Abstract
The gas-phase viscosity of the methane-chlorodifluoromethane (R22) system was measured in the temperature range from 298.15 to 373.15 K and at pressures up to 5MPa. The measurements were performed with a Maxwell type oscillating-disc viscometer. The viscosity at atmospheric pressure was correlated by three methods: the Chapman-Enskog equation, the Sutherland equation with Wilke combination factors and the Sutherland equation with Brokaw factors. It was found that the results calculated from the Sutherland equation with Brokaw combination factors gave the best agreement with the experimental data. The viscosity data at various pressures could not be correlated successfully by the residual viscosity correlations of Dean and Stiel or the equation of Pedersen et al. A new empirical equation for the correlation factor was proposed that extends the corresponding states viscosity equation with methane as the reference substance to the polar substance R22.
