1. Droplet Water Cooling Tower

Water at 110F is to be cooled to 85F in a water spray tower. Each of the water and air(85F wet bulb, 75F dry bulb) streams flows at 10,000 lb/hr. The droplets 2000 μ/m in diameter.

Calculate the tower height, Z, and tower diameter, D, needed so that the Z/D ratio is about 4.

2. Dewvaporation Desalination

A Dewvaporation tower with a 2000 sqft heat transfer wall produces distillate at a rate of 1000 gallons/day (gpd). The ambient air is 110F and 10% relative humidity. With the distillate maintained at 1000 gpd, what tower high evaporation temperature, Tez, yields the maximum energy reuse factor, f (show a plot of f vs Tez)? At this optimum condition, what are the values of f, Tez, and air flow rate, G?

(note: Each of two water films on the heat transfer wall has a thickness of 0.1mm. The plastic heat transfer wall has a thickness of 0.008 inches with a thermal conductivity of 0.1 BTU/ft hr F.)