Unveiling the Benefits of Condensed Water Reclaimed for Evaporative Cooling Tower in Part I: Water Conservation

The water conservation bodies have recited the use of grey-water to alleviate water consumptions. The intrinsic mineral-free condensed water is not only an ideal dilution but also a by-product of air-conditioning, which may be reclaimed at no extra cost and energy, is conducive to the efficacy of chemical reagents for descaling. The major water evaporation losses are replenished with fresh water that increases the mineral concentrations with time and aggravates water scale formations. The total dissolved solid (TDS) are effectively lowered by bleed-off that is determined by the cycles of concentration (CoC). The higher CoC is, the less bleed-off will be. The electrical conductivity (EC) controller controlled the level of TDS with auto bleed-off valve which is complementary to chemical dosing system that retards the nucleation and crystal growth in the mineral laden water. Considering that the maximum industrial standard 2,500ppm, fresh make-up water 130ppm, and condensed water 69ppm, CoC 19.2 was set. Consequently, 44 % make-up and 80% bleed-off water were saved that would resulted in the greenhouse gas (GHG) emissions reduction of around 7,500 kg CO2e/yr.