液体非电解质水溶液粘度的预测

在Teju-Rice液体混合物粘度模型的基础上,对常用的液体混合物粘度关联式进行了分析和比较;导出了适用于二元和多元非电解质水溶液的粘度模型;结合实际数据导出的水溶液二元作用参数的估算式可进行水溶液粘度的预测。用该模型计算了7个体系398个不同温度和组成的二元水溶液和4个体系189个不同温度和组成的三元水溶液的粘度,结果表明,计算值对实验数据的总平均相对偏差分别为6.848%和5.043%,本文水溶液粘度估算式的计算准确性优于Teju-Rice法。     

非电解质水溶液的粘度方程

在Eyring的液体粘性流动模型基础上,根据Rother等的假定和Shealy与Sand ler的水溶液过量自由焓溶质聚集模型,导出了一个双参数非电解质水溶液的粘度模型。利用该模型可由二元水溶液的2个模型参数预测多元水溶液的粘度。用该模型计算了6个体系391个不同温度和组成的二元水溶液和3个体系164个不同温度和组成的三元水溶液的粘度,计算值与实验值的总平均相对偏差分别为1.732%和2.977%,计算值与实验数据吻合很好。     

有机物水溶液粘度的关联和预测

在Eyring的液体粘性流动模型的基础上,根据Sandler的水溶液过量自由焓溶质聚集模型,导出有机物水溶液的粘度模型。利用该模型方程参数与温度的关系,可预测低压下各种温度和不同组成的有机物水溶液的粘度。用该模型计算了7个体系442个不同温度和组成的二元水溶液和3个体系164个不同温度和组成的三元水溶液的粘度,计算值与实验值的总平均相对偏差分别为1.554%和2.588%,计算值与实验数据吻合很好。     

甲醇和乙醇的水溶液粘度、密度和导热系数的估算

根据作者导出的非电解质水溶液的粘度模型,提出了估算低压下甲醇和乙醇水溶液粘度的估算式,并根据对实验数据的回归分析,提出了甲醇和乙醇水溶液的密度和导热系数估算式。利用这些计算式计算了不同温度和组成下的甲醇水溶液和乙醇水溶液的132个粘度数据、130个密度数据和32个导热系数数据,计算值与实验值的平均计算偏差分别为1.888%、0.540%和0.969%;计算了不同温度和组成下的甲醇-乙醇-水三元溶液的115个粘度数据和116个密度数据,计算值与实验值的平均相对偏差分别为2.556%和0.351%。计算结果表明,计算值与实验数据吻合很好。     

有机物水溶液导热系数的关联

根据对有机物水溶液导热系数影响因素的分析,在Horvath液体导热系数关系式的基础上,导出了估算有机物水溶液导热系数的计算模型;利用该模型计算了14个体系中447个数据点的不同温度和组成的二元水溶液导热系数;结果表明,计算值与实验数据吻合很好,其与实验值的总平均相对偏差为1.03％,计算准确性优于文献方法。本文计算方法简单方便,只需知道水溶液各组分的临界温度、临界体积和导热系数数据,就可以直接预测各种温度和组成的有机物水溶液混合物的导热系数。     

强电解质混合物水溶液粘度的计算

本文介绍一种用离子贡献法计算强电解质水溶液粘度的通用模型。此模型不仅可以计算单一强电解质水溶液在各种温度和浓度下的粘度、而且还可以计算多种强电解质混合物在各种温度和浓度下的粘度。经过实践证明、精确度能满足工程设计的要求。     

Lee-Kesler状态方程在含极性组分物系粘度计算中的应用

将Ｌｅｅ Ｋｅｓｌｅｒ 状态方程用于Ｄｅａｎ Ｓｔｉｅｌ 粘度方程中求解密度值，计算了８ 组含极性组分的液体混合物粘度，得出较准确的计算结果。     

计算液体混合物导热系数的新型方程

依据Ｃｈａｐｍａｎ导热理论关于液体导热系数与粘度的关系，结合由Ｅｙｒｉｎｇ反应速率理论及ＮＲＴＬ方程导出的液体粘度关联式，得到一个计算液体混合物导热系数的新型方程。经对１８个二元体系和４个三元体系、１个四元体系共１６４６个数据点的检验，结果较为满意，与文献值或实测值相比总的平均误差仅为０．３９４％。     

应用马丁─侯状态方程计算含氨气体混合物的物性参数

本文将马丁—侯状态方程用于计算气体混合物的恒压热容、粘度和导热系数．含氨气体混合物的恒压热容为理想气体混合物热容与真实气体混合物剩余热容之和，根据剩余粘度法计算粘度，剩余导热系数法计算导热系数．三种压力，不同温度条件下气体混合物恒压热容、粘度和导热系数的计算结果表明：计算值与实验值相吻合．并分别拟合了合成氨生产三种工艺含氨气体混合物恒压热容、粘度、导热系数的计算式。     

Eyring模型的修正及液体混合物粘度的研究

<正>在化工传质和流体力学中,粘度是一个不可缺少的物性.为此,已建立了许多计算液体混合物粘度的经验和半经验方程,其中不少建立在 Eing粘度理论的基础上,但这些方程都含有 2个或多个     

Viscosities of coal—water—methanol mixtures

A plot of viscosity measurements for coal—water—methanol mixtures vs. percentage methanol in the liquid indicates that the viscosities of both coal—water and coal—alcohol slurries are increased by the addition of the second liquid. The shape of the slurry viscosity curve is very similar, on a greatly exaggerated scale, to the plot of viscosity versus percentage methanol for the pure liquid mixtures. Measurements were made as a part of a test program involving coal—water-methanol fuels. Initial mixtures were 60 wt% Pittsburgh seam coal in liquids composed of varying proportions of water and methanol. Slurries of Montana Rosebud and Texas Lignite coals in water—methanol mixtures also displayed viscosity maxima, but at different fractions of methanol. There was no viscosity peak for 40, 50 or 55% petroleum coke slurries. Slurries of ground glass in water-methanol mixtures were evaluated for comparison and a viscosity maximum was observed, although the peak occurred at a methanol concentration somewhat lower than it occurs in the pure liquid mixture.     

A modified entropic expression for the analysis of swelling behavior of polymeric membranes in solutions

The linear mixed relation for mixed molar volume and free-volume were modified to derive our new activity expression attributed to the combined combinatorial and free volume contributions. The validity and applicability of this expression were demonstrated by calculating the solvent activity in polymer solutions and analyzing the swelling behaviors for polymeric membranes. The average absolute deviation (AAD) of these calculated results from the experimental values of solvent activities for polymer solutions was employed for comparison. It is shown that the modified model can yield better results than the original one for most of the systems considered. The swelling behavior of poly vinyl alcohol (PVA) membranes in water/glycol (EG) mixture over a wide range of concentrations was analyzed. The activity of solvents in the liquid and the membrane was calculated by the UNIQUAC model and this present modified model, respectively. The estimations are consistent with experimental data roughly at temperatures of 333 and 343 K. It is found that the modified model is a suitable alternative to the Flory-Huggins equation for the analysis of the swelling behaviors of polymeric membranes in solutions.     

基于PR方程的碳酸二甲酯摩擦理论黏度模型

在对文献中发表的碳酸二甲酯黏度实验数据进行全面收集的基础上,将摩擦理论与工程上常用的Peng-Rob inson状态方程(PR方程)结合建立了碳酸二甲酯的液相黏度模型,通过最小二乘法回归得到了模型中的各系数。结果表明:在拟合范围内,碳酸二甲酯黏度模型的计算值与实验数据绝对平均偏差和最大偏差分别为1.78%和6.34%。所建立的黏度模型适用的温度范围为283—383 K,压力范围为饱和压力接近于100 MPa,文章为碳酸二甲酯作为替代燃料等的进一步深入研究和工程应用提供了黏度计算模型。     

旋转膜乳化法制备均一魔芋葡苷聚糖凝胶微球

以天然多糖魔芋葡苷聚糖(KGM)为材料,采用旋转膜乳化法结合化学交联法制备均一的魔芋葡苷聚糖凝胶微球,以3种不同粘度的12%(w) KGM水溶液为分散相(水相)、液体石蜡(LP):石油醚(PE)混合油相为连续相,考察了乳化剂种类对KGM乳液稳定性的影响及水相粘度、油相配比和膜管转速对KGM成球的影响. 结果表明,KGM水相粘度越高,相应的最佳油相粘度越低,最佳KGM水相粘度为1548 mPa×s,最佳油相体积比为LP:PE=5:1,最优膜管转速为400 r/min,利于KGM乳液稳定的乳化剂是4%(w) Span 80. 该条件下制得粒径约70 μm、粒径分布系数Span<1.0的均一KGM微球.     

Modeling the thermal and physical properties of liquid and gas mixtures of Fischer–Tropsch synthesis products

The method of pseudocritical thermodynamic parameters and the Lee-Kesler equation of state are used for calculating the thermal and physical properties of a solution and a mixture of gaseous paraffins that are major constituents of Fischer-Tropsch synthesis products. The dynamic viscosities of a solution and a vapor are modeled using an original procedure proposed by the authors. A surface tension is calculated by the parachor method. The composition of liquid and gaseous products is found using a stable iteration scheme proposed by the authors. The model is tested by a comparison with experimental data from the literature for model mixtures of hydrocarbons. The results of calculating the composition and thermophysical properties of a mixture of paraffins that model the composition of synthesis products at different values of the chain propagation parameter, temperatures, and pressures are presented.     

Density, viscosity, and surface tension of water+ethanol mixtures from 293 to 323K

Density, viscosity, and surface tension of liquids are important physicochemical properties which affect mass and heat transfer in solutions. The density, viscosity, and surface tension of binary mixture of water+ethanol at 293, 298, 303, 308, 313, 318, and 323 K are reported and compared with the available literature data. The findings of these comparisons show how the measured data are reproducible from different laboratories. The molar volume of water+ ethanol mixtures are also calculated using measured density values. The Jouyban-Acree model was used for mathematical correlation of the data. The relative deviation (RD) was used as an error criterion and the RD values for correlation of density, viscosity, surface tension and molar volume data at investigated temperatures are 0.1±0.1%, 10.4±9.5%, 4.2±3.6%, and 0.3±0.3%, respectively. The corresponding RDs for the predicted properties after training using the experimental data at 298 K are 0.2±0.2%, 14.1±15.8%, 5.4±4.6% and 0.4±0.3%, respectively, for density, viscosity, surface tension, and molar volume data. This study shows that the Jouyban-Acree model can correlate/predict physicochemical properties of the mixtures of solvents at different temperatures with acceptable error in calculation.