Viscosity of vapor

Consider the mass, thermal and momentum balance equations. The key assumption of the present analysis is that the Knudsen number of the flow in the capillary is sufficiently small. This allows one to use the continuum model for each phase. Due to the moderate flow velocity, the effects of compressibility of the phases, as well as mechanical energy, dissipation in the phases are negligible. Assuming that thermal conductivity and viscosity of vapor and liquid are independent of temperature and pressure, we arrive at the following equations ... 

A low viscosity is <2 or <3 centipose (cP) or centistokes (cSt). Tap water has a viscosity of about 1 cP. A viscosity of —50 cP is quite high. Warm maple syrup has this sort of viscosity. The viscosity of vapors is almost always very low. 

The only experimental data for the low-pressure viscosity of vapor hydrogen sulfide are those of Rankine and Smith (1921). The values... 

Figure 13-6 The Eckert flood velocity correlation. (Fp = packing factor, ft"1 see Table 13-7. g = acceleration of gravity, ft/s2. Gvsf = mass velocity of the vapor, superficial, flood, lb/s-ft2. wL = liquid mass flow rate, lb/s. wv = vapor mass velocity, lb/s. pv = density of vapor, lb/ft3. pL = density of liquid, lb/ft3. p, = viscosity of vapor, lb/ft-s. pw — viscosity of water, lb/ft-s.) [J. S. Eckert, Chem. Eng. Prog.. 63(3) 39 (1949), by courtesy American Institute of Chemical Engineers.]...

ESTIMATE PHYSICAL PROPERTIES ACCURATELY. III. VISCOSITY OF VAPORS AND LIQUIDS. 

RELATION BETWEEN HEAT CONDUCTANCE AND VISCOSITY OF VAPORS OF PARAFFIN HYDROCARBONS. 

THE VISCOSITY OF VAPOR FROM METHYL CHLOROACETATE BETWEEN 80 AND 150 C. AND ITS SATURATION PRESSURE BETWEEN 77 AND 130 C. 

A GENERALIZED APPROACH FOR PREDICTING THE REDUCED VISCOSITY OF VAPOR REFRIGERANTS. 

V = Rate of a droplet settling under the influence of gravity g = Gravitational constant vis = Viscosity of vapor r = Radius of the droplet... 

Al correction factor for wetting of the packing, by the liquid pv = density of the vapor g = conversion factor for consistent units u = superficial gas velocity, i.e., linear gas velocity based on the total cross section of the tower d size of packing, nominal fx viscosity of vapor... 

Example 6-14. Viscosity of Vapors. A 60 API gasoline has an average boiling point of 260 F. According to Figs. 5-9 and 5-12, it has the following properties ... 

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