EXAMPLE 19.3. A counterflow induced-draft cooling power operates with inlet and exit water temperabures of 105 and 85 F when the air has dry-bulb and wer-ballb temperatures, respectively, of 90 and 76F. The tower has 4 ft of stacked plastic fill, and the flow rates are Gy=2,000lb/hft2 and Gs=2,200lb/hft2(a) Determine the number of transfer units, the beight of a transfer unit based on the overall gasphase driving force, and the temperature approach. (b) If the cooling lovi remain the same but the air temperature drops to 70F with a wet-bulb temperature of 60FF2 predict the water temperature and the temperaliure approsch. Tg19.6(b) 19.10. For the cooling tower described in Example 19.3. predict the intlet and exit water temperatures if the dry-bulb and wet-bulb temperatures are 100 and 68F