Expansion Coefficients of Liquids

Results for thermal expansion coefficient of liquids are presented for major organic chemicals. The results are especially helpful in the design of relief systems for process equipment containing liquids that are subject to thermal expansion. 

The following equation was selected for correlation of thermal expansion coefficient of liquid as a function of temperature ... 

A comparison of calculated and actual data values for thermal expansion coefficient of liquid in Figure 7-2 for a representative compound. The graph indicates good agreement of calculated and data values. 

The correlation results maybe used for calculation of thermal expansion coefficient of liquid and volumetric flow from thermal expansion. Examples are shown in Table 7-2. 

Estimate the thermal expansion coefficient of liquid for n-pentane (CSH12) at 40 C. 

According to Ferry12 the free-volume per cm of substance, i. e. the fractional free-volume /, is hard to define exactly and should be regarded as merely a useful semi quantitative concept. Specifically, the thermal expansion coefficients of liquids for the most part reflect the increase in fractional free-volume only a small part is connected with the anharmonic dependence of potential energy or interatomic and intermoleeular distances. 

Smith, W. T., Greenbaum, S. and Rutledge, G. P. (1954) J. Phys. Chem. 58, 443. Correlation of critical temperature with thermal expansion coefficients of organic liquids. 

Consider Problem 9-9, part a. This time use alcohol as a liquid medium with a thermal expansion coefficient of 1.12 X 10 3/°C. The heat capacity of the alcohol is 0.58 kcal/kg °C, and its density is 791 kg/m3. Determine the relief size required. 

The results for thermal expansion coefficient are given in Table 7-1 for major organic chemicals. The presented values are applicable to a wide variety of substances. The tabulation also discloses the temperature range for which the equation is useable. The respective minimum and maximum temperatures are denoted by TMIN and TMAX. Spot values are provided at 25 C for both thermal expansion coefficient and liquid density. 

Thermal Expansion Coefficient for Liquids The coefficient of volume expansion for liquids is the ratio of the change in volume per degree to the volume at -17.8°F (0°C). The value of the coefficient varies with temperature. 

Mechanical Coefficients of Liquids by a Differential Expansion Method 213... 

The jump in volume is illustrated in Figure 3.1 the slope of the line FC is the thermal expansion coefficient of the crystalline phase at the melting point the volume jumps from C to B, and the higher slope of BA denotes the expansion coefficient of the liquid phase. 

Stokes, R. H. The Molar Volumes and Thermal Expansion Coefficients of Solid and Liquid Potassium from 0—85°C. J. Phys. Chem. Solids, 27, 51—56 (1966). 

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