where APG is the pressure drop across the packed bed (kPa) and z is the height of the
tower. The validity of the correlation was explored by Li [15], and it has excellent
agreement with the experimental data.
The pumping power required for the diffusion tower liquid is calculated as,
E, = "m P = LA gH (4.4)
Thus the total pumping power is calculated as,
E,,,a1 = E, + EG (4.5)
The energy consumption rate per unit of fresh water production is defined as,
Ef, =totax (4.6)
m,,
The fresh water production rate and energy consumption rate are two important
parameters that characterize the performance of the DDD process. The fresh water
production rate characterizes the quantity of fresh water produced at a given set of
operating conditions while the energy consumption rate denotes how much energy is
consumed per unit of fresh water produced. The two values are important in finding the
optimal operating conditions. An ideal DDD process would have a high fresh water
production rate and a low energy consumption rate.
Heated Air/Heated Water Results and Discussion
Using the analysis described above and the theory discussed in Chapter 3, a
parametric analysis is performed to determine the effects of certain operating variables on
the performance of the heated air/heated water process. In performing the analysis, the
air inlet temperature, water inlet temperature, specific packing area, diameter of the
packing material, and inlet humidity ratio were all held constant at 600 C, 600 C, 267