Vapor thermal conductivity

Similar to the viscosity, the thermal conductivity of vapors and gases can be estimated from the kinetic gas theory. As well, its behavior is similar. It increases with temperature, and at moderate pressures (0.01... 1 MPa) it is hardly a function of pressure. A fourth degree polynomial 

For nonpolar components, the vapor thermal conductivity can be estimated by the Chung equation [85] 

For polar components, the error will be larger than for nonpolar components. In these cases, the Roy-Thodos method [6] is recommended. 

Estimate the thermal conductivity of gaseous 2-methyl pentane at T = 373.15 K and P = 0.1 MPa using the Chung equation. The given data are 

It should be mentioned that the pressure dependence of the thermal conductivity of gases is quite strange. For very small pressures (P 10 mbar), when the mean free path is large in comparison with the vessel dimensions, the thermal conductivity is proportional to the pressure and to the distance d between the walls of the vessel perpendicular to the heat flux direction  

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Many of the common properties of isoprene have been presented graphically (9). These include vapor pressure, heat of vaporization, Hquid heat capacity, vapor heat capacity, Hquid density, vapor viscosity, Hquid viscosity, surface tension, and vapor thermal conductivity. 

Vinyl acetate is a colorless, flammable Hquid having an initially pleasant odor which quickly becomes sharp and irritating. Table 1 Hsts the physical properties of the monomer. Information on properties, safety, and handling of vinyl acetate has been pubUshed (5—9). The vapor pressure, heat of vaporization, vapor heat capacity, Hquid heat capacity, Hquid density, vapor viscosity, Hquid viscosity, surface tension, vapor thermal conductivity, and Hquid thermal conductivity profile over temperature ranges have also been pubHshed (10). Table 2 (11) Hsts the solubiHty information for vinyl acetate. Unlike monomers such as styrene, vinyl acetate has a significant level of solubiHty in water which contributes to unique polymerization behavior. Vinyl acetate forms azeotropic mixtures (Table 3) (12). 

In the second edition of this volume, special attention has been paid lo improving the accuracy of the estimation techniques used for liquid heat capacity, vapor and liquid viscosity. and vapor thermal conductivity. Improved methods of extending data on liquid density and thermal conductivity have been used m this edition New experimental data has also been included. Particular attention has been paid to include new data on aqueous solution and pressure effects on physical properties... 

Figure 23-13. Vapor thermal conductivity of C<-C aldehydes from OX to i 500 C...

The vapor thermal conductivities have been estimated by the method ol Roy and Thoda Sonic vjpin thermal con ductivily data have been reported for acetaldehyde.24 Calculated values agree within an average ot 59r... 

The vapor thermal conductivities haw hcen cmimated by the method of Owcn> and Thodos.yi... 

Figure 25-10 Vapor thermal conductivity of miscellaneous aldehydes from O C to 500 C.

The vapor thermal conductivity of all four compounds was estimated by the method of Roy and Ihodo, The liquid thermal conductivities were estimated by the method of Robbins and Kingica. ... 

Figure 28-14. Vapor thermal conductivity ot ketones trom O C to +500 C...

The vapor thermal conductivities were estimated by th method of ftos and Thndos.- with a probable error of abnu... 

Figure 27-11. Vapor thermal conductivity ot ether from O to 50CTC...

Gribkova has measured the vapor thermal conductivity at WOT of ethyl, propyl, and butyl ether The vapor thermal conductivities of all four compounds were estimated by the method of Roy and Thodos r... 

Mad/hidov ct uP present vapor thermal conductivity data for methyI acetate from riOC t > 350 0. for butyl acetate from I2TC to 3WC. and ethyl acetate from IOCfC to 30ft C n e vapor thermal conductivities of all four oxnpoufwH were calculated by the inethud ol Roy and Thodov r... 

Figure 31 11. Vapor thermal conductivity lor cycfcc ethers Iron 0 C to 600 C...

Vines and Rennet have mrtoured the vapoi tlteimal conductivities of dioxanc from HKi-j to l5tt C The vapor thermal conductivity ol all lour conqxrnnds was estimated hv the... 

Figure 32-16. Vapor thermal conductivity ol melhytamines Irom O C to - 500 C.

Hu- vapor thermal conductivity of methylaminc has been measured town bf f to 258 0 and for dimethylaminc and miTKlhylamine from 37 C to 2T7°CV1J ... 

Vines tind Bonnet have measured the vapor thermal conductivities of dietbylomine and tncthylaminc from HOT to... 

ISOTV4 Tlte method f Roy and Thndos was used to calculate the vapor thermal conductivities over the 0-500T ... 

Tlic vapor thermal conductivities were calculated by the method of Roy and Thodos.17... 

It is, therefore, hardly surprising that some confusion has arisen over the units in which detector sensitivity is measured. Instrument manufacturers have avoided the problem by not employing concentration as a unit of sensitivity, leaving the analyst to convert the detector sensitivity given in RI units %carbon etc. to g/ml of a given solute for calculation purposes. This might well be considered unreasonable by the analyst, who can not easily calculate the mass and concentration sensitivity of his/her equipment and often does not know the vapor thermal conductivity, the refractive index or electrical conductivity etc. of the solutes contained in the mixture being analyzed. Furthermore, in almost all analyses the mass concentration of the components are the quantity of real interest. 

TABLE 2-314 Vapor Thermal Conductivity of Inorganic and Organic Substances [W/(m-K)]... 

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