泡沫发生器内气液不稳定流动规律研究

泡沫发生器是冲砂洗井的主要应用设备,对于泡沫发生器结构的设计,目前国内外学者设计的泡沫发生器多用于煤矿井下,结合油田实际生产情况特点,在同心管式泡沫发生器结构上进行设计优化,建立泡沫发生器实验模型,利用PIV技术系统来研究泡沫发生器内的液体不同表观速度、气体的不同表观速度对泡沫液流的影响。     

射流式泡沫发生器内部流场的数值模拟

通过数值模拟方法,运用FLUENT模拟射流式泡沫发生器内部气液两相流流场运动规律,并分析不同气液比对泡沫发生器内部气相体积分布影响。结果显示,不同气液比情况下,射流式泡沫发生器内气液两相流的静压和速度分布表现不同。该成果为疏松砂岩油藏以及油田冲砂洗井作业提供指导,为后续射流式泡沫发生器结构设计提供理论依据。     

苯酚储罐泡沫发生器的优化应用

针对苯酚储罐上泡沫发生器内存在严重的结晶问题,对泡沫发生器进行优化升级,结果表明采用蒸汽伴热的方式对泡沫发生器进行改造后,效果良好,提高了苯酚储罐运行的稳定性.     

高效泡沫发生器流动规律研究与结构优选

本文对比同工况下不同泡沫发生器的处理效果,得出最佳的结构,再对比不同工况下试验结果,确定最优参数。模拟结果表明:气相入口压力的改变相比液相对发生器内部流场影响小;泡沫体积增大,不论是气相入口压力,还是液相流速的变化,泡沫体积大的其泡沫衰减时间均更长。     

一种污染土壤异味高效阻隔系统的开发与应用

介绍了一种污染土壤异味快速、高效阻隔系统,该系统集泡沫发生器、发电、供气、药剂储存及自动化控制等功能于一体;其特殊设计的泡沫发生器,强化了发泡过程,所发泡沫更细腻、均匀、稳定,喷洒范围更广;优选的配套设备保证了发泡过程的平稳性和连续性。     

泡沫酸化在江苏油田陈3平1井的应用

本文介绍了江苏油田压裂队的NPU900-35型制氮注氮设备和胜利油田的泡沫发生器在陈3平1井开展氮气泡沫酸化工艺研究施工,得到了很好的应用,取得了明显的增产效果和经济效益。     

井下泡沫发生器内流场数值模拟及结构优选

井下泡沫发生器的应用可以避免泡沫从地面注入井下过程中的消泡问题,改善泡沫驱油的效果.但是由于井下径向空间有限,其内部泡沫发生结构的设计受到诸多因素的限制.应用Fluent软件,对射流挡板式、螺旋挡板式和螺旋搅拌式3种不同的井下泡沫发生结构进行了内部流场的数值模拟,对比分析了流场的迹线、速度分布、气液相分布和压力分布情况...     

消防泡沫在液体燃料上铺展性能研究综述

泡沫灭火剂是扑灭液体火最有效的灭火剂之一。泡沫对不同的燃烧液体有不同的灭火效果。虽然灭火效果与燃料的闪点密切相关，但泡沫覆盖面积是最关键的因素。对泡沫铺展过程的研究将为设计灭火设备和改进消防战术提供有效的理论依据。研究泡沫灭火剂在燃油表面灭火过程中的铺展覆盖情况至关重要。本文对泡沫灭火剂在易燃液体上的铺展研究现状进行梳理，重点分析目前已有的实验研究和理论模型。     

纳米颗粒CO2泡沫体系稳定性机理研究

近年来纳米颗粒/表面活性剂复合体系提高CO2泡沫驱性效果明显,其稳定泡沫的机理越来越受到关注。通过研究不同纳米颗粒体系泡沫的ZETA电位、接触角,深入的研究泡沫稳定的机理,为泡沫稳定剂的选取提供了一个新的筛选斱式。研究结果表明:泡沫体系的ZETA电位与接触角共同决定了泡沫的稳定性,发泡体系溶液的ZETA电位越高、与岩心的接触角越接近90°,纳米颗粒对泡沫液膜吸附强度越高,泡沫越稳定。     

内蕴时间塑性理论在聚氨酯泡沫材料中的应用

聚氨酯泡沫材料是一种典型的缓冲吸能材料,内蕴时间理论可有效地描述泡沫材料的这种力学特性。本文针对聚氨酯泡沫材料定义了应变率相关的内蕴时间,通过引入Gibbs自由能,推导了聚氨酯泡沫材料的等温小变形本构关系,初步将内时理论引入到聚氨酯泡沫材料本构关系中。本文也为聚氨酯泡沫材料的本构关系研究提供了新的思路。     

烷基糖苷的泡沫扫描研究

采用泡沫扫描方法全面研究了APG质量浓度、N2流量和NaC l质量浓度对APG泡沫性能的影响。结果表明,在1000 s内所有样品泡沫高度不变,稳泡性很好,除ρ(APG)=0.25 CMC泡沫时间为149 s外,其余质量浓度下发泡时间都在(144±2)s,随表面活性剂质量浓度增加,泡沫相对电导、泡沫最大密度和泡沫稳定指数值都增加。N2流量对体系发泡性能影响较大,最佳N2流量为40 mL/min。随盐含量增加发泡时间微减少,而泡沫稳定指数增加。在稳泡阶段,随时间延长和N2流量增加,泡沫数量越来越少,泡沫单个面积越来越大。盐含量高时泡沫数量较多。随表面活性剂质量浓度增加,泡沫数量增加,但泡沫总面积和平均面积减小。     

一种新型蛋白质混凝土发泡剂的研制及性能研究

以啤酒废酵母为原材料,制备一种新型的蛋白质混凝土发泡剂并通过正交实验对水解条件进行优化。研究了发泡剂以及不同添加剂对其发泡性能和泡沫稳定性的影响,结果表明表面张力是发泡剂发泡性能提升的重要因素,但对泡沫稳定性没有决定性影响;适当增加溶液黏度可延长其泡沫稳定时间,其中添加卡拉胶0.1%/100 mL发泡液时,发泡体积为725 mL,其泡沫稳定时间也超过了25 h。     

Foam separation: The principles governing surfactant transfer in a continuous foam column

Surface-active agents have been removed from solution by foaming in a continuous flow foam column and the results have been analysed in terms of a mass balance and the surface adsorption equilibrium. The analysis permits the prediction of column performance at other operating conditions. The analysis was tested during foaming experiments with the surfactant sodium dodecylbenzenesul-phonate in dilute aqueous solution. The maximum value of the surfactant surface adsorption determined by experiment agreed well with predictions from surface tension measurements. It is possible also to predict the effect of the operating variables, such as feed-liquid and air-flow rates, and of feed concentration on the quantitative removal of surfactant. The predictions were confirmed by experiment. The foam column as operated for these experiments with feed injection into the liquid pool of the column (‘pool feed’) was shown to represent a single equilibrium stage and the derived working equation to be that of an operating line. It follows that there is greater advantage to be gained from multi-stage operation if this can be simply accomplished. Column operation where feed liquid is injected into the foam phase, so-called ‘foam feed’, can provide a multi-stage system.     

Microcellular sheet extrusion system process design models for shaping and cell growth control

The feasibility of shaping a nucleated polymer/gas solution represents a significant advancement for microcellular plastics process technology. Through proper design of the foaming die, nucleated solution flows can be shaped to arbitary dimensions while maintaining the functional independence of cell nucleation, cell growth and shaping. To maintain funcational independence, stringent pressure and temperature design specifications, which supersede those of conventional foam processing, must be met by the foaming die design. As a means of aiding the design process, a model is developed for predicting pressure losses and flow rates of nucleated polymer/gas solutions. A comparison of the model predictions and the actual foaming die design performance shows good agreement for limited data. These relatively simple models capture the major physics of the complicated two-phase flow field and provide a sound base from which scale-up of the foaming die concept can be achieved. The nucleated polymer/gas solution flow models predict highly nonlinear volumetric flow rates contrasting constant flow rates predicted for the neat polymer flow. In addition, a convenient method for classifying nucleated polymer/gas solution flow is presented based on a dimensionless ratio of the characteristic flow rate to the characteristic gas diffusion rate.     

Numerical simulation of polymer foaming process in extrusion flow

Computer simulations of polymer foaming processes in extrusion flow have been carried out in order to improve current understanding of viscoelasticity and bubble growth effects on die-swelling in the production of polymer foam. The linear and non-linear viscoelastic materials functions of a commercial low density polyethylene (LDPE) melt have been extracted by fitting its rheometric data with constitutive models including a simple viscoelastic model (SVM), the exponential Phan-Thien–Tanner (EPTT) model and the double convected pom–pom (DCPP) model. Simulations of LDPE melt under extrusion flow without foaming show that the predictions of the die-swell by the SVM are in reasonably good agreement with the results obtained from the EPTT and DCPP models. By comparison of the simulation results of LDPE foaming in extrusion flow using the Bird–Carreau model and the SVM, a cooperative effect of polymer viscoelasticity and bubble growth on the die-swell has been quantified. The numerical results also show that the density of polymeric foam decreases significantly with the increasing concentration of foaming agent, and that the combination of the SVM and bubble growth model can account for some essential physics of polymer foaming process in extrusion flow.     

基于响应曲面法的三相泡沫灭火剂基础配方优化设计

为得到发泡及稳定性能优异的三相泡沫,响应曲面法优化设计三相泡沫灭火剂基础配方。通过单因素实验确定表面活性剂及固相粉体为SDS、Fc-134、6501、2000目（6.91 μm）合成云母粉,以发泡高度及稳定时间为响应值,研究其交互作用。利用Box-Behnken方法,建立的二次回归模型显著可靠,该模型预测SDS、Fc-134、6501浓度分别为2.64%,0.096%,3%,合成云母添加量为10 g时,为最优组合,预测发泡高度1533.86 ml,稳定时间12.8792 min,实验得到发泡高度为1550 ml,稳定时间为12 min,误差分别为1.05%,6.82%。与未优化三相泡沫比较在发泡高度及稳定时间分别提高14.8%、26.3%。结果表明,经优化设计三相泡沫发泡及稳定性能较未优化三相泡沫有明显提高且响应曲面法建立的预测模型误差较小,因此,该模型可用于提升三相泡沫灭火剂的发泡及稳定性能,为三相泡沫灭火剂配方设计提供参考。     

UV induced microcellular foaming—A new approach towards the production of 3D structures in offset printing techniques

The generation of microcellular foams via a photochemical initiation mechanism is a new approach aimed at the one step production of three dimensional structures in offset printing techniques. The photochemical foaming involves the excitation of a selected photoacid generator with ultra-violet (UV) light to release Brønsted acids. Carbon dioxide, formed upon the reaction of the Brønsted acid with calcium carbonate particles, is used as blowing agent. In order to achieve efficient proton formation and consequently generate a sufficient amount of blowing agent, photosensitizers are employed. Long wavelength absorbing anthracene derivates are added to capture a higher fraction of the light source, a conventional mercury arc lamp, to sensitize the photolysis of the photoacid generator. The microcellular foaming was performed with a commercially available UV curable offset ink formulation containing triacrylate oligomers. To ensure that the gas bubbles are trapped in the cured resin a balance has to be found between the curing speed of the ink and the foaming speed. In the present study crucial process parameters including photoacid generator level, choice of photosensitizer, light intensity and concentration of calcium carbonate particles are evaluated and their influence on the foam properties are discussed. Both the cell morphology and the expansion of the film thickness are characterized with optical microscopy and mechanical methods. The results clearly show that the UV assisted foaming leads to the formation of dense and uniform microcells by applying optimized process parameters. Moreover, the relative thickness of the ink layer can be raised up to 90% which makes the one-step production of three dimensional structures (e.g. reliefs) at short reaction times and ambient temperatures feasible.     

发泡量对HIPS及其复合材料微发泡行为的影响

采用化学发泡法制备出高冲击强度聚苯乙烯(HIPS)微发泡材料及HIPS/纳米有机蒙脱土(nano-OMMT)复合微发泡材料。研究了发泡量对HIPS及其复合材料微发泡行为的影响。结果表明:随着发泡量的增加,发泡材料呈现欠发泡、均衡发泡、过发泡状态。发泡量取10%时,复合材料的发泡效果最好。nano-OMMT在发泡过程中起到成核剂的作用,促进泡孔成核,有效地改善了发泡质量。     

AN EXPERIMENTAL STUDY OF GAS HOLDUP IN TWO-PHASE BUBBLE COLUMNS WITH FOAMING LIQUIDS

Gas-liquid upward flow experiments have been performed in two bubble columns of different diameters (0.10 and 0.29 m,) using air as gas phase and several liquids: water, aqueous solutions of ethanol and glycerine, kerosene, and a solution of a surfactant in kerosene. The main goal of the study is the analysis of foaming systems, including the comparison of their behavior with respect to non-foaming systems. The gas holdup was determined experimentally as a function of the gas and liquid superficial velocities in bubbling, churn-turbulent and foaming regimes. It was found that, for foaming systems, semi-batch operation enhances foam formation, yielding higher holdups than those obtained in continuous operation at very low liquid velocities. Opposite to what is observed in non-foaming systems, the liquid superficial velocity affects the gas holdup appreciably in foaming systems. An increase in column diameter results in a decrease in gas holdup for all the systems studied. In aqueous foaming systems, this trend is more drastic since foam is inhibited as the column diameter increases.     

Foam Control Additives In MSF Desalination

Excessive foaming in multistage flash desalination plants can give rise to salt-contaminated distillate and reduced operating efficiency. Plant operating variations in pressure, temperature, flow, and seawater feed composition and alkalinity can perturb vapor/liquid equilibria, resulting in increased levels of foam. Since such foaming is not always controlled by mechanical means, additives are often needed to control foaming level.In addition to controlling foam, a useful additive must not interfere with heat transfer or with the performance of the scale control additive; it must not contain steam-volatile components that can contaminate the distillate; it must be stable at MSF operating temperatures and residence times; and it should be compatible with the antiscalant feed solution.Antifoam performance data for over 60 candidates in 7 chemical classes were determined according to these criteria. The most effective structural class was found to be the polyglycol monoalkyl ethers. Foam control effectiveness within this class was shown to be a function of ethylene oxide content and alkyl chain length. The most effective additive found in this study is offered commercially as FLOCON Antifoam AF-4. FLOCON AF-4 has been used successfully in high-temperature MSF plants.