droplets, the radius of droplet, and the surfactant concentration. Whether the non-coalescence behavior occurs in the electric field is determined by the competition of electric force and capillary force, which dominates the evolution of tiny connection channel.  相似文献   

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外加电场下气固流化床的数值模拟   总被引:1,自引:1,他引:0       下载免费PDF全文
工业流化床中通常存在显著的静电效应,会影响流化床的流体力学特性,并常常带来一定的安全隐患,而引入外加电场可以达到\"化害为利\"的作用。为了获知外加电场下流化床内的流体力学特性,本文采用CFD耦合静电模型及解耦求解的方式,研究了外加电场下气固流化床内的轴向电势分布和颗粒的运动规律。研究结果表明,传统流化床的轴向电势分布呈Z形,与实验结果一致,引入直流电场后,颗粒自身产生的电场正电势区域明显增大,而负电势区域也有小幅增大。直流电场可以使得壁面处小颗粒的聚集减少,但在床中心出现明显的颗粒聚集。在交流电场下,小颗粒在壁面处的分布比正常流化床时的稀疏。通过对颗粒自身产生电场的分析,发现近分布板区和料位区的电场方向不同,近分布板区的电场指向床中心,而料位区的电场指向壁面。  相似文献   

20.
梁继勇 《上海涂料》2011,49(9):49-50
分析了静电喷枪产生故障的原因。提出了一种快速判断静电喷枪空间电场的方法。讨论了这种方法的原理和使用中的注意事项。  相似文献   

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