njit-etd1961-002 - New Jersey Institute of Technology

4log Ti φ(Tr) (αc 7) )(Tr) Equation (5)ErThe value of was determined using the knownnormal boiling point of formaldehyde at ¹ atmosphere.(F) Specific volumes of the saturated liquid weredetermined from -¹0 ° C. to ¹4¹ ° C. by the method ofWatson ² . The data required for the calculationsare the critical temperature and critical compressibilityfactor and a single known accurate densitymeasurement as a reference state. The liquid densityat -²0°C. was available 7 , and was employed inconjunction with the reduced density table by thefollowing equation ² :DiD2(D, ) Equation (6)Specific volumes were then obtained by the reciprocalsof the calculated liquid densities.(G) Specific volumes of the saturated and superheatedvapor were calculated using the generalizedcompressibility factors 4 which were derived fromthe correlation of Lydersen, Greenkorn and Hougen.Calculation was done using:PV ZRT Equation (7)(H) The saturated formaldehyde liquid at -¹9°C.was taken as the reference point for the zero valueof enthalpy and entropy.(I) The latent heat of vaporization at the normalboiling point listed by Walker ¹6 as 5.57Kcal/g-mole at -¹9 ° C. was used to calculate thevalue of the latent heat of vaporization from-¹0 ° C. to the critical temperature. The equationderived by Watson ¹7 was used;