分散液液微萃取技术在毒品分析中的应用

毒品分析是现代禁毒工作的重要内容,对打击毒品犯罪活动,确定毒源地,评估毒品市场,从而有针对性的开展禁毒工作有十分重要的意义,分散液液微萃取作为现代样品分析中非常流行的分析方法,因操作简单,提取速度快,预浓缩系数高,提取回收率高,低成本等特点被广泛应用,并不断开发出新的萃取模式。对分散液液微萃取在毒品分析中的应用进行了综述。     

机械蒸汽再压缩技术在钛白黑钛液浓缩中应用

叙述了蒸发二次蒸汽经压缩机提高压力后,重新返回蒸发系统作为热源应用的黑钛液浓缩技术。其内容涵盖了机械蒸汽再压缩(MVR)技术的原理,工艺流程及离心式压缩机、降膜蒸发器等主要设备。该项技术与当前行业内正在推广的"多效浓缩技术"相比,吨钛白黑钛液浓缩的能耗由187.66 kg标煤降至20.01 kg标煤,节省能耗约89%,又能实现单套装置大型化,是一项可供选择的工艺路线。     

分散液液微萃取用于苦瓜HPLC指纹图谱的研究

采用超声辅助提取苦瓜中的活性成分,利用分散液液微萃取（DLLME）技术对提取液进行浓缩,设计正交试验优化DLLME条件。在优化条件下,对不同产地苦瓜的超声提取液进行微萃取,萃取液进行HPLC分析,确定6个共有峰作为苦瓜的指纹峰,采用《中药色谱指纹图谱相似度评价系统》2004A版评价指纹谱图,不同产地苦瓜的HPLC指纹谱图与对照谱图（长沙苦瓜）之间的相似度均大于0.960。本研究为天然产物的鉴定和质量控制提供了一个新的途径。     

陶瓷膜在苹果果胶浸提液浓缩中的应用研究

采用国内生产的陶瓷膜对苹果果胶提取液浓缩的实验研究表明：使用陶瓷膜对果胶提取液的浓缩是可行的；确定了用陶瓷膜对果胶提取液浓缩的合适操作参数；用膜浓缩法制得的果胶与用传统的真空浓缩法制得的果胶质量进行了对比，膜浓缩制得的果胶品质大大优于真空浓缩制得的果胶。     

液液萃取-气相色谱质谱法测定水样中20种多氯联苯

建立了液液萃取-气相色谱质谱法测定水样中20种多氯联苯的分析方法,以二氯甲烷为萃取剂,对水样进行液液萃取。收集萃取液进行浓缩、净化、再浓缩,气相色谱质谱法测试。目标物经HP-5MS UI色谱柱分离,选择离子模式扫描,内标法定量。结果表明,在5.0～500.0μg/L浓度范围内呈现良好的线性关系,线性相关系数在0.996～0.999范围内,方法检出限为0.2～1.4μg/L。对地下水、地表水、生活污水实际样品进行加标验证。该方法检出限低、灵敏度高、准确度高、重现性好,可满足批量水样中20种多氯联苯的检测要求。     

从废刻蚀液中回收铜

废刻蚀液是络合的铜氨离子液体,通过加入硫酸的简单处理变为硫酸铜溶液,然后浓缩结晶,析出五水硫酸铜     

电渗析处理电镀镍回收液的实验研究

采用电渗析法对电镀镍回收液进行分离浓缩实验。实验表明,选用BJT离子交换膜,在溶液Ni2+初始浓度为2 g/L、电压值为7.5 V、浓缩室和淡化室流量均为8 L/h时,Ni2+浓缩到8.39 g/L,有机物的相对去除率达46.46%。电渗析法能实现镍回收液中镍离子与杂质的分离,达到净化回收液和浓缩镍离子的目的。     

环己酮皂化液蒸发浓缩技术的研究进展

介绍了环己酮皂化液的性质和传统蒸发浓缩工艺存在的问题,综述了多段蒸发、强制循环、喷雾闪蒸、蒸发助剂、快速冷却破晶蒸发等蒸发浓缩改进技术,指出了今后应注重各种蒸发技术的综合运用。     

从废刻蚀液中回收铜

废刻蚀液是络合的铜氨离子液体,通过加入硫酸的简单处理变为硫酸铜溶液,然后浓缩结晶,年出五水硫酸铜。     

液膜法提取浓缩氨基酸

本文研究了用液膜法提取浓缩谷氨酸。用ＴＯＭＡＣ为载体，ＥＣＡ４３６０Ｊ为表面活性剂，在适当的酸度下，以氯离子的浓度差作推动力，提取率可达６０％，浓缩倍数可达５倍。谷氨酸可以克服１１－１２倍的浓度梯度进行能动的膜输送而进入内相，这比文献报导的数值高出近一倍。     

FLOW BOILING HEAT TRANSFER IN A NEW VAPOR-LIQUID-SOLID THREE-PHASE CIRCULATING FLUIDIZED BED EVAPORATOR

In order to enhance heat transfer and solve the fouling problems in boiling processes, a boiling system was designed by adding solid particles to the boiling liquid. In this paper, both theoretical analyses and experimental studies on the flow boiling heat transfer in a vapor-liquid-solid three-phase circulating fluidized bed evaporator were carried out. Based on the analysis of the heat transfer characters of this three-phase flow boiling, a mathematical model for predicting the flow boiling heat transfer coefficients of the vapor-liquid-solid three-phase circulating fluidized bed evaporator was developed. The experiments show that, in the presence of solid particles the flow boiling heat transfer is enhanced and is about 2 times that of the vapor-liquid two-phase one. The predicted results of the flow boiling heat transfer coefficients agreed well with the experimental data.     

三相循环流化床蒸发器强化传热的研究

采用汽-液-固三相循环流化床新型蒸发器蒸发麦草浆黑液,讨论了热通量、流速和粒子体积分数对三相流沸腾传热系数的影响。试验表明,三相流沸腾传热系数随热通量、黑液流速和粒子体积分数的增加而增大。且对黑液这种高粘度流体使用该蒸发器,其三相流沸腾传热系数比汽液两相流沸腾传热系数提高约20%～30%。     

加入惰性固体粒子的二元物系的流动沸腾传热特性

引　言流动沸腾传热广泛存在于石油、化工、轻工、动力及能源等各个领域 ,但三相流动沸腾传热的研究极少 .李修伦等[1]在流动沸腾系统中加入惰性固体粒子 ,进行了汽 -液 -固三相流沸腾传热的初步研究 .李修伦、闻建平[2 ,3]进一步将三相流和沸腾换热相结合 ,较好地解决了沸腾传热强化和防垢、除垢问题 .李修伦、张利斌等[4 ]又采用循环流化床技术 ,结合粒子在沸腾系统中的强化特性 ,开发了汽 -液 -固三相循环流化床蒸发器 ,它具有良好的强化传热和防、除垢性能 .上述研究均属于单组分三相流动沸腾传热 ,而关于二元物系三相流动沸腾传热的研…     

汽液固三相流动沸腾传热计算与实验研究

对汽液固三相循环流化床中流动沸腾传热进行了理论分析和实验研究 ,在此基础上结合渐进模型及表面更新机理建立了汽液固三相流动沸腾传热模型 ,模型计算值和实验数据吻合较好 ,最大偏差在 18%以内     

Studies on the hydrodynamic and heat transfer in a vapor-liquid-solid flow boiling system with a CCD measuring technique

The vapor-liquid-solid (V-L-S) flow boiling evaporator has the features of fouling preventing and heat-transfer enhancing. However, the mechanisms of flow and heat-transfer are still not well understood due to the system complex and the limitation of the measuring methods due to the characteristic of opaque of the system in practice. In this paper, a charge coupled device (CCD) measuring system is developed to investigate the hydrodynamic characteristics including the axial profiles of solid holdup and of solid velocity in a V-L-S three-phase natural circulating flow boiling system. The CCD measuring technique makes the three-phase qualitative observation and quantitative research possible. The heat-transfer characteristic of this system is also studied. The main results are as follows. The distributions of solid holdup and velocity are not uniform along the axial direction of the heating tube and both in liquid-solid two-phase region and in V-L-S three-phase region; however, the particle velocity in V-L-S three-phase region is much higher than that in liquid-solid two-phase region in heating tube. When increasing the heat flux, the solid holdup first increases and then decreases and the solid velocity gradually increases in heating tube. But in circulating tube, both the solid holdup and the solid velocity gradually increase. With the increase of the volume of added solid particles, the measured local solid holdup increases in both tubes; however, the variation of the solid velocity with the increase of the solid particles shows a characteristic of the wave and the general tendency is climbing for both tubes. The solid particles holdup in heating tube is always larger than that in circulating tube and the solid velocity in heating tube is lower than that in circulating tube. The presence of solid particles enhances the boiling evaporation process. The heat-transfer coefficient of the system increases with the increase of the heat flux and the volume of added solid particles. These research results provide some valuable references for the academic interest and for the industry application of this fouling preventing and heat-transfer enhancing installation.     

流态化固体颗粒对载气蒸发传热的强化

Heat transfer characteristics are studied for gas carrying evaporation with fluidized solid particles in a vertical rectangular conduit. Experimental results show that heat transfer of gas carrying evaporation is enhanced and the superheat of liquid in contact with heating surface lowers remarkably by introducing solid particles. Nucleate boiling on the heating surface is suppressed to a considerable degree. The mechanism of heat transfer enhancement by fluidized solid particles is analyzed with the consideration of collisions of solid particles with the boiling vapor bubbles.     

固体颗粒对池沸腾换热表面上结垢影响的机理分析

报道了固体颗粒对池沸腾换热表面结垢特性影响的实验研究结果。沸腾工质为ＣａＳＯ４水溶液，换热表面材料为紫铜，固体颗粒是０．５～１ｍｍ的玻璃珠。实验结果表明，在平表面池沸腾条件下引入固体颗粒只能在较短的运行时间内起到强化换热的作用。当运行时间较长时，不仅不能强化换热，反而因结垢而使得换热恶化。     

FLOW BOILING HEAT TRANSFER WITH FLUIDIZED SOLID PARTICLES

In order to solve the fouling problems in boiling processes,a boiling system was designedby adding solid particles to the boiling liquid In this paper.both theoretical analyses andexperimental studies on the boiling heat transfer in such a three-phase flow boiling were carried out.Based on the analysis of heat transfer characters of this three-phase flow boiling,a mathematical mod-el for the heat transfer coefficient of flow boiling was developed.The experiments show that,in thepresence of particles the boiling heat transfer is enhanced and is about 2 times that of the vaporliquid two phase one with better flow stability.The fluidized particles rub the heat transfer wall toprevent and to clean the fouling.     

Heat Transfer and Pressure Drop of Vapor-Liquid-Solid Three-Phase Boiling Flow of Binary Mixtures

Experimental studies on vapor-liquid-solid three-phase flow boiling heat transfer and overall pressure drop of ethanol-water binary mixtures in a vertical tube with solid particles added were carried out. Based on the analysis of the heat transfer characteristics of this three-phase flow boiling, a mathematical model for predicting the three-phase flow boiling heat transfer coefficients of ethanol-water binary mixtures was developed. The results show that with the presence of inert solid particles in binary mixtures, flow boiling heat transfer is enhanced and is about twice that of vapor-liquid two-phase heat transfer. The predicted results of the flow boiling heat transfer coefficients of ethanol-water binary mixtures agreed well with the experimental data.