流动过冷沸腾传热强化及阻垢

在流动沸腾传热实验中,考察了CaCO3污垢溶液的形成过程及各种工艺条件对流动过冷沸腾传热的影响. 研究条件包括流体速度、溶液温度、CaCO3溶液浓度及热通量,实验中发现了一些规律. 同时还考察了不同阻垢剂[聚天冬氨酸(PASP)、2-膦酸丁烷-1,2,4-三羧酸(PBTCA)及氨基三甲叉膦酸(ATMP)]对流动过冷沸腾传热的影响. 结果表明,所选阻垢剂均能抑制污垢的生成并降低了污垢热阻,而且存在最佳浓度范围. 但不同阻垢剂的阻垢效果不尽相同,在本实验条件下,ATMP的阻垢效果最好,PBTCA次之,PASP的阻垢效果较差.     

羧甲基葡聚糖的快速沉降法阻垢特性研究

工业循环冷却水中的碳酸钙污垢一直是困扰工业生产者的重要问题,使用快速沉降法（FCP）研究了不同浓度的羧甲基葡聚糖对于碳酸钙污垢的抑制作用。控制溶液中的钙离子浓度为200 mg/L,羧甲基葡聚糖的浓度分别为0.5、1、2和4 mg/L时,对羧甲基葡聚糖的阻垢性能进行分析。结果表明,羧甲基葡聚糖对于减缓碳酸钙的成核过程有明显效果,此外,它也显著降低了碳酸钙成核后晶体的生长速率。当羧甲基葡聚糖的浓度为4 mg/L时,羧甲基葡聚糖对于碳酸钙的成核及晶面生长起到了完全抑制的作用,对于工业应用中碳酸钙的防垢处理,提升换热效率具有借鉴意义。     

三元共聚物防垢剂的合成与性能研究

以水为溶剂,过硫酸铵为引发剂,马来酸酐、乙酸乙烯酯和丙烯酸为原料,合成了三元共聚物防垢剂,并对其进行了性能评价。研究了三元共聚物的质量浓度、温度及体系pH值等条件对其防垢率的影响。结果表明,合成的马来酸酐/乙酸乙烯酯/丙烯酸三元共聚物防垢剂对碳酸钙的防垢效果较好。     

聚羧酸类阻垢剂对碳酸钙的沉淀及溶解过程的影响研究

利用VB语言自编的计算机程序对不同形态CaCO3在各种条件下的溶解度 进行了计算,并对过饱和体系进行了分析,在此基础上研究了PAA1、PAA2、PMA－AA,PPMA四种聚羧酸类阻垢剂对CaCO3的再溶解和沉淀过程的影响,从阻垢剂对CaCO3沉淀形态影响的角度,解释了阻垢剂对CaCO3过饱和溶液亚稳态的影响和阻垢剂的阻垢作用。     

An integrated radiotracer approach for the laboratory evaluation of scale inhibitors performance in geological environments

The applicability of a newly developed radiotracer technique as a reliable laboratory procedure for the evaluation of scale inhibitors performance to prevent mineral precipitation is demonstrated. The performance of two new environmentally friendly inhibitors to prevent calcite and barite scale was evaluated experimentally in connection with a standard phosphonate-type scale inhibitor using the radioactive tracer technology. The radiotracers ⁴⁷Ca and ¹³¹Ba were employed in order to monitor at real-time calcite and barite scale formation, respectively. The results show that the developed radiotracer technique can be established as a novel method for the determination of the minimum inhibitor concentration (MIC) under dynamic, reservoir conditions. In addition, the radioactive tritiated water (HTO) was used as a reference water tracer to identify the inhibitors’ properties, such as adsorption/desorption characteristics, in sandpack-flooding tests. Further issues regarding the implementation of the radiotracer technology for the laboratory evaluation of scale inhibitors performance are also discussed.     

循环冷却水系统碳酸钙垢的形成及控制研究

主要研究了循环冷却水系统碳酸钙垢形成的动力学过程及阻垢剂对它的影响,并对几种有机磷酸阻垢剂的阻垢性能进行了评价。试验表明,阻垢剂的存在会对碳酸钙结垢过程产生较大影响,但不同阻垢剂对不同动力学过程起主导作用。     

Efficiency of five scale inhibitors on calcium carbonate precipitation from hard water: Effect of temperature and concentration

The effects of temperature and concentration of five scale inhibitors (three polyphosphates, one polyphosphonate and one polycarboxylate) on calcium carbonate (CaCO₃) precipitation from hard water are reported in this paper. The CaCO₃ precipitation from calcocarbonically pure water was induced by imposed potential and studied on gold electrode by chronoamperometry technique. With this technique, the efficiency of preventing CaCO₃ precipitation was determined for all scale inhibitors. The composition of these scale inhibitors were analysed by ICP-AES technique and no or few toxic elements were detected. For each tested inhibitor, the optimal concentration was determined and their efficiency was studied in the range temperature 20-50 °C. SEM/EDS and Raman spectroscopy techniques were used to analyse the microstructure and the elemental composition of the formed scale. Only polyphosphonates remain efficient at 50 °C. All the tested inhibitors were shown to act by threshold effect.     

端羧基超支化型绿色阻垢剂的制备及阻垢性能

采用熔融聚合法以木糖醇为中心核,成功制备了端羧基超支化型绿色阻垢剂,通过红外光谱仪和核磁共振对其结构进行了表征,采用静态阻垢法探讨了阻垢剂的添加量、水样环境的pH和水样温度对其阻碳酸钙和硫酸钙的能力。结果表明,端羧基超支化型绿色阻垢剂在较宽的温度范围及水体环境的pH=6~9时,对钙垢（CaCO₃和CaSO₄）均具有优异的阻垢性能,且当阻垢剂添加量为24 mg/L时,其对碳酸钙垢的阻垢效率达到了91.6 %;当阻垢剂的添加量为15 mg/L时,其对硫酸钙的阻垢效率达到了94.7 %;端羧基超支化型绿色阻垢剂的使用,均能极大程度地降低了钙垢晶体的规整性,且对于碳酸钙垢而言,端羧基超支化型绿色阻垢剂的使用还可以使碳酸钙垢的晶格发生畸变,从而达到分散阻垢的目的。     

低磷阻垢剂在低温多效海水淡化过程中的应用

以羟基乙叉二膦酸(HEDP)、端羧基超支化聚酯(CHBP)、水解聚马来酸酐(HPMA)、聚丙烯酸(PAA)为原料,研制出一种具有环保功能的低磷复配高效阻垢剂,利用傅里叶红外光谱(FTIR)对CHBP的分子结构进行了表征,通过静态阻垢实验和模拟低温多效蒸馏海水淡化体系下的铜管垢样生长实验考察了低磷阻垢剂的阻垢性能。采用扫描电镜(SEM)和X射线衍射(XRD)分析了垢样的形貌和晶体结构。结果表明,该低磷阻垢剂的最佳配方为m(HEDP)∶m(CHBP)∶m(HPMA)∶m(PAA)=1∶9∶80∶10,在其质量浓度为15 mg/L时,碳酸钙阻垢率为87.5%。阻垢剂中的羧基是阻止碳酸钙垢形成的主要因素。CHBP的引入降低了配方中的总磷含量。加入该阻垢剂后,铜管上垢样的形貌发生了改变,易在水相中悬浮而随水流走,从而难以沉积生长在换热器的表面。     

Influence of phosphate and iron on the extent of calcium carbonate precipitation during anaerobic digestion

The extent to which calcium carbonate deposition in an anaerobic reactor can be reduced by adding inhibitors (phosphate and iron) of calcium carbonate crystal growth was investigated. At several concentrations of the additive, the extent of precipitation was assessed in continuous experiments with laboratory‐scale reactors. In the reactor, phosphate concentrations as low as 0.5–5 mg total‐P dm⁻³ were found to severely inhibit CaCO₃ precipitation. However, iron did not inhibit the deposition of CaCO₃, which was found to be due to the fact that iron, in contrast to phosphate, only inhibits the growth of calcite and not the formation of aragonite. The results led to the conclusion that only additives which inhibit the formation of both aragonite and calcite can be used as effective inhibitors during anaerobic digestion. A chemical equilibrium model was developed and shown to be a useful tool to calculate the extent of calcium carbonate deposition during anaerobic digestion provided the proper apparent solubility product of calcium carbonate can be estimated. © 1999 Society of Chemical Industry     

几种阻垢剂阻碳酸钙垢性能的研究

由于强化采油技术的深入,水体性质的变化造成原有的阻垢剂性能变差.作者针对油田某区块的结垢物组成和水体特点,选择了5种不同结构的阻垢剂,采用静态实验方法和具有类似该区块矿化度组成的模拟水体,根据阻碳酸钙垢性能来进行阻垢剂单剂筛选和复配研究.结果表明:阻垢条件为70℃,时间2h,单剂考察优选阻垢剂MH-2,质量浓度为40m...     

运用恒定组分技术评价化学阻垢剂的阻垢效果

建立了基于单一电导率监测 ,保持碳酸钙溶液析晶过程中 ,溶液中各组分浓度恒定的“恒定组分”实验技术 ,研究了不同种类的非化学配比阻垢剂的阻垢效果和不同浓度的PBTC的阻垢效果。发现不同的阻垢剂或者相同阻垢剂不同剂量所起到的阻垢效果反映在“抑制平台”的长短上。平台期过后 ,晶体的生长与不加阻垢剂的实验无显著的区别。实验图形反映了恒定组分系统具有很高的灵敏度和高度的可重复性。我们认为 ,平台长短反映了阻垢效果 ,可以作为评价阻垢剂效能的指标     

Calcium carbonate inhibition by a phosphonate-terminated poly(maleic-co-sulfonate) polymeric inhibitor

The precipitation of calcium carbonate scale on heat transfer surfaces widely occurs in numerous industrial processes. For the control of calcium carbonate scale and in response to environmental guidelines, the new low phosphonic copolymer was prepared through reaction of maleic anhydride with sodium p-styrene sulfonate in water with redox system of hypophosphorous and hydrogen peroxide as initiator. The anti-scale property of the low phosphonic copolymer towards CaCO₃ in the artificial cooling water was studied through static scale inhibition tests, and the effect on formation of CaCO₃ was investigated with combination of scanning electronic microscopy (SEM), X-ray powder diffraction (XRD) analysis and Fourier transform infrared spectrometer, respectively. The results showed that the low phosphonic copolymer was excellent calcium carbonate scale inhibitor in artificial cooling water. The crystallization of CaCO₃ in the absence of inhibitor was rhombohedral calcite crystal, whereas a mixture of calcite with vaterite crystals was found in the presence of the low phosphonic copolymer. For actions of carboxyl and phosphonic acid groups, the calcite was inhibited and the metastable vaterite was stabilized in the presence of the low phosphonic copolymer during the CaCO₃ formation process.     

聚环氧琥珀酸的改性及其阻垢机理的研究

聚环氧琥珀酸是一种无磷、无氮、生物降解性很好的绿色阻垢缓蚀剂,对碳酸钙垢阻垢效果很好,但对磷酸钙垢阻垢效果和对锌盐的稳定能力很差,可以在PESA中引入磺酸基。文章是以马来酸酐和2-丙烯酰胺-2-甲基丙磺酸(AMPS)为原料,合成改性聚环氧琥珀酸(MPESA),并比较两种阻垢剂的阻垢效果。最后通过测定PESA对碳酸钙晶体成核诱导期的影响、扫描电镜、X射线衍射等手段分析PESA对碳酸钙垢的阻垢机理。     

碳酸钙晶型的肉豆蔻酸调控研究

采用硝酸钙和碳酸钠的复分解反应制备碳酸钙,通过加入肉豆蔻酸对碳酸钙的晶体结构和表面性质进行调控,采用SEM、XRD、FT-IR、TG和XPS等方法研究了添加肉豆蔻酸对碳酸钙晶体结构的影响。结果表明,加入肉豆蔻酸之后,碳酸钙的晶体结构由球霰石变成方解石,形貌由球形变成了不规则的长方体形;碳酸钙的表面全部被活化,由亲水性变成疏水性,表面疏水后,碳酸钙的团聚程度明显降低;肉豆蔻酸的羧基阴离子和钙离子发生了化学结合反应,增强了碳酸钙结构的稳定性。总之,肉豆蔻酸的加入为碳酸钙的晶型调控与表面改性提供了一条简单的思路。     

烟柴杆提取物的阻垢和缓蚀性能

研究了烟柴杆提取物提取方式对阻垢性能的影响,以水作溶剂所得烟柴杆提取物对碳酸钙、硫酸钙和磷酸钙均有较好的阻垢效果。通过红外、XRD、SEM对烟柴杆提取物阻垢机理进行研究,认为所得提取物对沉积物质具有阻垢性能是其螯合作用和晶格畸变作用的协同表现。采用旋转挂片法和极化曲线对提取物缓蚀机理进行分析,烟柴杆提取物作为碳钢缓蚀剂,属于阳极型的缓蚀剂。由于烟柴杆提取物具有优良的生物降解性,所以是一种对环境友好型的水处理剂。     

Electrodeposition of a calcareous layer: Effects of green inhibitors

The reduction of mineral scale is a challenge in many industrial fields and environmental issues relating to eutrophication are leading industry to develop environmentally friendly solutions to scale control. The effects of three green (carboxymethyl inulin (CMI), polymaleic acid and polyaspartic acid) and one non-green (polyphosphinocarboxylic acid (PPCA)) scale inhibitors on calcium carbonate nucleation and growth have been studied using electrodeposition. The study of chronoamperometry associated with deposition for a duration of 24 h has pointed to some important information relating to the interactions occurring between the inhibitors and the metal surface. PPCA, polymaleic acid and polyaspartic acid are surface active and 4 ppm of these inhibitors generated a significant reduction in the weight of calcium carbonate deposition. The study of the current density variation did not show any obvious interactions between the metal surface and the CMI. Microscopic observations after 4 and 24 h have shown that the inhibitors generate specific changes in the crystal morphology and that PPCA, CMI and polyaspartic acid lead to vaterite formation in preference to calcite seen in uninhibited solutions.     

一种复合阻垢剂在玉米浆蒸发器上的应用研究

通过对某淀粉厂玉米浆蒸发器上的玉米浆、垢样进行分析,并结合外在控制指标对玉米浆质量的影响,研究了该玉米浆蒸发器的结垢问题。结果表明,该玉米浆蒸发器有明显的碳酸钙、硫酸钙结垢倾向。针对玉米浆蒸发器温度较高、玉米浆中有机质含量高、粘度高的特点,开发出一种适合该环境的复合型阻垢剂。现场应用研究表明,当加药浓度为100 ppm时,成垢离子Ca~(2+)、SO_4~(2-)、CO_3~(2-)的保有率均有明显提高,玉米浆蒸发器的结垢倾向得到了有效控制。     

马尾松木素磺酸钠分散、阻垢、缓蚀性能的研究

测定了木素磺酸钠 (木钠 )在循环冷却水中的分散、阻垢和缓蚀性能。研究发现 ,由于木钠能够大幅度增加碳酸钙颗粒的Zeta电位 ,使其对碳酸钙有较好的分散作用 ;木钠能络合部分Ca2 + ,但是络合能力较弱 ,对碳酸钙的静态阻垢率较低 ,为 2 %～ 5 % ;投加量在小于 5 0× 10 -6kg/L时加快了 2 0 #碳钢的腐蚀 ,大于 10 0× 10 -6kg/L时的缓蚀率为 3%～ 2 0 % ,极化曲线显示木钠属阴极型缓蚀剂     

Determining kinetics of calcium carbonate precipitation by inline technique

Calcium carbonate, CaCO₃, is one of the most common scale components found in oilfield production wells and surface facilities. The prediction of kinetics of scale deposit depends on the understanding of the CaCO₃ precipitation from solution. The formation of CaCO₃ is also of practical importance in a number of areas such as in paper coatings or as fillers for rubber materials.CaCO₃ precipitation studies reported in literature are based on either solution properties or using offline size/mass analysis. In the present work inline in situ technique is utilised which gives a direct measurement of the number and size of crystals. The inline image technique by FBRM, Mettler Toledo gives relatively accurate measurements. The method of moments was utilised to determine the crystal size and hence the growth rate.The effects of the solution composition on the spontaneous nucleation and the crystal growth rate have been examined. From the measurements of the crystal growth kinetic data, the crystal growth rates were estimated which are found to be an exponential function of calcium ion concentration.