Inlet liquid temperature

For prehminary screening and easibility studies or for rough cost estimates, one may wish to employ a version of the isothermal method which assumes that the liquid temperatures in the tower are everywhere equal to the inlet-liquid temperature. In their analysis of packed-tower designs, von Stockar and Wilke [Ind. Eng. Chem. Fun-dam. 16, 89 (1977)] showed that the isothermal method tended to underestimate the reqmred depth of packing by a factor of as much as 1.5 to 2. Thus, for rough estimates one may wish to employ the assumption that the temperature is equal to the inlet-liquid temperature and then apply a design fac tor to the result. 

Fig. 8.7a-c The effect of inlet liquid temperature, gap size and wall heat flux from the wall on the pressure in inlet cross-section pressure of the micro-channel. Reprinted from Peles et al. (2000) with permission... 

Fig. 8.9a-c The dependencies of vapor temperature, pressure and velocity in the outlet cross-section of the capillary on the inlet liquid temperature (a) the dependence of Ar(r ), (b) the... 

The total enthalpy of the inlet gas as Btu/lb-mol BDG can be calculated from the water vapor content and the heat capacity of the inert gas. Because water vapor is being condensed throughout the packed bed, the exit gas is saturated with the water. Because the condensate is of the same composition as the irrigating liquid, specifying the inlet liquid temperature usually fixes the exit gas temperature within a narrow range. Thus, the exit gas enthalpy can also be calculated. 

Using the velocity field from equation (6.169), the energy equation (6.170) can be solved numerically for constant wall temperature boundary condition with given inlet liquid temperature. The representative Nusselt number distribution is shown in Figure 6.22. 

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