VIABILITY STUDY OF RETRIEVING THE EVAPORATED WATER IN A MECHANICAL DRAFT CROSS FLOW COOLING TOWER

Cooling towers use evaporative heat transfer to reduce process water temperature. In mostly cases, the amount of water lost to evaporation is irrelevant, but in the present case of study, the amount of makeup water due to evaporation, is around 700 m(3)/h. That alone is a considerable amount of fresh water that needs to be removed from the local rivers and is currently having a negative impact in the fresh water availability for consumption. This study explores viable solutions to recover some of the evaporated water, but not compromising the effectiveness of the cooling tower. The plant is located in the southeast region of Brazil where temperature and humidity vary considerably along the year. The present study focuses on retrieving the evaporated water through condensation and capturing fog without compromising the cooling tower performance. Data from the actual cooling tower was used in the thermodynamic analysis. Computational fluid dynamics (CFD) was used to simulate the mixing of air leaving the cooling tower with outdoor air. An experimental setup is also being developed to reproduce the condensation process.