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乳状液膜旋流静电综合力场连续破乳器研究 总被引:5,自引:0,他引:5
研究了乳状液旋流、脉冲高压静电综合力场对连续破乳的影响,考察了影响乳状液破乳的主要因素:并对破乳机理进行了探讨。结果表明,乳状液在高压静电场中产生旋流运动,从而使乳状液既受到静电场的静电作用而极化,又受到旋流剪切力的作用,在离心力和静电力的综合作用下实现连续破乳。而且该破乳器存在最佳的破乳电压和破乳频率,在油内比为2:1时,破乳效果较佳。 相似文献
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归纳了近年来对原油乳状液破乳机理和破乳方法的研究进展,介绍了各种方法的特点、破乳机理和发展现状,对今后乳状液破乳工作的发展提出了建议。 相似文献
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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
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稠油在热采高温作用下,容易在油层中发生乳化行为,形成稳定的油包水乳状液,给地面产出液处理流程造成一定的负担。通过分析热采放喷后产出液的含水率为28%、脱水原油的黏度为2 300 mPa·s、胶质与沥青质含量和为24.33%,从醇类、酚醛树脂类、多烯多胺类、复配类的防乳破乳剂中优选出防乳破乳剂PEC-12,幵分析了破乳温度、防乳破乳剂浓度、乳状液含水率对PEC-12防乳破乳剂破乳效果的影响。结果表明,随着破乳温度从50℃升高至80℃,防乳破乳剂的破乳率从44.6%逐渐升至98.2%。防乳破乳剂最经济有效的浓度为200ppm。乳状液中含水率从20%增至40%时,防乳破乳剂的脱水率从62.5%增至93.8%。矿场试验表明,在注热过程中添加防乳破乳剂是一种能有效抑制稠油反相乳化的有效措施,添加PEC-12防乳破乳剂后,地面处理流程显示油包水乳状液总量降低80%,稠油乳状液破乳效果好,处理负担明显减轻,同时跟地面产出液破乳剂发生了协同破乳作用,使处理后的污水中含油量达到设计要求,满足回注地层的水质要求。 相似文献
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<正>液膜分离技术中最关键的一步是破乳,它决定着液膜分离的效率与效果。黎念之采用绝缘电极交流电破乳’‘’,Bailes”‘、严忠等’‘’从改变电源和电极类型等方面开展研究,使电破乳技术成为目前液膜分离过程最有效的破乳方法。但实践证明,含水量较高的W们型乳状液液膜体系,常因加不上电压而使破乳难以进行。而且电破乳时,常常在油水界面形成含水量很高的絮状物(通称sPonge),其中含有大量被提取物,直接影响了液膜的分离效率。为此,作者开发了研磨破乳技术 相似文献
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《Chemical engineering journal (Lausanne, Switzerland : 1996)》2002,85(2-3):357-368
The technology for electrostatic enhancement of coalescence of water droplets in oil emulsions is critically reviewed. Historically, the electrostatic coalescer was invented for the petroleum-related industries in California [US Patent 987 115 (1911)]. Nowadays, this technology is generally considered for the separation of an aqueous phase dispersed in a dielectric oil phase with a significantly lower dielectric constant than that of the dispersed phase. Various designs have been introduced, with most using alternating current (AC) electric fields with mains frequency (50 or 60 Hz). The direct current (DC) electric field has been less common in the past as compared to the AC. In 1981, the concept of pulsed DC electric fields was introduced, together with insulated electrodes [Trans. IChemE 59 (1981) 229–237; UK Patent 217 1031A (1986)]. Since then, this has become more common in the electrocoalescence technology. Pulsed DC and AC fields are especially useful, when the aqueous phase content of the emulsion is high, to prevent short-circuiting between the pair of electrodes. Processing of oil from old wells is a good example, where the volumetric water content could vary significantly. Reported work by some workers indicates the existence of an optimum frequency, which depends on the electrode coating material, its thickness and the liquid emulsion composition. This is however, a contentious issue which has not been completely resolved. The characteristics and geometry of the electrode system (generally cylindrical or plate) influence the performance of the electrostatic coalescer, and are closely related to the type of the applied electric field and the emulsion used. There are basically two types of electrode: uninsulated electrode and insulated electrode. Combination of electrocoalescence and mechanical separation (e.g., centrifugal force) has also been introduced. Heating and the addition of chemicals have been shown to further enhance the electrocoalescence of water droplets. Other methods that can be combined with the electrical treatment are filtration, methods employing high pressure and temperature, and mixing. This review paper also looks at some of the current specific industrial applications using the electrocoalescence technology. Besides the oil and petroleum industries, this technology has potential applications in the edible oil industries such as palm oil, sunflower oil and vegetable oil processing. Most of the currently available equipment is very big and bulky, having a large inventory of emulsion. Therefore, we see the future trend for new developments to be in the direction of inventing small portable devices, incorporating features such as optimum electric fields and combined electrical and centrifugal forces to further enhance the separation of water-in-oil emulsions. Furthermore, a better understanding of the fundamentals of electrocoalescence will enable a better design of the geometry of the electrodes, of the flow field with respect to the electric fields, the type of dispersion used and the type of the applied electric field. 相似文献
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传统电脱水器采用裸电极,含水率较高时在高强电场作用下容易发生击穿现象,今设计了包覆绝缘层的高压电极并加工了新型静电聚结器,可有效避免击穿现象的发生。采用水/原油乳状液为实验介质,并利用显微高速摄像系统结合图像处理技术对水滴的聚结规律进行了观察和分析,探索了电场强度、流量、含水率等因素对水滴聚结特性的影响。结果表明:包覆绝缘层的高压电极可有效防止电击穿现象的发生,增加电场强度有助于油水分离,但高于临界场强后容易导致液滴破碎;含水率为10%、20%、30%时,最优电场强度不同,分别是372、320和204 kV m 1;含水率10%和30%乳化物液滴粒径增大倍数明显大于含水率20%的工况;电场作用时间影响液滴聚结效果,高强电场在低流量下具有很显著的作用;随着流量的增加电场作用降低,但高强电场在高流量下依然使液滴粒径明显增大。 相似文献
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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
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采用静电雾化方法进行了W/O玉米油乳化液制备的实验研究,在雾化流量2.8~15 mL/min、电极施加电压5.2~11 kV的条件下,用Winner99颗粒图像测试仪测试了所制乳化液的离散相滴径,分析了施加电压及雾化流量对平均滴径及滴径分布的影响. 结果表明,静电雾化法可制备离散相滴径比搅拌法更均匀的乳化液,离散液滴平均滴径约为28 mm且绝大多数液滴直径为20~40 mm,其稳定性明显优于搅拌法所制乳化液. 乳化液离散相滴径与施加电压及雾化流量密切相关,电压增大、雾化电流增大,乳化液离散相滴径急剧减小,滴径分布变窄. 流量增大,单位时间内液滴携带及输运的电量增大,故雾化电流增大;但液滴荷积比随流量增大而减小,故滴径变大,滴径分布变宽. 高电压、低流量有助于获得稳定性更好的乳化液. 相似文献
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通过控制不同单体的加料速度,采取递变加料的方式,合成了具有类似“洋葱”结构的梯度乳液聚合物,并对影响聚合物梯度结构的相关因素进行了探讨,测试了梯度乳液聚合物成膜后豹力学性能。实验发现,加料速度和乳化剂的用量都会影响到聚合物梯度构造的形成,梯度聚合物的成膜物在抗拉伸强度和断裂伸长率方面都有不错的表现,具备良好的力学性能。 相似文献
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依据乳化炸药微观结构特点,通过水溶法测量游离态硝酸铵含量,判定乳化炸药的乳化效果,并且依据乳化炸药使用质量要求,通过测量成品炸药密度,判定乳化炸药工程使用质量,两者综合判定检验大规格乳化炸药的质量。通过与GB18095-2000标准检验和高低温循环试验比对,验证了该新方法能够有效检验大规格乳化炸药的使用质量和储存期。 相似文献
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《分离科学与技术》2012,47(10-11):1329-1340
Abstract The action of an electric field on an emulsion produced effects like drop disintegration and promoted coalescence. High and low field intensities modify droplet displacements due to electrostatic forces. In this investigation a water-in-oil type of emulsion was prepared using distilled water and soap as the surfactant. After mixing, these emulsions were separated under an applied direct current high voltage electric field at a fixed 2.09 kV applied output voltage across the system. The time of coalescence, upper plate position, mixing time, and dispersion/coalesced phase volume interface are the parameters considered to influence the coalescence parameter and dispersion band hold-up. The results show that the prepared emulsion can be separated back into its bulk phases by using electric fields. The degree of separation depends on the applied voltage. 相似文献
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一种可自交联有机硅乳液的制备 总被引:2,自引:0,他引:2
通过苯乙烯乳液聚合成种子,再在种子核外生成苯乙烯与甲基丙烯酸-3-三甲氧基硅丙酯(MPS)的共聚物,形成核-壳型乳胶粒,从而得到自交联型的水分散涂料。这种含硅涂料能在涂覆过程中发生自交联反应,不仅有效提高了涂层的光滑度、耐候性和耐沾污性,更减少了可挥发性有机溶剂(VOC)的排放量。通过透射电子显微镜(TEM)和动态光散射仪(DLS)研究了反应条件对所得乳液型涂料稳定性的影响。发现在MPS参与的乳液共聚合过程中,需选用离子型乳化剂,保持介质pH值在7左右,控制MPS浓度来提高乳液稳定性,防止乳胶粒聚并。并用红外光谱(FTIR)和^29Si固态核磁谱(NMR)表征了所得聚合物的微结构。 相似文献